Demographic investigation of mammary carcinoma in Northern Sweden

The age standardized incidence rates for female breast carcinoma were calculated for the 3 northernmost counties in Sweden and their municipalities for the period 1959 to 1971. Large variations were found that could not be explained by random distribution. Lower incidences were encountered in the less urbanized municipalities in the western and northern parts. The largest relative difference between low-incidence and high-incidence municipalities concerned the post-menopausal period.