Breast cancer in 3,558 women: age as a significant determinant in the rate of dying and causes of death.

The forces of mortality created by cancer of the breast have been examined utilizing data collected during the past 19 years by the Syracuse, N. Y., Upstate Medical Center Cancer Registry on 3,558 women. Except for 15 lost to follow-up, all have been contacted annually through 1974 or until death. Time and cause were recorded for all deaths. In April, 1975, 1,883 remain alive and in the registry and 1,660 women have died. Using life-table analyses and considering deaths due only to breast cancer, mortality rates were calculated for three age groups--21 to 50 years, 51 to 70 years, and 71 to 100 years. Breast cancer expresses its lethality most vigorously in the oldest group. The half-death time (50% mortality rate) for the youngest group was 13 years, for the middle group 8 years, and for the oldest group 5 years. The rate of dying was a function of both age and stage at diagnosis. At 16 to 18 years after diagnosis, deaths due to breast cancer begin to disappear. Eighty-eight percent of the women who died following a diagnosis of cancer of the breast have died of their breast cancer. Age as well as stage at diagnosis are significant determinants on the length of survival and cause of death.