The changing pattern of neoplastic disease in Canadian Eskimos.

The records of the two main referral centres for the western and central Arctic were reviewed for Eskimo patients with cancer diagnosed between 1949 and 1974 inclusive. To these were added the records for the past 6 years of patients from the eastern Arctic, giving the toatal of 180 histologically proved cases of malignant disease. Athe data were analysed for prevalence, relative frequency, geographic distribution and changes with time of the various neoplasms. Salivary gland and renal neoplasms have in recent years been displaced by cancer of the lung and uterine cervix as the most common malignant tumours in Canadian Eskimos. The prevalence of lung cancer in Eskimo women, particularly of the central Artic, is striking. Cancer of the nasopharynx kept the same relative position during early and late years of the survey period. Breast cancer is still uncommon in Eskimos. Lactation rather than gestation history appeared to be an important protective factor. Cases of cervical cancer outnumbered those of breast cancer by 18 to 4, in sharp contrast to the relative proportions of these tumours in all Canadian women.