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.