nasopharyngeal carcinoma

see also:

• neoplasia / cancer / tumours
• ears, nose and throat surgery (ENT)
• oropharyngeal cancer

• nasopharyngeal carcinoma is a rare cancer of the naso-pharyngeal region
• there are 3 main sub types:
  • type 1: SCC - mainly older adults
  • type 2: non-keratinizing carcinoma
  • type 3: undifferentiated carcinoma - mainly younger children, adolescents

• it is vastly more common in certain regions of South-East Asia (mainly middled aged) and Africa (mainly children) than elsewhere, with viral (esp. EBV), dietary and genetic factors implicated in its causation
• in 2010, NPC resulted in 65,000 deaths globally
• less than 1 case per 100,000 in most populations
  • in these low risk populations, first peak occurs in late adolescence/early adulthood (ages 15–24 years), followed by a second peak later in life (ages 65–79 years)
• 25x higher in southern China and also is high in Taiwan hence called the Cantonese cancer which may be related to genetics and diet

• past EBV infection (mainly type 2 and 3 cancers)
  • EBV DNA was detectable in the blood plasma samples of 96% of patients with non-keratinizing NPC, compared with only 7% in controls.
• past HPV infection (mainly type 1 cancers)
• genetic factors:
  • Asian or Chinese ancestry
  • rare familial clusters
• heavy alcohol consumption
• cigarette smoking
  • 2-6 fold increased risk - mainly type 1
• wood fire smoke:
  • in southern China and North Africa, it has been suggested that high smoking rates come from wood fires in the country rather than cigarette smoking
• environmental carcinogens
• consumption of preserved meats and salted fish containing carcinogenic volatile nitrosamines
• chronic sinusitis is being investigated as a possible risk factor