Nasopharyngeal Carcinoma (NPC) - Summary

Nasopharyngeal Carcinoma (NPC)

Anatomy

  • Nasopharynx connects the nasal cavity to the oropharynx.
  • Anteriorly: posterior choanae and nasal cavity.
  • Roof: sphenoid bone and the clivus
  • Posteriorly: clivus + 1st cervical vertebra
  • Inferiorly: oropharynx and soft palate
  • Laterally: Eustachian tubes and tori.
  • Rosenmüller’s fossa is the most common location for cancers to arise.
  • Lined by stratified squamous epithelium or pseudostratified columnar epithelium.

Functions

  • Conduit for air.
  • Aerates the middle ear via the Eustachian tube.
  • Contributes to the resonance of sound during speech.

Epidemiology

  • Uncommon in most parts of the world; endemic in Southern China, South East Asia, and Alaska.
  • Incidence varies by region, e.g., Africa has a lower incidence than endemic areas.
  • Bimodal age distribution: 4th to 5th decade of life and late teens.
  • Male to female ratio is 2 to 3:1.

Aetiology

  • Multifactorial: genetic, viral, and dietary factors.
  • Genetic: Chinese have a greater susceptibility.
  • Viral: Epstein-Barr virus (EBV) is closely associated.
  • Dietary: Dry, salted fish increases risk; fruits and vegetables are protective.

Clinical Presentation

  • Poor accessibility of the site impedes early diagnosis.
  • Four main groups of symptoms: nasal, otologic, ophthalmo-neurologic, and cervical nodal metastasis.
    • Nasal: Discharge, epistaxis, nasal blockage.
    • Otologic: Hearing loss, aural fullness, tinnitus, serous otitis media.
    • Ophthalmo-neurologic: Headache, facial pain, cranial nerve palsies.
    • Cervical nodes: Enlargement.

Diagnosis

  • History and physical examination, including endoscopic visualization.
  • Biopsy (primary lesion or neck node) is the gold standard.

Workup

  • Laboratory Studies: Routine blood work, EBV titres.
  • Imaging Studies: CT scan (tumor extent), MRI (intracranial extension), Bone scans (distant bony metastasis), CXR (lung metastasis).

Histology

  • WHO classification:
    • Type I: Keratinizing squamous cell carcinoma.
    • Type II & III: Non-keratinizing carcinoma (differentiated and undifferentiated).
    • Types II and III are endemic forms associated with EBV.

Staging

  • Variety of systems used: Am Jt Cmttee for Ca Staging, International Union Against Ca, Ho System.

Treatment

  • Multidisciplinary approach: ENT surgeon, oncologist, radiologist, pathologist, etc.
  • Modalities:
    • Radiotherapy: Primary modality, 65-70Gy.
    • Chemotherapy: Neoadjuvant, adjuvant, or concurrent with radiotherapy.
    • Surgery: Limited role.

Surgical Management

  • Limited role in management.
  • Indications include:
    • Diagnosis and biopsy.
    • Treatment of recurrent or residual nodal disease.
    • Tracheostomy in airway obstruction.

Follow Up Plans

  • Important part of care.
  • Involves oncologist, head and neck surgeon, speech therapist, and dentist.
  • Frequency: 2-3 months for the first 3 years, then 6 monthly, then yearly.