Cancer risk in the reindeer breeding Saami population of Sweden, 1961-1997.

The Saami people are the natives of northern Scandinavia and the Kola Peninsula. In a cohort of 2033 Swedish reindeer breeding Saamis, the cancer risks between 1961 and 1997 were studied. In total, 193 cases of cancer were observed versus 322 expected in the general Swedish population and 249 in a geographically matched reference population of non-Saamis. In comparison to non-Saamis living in the same area, the reindeer breeding Saamis showed a statistically significant lower risk of developing cancer of the prostate and of malignant lymphoma, whereas the risk of stomach cancer was significantly higher. Although there were no statistically significant changes of cancer risks over time, temporal trends were indicated towards a decreased risk of cancer in the stomach and the prostate. The results suggest that the explanations of the low cancer risk of the reindeer breeding Saamis, in relation to the non-Saamis in the same environment, are to be found among lifestyle and/or genetic factors.