Comparison of cancer incidence in Iran and Iranian immigrants to British Columbia, Canada.

Migrant studies provided strong evidence about the role of environment and life style in cancer risk. Iran has experienced many immigrants to other countries with different cultures and environment. This study compares cancer incidence rates in Iran, Iranian immigrants to British Columbia (BC), Canada, and the BC general population. Cancer incidence rates were computed from two population-based cancer registries in Iran and from the BC cancer registry. A listing of common Iranian surnames and given names was produced to identify Iranian immigrants within the BC cancer registry. Age-standardized rates (ASRs) were calculated using mid year census data. The overall cancer incidence rate for Iranian female immigrants was intermediate between rates for Iran and the BC general population, and the rate for Iranian male immigrants was lower as compared to the other population groups. For female Iranian immigrants, the incidence of breast cancer was increased four-fold, and for colorectal cancer two-fold, as compared to Iranian rates. A dramatic decrease was found in the incidence of both stomach and oesophageal cancers for Iranian immigrants of both sexes. For male Iranian immigrants, the incidence of prostate cancer was increased as compared to Iranian rates. Differences in incidence rates of specific cancers were observed between BC Iranian immigrants and Iran, with cancer patterns in Iranian immigrants being more similar to the BC general population. This warrants further investigation into differences in lifestyle and cancer detection.