Minimal breast cancer. An update.

In 1971, minimal carcinoma of the breast was defined as those carcinomas which were duct carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS) and those invasive carcinomas that measured 5 mm or less in greatest diameter. Since then the concept has been challenged; the definition has been modified; there has been new knowledge about the forms of carcinoma included in the definition with reference to natural history and response to therapy and there has been documented experience with patients who have minimal mammary carcinoma. These all re-enforce the validity of the original concept. The author reviews this information as well as that of some of the patients of the Breast Cancer Detection and Demonstration Projects jointly sponsored by the American Cancer Society and the National Cancer Institute, discusses some problems with specimen handling, and identifies areas that need additional study.