Cancer of the male genital tract in Circumpolar Inuit.

In an international collaboration project we combined cancers of the male genital tract among Inuit identified from routine cancer registry systems in the Circumpolar region (Alaska, Canada and Greenland) and compared incidence rates with rates in Denmark, Connecticut (USA) and Canadian non-Inuit. We observed a low risk of prostate cancer (standardized incidence ratio (SIR) 0.2-0.3) and the incidence rate of 7.8 per 100 000 (world standard) is among the lowest in the world. Dietary and not diagnostic factors are likely explanations of this finding. Testicular cancer also occurred with low rates (SIR 0.3-0.7) although only significantly so when compared with Denmark and Connecticut (USA) which have some of the world's highest incidence rates of this cancer. Penile cancer occurred with relatively high risk (SIR 1.8-3.0) based on rates among non-Inuit. The incidence is, however, lower than anticipated considering the possibility for shared risk factors with cancer of the uterine cervix.