Cancer mortality in Italian migrants and their offspring in Canada.

Studies on the offspring of migrants provide important information on the contribution of environmental and genetic factors in the etiology of various cancers. The aim of the present study is to analyze the cancer risk in Italian-migrants (Canadian residents born in Italy) and their offspring compared with the host population. Odds ratios (OR) and 95 percent confidence intervals (CI) by site and birthplace categories (migrants, pure and mixed Italian-parentage Canadians) were calculated by means of a case-control study using the 'other cancer deaths' as controls and taking the host population as the reference category. The study shows that Italian migrants retain a significantly low risk for a series of cancers: colon (OR = 0.9 in males and 0.7 in females); lung (OR = 0.8 in males and 0.5 in females); and breast (OR = 0.9). For all of these sites, risks in the offspring of Italian migrants were not different from those of the host population, with some differences between the genders with respect to cancer of the colon. Stomach cancer presents a significantly high rate in migrants (OR = 1.9 in males and 2.4 in females), consistent with the population of Italy; in their offspring, risks are similar to those in the host population. The risk of cancer in the offspring of migrants is, for many sites, intermediate between the host population and the Canadian residents born in Italy. This finding possibly is related to the larger integration of the offspring than their parents in the cultural and social environment of the host population.