BREAST-CANCER INCIDENCE, PREVALENCE, MORTALITY, AND SURVIVORSHIP IN ROCHESTER, MINNESOTA, 1935 TO 1974

Abstract

The epidemiologic features of breast cancer in Rochester, Minnesota were studied over the 40-yr period 1935-1974. During this time, the age-adjusted incidence rate increased 25% to 82.7/100,000 person-yr. Most of the increase occurred among women 45-64 yr of age. The incidence of breast cancer increased with advancing age, as did breast cancer prevalence, which was 901.4/100,000 women on Jan. 1, 1975. Age-adjusted mortality rates declined slightly from 24.9 to 23.3/100,000 person-yr during the study period. Survival after the diagnosis of breast cancer seemed to improve somewhat among women who were less than 45 or more than 65 yr old at the time of diagnosis. This was associated with a decline in the proportion of these women with regional lymph node involvement or distant metastases present at the time of initial diagnosis.