[Intraductal spread of carcinoma: a risk for breast conserving surgery].

Intraductal spread of carcinoma (ISC) was defined as "DCIS clearly present extending beyond terminal duct-lobular unit, or present prominently within large ducts," using a sequential slicing of tissues and 3-D reconstruction of tumors. We then analyzed the relationship between ISC in specimens obtained by breast conserving surgery (BCS) and carcinoma residue in specimens obtained by total mastectomy. We found a strong correlation between the ISC factor in BCS tissues and the carcinoma residue in mastectomy specimens. Among 12 patients under observation without mastectomy, 3 patients subsequently developed breast carcinoma. Two of the 3 patients demonstrated ISC in BCS specimens. One of 10 patients without ISC, however, developed carcinoma, suggesting that the ISC is a risk factor in breast conserving surgery for breast cancer patients.