Pathologic complete response rates observed in women with locally advanced and inflammatory breast cancer receiving neoadjuvant carboplatin and paclitaxel.

Abstract

1035 Background: Pathologic complete response (pCR) following neoadjuvant chemotherapy (NCT) is predictive of outcome in patients with locally advanced breast cancer (LABC). A non-anthracycline containing NCT regimen (Sikov et al. JCO 10/09) may reduce the risk of associated secondary hematologic malignancies and cardiac toxicity while yielding comparable pCR rates. Methods: A retrospective review of all LABC and inflammatory breast cancer (IBC) cases treated from 4/09 to 12/11 with a NCT regimen of carboplatin (AUC of 6, administered on day 1) and paclitaxel 80 mg/m2 (given weekly on a 21-28 day cycle) was conducted at the City of Hope Cancer Center (COHCC). Pts with HER2+ (HER+) tumors received trastuzumab during the NCT treatment. All pCRs (pCR of primary only – "pCR1°"; pCR of primary and lymph nodes – "pCR-All") were determined by a COHCC pathologist based on final surgical specimens. Results: 38 pts were identified, with 39 breast primaries; 18% had IBC, 62% of LABCs/IBCs were hormone receptor positive (HR+), 46% of tumors were HER2+, and 26% were triple negative. Median age was 51 [27-63]. All pts completed the planned number of cycles. Four pts required carboplatin dose reductions, 4 pts required dose reductions in paclitaxel, 3 pts had paclitaxel changed to nab-paclitaxel, and 17 pts required G-CSF to complete their planned treatment. One pt receiving trastuzumab experienced asymptomatic LVEF decline below normal limits. Conclusions: A non-anthracycline-containing NCT regimen of carboplatin/paclitaxel was well tolerated and resulted in high pCRs when given to triple negative (HER2-/HR-) pts, and HER2+ pts, especially with HER2+HR- subtypes. The findings warrant further studies of this regimen in a prospective randomized setting. [Table: see text]