Risk of infiltrating breast cancer subsequent to lobular carcinoma in situ. The Coordinating Center and Writing Committee of FONCAM (National Task Force for Breast Cancer).

The authors report on a retrospective consecutive multicentric series of 60 cases with histologic evidence of lobular carcinoma in situ (LCIS), followed for an average of 5.3 years. In the course of the follow-up, ipsilateral LCIS or infiltrating carcinoma occurred in 3 or 5 cases, respectively. Two LCIS reoccurrences and all ipsilateral infiltrating carcinomas were observed in 37 patients treated by limited surgery. Contralateral synchronous or metachronous carcinoma was observed in 3 or 2 cases, respectively (intraductal = 3, infiltrating = 2). Three patients died of breast cancer (2 with ipsilateral, 1 with ipsilateral and contralateral infiltrating carcinoma). The study confirms the higher risk of ipsilateral and contralateral cancer in LCIS patients and warns about the possible hazards of limited surgery in these cases.