Comparison of neoadjuvant paclitaxel and carboplatin with neoadjuvant letrozole in postmenopausal patients with receptor-positive locally advanced breast cancer (LABC).
Sub-category: Local-Regional Therapy
Category: Breast Cancer--Local-Regional and Adjuvant Therapy
Meeting: 2009 ASCO Annual Meeting
Citation: J Clin Oncol 27:15s, 2009 (suppl; abstr 608)
Abstract No: 608
Author(s): D. Sinha, A. K. Bahadur, K. Singh, A. K. Rathi; Maulana Azad Medical College, Delhi, India
Background: For the treatment of LABC using a regimen with the highest likelihood of shrinking the tumor should improve the outcome. Paclitaxel was the first taxane to show activity in breast cancer. The advent of endocrine therapy in the neoadjuvant setting allows downstaging of tumors with less morbidity. The aromatase inhibitors are now the treatment of choice in neoadjuvant setting for elderly patients with estrogen receptor-positive breast cancer. Methods: This prospective, randomized, comparative study assessed the effect of three cycles of neoadjuvant chemotherapy vs. three months of neoadjuvant hormonal therapy in terms of loss of clinical and pathological primary tumor size. Inclusion criteria required postmenopausal patients with non-metastatic, ER and/or PR positive LABC with no co-morbidity. Forty eligible patients were randomly assigned into 2 groups of 20 patients each: Group A treated with 3 cycles of 3 weekly injections of paclitaxel (175 mg/m2) and carboplatin (AUC 6) assessed after each cycle; group B received oral Letrozole 2.5mg once daily for 3 months assessed every 4 weeks. Surgery was done and primary specimen was pathologically examined. Results: Clinically mean loss in primary residual tumor compared to volume at presentation in group A vs. group B at 1st review was 45% vs. 35% (p: 0.536), 63% vs. 57% at second (p: 0.176), and 71% vs. 74% at third review (p: 0.062).Clinical complete response (WHO criteria) and stable disease each were seen in 14% in either group of patients (p: 0.632), partial response in 65% group A and in 72% group B (p: 0.117); no progressive disease was seen in either. All patients underwent surgery. The mean pathological primary cell kill in group A vs. group B was 81% vs.78 %(p:0.918). Resected nodes were pathologically positive for tumor in 47% group A and 60% group B patients (p: 0.269). Conclusions: Neoadjuvant hormonal therapy using oral Letrozole in receptor positive LABC in post menopausal women is as effective as three weekly paclitaxel and carboplatin in downstaging the tumor.