Human Papillomavirus

HPV stands for Human Papillomavirus

  • It is a DNA virus with multiple subtypes.
  • High-risk types, especially HPV-16 and HPV-18, are oncogenic and associated with cancers such as:
  • Low-risk types (e.g., HPV-6, HPV-11) typically cause benign warts.

In head and neck cancer, HPV-16 is the predominant high-risk subtype driving tumor development.

HPV in Head & Neck Cancer

1. Epidemiology

  • HPV-positive HNC is increasing, especially in oropharyngeal squamous cell carcinoma (OPSCC) (tonsil, base of tongue).
  • Most common type: HPV-16 (~90% of cases).
  • Typically affects younger patients with less smoking history.

2. Pathophysiology

  • HPV oncoproteins E6 and E7 inactivate p53 and Rb, leading to uncontrolled cell proliferation.
  • Results in distinct molecular and clinical profile compared to HPV-negative HNC.

3. Clinical Features

  • Tumors often present as tonsillar or base of tongue masses.
  • Cervical lymphadenopathy is common at presentation.
  • Patients are generally non-smokers or light smokers, younger, and healthier than HPV-negative patients.

4. Prognostic Significance

  • HPV-positive OPSCC has significantly better prognosis than HPV-negative disease.
  • Better response to chemoradiation, lower recurrence, higher survival.

5. Diagnosis

  • p16 immunohistochemistry (IHC) is used as a surrogate marker for HPV positivity.
  • HPV DNA or RNA testing can confirm.
  • HPV testing is standard for oropharyngeal cancers, not routine for oral cavity, larynx, or hypopharynx.

6. Implications for Therapy

  • HPV-positive tumors may allow for treatment de-escalation in clinical trials due to favorable prognosis.
  • Standard therapy still includes surgery, radiation, and/or chemoradiation, but trials are ongoing for reduced intensity regimens.

7. Risk Factors

  • Sexual behavior: oral sex, multiple partners
  • Less associated with tobacco/alcohol than HPV-negative HNC

8. Summary Table

Feature HPV-Positive HNC HPV-Negative HNC
Common site Oropharynx (tonsil, base tongue) Oral cavity, larynx, hypopharynx
Age Younger (40–60) Older (50–70)
Risk factors HPV exposure Tobacco, alcohol
p16 status Positive Negative
Prognosis Favorable Poorer
Response to therapy Better Worse
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