Recent trends in the management of breast cancer. 1. Carcinoma in situ of the breast.

Because of widespread screening for breast cancer, noninvasive (in-situ) cancer of the breast is diagnosed with increasing frequency. The two variants--lobular carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS)--can be cured with conservation of the breast. The diagnosis of LCIS indicates a high risk for future development of invasive carcinoma in either breast. Bilateral total mastectomy, with reconstruction if desired, is the only method of eliminating this risk, but local excision alone with close observation is acceptable. For DCIS, total mastectomy, with or without low axillary lymph-node dissection, offers near-complete cure. For selected cases, wide local excision, with or without dissection of the low axillary nodes, followed by breast irradiation provides survival rates comparable to those for mastectomy and a low risk of recurrence in the breast. Studies are in progress to determine if breast irradiation after local excision is necessary in all instances.