Nab-paclitaxel (Nab-P) in Metastatic Breast Cancer (MBC) in Elderly Patients: A Real Life Setting (NEREIDE Study)

Background: Elderly patients (pts) with MBC are under-represented in clinical studies and treatment is largely based on limited retrospective subgroup analyses. However, the 3 ESO-ESMO guidelines for Advanced Breast Cancer suggest that the management decisions should not be based on age alone. Methods: This is an observational, retrospective, multicenter study conducted in 11 Oncology Sicilian Centers that evaluated safety and efficacy of nab-P in pts with HER2 negative MBC with age ≥ 65 years. We included 70 pts. Intrinsic molecular subtype: Luminal A (18.8%), Luminal B HER-2 negative (62.5%) and Triple negative (18.8%). The most common metastatic sites were: visceral plus bone (31.4%), bone (15.7%), lung (10%), visceral plus lymph nodes (10%). 33% of pts received nab-P as 4th line treatment. 87.1% of all pts received nab-P at doses 260 mg/m23-weekly and 12.9% received nab-P 125 mg/m2weekly. 28.6%, 25.7% and 26.2% of pts received previous treatment with taxanes in the neo-adjuvant and metastatic setting, respectively. Primary endpoint was safety of nab-P treatment. Secondary endpoints were overall response rate (ORR), progression free survival (PFS) and overall survival (OS).PFS and OS curves were estimated using the Kaplan-Meier method. ORR was defined as complete or partial response (CR+PR) according to RECIST 1.1 criteria. Adverse events (AEs) were assessed according to CTCAEv4.0. Results: 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 AEs were G2-3 and 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% (CR in 6.3% and PR in 25% of pts). 39.1% of pts reported a stable disease. mPFS was 6 months (95% CI 2-38) and mOS was 40.5 months (95% CI 7-255). Conclusions: Our real-life study showed that the treatment with nab-P 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. Legal entity responsible for the study: Vincenzo Adamo. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.