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.

Cancer occurrence in Iran in 2002, an international perspective.

For almost 30 years no population-based cancer statistics have been available with which to estimate the cancer burden in Iran. In 2002 and 2003 two separate reports of population based cancer registries were published from Iran and the cancer incidence rates from these sources have permitted informed estimates of cancer incidence and mortality to be prepared. They suggest that more than 51,000 cases of cancer are diagnosed and 35,000 deaths due to cancer occur each year. The 5 most common cancers in males (by ASR) are stomach (26.1 per 10(5)), esophagus (17.6 ), colon-rectum (8.3), bladder (8.0) and leukemia (4.8), and in females are breast (17.1), esophagus (14.4), stomach (11.1), colon-rectum (6.5) and cervix uteri (4.5). The incidence rates of esophageal and stomach cancer in Iran are high, well above the world average, while the incidence of lung cancer is very low. Breast cancer, although the most common cancer of females in Iran, has rates that are low by world standards, especially those observed in Europe and USA. Similarly, the incidence of cervix cancer in Iran is very low, even lower than such low risk countries as China, Kuwait and Spain. Comparing these rates with the data of 30 years ago, the incidence of esophageal cancer has decreased dramatically, but gastric cancer has increased about two fold.