Feasibility of breast conservation surgery in locally advanced breast cancer downstaged by neoadjuvant chemotherapy: a study in mastectomy specimens using simulation lumpectomy.

BACKGROUND The response of locally advanced breast cancer (LABC) to neoadjuvant chemotherapy (NACT) offers these patients previously treated by mastectomy, the chance for breast conservation. AIM This study aims to assess the feasibility of lumpectomy in patients with LABC treated by NACT, with residual tumor < or =5 cm. SETTINGS, DESIGN: Single group prospective study from August 2001 to June 2003 in a teaching hospital. MATERIALS AND METHODS Thirty patients with LABC whose tumors reduced with NACT to 5 cm were included. Simulation lumpectomy was performed on the mastectomy specimens to achieve 1 to 2 cm clearance from tumor and hence margin negativity. Multiple sections of the inked margin were studied. STATISTICAL ANALYSIS Margin positivity was correlated with patient factors. Chi square test and Fisher's exact test used as appropriate. P value 0.05 was considered significant. RESULTS AND CONCLUSIONS After three cycles of NACT, 4 patients (13%) had complete clinical response including 2 with complete pathological response. Twenty-two (73%) showed partial response and 4, no response. Fourteen out of thirty (47%) had tumor involvement of margins. Tumors with post-chemotherapy size> 4 cm were margin positive in 10/13 (77%). Tumors with post-chemotherapy size>3 cm were margin positive in 13/24 (54%). Tumors with post-chemotherapy size 3 cm were margin negative in 5/6 (83%). Pre-chemotherapy tumor size and post-chemotherapy tumor size were significantly associated with margin positivity (P=0.003). Tumors in the subareolar location had significantly higher incidence of residual tumor in the nipple areola complex. (P=0.04). Margin positivity of lumpectomy on downstaged tumors can be reduced by removing the nipple areola complex in subareolar tumors and by limiting breast conservation to tumors with post-chemotherapy size < or =3 cm.