Current surgical management of in situ cancer of the female breast.

Surgical procedures for breast cancer were compared in 468 cases with in-situ and 4,967 cases with invasive lesions. The cases were obtained from the Michigan Cancer Foundation Registry, a Surveillance, Epidemiology, and End Results (SEER) participant, and were incident-resident cases diagnosed from 1973-1978. For single, primary in situ or invasive cancer, the preferred mastectomy was modified radical. Partial and simple resections were used more often than radical procedures for non-infiltrating, especially lobular lesions. For cases with bilateral primates, with at least one in situ, the mastectomy of choice was the simple procedure for the in situ malignancy and modified radical for the invasive cancer. The change in preferred surgery for in situ lesions, from modified radical to simple mastectomy, was not due to any change in strategy for treatment of bilateral invasive disease, which remained modified radical resection.