Cancer of the breast in women born in southern Italy and who migrated to the city of Torino.

Individual demographic data of 459 women living in Torino with incident breast cancer diagnosed in 1979 were compared with those of a random sample of 1800 women drawn from the list of residents in the same city. Among women aged 25-44 and 45+ years, age-adjusted odds ratios for birth in southern Italy were respectively 1.3 (95% CL, 0.1-2.1) and 0.7 (95% CL, 0.5-0.9). In women aged 45+ years, odds ratios increased with length of residence in Torino.