Consecutive primary carcinomas of the breast.

The incidence of consecutive primary carcinoma of the breast in 1489 women was 1 percent per year and remained constant for 20 years. The age of women with bilateral carcinomas was 6 years younger than those who had single tumors. Survival after the second tumor tended to be better in women less than 50 years. Patients who developed metastases had a shorter interval between the first and second tumors than those who remained free from the disease. Prognosis was the same in those with nonsynchronous carcinomas as in those with single tumors, and the incidence of positive nodes was the same in both groups. The prognosis was poorest in those who developed synchronous tumors. Prophylactic postoperative radiotherapy did not affect the incidence of consecutive breast carcinomas and did not alter prognosis. The results stress the importance of observing carefully the remaining breast, especially in younger women.