Safety and efficacy of the treatment with Nab-paclitaxel in mEtastatic bREast cancer In elDerly patiEnts: NEREIDE study

Abstract

Background: Recommendations for treatment of metastatic breast cancer (MBC) in elderly patients ( pts) are limited because this subgroup of pts are largely under-represented in clinical studies and this treatment is largely based on limited retrospective subgroup analyses. However, the 3rd ESOESMO guidelines for Advanced Breast Cancer (ABC3) suggest that the management decisions should not be based on age alone. Material(s) and Method(s): This is an observational, retrospective, multicenter study conducted in 11 Oncology Sicilian Centers. The aim of this study was to assess the safety and efficacy of nab-paclitaxel (nab-P) treatment in pts with HER2 negative MBC with age >= 65 years.We evaluated 70 HER2-negative MBC pts. The intrinsic molecular subtype was: Luminal A (18.8%), Luminal B HER-2 negative (62.5%) and Triple negative (18.8%). The most common type of metastatic sites was: visceral plus bone (31.4%), bone (15.7%), lung (10%), visceral plus lymph nodes (10%). 33% of pts received nab-paclitaxel as fourth line treatment. 87.1% of all pts received nab-paclitaxel at doses 260 mg/m2 every 3 weeks and 12.9% received nab-P 125 mg/m2 weekly. 28.6%, 25.7% and 26.2%of pts received previous treatment with taxanes in the neoadjuvant, adjuvant and metastatic setting, respectively. The primary endpoint was to investigate the safety of nab-paclitaxel treatment. The secondary endpoints were to evaluate overall response rate (ORR), progression free survival (PFS) and overall survival (OS). PFS and OS curves were estimated using the Kaplan-Meier method. The ORR was defined as complete or partial response (CR + PR) according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria version 1.1. Safety profile was assessed according to CTCAEv4.0. Result(s): Median (m) age of pts who received Nab-P: 67 years (65-83). mECOG PS: 1 (range 0-2). The m cycles administrated was 6 (range 1-21). 35.5% of pts had a dose reduction and 11.5% of pts had treatment interruptions due to toxicity. The most frequent adverse events of Grade 2 and Grade 3 were observed in 47% of pts. The main toxicities were fatigue(61.5%), neuropathy (53.8%) and leukopenia (39.1%) and occurred in the 85.7% of pts treated with 3-weekly Nab-P. ORR was 31.3% and included a complete response in 6.3% of pts and a partial response in 25% of pts. 39.1% of pts reported a stable disease. Median PFS was 6 months (95% CI 2-38) and median OS was 40.5 months (95% CI 7-255). Conclusion(s): Our real-life study showed that the treatment with nabpaclitaxel is an effective and well-tolerated regimen in MBC elderly pts, even if previously treated with other taxanes. In particular, our data indicate that the weekly Nab-P can be safely administered in elderly MBC pts.