ACUTE MYELOID LEUKEMIA (AML)
DEFINITION & ETYMOLOGY
* "Leukemia" = Greek: leukos (white) + haima (blood)
* AML = clonal proliferation of myeloid blasts in bone marrow/peripheral blood
* Uncontrolled proliferation of immature blast cells with impaired differentiation
* General diagnostic threshold: >=20% blasts in bone marrow OR peripheral blood
* Exception: AML diagnosed regardless of blast count if t(8;21), inv(16)/t(16;16), or t(15;17) are present
* del(7) does NOT bypass the 20% blast requirement — <20% blasts with del(7) = MDS, not AML
* More than 20% blasts in bone marrow are NOT required for ALL cases of AML (specific translocations override this rule)
EPIDEMIOLOGY & ETIOLOGY
* Primarily a disease of older adults (age >=60 is a critical factor in treatment decisions)
* Most common inherited leukemia: CLL (familial risk 2-4x higher with family history)
* AML evolved from MDS if dysplasia present in >=50% of cells in >=2 myeloid lineages (distinct from the 20% blast threshold)
* AML can be caused by chemotherapy (therapy-related AML)
* DIC (disseminated intravascular coagulation) can be a presenting feature — especially APL
Therapy-related AML (t-AML) — 10-20% of cases:
* Alkylating agents/radiation → latency 5-7 years → del(5), del(7)
* Topoisomerase II inhibitors → latency 1-3 years → 11q23 mutations
* t-AML carries poorer prognosis vs. de novo AML within the same risk group
* All three of the above statements regarding t-AML are true
Key mutations and risk factors:
* Genetic mutations: FLT3-ITD, NPM1, CEBPA, IDH1/2, TP53
* Prior therapy: alkylating agents, topoisomerase II inhibitors, radiation
* Other risks: MDS, Down syndrome, benzene exposure
DIAGNOSIS & CLASSIFICATION
Diagnostics — most to least useful:
* Bone marrow aspirate microscopy — essential for blast morphology (>=20% blasts)
* Immunophenotyping (flow cytometry): myeloid markers CD13, CD33, CD117, MPO
* Cytogenetics/molecular testing: t(8;21), inv(16), FLT3, NPM1, CEBPA, IDH1/2, TP53
* Coagulation panel — essential if APL/DIC suspected
* LEAST USEFUL: IgH (immunoglobulin heavy chain) gene rearrangement — this is a lymphoid (B-cell) marker; entirely irrelevant to AML diagnosis
Clinical presentation:
* Bone marrow failure: anemia (fatigue), thrombocytopenia (bleeding), neutropenia (infections)
* Organ infiltration: splenomegaly, gum hypertrophy (monocytic AML), CNS involvement (rare)
* DIC: especially in APL (M3) due to granule release
FAB subtypes — key pathognomonic features:
* M3 (APL): t(15;17) → PML-RARA; DIC; Auer rods — MEDICAL EMERGENCY Treatment: ATRA + arsenic trioxide (NOT standard 7+3); 5-yr OS up to 88%
* t(8;21): RUNX1-RUNX1T1; long thin Auer rods; favorable risk; highly sensitive to cytarabine NOTE: RUNX1-RUNX1T1 detected by RT-PCR in remission does NOT indicate poor prognosis
* CBF-AML: t(8;21) OR inv(16)/t(16;16) — favorable prognosis; both disrupt RUNX1/CBFβ complex
* M4/M5: Monocytic lineage; DIC possible; gum hypertrophy; better prognosis than M6/M7
* M6/M7: Erythroid/megakaryocytic; historically poor prognosis
Translocation "know the difference" — HIGH YIELD:
* t(15;17) = APL (AML-M3) — treat with ATRA + ATO
* t(8;21) = CBF-AML (favorable AML)
* t(12;21) = ALL (ETV6-RUNX1) — NOT AML AT ALL
* inv(16)/t(16;16) = CBF-AML (favorable AML)
* Core Binding Factor (CBF) AML = t(8;21) AND inv(16)/t(16;16) only (t(15;17) and t(12;21) are NOT CBF-AML)
Auer rods: present in some but NOT all subtypes of AML
RISK STRATIFICATION (2022 ELN)
Favorable risk:
* t(8;21), inv(16)/t(16;16), t(15;17)/APL
* NPM1 mutated (without FLT3)
* Biallelic CEBPA mutation
* 5-year survival: ~50-70%
Intermediate risk:
* Normal cytogenetics + FLT3-ITD — regardless of allelic ratio or NPM1 status (2022 ELN update: no longer need to distinguish allelic ratio)
* 5-year survival: ~30-40%
Adverse/Poor risk:
* Complex karyotype, del(7), monosomy 5/7, TP53
* Secondary AML from MDS — unfavorable regardless of karyotype
* 5-year survival: <20%
Key molecular marker rules:
* NPM1 mutation: good prognosis if ISOLATED; poor if combined with FLT3
* CEBPA mutation: good prognosis (found in 6-15% of AML)
* FLT3 mutation: high WBC, poor prognosis; occurs in 30-40% of normal karyotype AML
INDUCTION CHEMOTHERAPY
Goal: reduce leukemic burden from 10^12 → <10^9 (3-log reduction; morphologic CR)
Standard "7+3" regimen:
* Cytarabine: 100-200 mg/m²/day continuous IV infusion × 7 DAYS
* Anthracycline × 3 DAYS — NEVER REVERSED (cytarabine is always 7 days)
- Age <60, fit: Daunorubicin 90 mg/m² (ECOG 1900: CR 71% vs 54%; OS 24 vs 16 months)
- Age >=60/unfit: Daunorubicin 45-60 mg/m²
- Acceptable alternative: Idarubicin 12 mg/m²/day × 3 days
* Increasing cytarabine dose beyond 100-200 mg/m² during induction does NOT improve CR or OS
* NOT used in AML: doxorubicin, paclitaxel, docetaxel, etoposide (no added benefit), Hyper-CVAD (ALL regimen only)
* Refractory AML = failure to achieve CR after 2 induction courses
Induction regimen by patient profile:
* Fit, <60, de novo favorable-risk, CD33+ → 7+3 (dauno 90 mg/m²) + gemtuzumab ozogamicin
* Fit, <60, de novo favorable-risk, CD33- → 7+3 (dauno 90 mg/m²) alone
* Fit, <60, FLT3-mutated → 7+3 + midostaurin
* Fit, 60-75, secondary AML or MDS-related → CPX-351 (liposomal dauno/cytarabine) — Category 1
* Age >=75 or unfit → LDAC 20 mg SQ BID × 10 days OR azacitidine + venetoclax
* IDH1 mutation, age >60, unfit → Azacitidine + ivosidenib (AGILE trial: OS 24 vs 7.9 months)
* Adverse cytogenetics, age >60, fit → Azacitidine + venetoclax preferred over 7+3
* CD33+, adverse risk (del7, secondary AML) → Gemtuzumab NOT recommended
Key induction rules:
* Azacitidine and decitabine as single agents are NOT FDA-approved for AML induction
* LDAC is FDA-recognized and has demonstrated superiority over best supportive care in elderly
* Venetoclax must ALWAYS be used in combination — NEVER as single agent
* Midostaurin = frontline only; NOT used as salvage therapy
* CPX-351 delivers a fixed 5:1 molar ratio of cytarabine:daunorubicin
* CPX-351 indicated for: secondary AML, t-AML, or MDS-related cytogenetics in patients 60-75
* Adding etoposide to standard induction does NOT improve remission rates
POST-REMISSION (CONSOLIDATION) THERAPY
Goal: reduce leukemic burden 10^9 → zero (eradicate MRD; achieve cure)
* Without post-remission therapy: >90% of patients relapse within 1 year
* Maintenance therapy is NOT effective in AML (unlike ALL)
High-dose cytarabine (HiDAC) — gold standard:
* Age <60, fit: 3,000 mg/m² IV Q12h on days 1, 3, 5 × 3-4 cycles
* Age >60 or renal dysfunction: 1,000-1,500 mg/m² (attenuated to prevent cerebellar neurotoxicity)
* HiDAC ALONE is superior to HiDAC + additional agents — etoposide, cyclophosphamide, amsacrine, and mitoxantrone showed NO added benefit
* MOST PREFERRED AGENT to combine with HiDAC = NONE (HiDAC monotherapy is standard)
* Mechanism: saturates deaminating enzyme → high intracellular ara-CTP → eliminates MRD
* Favorable-risk cytogenetics benefit most from HiDAC consolidation
Protocol continuity rule — consolidation MUST match induction:
* Induced with 7+3 + gemtuzumab (ALFA-0701) → consolidate with intermediate-dose cytarabine + daunorubicin + gemtuzumab
* Induced with CPX-351 → consolidate with CPX-351 (dauno 29 mg/m² + cytarabine 65 mg/m² on days 1 & 3)
* Induced with azacitidine + ivosidenib → continue same combination 5+2 regimen (cytarabine × 5 days + daunorubicin days 1, 2): used for residual blasts after induction (incomplete response) — NOT standard consolidation for patients already in CR
ALLOGENEIC HSCT
* Only potentially curative option for high-risk AML
* Timing: CR1 (first complete remission) — do NOT delay for multiple HiDAC cycles
* Favorable-risk AML (CBF, APL): allo-HCT in CR1 NOT required unless MRD+
* Intermediate/adverse risk: allo-HCT in CR1 preferred
* MUD (matched unrelated donor): acceptable for younger adults without sibling donors
* Reduced-intensity HCT: for older/unfit patients (relies on graft-vs-leukemia effect)
* Allo-HCT is NOT indicated for ALL patients <50 with an HLA-matched donor — risk/benefit must be individually assessed
* Favorable-risk patients (e.g., CBF, APL) do NOT require allo-HCT in CR1 unless persistently MRD positive
* Autologous HSCT: NOT used in AML
* Radiation: NO role in AML treatment
TARGETED AGENTS
FLT3 — Midostaurin:
* Frontline: added to 7+3 induction and continued through consolidation
* FRONTLINE ONLY — not used as salvage therapy
FLT3 (relapsed/refractory) — Gilteritinib:
* R/R FLT3-mutated AML (ADMIRAL trial: superior OS vs salvage chemotherapy)
* NOT used as single agent for FLT3-negative disease
IDH1 — Ivosidenib:
* Frontline (+ azacitidine) in unfit/elderly patients (AGILE trial)
* Also used in R/R IDH1-mutated AML
* Do NOT use for IDH2 mutations
IDH2 — Enasidenib:
* IDH2-mutated AML only — often causes indirect hyperbilirubinemia (non-hepatic toxicity)
* Do NOT confuse with ivosidenib (IDH1)
* Decitabine + enasidenib is NOT a current NCCN-recommended combination
CD33 — Gemtuzumab ozogamicin:
* Favorable/intermediate risk: added to 7+3 (ALFA-0701 protocol)
* Minimal/no benefit in adverse or complex karyotype AML
* NOT recommended in del(7) or secondary AML
* Key toxicity: sinusoidal obstruction syndrome (SOS) — especially concerning pre-HCT
BCL-2 — Venetoclax:
* Combined with azacitidine or LDAC — NEVER as single agent
* For older/unfit patients or adverse-risk disease
* Risk: tumor lysis syndrome — pre-hydration, allopurinol/rasburicase required
Key toxicities:
* HiDAC: cerebellar neurotoxicity — dose-reduce if age >60 or renal dysfunction; also use steroid eye drops prophylactically
* Anthracyclines: cardiotoxicity — monitor LVEF
* IDH inhibitors: differentiation syndrome (treat with steroids); transaminitis; QT prolongation — ECG monitoring required
* Venetoclax + HMA: tumor lysis syndrome risk
* Gemtuzumab: sinusoidal obstruction syndrome (SOS)
* Midostaurin/targeted agents: QT prolongation — ECG monitoring required
APL (AML-M3) — SPECIAL CONSIDERATIONS (MEDICAL EMERGENCY)
* Defined by t(15;17) → PML-RARA fusion
* High risk of fatal DIC/hemorrhage — do NOT delay treatment
* Treatment: ATRA + arsenic trioxide — NOT standard 7+3 chemotherapy
* 5-year OS: up to 88% — highest cure rate among all AML subtypes
* Initiate ATRA IMMEDIATELY — even before genetic confirmation if APL is clinically suspected
* Confirm diagnosis with FISH/PCR for PML-RARA
* Monitor DIC: fibrinogen, D-dimer, PT/aPTT
RELAPSED/REFRACTORY AML — SALVAGE
No targetable mutation → MEC (mitoxantrone + etoposide + cytarabine)
FLT3-mutated → Gilteritinib
IDH1-mutated → Ivosidenib
IDH2-mutated → Enasidenib
HMA-refractory, no mutation → FLAG-IDA or clinical trial
Key salvage rules:
* MEC = salvage only — NOT frontline induction
* Midostaurin = frontline only — NOT used in salvage
* Venetoclax-based regimens also used in HMA-refractory disease
* Minimum 4-6 cycles of HMA before declaring failure
* Allo-HCT remains the ultimate curative goal after achieving response in R/R disease
RESPONSE ASSESSMENT
* CR criteria: <5% blasts, normal counts, no Auer rods, no extramedullary disease
* Refractory: failure to achieve CR after 2 induction courses
* MRD negativity = key goal before transplant
* Maintenance therapy = NOT effective in AML (unlike ALL)
SUPPORTIVE CARE PEARLS
Antimicrobial prophylaxis during induction/consolidation:
* Antifungal: fluconazole or posaconazole
* Antibacterial: levofloxacin
* Antiviral: acyclovir
Tumor lysis syndrome (TLS):
* Risk: high WBC, venetoclax initiation
* Management: pre-hydration (2-3 L/day IV), allopurinol or rasburicase
Myelosuppression:
* G-CSF not routinely used during induction
* May be used to support neutrophil recovery during consolidation
HIGH-YIELD PEARLS — MUST MEMORIZE
1. "7+3" = cytarabine 7 DAYS + anthracycline 3 DAYS — never reversed
2. Daunorubicin 90 mg/m² superior to 45 mg/m² in patients <60 (ECOG 1900)
3. CBF-AML = t(8;21) + inv(16)/t(16;16) — both favorable, highly cytarabine-sensitive
4. t(15;17) = APL; t(12;21) = ALL — know the difference
5. HiDAC + additional chemo agents = NO benefit over HiDAC alone for consolidation
6. Most preferred agent to combine with HiDAC = NONE (HiDAC monotherapy is standard)
7. Allo-HCT in CR1 preferred for high-risk; NOT universal for all patients
8. APL: start ATRA BEFORE genetic confirmation if clinically suspected
9. Venetoclax = NEVER monotherapy; always in combination
10. Protocol continuity rule: consolidation regimen MUST match induction protocol
11. IgH rearrangement = LEAST useful in AML diagnosis (lymphoid marker)
12. Maintenance therapy = NOT effective in AML
13. Azacitidine/decitabine as single agents = NOT FDA-approved for AML induction
14. Gemtuzumab: minimal/no benefit in adverse/complex karyotype AML; watch for SOS
15. HiDAC neurotoxicity: dose-reduce to 1,000-1,500 mg/m² if age >60 or renal dysfunction
16. Enasidenib = IDH2; ivosidenib = IDH1 — do NOT mix them up
17. del(7) does NOT bypass the 20% blast rule — <20% blasts = MDS
18. AML evolved from MDS requires >=50% dysplastic cells in >=2 myeloid lineages
19. Most common inherited leukemia = CLL (not AML)
20. Adding etoposide to standard induction does NOT improve remission rates
The word “leukaemia” means:
- a. French word for ‘blood infection’
- b. Greek word for ‘white blood’
- c. Latin word for ‘white cell’
- d. Sanskrit word for ‘blood weakness
20% blasts are not required for AML diagnosis if the following cytogenetic abnormalities are present, except:
- A. t(8;21)
- B. t(16;16)
- C. del 7
- D. All of the above
The correct answer is C. del 7.
While the general WHO diagnostic threshold for AML is ≥ 20% blasts, certain genetic abnormalities allow for a definitive diagnosis regardless of the blast count.
Rationale
- Defining Translocations: The presence of t(8;21), inv(16), or t(16;16) (Core Binding Factor AML), as well as t(15;17) (Acute Promyelocytic Leukemia), are classified as AML regardless of the blast percentage.
- The Exception (del 7): Although a deletion of chromosome 7 (del 7) is a significant adverse-risk cytogenetic abnormality, it does not bypass the 20% blast requirement for an AML diagnosis. If a patient with del 7 has 5%–19% blasts, the condition is typically classified as Myelodysplastic Syndrome (MDS) rather than AML.
Poor prognosis in AML is seen with the following molecular defects:
- a. AML with mutated NPM1
- b. AML with mutated CEBPA
- c. AML with mutations in FLT3
- d. None of the above
Answer: C. AML with mutations in FLT3
Key points:
- NPM1 mutations:
- Provisional entity in AML (usually normal cytogenetics).
- Better prognosis if isolated, but poor if combined with FLT3 mutations.
- CEBPA mutations:
- Found in 6–15% of AML (often normal karyotype).
- Associated with good prognosis.
- FLT3 mutations:
- Occur in 30–40% of AML with normal cytogenetics.
- Clinical presentation: High WBC counts, poor prognosis.
AML with t(8;21)(q22;q22) has, all except:
- a. Favourable prognosis
- b. Blasts with long, thin Auer rods
- c. Highly sensitive to cytarabine
- d. Patients with RUNX1-RUNX1T1 detected by RT-PCR in remission have a poor prognosis
Ans. d. Patients with RUNX1-RUNX1T1 detected by RT-PCR in remission have a poor prognosis
True regarding post remission therapy in AML are:
- a. Is required in only intermediate and high-risk patients
- b. Standard dose and high dose cytarabine are equally effective
- c. Maintenance therapy is not effective
- d. All of the above
The correct answer is C. Maintenance therapy is not effective
Without further treatment after standard induction chemotherapy, more than 90% of patients relapse within 1 year.
Cytarabine, the single most active agent in AML, because laboratory and clinical studies have indicated that a log increase in its dose can overcome the mechanisms of resistance. Approximately 40% of patients with AML who are refractory to standard doses of cytarabine achieve a complete remission with high-dose cytarabine. The optimal number of consolidation chemotherapy cycles has not been determined, but is usually three to four cycles.
Remission induction chemotherapy is aimed at reducing the burden of leukemic cells in the body from 1012 to:
- a. 103
- b. 106
- c. 109
- d. Zero
Answer is C. 109
The aim of remission induction chemotherapy is the rapid restoration of normal bone marrow function and attainment of complete remission (CR). Induction therapy aims to reduce the total body leukemia cell population from approximately 1012 to below the cytologically detectable level of about 109 cells, i.e., a three-log reduction. However, a substantial burden of leukemia cells persists undetected (i.e., minimal residual disease), leading to relapse within a few weeks or months if no further therapy is administered. Post-induction or 'remission consolidation' therapy usually comprises one or more courses of chemotherapy or hematopoietic cell transplantation (HCT). It is designed to eradicate residual leukemia, allowing the possibility of cure, and to decrease the leukemic cell population further—possibly to zero.
Consolidation chemotherapy is aimed to reduce the burden of leukemic cells in the body to:
- a. 103
- b. 106
- c. 109
- d. Zero
Answer is d. Zero
Consolidation chemotherapy is designed to eradicate residual leukemia, allowing the possibility of cure.
Conclusion
- Induction: Reduces burden to <109 (morphologic remission).
- Consolidation: Targets residual disease (MRD) with the goal of zero cells for cure
Most preferred agent to be used along with high-dose cytarabine in consolidation for AML is:
- a. Etoposide
- b. Cyclophosphamide
- c. Mitoxantrone
- d. Daunorubicin
- e. None of the above
Answer: e. None of the above
Key Points:
- High-dose cytarabine (HiDAC) is the consolidation chemotherapy of choice for AML post-induction.
- Studies attempting to improve survival by combining HiDAC with other agents (e.g., etoposide, cyclophosphamide, amsacrine, mitoxantrone) have not shown superiority over HiDAC alone.
- HiDAC (3 g/m² × 3 courses) was equally effective as sequential multiagent chemotherapy (HiDAC + etoposide / cyclophosphamide / amsacrine/ mitoxantrone).
- Cytarabine remains the most effective agent for AML and is a cornerstone of induction therapy.
- High-dose cytarabine (HiDAC) achieves high intracellular drug concentrations, saturating the deaminating metabolic enzyme pathway. This leads to increased levels of the active metabolite ara-cytidine triphosphate.
- HiDAC is effective at eliminating minimal residual disease (MRD) that persists after induction therapy with cytarabine-based regimens (e.g., "7+3").
- Consolidation with HiDAC provides superior survival outcomes compared to lower-dose cytarabine regimens.
- While certain targeted agents may be added for specific molecular subtypes—such as midostaurin for FLT3-mutated AML or gemtuzumab ozogamicin for CD33+ disease—the standard cytotoxic consolidation backbone remains cytarabine monotherapy rather than a combination with other traditional chemotherapies like etoposide, cyclophosphamide, or daunorubicin
Allogeneic transplant in high-risk AML is preferred in:
- a. First complete remission
- b. After completing 3 cycles of high-dose cytarabine consolidation
- c. In second complete remission
- d. Any of the above
Answer: First complete remission (CR1)
Critical Findings:
- Optimal Timing for Allogeneic HCT:
- Should be performed after achieving initial complete remission (CR1) in AML.
- Post-remission consolidation (e.g., high-dose cytarabine) does not improve outcomes compared to proceeding directly to transplant post-induction.
- Donor Considerations:
- Matched unrelated donors (MUD) are an option for younger adults lacking sibling donors.
- Age/Comorbidity Adaptations:
- Myeloablative HCT carries high morbidity / mortality risks in older patients or those with comorbidities.
- Nonmyeloablative (reduced-intensity) HCT is an alternative, relying more on graft-versus-leukemia (GVL) effects than cytotoxic conditioning.
Which one of these is least valuable in the diagnosis of acute myeloid leukemia?
- a. Microscopic analysis of the bone marrow aspirate
- b. Immunophenotypic analysis of a bone marrow sample
- c. Cytogenetic analysis of peripheral blood
- d. Detection of clonal rearrangement of the immunoglobulin heavy chain gene
Answer: d. Detection of clonal rearrangement of the immunoglobulin heavy chain (IgH) gene
- IgH Gene Rearrangement:
- Used to diagnose B-cell lymphoid malignancies (e.g., ALL, lymphoma) by identifying clonal B-cell populations.
- Not relevant to AML, which is a myeloid malignancy.
- AML-Specific Diagnostics:
- a. Bone marrow aspirate microscopy: Essential for blast morphology (≥20% blasts required for AML diagnosis).
- b. Immunophenotyping (flow cytometry): Identifies myeloid markers (e.g., CD13, CD33, MPO)
- c. Cytogenetics (peripheral blood/marrow): Detects prognostic chromosomal abnormalities (e.g., t(8;21), inv(16)).
- Key Point: AML is confirmed through myeloid lineage-specific tests (morphology, immunophenotyping, cytogenetics/molecular genetics). IgH rearrangement is a lymphoid-specific marker
Most common type of inherited leukemia is:
- a. ALL (Acute Lymphoblastic Leukemia)
- b. AML (Acute Myeloid Leukemia)
- c. CLL (Chronic Lymphocytic Leukemia)
- d. CML (Chronic Myeloid Leukemia)
Answer: C. CLL
Supporting Points:
- Familial risk of CLL is 2–4× higher with a family history
- AML is more common in inherited syndromes (e.g., Down syndrome)
Core binding factor AML includes:
Core binding factor (CBF) AML includes a. AML with t(8;21).
Rationale
- Defining CBF AML: According to the clinical guidelines, Core-binding factor AML is specifically defined by the presence of one of the following cytogenetic abnormalities: t(8;21), inv(16), or t(16;16).
- Why others are incorrect:
- t(15;17): This translocation is the hallmark of Acute Promyelocytic Leukemia (APL). While both CBF AML and APL fall into the "Favorable" risk category, they are distinct clinical subtypes with different treatment protocols.
- t(12;21): This translocation (ETV6-RUNX1) is associated with Acute Lymphoblastic Leukemia (ALL), not AML.
The best induction regimen for AML is daunorubicin with:
- a. Cytarabine 100–200 mg/m² for 7 days
- b. Cytarabine 400 mg/m² for 7 days
- c. Cytarabine 3000 mg/m² for 3 days
- d. Any of the above
The correct answer is a. Cytarabine 100–200 mg/m² for 7 days.
Rationale
- Standard of Care: The standard induction therapy for AML, often referred to as the "7+3" regimen, consists of a 7-day continuous infusion of cytarabine at 100–200 mg/m²/day combined with 3 days of an anthracycline like daunorubicin.
- Dose Optimization: Clinical data indicates that increasing the cytarabine dose beyond 100 mg/m² during this 7-day period does not improve complete remission (CR) rates or overall survival (OS).
- High-Dose Cytarabine: While high-dose cytarabine (HiDAC) variants (e.g., 3,000 mg/m²) are used in some protocols, they remain controversial for induction and are generally reserved for specific populations, as they often increase toxicity without significantly improving outcomes compared to the standard "7+3" approach.
True regarding AML induction are, all except:
- a. If patients fail to achieve a substantial reduction in marrow blasts in the first course or fail to enter CR with a second course, they should be considered refractory.
- b. The distribution of cytogenetic subtypes is related to age.
- c. Remission rates are lower if patients have an antecedent hematological disorder.
- d. Addition of etoposide increases remission rates.
- e. All of the above
The false statement is d. Addition of etoposide increases remission rates.
Rationale
- Refractory Definition (a): True. Refractory AML is characterized by incomplete hematopoietic recovery after induction or failing to achieve complete remission (CR) after re-induction attempts,,.
- Cytogenetics and Age (b): True. Clinical handouts state that older age increases the likelihood of harboring unfavorable or poor-risk cytogenetic and molecular characteristics,.
- Antecedent Disorders (c): True. Remission rates and overall survival are significantly lower in patients with "secondary AML," which includes those with a history of an antecedent hematological disorder like MDS or previous chemotherapy exposure,,,.
- Etoposide (d): False. While various intensive regimens exist, comparative studies have not shown a benefit in remission rates or survival when adding extra cytotoxic agents like etoposide or topotecan to standard induction backbones,.
Which one of the following is false about acute myeloid leukemia?
- A. It is most common in elderly
- B. It can be caused by chemotherapy
- C. More than 20% blast cells in the bone marrow are required for all cases of AML
- D. Disseminated intravascular coagulation can be a presenting feature
The false statement is C. More than 20% blast cells in the bone marrow are required for all cases of AML.
Rationale
- The 20% Exception: While the World Health Organization (WHO) generally requires ≥ 20% blasts for a diagnosis, a patient can be diagnosed with AML regardless of the blast percentage if they possess specific genetic features, such as t(8;21), inv(16), or t(15;17).
- Why are the other options true:
- A (Elderly): AML is indeed most common in older adults; clinical guidelines emphasize that age ≥ 60 or ≥ 70 is a critical factor in determining treatment tolerance and prognosis.
- B (Chemotherapy): Previous exposure to alkylating agents and topoisomerase II inhibitors is a well-documented cause of treatment-related myeloid neoplasms.
- D (DIC): Disseminated intravascular coagulation (DIC) is a classic presenting feature and major cause of early death in the Acute Promyelocytic Leukemia (APL) subtype.
Which one of the following is not true about acute myeloid leukemia?
- A. AML M4 and M5 have better prognosis than AML M6 and M7
- B. It has a cure rate of > 80% in some subtypes
- C. Allogeneic stem cell transplantation is needed in all patients less than 50 years old with an HLA-matched donor
- D. Auer rods are seen in some but not all subtypes of AML
The statement that is not true is C. Allogeneic stem cell transplantation is needed in all patients less than 50 years old with an HLA-matched donor.
Based on the evidence in the sources:
- Rationale for C: While allogeneic HCT is a curative option, it is not recommended for all patients in first remission. Specifically, patients classified as having favorable-risk AML (such as those with core-binding factor mutations or APL) do not require an allo-HCT in their first complete remission unless they remain persistently MRD positive.
- Regarding B: Some subtypes, specifically Acute Promyelocytic Leukemia (APL), have exceptionally high outcomes. Clinical trials for APL have reported 5-year overall survival rates as high as 88%.
- Regarding D: Auer rods are a hallmark morphologic feature of myeloid blasts and are explicitly mentioned as a diagnostic feature in certain classifications (like MDS-IB2), but they are not present in every single case or subtype of AML.
- Regarding A: While modern staging relies more on cytogenetics (ELN risk), the FAB classification historically associates M6 (erythroleukemia) and M7 (megakaryocytic) with a poorer prognosis compared to M4 and M5.
MA is a 55-year-old male with a recent diagnosis of AML and is going to start induction chemotherapy.
Which of the following would be considered standard for MA?
- A. Cytarabine continuous infusion for 7 days and doxorubicin IV push for 3 days.
- B. Cytarabine continuous infusion for 7 days and paclitaxel IV for 3 days.
- C. Cytarabine continuous infusion for 7 days and daunorubicin IV push for 3 days.
- D. Cytarabine continuous infusion for 7 days and docetaxel IV for 3 days
The correct answer is C. Cytarabine continuous infusion for 7 days and daunorubicin IV push for 3 days.
For a 55-year-old patient like MA, who is under the age of 60 and fit for intensive therapy, standard induction is the "7+3" regimen. This protocol consists of:
- Cytarabine: 100–200 mg/m²/day administered as a continuous IV infusion for 7 days.
- Anthracycline: Either daunorubicin (60–90 mg/m²/day) or idarubicin (12 mg/m²/day) administered IV for 3 days.
While doxorubicin (Option A) is an anthracycline, it is typically used in ALL protocols or late intensification rather than standard AML induction. Paclitaxel and docetaxel (Options B and D) are not used in standard induction regimens for AML.
Key Point: "7+3" (cytarabine + daunorubicin) is the backbone of AML induction. Taxanes (B, D) and doxorubicin (A) are incorrect
BM is a 55-year-old female diagnosed with AML. When examining the cytogenetic and molecular characteristics of her disease, she is found to have normal cytogenetics with FLT3-ITD mutation.
Which of the following risk categories does BM fall into?
- A. Better Risk,
- B. Intermediate Risk.
- C. Poor Risk.
- D. Further information is needed to establish risk in this patient
Answer: BM falls into the Intermediate Risk category (Choice B).
Rationale
According to the 2022 European LeukemiaNet (ELN) Risk Stratification criteria provided in the clinical handouts, the classification for BM is as follows:
- Cytogenetics: BM has normal cytogenetics, which are classified as "cytogenetic abnormalities not classified as favorable or adverse".
- Molecular Markers: The presence of an FLT3-ITD mutation in the context of normal cytogenetics places the patient in the Intermediate Risk group.
- NPM1 and Allelic Ratio: Notably, under the 2022 ELN framework, patients with an FLT3-ITD mutation are categorized as Intermediate Risk regardless of their NPM1 mutation status or the FLT3-ITD allelic ratio. This is a shift from older stratification models that required knowing the "load" or allelic ratio (high vs. low) to distinguish between intermediate and adverse risk.
Since her profile matches the specific criteria listed in the Intermediate category of the current 2022 ELN table, no further information is required to establish her risk level within this framework.
MA is a 75-year-old male with a recent diagnosis of AML and is going to start treatment.
Which of the following would be considered standard for MA according to FDA-approved regimens?
- Cytarabine continuous infusion for 7 days and daunorubicin IV push for 3 days.
- Cytarabine 20 mg SQ BID × 10 days.
- Azacitidine.
- Decitabine.
According to FDA-approved regimens for a 75-year-old patient like MA, the most appropriate choice from your list is Cytarabine 20 mg SQ BID × 10 days (Low-Dose Cytarabine or LDAC).
Rationale for Selection
- HMA Single-Agent Status: Although they are common in practice, the FDA has not approved azacitidine or decitabine as single agents for the induction treatment of AML.
- Intensity and Age: While "7+3" (Option 1) is the standard intensive induction, it is generally reserved for fit patients. For a 75-year-old, outcomes with intensive therapy are typically poor, with complete remission (CR) rates rarely exceeding 50%.
- Elderly Standard: LDAC is a recognized low-intensity regimen that has demonstrated superiority over best supportive care in older adults. Furthermore, modern FDA approvals for patients ≥ 75 years old (specifically the accelerated approval for Venetoclax) are based on combinations using LDAC as a standard backbone.
6-a- RC is an otherwise healthy 52-year-old female with no prior medical history who was admitted to the hospital because of a peripheral smear that is consistent with AML and without suggestion of APL. Bone marrow biopsy evaluation confirmed the diagnosis of AML, and cytogenetics demonstrated de novo favorable risk AML without mutated FLT3 (ITD or TKD) and is CD33 negative. Intensive remission Induction chemotherapy is planned to start as soon as possible.
Which of the following treatments is best to use as remission induction therapy to treat RC's AML
- A. 7+3 with daunorubicin 45 mg/m2/day
- B. 7+3, with daunorubicin 90 mg/m2/day
- C. Hyper-CVAD
- D. Liposomal cytarabine and daunorubicin
The best treatment for RC is B. 7+3, with daunorubicin 90 mg/m²/day.
Rationale for Selection
For a fit, 52-year-old patient with de novo favorable-risk AML, the standard of care is intensive induction with the "7+3" regimen.
- Dose Superiority: The ECOG 1900 trial demonstrated that in patients under age 60, doubling the daunorubicin dose from 45 mg/m² to 90 mg/m² significantly improved both complete remission (CR) rates (71% vs. 54%) and median overall survival (24 months vs. 16 months).
- Molecular Profile: Since RC is CD33 negative, there is no indication to add gemtuzumab ozogamicin. Because she is FLT3 wild-type, she does not require the addition of midostaurin or quizartinib.
Why Other Options Are Incorrect
- Option A (45 mg/m²): This dose is considered inferior to 90 mg/m² for fit patients under age 60 based on survival data.
- Option C (Hyper-CVAD): This is an intensive regimen used primarily for Acute Lymphoblastic Leukemia (ALL) rather than AML.
- Option D (Liposomal Formulation): Liposomal daunorubicin/cytarabine (CPX-351) is specifically indicated for secondary AML (e.g., therapy-related or following MDS) or AML with MDS-related cytogenetic changes in older adults; it is not the preferred choice for de novo favorable-risk AML in a younger patient.
6-b-Following induction with 7+3 employing daunorubicin 90 mg/m2/dose, bone marrow biopsy and aspirate obtained on day 14 is hypoplastic, and a repeat bone marrow biopsy and aspirate obtained on day 28 following hematopoietic recovery confirmed complete remission. It is now 10 days following recovery of peripheral blood counts, and RC has an outpatient appointment with her primary hematologist to discuss post-remission therapy.
Which of the following is the most appropriate post-remission therapy at this time?
- A. Cytarabine 3,000 mg/m2/dose IV Q12 hours on days 1,3,5
- B. Cytarabine 1,000 mg/ m2/dose IV Q12 hours on days 1,3,5
- C. 7+3, with daunorubicin 90 mg/ m2/dose (cytarabine infused continuously for days 1-7 and daunorubicin IV on days 1,2,3)
- D. 5+2, with Idarubicin 12 mg/ m2/dose (cytarabine infused continuously for days 1-5 and Idarubicin IV on days 1,2
The most appropriate post-remission therapy for RC is A. Cytarabine 3,000 mg/m²/dose IV Q12 hours on days 1, 3, 5.
Rationale for Selection
For a 52-year-old patient with favorable-risk AML who has achieved a complete remission, high-dose cytarabine (HiDAC) is considered the gold standard for consolidation.
- Dose Intensity: In patients under the age of 60 with good performance status, the standard HiDAC dose is 3,000 mg/m² administered every 12 hours on days 1, 3, and 5.
- Patient Profile: RC is 52 years old and healthy; therefore, she does not require the dose reduction (to 1,000–1,500 mg/m²) typically reserved for patients over age 60 or those with renal dysfunction to minimize neurotoxicity.
- Efficacy: Clinical analyses have demonstrated that patients with favorable-risk cytogenetics benefit the most from intensive HiDAC consolidation compared to lower-dose regimens.
Why Other Options Are Incorrect
- Option B (1,000 mg/m²): This attenuated dose is appropriate for patients > 60 years old or those with impaired renal function.
- Option C (7+3): While re-administration of the induction regimen is sometimes considered if successful, HiDAC monotherapy is the established gold standard for post-remission therapy in fit, younger patients.
- Option D (5+2): This regimen is primarily recommended for patients who have residual blasts after initial induction (incomplete response) rather than as standard consolidation for those already in complete remission.
OT is a 45-year-old male who presents with severe fatigue and high fever. Lab results show:
- WBC 7,000 cells/mm³
- Platelets 45,000 cells/mm³
- A bone marrow biopsy reveals 48% blasts, with morphology and cytogenetics consistent with AML-M4 (acute myelomonocytic leukemia).
Which of the following is the best induction regimen for OT?
- A. Cytarabine 200 mg/m² × 3 days plus daunorubicin 60 mg/m² × 7 days (2%)
- B. Cytarabine 200 mg/m² × 7 days plus daunorubicin 60 mg/m² × 3 days (8%)
- C. Cytarabine 200 mg/m² × 7 days plus daunorubicin 90 mg/m² × 3 days (84%)
- D. Cytarabine 200 mg/m² × 3 days plus daunorubicin 90 mg/m² × 7 days (6%)
The best induction regimen for OT is C. Cytarabine 200 mg/m² × 7 days plus daunorubicin 90 mg/m² × 3 days.
Rationale for Selection
For a 45-year-old patient who is fit for intensive therapy, the standard frontline treatment is the "7+3" regimen. The choice of daunorubicin dosing is critical for younger patients:
- Age and Intensity: In patients under age 60, the ECOG 1900 trial demonstrated that intensive daunorubicin dosing at 90 mg/m² significantly improves complete remission (CR) rates (71% vs. 54%) and overall survival (24 months vs. 16 months) compared to lower doses.
- Dose Superiority: This benefit was specifically noted in patients under age 50 and across various cytogenetic risk groups.
- Regimen Structure: Choice C correctly identifies the "7+3" structure, which consists of 7 days of continuous infusion cytarabine and 3 days of an anthracycline.
Choices A and D are structurely incorrect (backwards days), and Choice B utilizes a daunorubicin dose that is considered inferior to 90 mg/m² for fit, younger patients under age 60 in the absence of additional targeted agents.
OT is a 45-year-old male who presents with severe fatigue and high fever. WBC 71,000 cells/mm³ and platelets 45,000 cells/mm³. A bone marrow biopsy showed >61% blasts. The morphology and cytogenetics of the biopsy revealed AML - M4 acute myelomonocytic leukemia.
Which of the following is the best induction regimen for OT?
- A Cytarabine 100mg/m² x 3 days plus daunorubicin 90mg/m² x 7 days.
- B Cytarabine 100mg/m² x 7 days plus daunorubicin 90mg/m² x 3 days.
- C Cytarabine 100mg/m² x 7 days plus daunorubicin 45mg/m² x 3 days.
- D Cytarabine 100mg/m² x 3 days plus daunorubicin 45mg/m² x 7 days.
The best induction regimen for OT is B. Cytarabine 100mg/m² x 7 days plus daunorubicin 90 mg/m² x 3 days.
Rationale for Selection
For a 45-year-old patient who is fit for intensive therapy, the gold standard is the "7+3" regimen.
- Regimen Structure: The "7+3" protocol requires 7 days of continuous infusion of cytarabine and 3 days of an anthracycline. Choice B correctly identifies this sequence, whereas choices A and D invert the schedule.
- Optimal Daunorubicin Dosing: In patients under age 60, the ECOG 1900 trial demonstrated that intensive daunorubicin dosing at 90 mg/m² is superior to 45 mg/m².
- Clinical Outcomes: The 90 mg/m² dose resulted in significantly higher complete remission (CR) rates (71% vs. 54%) and improved median overall survival (24 months vs. 16 months). Consequently, clinical guidelines specify that the 90 mg/m² dose should be employed for patients in this age group.
While Choice C uses the correct "7+3" schedule, the 45 mg/m² dose of daunorubicin is considered suboptimal for a fit 45-year-old patient.
ML is a 49-year-old female who presents with WBC 9,100. Hgb 133, Hct 40, and platelets 63,000. The cytogenetic work-up revealed t(15:17).
What type of acute myelogenous leukemia (AML) is this patient likely to have?
- A. AML-M0 Acute myeloblastic leukemia without maturation (5%)
- B. AML-M4 Acute myelomonocytic leukemia (6%)
- C. AML-M3 Acute promyelocytic leukemia (87%)
- D. AML-M6 Acute erythroleukemia (1%)
The correct answer is: C. AML-M3 Acute promyelocytic leukemia (87%)
- Key Rationale:
- t(15;17) Translocation is the pathognomonic genetic abnormality of acute promyelocytic leukemia (APL, AML-M3)
- Supporting Clinical/Lab Features:
- Why Not Other Options?
- A. AML-M0: Associated with minimal differentiation (CD34+), no specific translocation
- B. AML-M4: Linked to inv(16) or t(9;22), not t(15;17).
- D. AML-M6: Involves erythroid predominance, often with complex karyotypes.
- Urgency:
- APL is a medical emergency due to the high risk of DIC and fatal hemorrhage.
- Treatment requires ATRA (all-trans retinoic acid) + arsenic trioxide (not standard chemo)
- Action Steps for This Patient:
- A. Confirm diagnosis with FISH/PCR for PML::RARA.
- B. Initiate ATRA immediately (even before genetic confirmation if APL suspected).
- C. Monitor DIC (fibrinogen, D-dimer, PT/APTT)
RO is a 44-year-old female admitted due to symptoms of newly-diagnosed AML; NPM1, FLT3-ITD, and FLT3-TKD mutation negative. Her cytogenetics reveal t(8;21). Which of the following is the most appropriate to initiate in RO at this time?
- A. 7+3 plus venetoclax
- B. 7+3 plus gemtuzumab
- C. Liposomal cytarabine and daunorubicin
- D. Azacitidine and venetoclax
The most appropriate treatment for RO is B. 7+3 plus gemtuzumab.
Rationale
- Cytogenetic Risk: RO has t(8;21), which identifies her disease as Core Binding Factor (CBF) AML. This is classified as a favorable-risk subtype.
- Preferred Regimen: For patients fit for intensive therapy with favorable-risk cytogenetics, the NCCN prefers the addition of gemtuzumab ozogamicin to the standard "7+3" induction backbone.
- Evidence: Clinical meta-analyses have demonstrated that the benefit of adding gemtuzumab is most significant in patients with these favorable-risk features.
Why Other Options Are Incorrect
- A (7+3 + venetoclax): This combination is not currently a standard of care for AML induction.
- C (Liposomal formulation): This is typically reserved for secondary AML (e.g., therapy-related or following MDS) and is not the preferred choice for CBF AML.
- D (Azacitidine + venetoclax): This low-intensity regimen is indicated for patients who cannot tolerate intensive chemotherapy due to age or comorbidities, which does not apply to the healthy 44-year-old RO.
Ten days following confirmation of complete remission from induction with 7 + 3 + Gemtuzumab, RO is to receive post-remission therapy. Renal and hepatic function are normal.
Which of the following treatments is most appropriate for RO’s secondary AML?
Which of the following treatments is most appropriate for RO at this time?
- A. Azacitidine and venetoclax
- B. Intermediate dose cytarabine, daunorubicin, and gemtuzumab
- C. Liposomal daunorubicin and cytarabine
- D. 5+2 (cytarabine continuous infusion x5 days + daunorubicin IV on days 1,2) with gemtuzumab
The most appropriate treatment for RO is **B. Intermediate dose cytarabine, daunorubicin, and gemtuzumab**.
Rationale
Protocol Adherence:
The NCCN recommends that post-remission (consolidation) therapy match the specific clinical protocol used during induction. RO’s initial treatment (7+3 with fractionated gemtuzumab) was based on the **ALFA-0701 study**, which utilized this specific three-drug combination for consolidation.
Because RO has Core Binding Factor (CBF) AML, she requires more intensive consolidation with higher doses of cytarabine rather than attenuated schedules like "5+2" to prevent relapse.
Ineligibility of Other Options:
Consolidation with azacitidine/venetoclax (Option A) or liposomal daunorubicin/cytarabine (Option C) is only appropriate if those specific regimens were used during the induction phase.
RO is a 64-year-old female with a history of diffuse large B-cell lymphoma (DLBCL) treated with R- CHOP eight years ago. She is admitted due to symptoms of newly-diagnosed AML with NPM1, FLT3-ITD, and FLT3-TKD mutation negative and CD33+. Her cytogenetics reveal del7. Prior to her admission, she was biking 15 kilometers per day.
Which of the following is the most appropriate to initiate in RO at this time?
- A. 7+3, daunorubicin 45 mg/m2/dose
- B. 7+3, daunorubicin 90 mg/m2/dose
- C. Liposomal cytarabine and daunorubicin plus gemtuzumab
- D. Liposomal cytarabine and daunorubicin
The correct answer is D. Liposomal cytarabine and daunorubicin.
Rationale
- Patient Profile: RO has secondary AML (due to previous R-CHOP therapy) and is over 60 years of age.
- Preferred Therapy: For fit patients aged 60–75 with secondary AML or MDS-related changes, liposomal daunorubicin/cytarabine (CPX-351) is a Category 1 recommendation because it demonstrated superior overall survival compared to standard "7+3" induction in clinical trials.
- Why others are incorrect:
- Choice A & B: Standard "7+3" is less effective than the liposomal formulation in this specific "secondary AML" population. Furthermore, 45 mg/m² of daunorubicin is considered suboptimal compared to higher doses.
- Choice C: Adding gemtuzumab ozogamicin is not recommended here. Patients with secondary AML or poor-risk cytogenetics (like del7) do not respond well to it, and the combination with the liposomal backbone has not been adequately studied.
B. Ten days following confirmation of complete remission from induction, RO is to receive post-remission therapy. Renal and hepatic function are normal.
Which of the following treatments is most appropriate for RO at this time?
- A. Cytarabine 3,000 mg/m2/dose IV Q12 hours on days 1,3,5
- B. Cytarabine 1,000 IV Q12 hours on days 1,3,5 mg/m2/dose + gemtuzumab ozogamicin 3 mg/m2
- C. Liposomal daunorubicin 29 mg/m2 and cytarabine 65 mg/m2 on days 1 and 3
- D. 5+2 (cytarabine continuous infusion x 5 days + daunorubicin IV on days 1,2)
The correct answer is C. Liposomal daunorubicin 29 mg/m² and cytarabine 65 mg/m² on days 1 and 3.
Rationale
- Protocol Continuity: RO achieved complete remission using liposomal daunorubicin/cytarabine (CPX-351) induction. Clinical guidelines recommend that consolidation therapy should match the induction protocol used in the phase III trial that led to the drug's approval.
- Proven Survival Benefit: The use of this specific liposomal consolidation regimen demonstrated an overall survival benefit in older patients with secondary AML when compared to standard "5+2" consolidation.
- Why others are incorrect:
- Choice A: While HiDAC is a standard of care for some AML patients, it was not studied in combination with a liposomal induction.
- Choice B: Intermediate-dose cytarabine plus gemtuzumab would only be appropriate if RO had received the specific induction protocol (ALFA-0701) involving gemtuzumab.
- Choice D: Standard "5+2" consolidation was the comparator arm in clinical trials and was found to be less effective than the liposomal formulation in this patient population.
A. LJ is a 62-year-old female presenting to the ED with a WBC 0.5 x 109/L and platelets 10 x 109/L. She has no past medical history and states she is training for the Boston marathon next month. Unfortunately, she is diagnosed with AML that is found to have a complex karyotype, an IDH1 mutation, and is CD33+.
Which of the following treatments is most appropriate for LJ at this time?
- A. Gemtuzumab ozogamicin
- B. Ivosidenib
- C. Azacitidine + venetoclax
- D. Decitabine + enasidenib
The most appropriate treatment for LJ is C. Azacitidine + venetoclax.
Rationale
- Cytogenetic Risk: LJ has a complex karyotype, which is classified as unfavorable or adverse risk.
- Age and Fitness: Although LJ is very fit (training for a marathon), she is 62 years old. For patients over 60 with unfavorable cytogenetics, the combination of a hypomethylating agent (azacitidine) and venetoclax is a preferred NCCN recommendation over intensive "7+3" chemotherapy, as it typically yields better response rates and survival in this specific risk group.
- Mutation Status: While she has an IDH1 mutation, single-agent ivosidenib (Option B) is generally reserved for elderly patients who are unfit for more intensive regimens; because LJ is fit, she should receive the more robust combination therapy.
Why Other Options Are Incorrect
- A (Gemtuzumab): This is generally used for patients with favorable or intermediate-risk cytogenetics; it has significantly reduced efficacy in patients with unfavorable cytogenetics like a complex karyotype.
- D (Decitabine + enasidenib): Enasidenib is an IDH2 inhibitor and would not target LJ's IDH1 mutation. Furthermore, this combination is not currently a recommended NCCN guideline.
LJ is a 79-year-old female presenting to the ED with a WBC 0.5 x 109/L and platelets 10 x 109/L. Unfortunately, she is diagnosed with AML with an IDH1 mutation, and is CD33+. She lives with her husband 10-min away from the infusion center and does not have any comorbidities.
Which of the following treatments is most appropriate for LJ at this time?
- A. Gemtuzumab ozogamicin
- B. Venetoclax
- C. Azacitidine + ivosidenib
- D. Decitabine + enasidenib
The most appropriate treatment for LJ is C. Azacitidine + ivosidenib.
Rationale
- Targeted Therapy for IDH1: LJ has a confirmed IDH1 mutation. The combination of azacitidine and ivosidenib is an NCCN-recommended, Category 1 treatment option specifically for patients who are over 60 years of age, unfit for intensive therapy, and harbor this mutation.
- Clinical Evidence: The Phase III AGILE study demonstrated that this combination significantly improved median overall survival (24 months vs. 7.9 months) and event-free survival compared to azacitidine alone.
- Patient Profile: Although LJ has no comorbidities, her age (79 years) places her in a category where low-intensity therapy is typically preferred, as most intensive therapy studies enrolled patients under 60–65.
Why Other Options Are Incorrect
- A. Gemtuzumab ozogamicin: This is not an NCCN-preferred therapy in this specific clinical setting.
- B. Venetoclax: While highly effective in AML, venetoclax is not used as a single agent; it must be used in combination with a hypomethylating agent or low-dose cytarabine.
- D. Decitabine + enasidenib: Enasidenib is an IDH2 inhibitor and would not target LJ’s IDH1 mutation. Furthermore, this specific combination is not currently an NCCN-recommended guideline.
SB is a 55-year old female with relapsed AML following a clinical trial with liposomal daunorubicin/cytarabine and gemtuzumab ozogamicin. She has a performance status of 0. A bone marrow biopsy is performed, revealing a normal karyotype and molecular markers that are negative for FLT-ITD, NPM1, and IDH1.
Which of the following would be the most appropriate treatment for SB’s relapsed AML?
- A. Midostaurin
- B. FLAG-IDA + ivosidenib
- C. MEC
- D. Gilteritinib
The most appropriate treatment for SB is C. MEC.
Rationale
- Absence of Targetable Mutations: SB’s molecular markers are negative for FLT3 and IDH1. Targeted agents like gilteritinib (Option D), which is for FLT3-mutated relapsed/refractory AML, and ivosidenib (Option B), which targets IDH1 mutations, are therefore inappropriate.
- Salvage Strategy: MEC (mitoxantrone, etoposide, and cytarabine) is an established intensive salvage chemotherapy regimen for patients without targetable molecular abnormalities.
- Frontline Limitation: Midostaurin (Option A) is only recommended for use in the frontline setting in combination with standard "7+3" induction, not as a salvage therapy for relapsed disease.
5. AML is said to have evolved from MDS if dysplasia is present in:
a. More than 50 percent of cells
b. More than 25 percent of cells
c. More than 30 percent of cells
d. More than 20 percent of cells
The correct answer is a. More than 50 percent of cells.
Rationale
Although your study materials primarily highlight the 20% blast threshold required for a general diagnosis of AML, the specific morphologic criteria for identifying multilineage dysplasia—which characterizes AML as having myelodysplasia-related changes—require that dysplasia be present in 50% or more of the cells in at least two myeloid lineages.
Related Diagnostic Thresholds from the Sources:
- MDS Diagnosis: Requires at least one cytopenia and MDS criteria, which include >10% dysmorphic cells (dysplasia), 5%–19% blasts, or specific MDS-associated cytogenetics.
- AML Diagnosis: Generally requires ≥ 20% blasts in the bone marrow or peripheral blood.
- AML-Equivalent: The 5th edition of the WHO classification regards MDS-IB2 (10%–19% bone marrow blasts or the presence of Auer rods) as an AML-equivalent for therapeutic purposes.
- Genetic Definition: Any percentage of blasts is considered AML if class-defining rearrangements like t(8;21), inv(16), or t(15;17) are present.
Remission induction therapy for high-risk AML should be:
- a. High-dose cytarabine
- b. 3+7+3 induction including etoposide
- c. High-dose cytarabine plus mitoxantrone
- d. 3+7 induction
The correct answer is d. 3+7 induction.
Rationale
Based on the induction strategy guidelines provided in the materials, the "7+3" regimen (7 days of cytarabine and 3 days of an anthracycline) is a Category 1 recommendation for all risk groups, including those with unfavorable-risk (high-risk) cytogenetics.
Analysis of Other Options
- a. High-dose cytarabine (HiDAC): While HiDAC is sometimes studied as part of induction, its use in this phase remains controversial, and it is more typically the standard for consolidation (post-remission therapy).
- b. 3+7+3 induction including etoposide: Although some regimens for patients under age 45 with high-risk disease may incorporate etoposide with HiDAC, the sources explicitly note that comparative studies have not shown a benefit when adding various intensive agents like topoisomerase inhibitors (etoposide) to the standard induction backbone.
- c. High-dose cytarabine plus mitoxantrone: This combination is characteristic of the MEC regimen, which is primarily utilized as a salvage therapy for relapsed or refractory AML rather than frontline induction.
True regarding treatment-related AML (t-AML) is:
- a. Alkylating agents or radiation therapy typically present after a latency period of 5–7 years.
- b. Topoisomerase II inhibitors have a shorter latency period of 1–3 years.
- c. Patients with t-AML have poorer outcomes compared to de novo AML within the same risk group.
- d. All of the above (Correct answer).
Answer: d. All of the above
The correct answer is d. All of the above.
Rationale
Based on the clinical characteristics of treatment-related AML (t-AML) and myelodysplastic syndromes (MDS) described in your sources:
- a. Alkylating agent latency (5–7 years): Exposure to alkylating agents or ionizing radiation characteristically leads to mutations in chromosomes 5 and 7 with a median onset of 5–7 years after therapy.
- b. Topoisomerase II inhibitor latency (1–3 years): t-AML/MDS following topoisomerase II inhibitors typically presents with mutations of chromosome 11q23 and has a significantly shorter latency period, cited in your materials as 2–3 years (frequently represented as 1–3 years in clinical practice).
- c. Poorer Outcomes: Secondary AML (including therapy-related) is explicitly categorized as unfavorable risk. These patients have decreased overall survival compared to those with de novo AML due to a higher likelihood of poor-risk cytogenetics and a diminished ability to tolerate intensive therapy.