Nasopharyngeal Carcinoma – Quick Review Notes

Anatomy

  • Hollow mucosal passage linking nasal cavity to oropharynx
  • Boundaries: anterior posterior choanae\text{posterior choanae}; roof sphenoid + clivus\text{sphenoid + clivus}; posterior clivus + C1\text{clivus + C1}; inferior soft palate/oropharynx\text{soft palate/oropharynx}; lateral Eustachian tube + torus tubarius\text{Eustachian tube + torus tubarius}
  • Rosenmüller’s fossa (posterior to torus) = commonest tumour site
  • Lining: stratified squamous or pseudostratified columnar epithelium; contains minor salivary & lymphoid tissue

Functions

  • Air conduit (warmed/humidified) to larynx/trachea
  • Middle-ear aeration & pressure equalisation via Eustachian tube
  • Contributes to speech resonance

Epidemiology

  • Uncommon globally; endemic in Southern China, South-East Asia, Alaska
  • Incidence 10!–53/100,00010!\text{–}53/100{,}000; Africa 5!–7/100,0005!\text{–}7/100{,}000; Ghana 1.2%1.2\% of all cancers
  • Bimodal: peak 4th!–5th\text{4}^{\text{th}}!\text{–}\text{5}^{\text{th}} decade & late teens
  • Male:female 2!–3:12!\text{–}3:1

Aetiology

  • Multifactorial: genetic, viral, dietary, environmental

Genetic

  • High susceptibility in Southern Chinese (≈100×100\times Caucasian rate)
  • Key alterations: allelic loss 3p, 9p\text{3p, 9p} → inactivation p14,p15,p16p14, p15, p16; mutations in AKT1,p53,MDM2,LMP1,PTENAKT1, p53, MDM2, LMP1, PTEN

Viral

  • Epstein–Barr virus strongly linked
    • Elevated IgA/IgG VCA & EA antibodies (IgA positive in 80!–85%80!\text{–}85\%)

Dietary

  • Childhood intake of salted, preserved fish/foods (nitrosamines)
  • Fruit/vegetable (vitamin C) intake protective

Other Risks

  • Cigarette smoke, alcohol, wood dust, incense, opium

Clinical Presentation

  • Site hard to examine → late diagnosis

  • Four symptom clusters:

    • Nasal: discharge, epistaxis, blockage, hyponasal speech, anosmia (≈80%80\% cases)
    • Otologic: unilateral serous otitis media, hearing loss, fullness, tinnitus
    • Ophthalmo-neurologic: headache, facial pain, CN III–VI palsies, diplopia, ophthalmoplegia, proptosis, blindness
    • Cervical: painless upper-jugular/posterior-triangle lymphadenopathy (often first sign)

Diagnosis & Work-up

  • History + full head & neck exam with rigid/flexible nasoendoscopy
  • Biopsy of primary or metastatic node = gold standard (usually transnasal)
  • Labs: routine bloods, EBV IgA/IgG titres
  • Imaging: CT/MRI head-neck (tumour extent, skull base, nodes), bone scan, CXR

Histology & Staging

  • WHO types:
    • Type I – keratinising SCC
    • Type II – differentiated non-keratinising
    • Type III – undifferentiated (II & III endemic, EBV-related)
  • Staging: AJCC/UICC TNM commonly used

Treatment Principles

  • Main goals: cure or palliation via multidisciplinary team

Radiotherapy (primary)

  • External beam to primary + neck
  • Total dose 65!–70 Gy65!\text{–}70\,\text{Gy} (effective stages I!–IVBI!\text{–}IVB)

Chemotherapy

  • Indicated for advanced loco-regional disease
  • Timing: neoadjuvant, concurrent, or adjuvant with RT
  • Active agents: cisplatin, 5!-FU5!\text{-FU}, doxorubicin, epirubicin, bleomycin, mitoxantrone, methotrexate

Surgery (limited role)

  • Diagnostic biopsies; neck dissection for residual/recurrent nodes; tracheostomy for airway; selected local/ skull-base resections or brachytherapy access

Follow-Up

  • Essential for recurrence detection & functional rehab
  • Schedule: every 2!–32!\text{–}3 months (first 33 yrs) → 6-monthly (yrs 44–55) → yearly to 77 yrs

Key Takeaways

  • NPC arises from nasopharyngeal epithelium, most commonly in Rosenmüller’s fossa
  • Strong EBV association and high prevalence in specific ethnic/geographic groups
  • Presents late with nasal, ear, neuro-ophthalmic symptoms, or neck nodes
  • Highly radiosensitive; combined chemo-RT improves outcomes in advanced disease; surgery mostly adjunctive
  • Early detection challenging—high clinical suspicion in at-risk populations is critical