Breast conservative surgery: is it appropriate for locally advanced breastcancer following downstaging by neoadjuvant chemotherapy? A pathological assessment

The application of breast conserving surgery to down-staged cases with loca lly advanced breast cancer (LABC) after neoadjuvant chemotherapy (NACT) is still a controversial issue with a variable incidence of locoregional failu res. In this study, the response of LABC to NACT was assessed pathologicall y and the elegible candidates for breast conserving surgery were identified retrospectively. The efficacy of preoperative clinical examination and mam mography in detecting these pathological changes were also evaluated. The study included 41 LABC cases. They received NACT (FAC) and were then su bjected to a mastectomy. The cases were examined clinically and by mammogra phy before starting treatment and immediately before surgery. Residual rumo urs in the mastectomy specimens were correlated with the pretreatment and p reoperative clinical and mammographic findings inorder to assess the effica cy of these tools for detection of NACT-induced changes. After 3 cycles of NACT, 78% of women showed an objective response. However, only 25% of them would have been eligible for breast conserving surgery. T he remaining responders had an increased incidence of either multifocality and or peritumoural in situ carcinoma. Both clinical examination and mammog raphy were inadequate for detection of these chemotherapy-induced changes a nd hence for selecting suitable candidates for breast conservation. This st udy has shown that tumour regression by NACT is probably induced by a proce ss of tumour segmentation and is associated with an increased incidence of ductal in situ lesions in the original tumour bearing area. (C) 1999 Harcou rt Publishers Ltd.