Morbidity and mortality in gynecological cancers among first- and second-generation immigrants in Sweden

We studied the effect of new environment on the risk in and mortality of gynecological cancers in first- and second-generation immigrants in Sweden. We used the nationwide Swedish Family-Cancer Database to calculate standardized incidence/mortality ratios (SIRs/SMRs) of cervical, endometrial and ovarian cancers among immigrants in comparison to the native Swedes. Risk of cervical cancer increased among first-generation immigrants with Danish (SIR = 1.64), Norwegian (1.33), former Yugoslavian (1.21) and East European (1.35) origins, whereas this risk decreased among Finns (0.88) and Asians (SIRs varies from 0.11 in Iranians to 0.54 in East Asians). Risk of endometrial (SIRs varies from 0.28 in Africans to 0.86 in Finns) and ovarian (SIRs varies from 0.23 in Chileans to 0.82 in Finns) cancers decreased in first-generation immigrants. The overall gynecological cancer risk for the second-generation immigrants, independent of the birth region, was almost similar to that obtained for the first generations. The birth region-specific SMRs of gynecological cancers in first- and second-generation immigrants co-varied with the SIRs. Risk of gynecological cancers among the first-generation immigrants is similar to that in their original countries, except for cervical cancer among Africans and endometrial cancer among North Americans and East Europeans. Our findings show that risk and mortality of gynecological cancers observed in the first-generation immigrants remain in the second generation. We conclude that the risk and protective factors of gynecological cancers are preserved upon immigration and through generations, suggesting a role for behavioral factors or familial aggregation in the etiology of these diseases.