nasopharyngeal carcinoma

Introduction

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