Nasopharyngeal carcinoma in alaskan eskimos, indians, and aleuts: A review of cases and study of epstein-barr virus, HLA, and environmental risk factors

Abstract

The records of thirty-one patients with nasopharyngeal carcinoma (NPC) diagnosed from 1966 through 1976 among the Alaskan native population (Eskimo, Aleut, Indian) were reviewed. There were 25 males and six females, which results in relatively high incidence rates per 100,000 of 13.5 for males and 3.7 for females. Clinical and pathologic features were similar to those found among southern Chinese NPC patients. Five-year survival rate was 48%. Antibodies to Epstein-Barr virus were higher in NPC patients than in patients with other tumors or matched controls. On histocompatibility testing Sin-2 was not detected, nor was there significantly increased frequency of A2. Instead, BW40 and a second locus blank occurred more often among NPC patients than among other groups. In response to a questionnaire, NPC patients more often reported use of salt fish in the childhood diet, smoking of cigarettes, and exposure to noxious inhalants than did controls, but the differences were not statistically significant.

The Enigmatic Epidemiology of Nasopharyngeal Carcinoma

“…In studies of Chinese populations, the relative risk of NPC associated with weekly consumption, compared with no or rare consumption, generally ranged from 1.4 to 3.2, whereas that for daily consumption ranged from 1.8 to 7.5 (136)(137)(138)(139)(140)(141). NPC risk is also elevated in association with other preserved food items, including meats, eggs, fruits, and vegetables, in southern Chinese, Southeast Asians, North Africans/Middle Easterners, and Arctic natives (38,39,(138)(139)(140)(141)(142)(143)(144)(145)(146)(147), as well as in low-incidence northern Chinese (148) and the U.S. population (excluding type I NPC; ref. 149).…”

“…The majority of casecontrol studies examining cigarette smoking and risk of NPC in a variety of populations reported an increased risk of 2-to 6-fold (9,39,40,73,142,(172)(173)(174)(175)(176)(177)(178)(179)(180)(181), establishing tobacco smoke as a consensus risk factor for NPC (182), although some studies found no association (24,38,74,137,141,148,154,(183)(184)(185)(186). Reports of a positive association between domestic exposure to secondhand smoke and risk of NPC (40,146,180) are likewise countered by studies with null findings (39,174).…”

“…Reports of a positive association between domestic exposure to secondhand smoke and risk of NPC (40,146,180) are likewise countered by studies with null findings (39,174). The discrepancy in findings may be due in part to differences in study design and/or exposure assessment, as well as study population; several of the studies reporting a positive association were conducted in low-or intermediate-incidence populations (9,142,173,(175)(176)(177)(178)180). In one U.S. study, an estimated two thirds of type I NPC was attributable to smoking, but risk of type II or III NPC was not associated with smoking (9).…”

Chemical Carcinogenesis and Nasopharyngeal Carcinoma

“…This indicates that consumption frequency of salt-preserved fish is associated with the risk of NPC. However, elevated NPC risk is also associated with other preserved food items, including meats, eggs, fruits, and vegetables [4][5][6][7][8][9][10][11][12][13][14][15].…”

Cancers of the Buccal Cavity and Pharynx in Circumpolar Inuit

“…With 98 cases diagnosed among men and 52 among women, nasopharyngeal cancer accounted for 4.7% of all malignancies during the period, a percentage equal to that of stomach cancer (Table 9). Based on the age-stan- was 1.9:l. Ninety-six percent of all carcinomas were histologically verified (Table 7).…”