nasopharyngeal carcinoma (NPC)

Etiology

• environmental: consumption of preserved foods with volatile nitrosamines eg. Cantonese style salted fish
• association with latent Epstein Barr virus infection

Epidemiology

• type III (undifferentiated carcinoma) more prevalent (~97%) in endemic areas such as southern China
• type I (keratinizing squamous cell carcinoma) more common in western countries
• latent Epstein Barr virus infection uniquely present in almost all NPC from endemic regions

Pathology

WHO classification

• type I: keratinizing squamous cell carcinoma
• type II: non-keratinizing squamous cell carcinoma
• type III: undifferentiated carcinoma - lymphoplasmacytic infiltrates typically prominant

Genetics

• associated with HLA-A2 subtype HLA-A*0207
• frequent loss of chromosomes 3p, 9, 11q, 13q, 14q, 16q
• recurrent gains of chromosome 12
• gene alterations
  • p16/CDNK2A hypermethylation/ 62-86% homozygous deletion
  • p14/ARF hypermethylation/ 54% homozygous deletion
  • p63 overexpression 100%
  • bcl-2 overexpression 80%
  • bcl-3 overexpression 60%
  • DAP kinase hypermethylation 76%
  • EGFR overexpression 85%
  • E-cadherin hypermethylation 52%
  • TSLC1 hypermethylation 34%
  • RASSF1A hypermethylation/mutation 67-83%
  • RARB2 hypermethylation 80%
  • OSCP1
• other implicated genes: NGX6, TP53, ACOT7L

Clinical manifestations

• neck mass/cervical lymphadenopathy
• blood tinged sputum
• nasal obstruction
• increasing nasal discharge
• tinnitus
• hearing loss
• headache

Management

• radiation therapy for stage I disease
  • tumors are highly radiosensitive
  • lymph node dissection NOT necessary
• radiation with adjuvant chemotherapy for more advanced disease
• chemotherapy has no effect on overall survival

More general terms

• squamous cell carcinoma (SCC)
• nasopharyngeal neoplasm

More specific terms

• nasal carcinoma

Additional terms

• head & neck cancer (HNC)

Database

• OMIM: https://mirror.omim.org/entry/161550
• OMIM: https://mirror.omim.org/entry/607107