Abstract P5-16-29: Nanoparticle albumin-bound paclitaxel as neoadjuvant chemotherapy of breast cancer: A meta-analysis
Authors: Zong Y , Wu J , Shen K 
Published: March 2017

Background: Nanoparticle albumin-bound paclitaxel (nab-Paclitaxel), a novel solvent-free taxane-based regimen, was hypothesized to have enhanced drug transport to tumors, shorter infusion schedules and no need for premedication. The value of nab-Paclitaxel in neoadjuvant systemic therapy (NST) for breast cancer remains uncertain. We performed a meta-analysis to assess efficacy and toxicity of nab-Paclitaxel compared to conventional taxane regimens (paclitaxel, docetaxel) within randomized clinical trials.

Methods: A systematic search was performed using the medical subject heading (MeSH) terms ''breast neoplasms'', as well as (1) breast cancer; AND (2) nab-Paclitaxel OR nanoparticle paclitaxel; AND (3) neoadjuvant OR preoperative OR primary systemic in both Pubmed databases and proceedings of oncologic meetings including ASCO, ESMO and SABCS. Pooled rates of pathological complete response(pCR), odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed-effect or random-effect model to determine the effect of neoadjuvant nab-paclitaxel.

Results: Twenty-one studies with 2357 patients were included, 3 of which (GeparSepto[1], ETNA[2], Showa trial[3]) were randomized clinical trials. The aggregate pCR rate (ypT0/is ypN0) was 32% (95% CI 25-38%) in unselected breast cancer patients and was 14%(95% CI 11-17%), 41%(95% CI 38-45%), 54%(95% CI 43-66%) in hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-), triple negative breast cancer(TNBC), HER2+ patients, respectively. Within the HER2+ population, pCR rate was 61%(95% CI 47-74%) for HR- and 40%(95% CI 28-52%) for HR+ tumors. Regarding randomized clinical trials, the probability of achieving pCR was significantly higher in the nab-paclitaxel group than in the conventional taxanes group (OR=1.383, 95%CI 1.141-1.676, p=0.001). A funnel plot of the effect size for each randomized trial against the precision showed no asymmetry, which indicating no potential publication bias. In the safety analysis (GeparSepto[1], ETNA[2]), hematological toxic effects were generally equivalent in nab-paclitaxel and paclitaxel group. For non-hematological toxic effects, all grades and grade≥ 3 peripheral sensory neuropathy occurred more frequently with nab-paclitaxel compared to paclitaxel (all grades, OR=2.090, 95%CI 1.016-4.302, p=0.045; grade≥ 3, OR=3.766, 95%CI 2.324-6.100, p&lt;0.001). Hypersensitivity was more common with paclitaxel than nab-paclitaxel at any grade and grade≥ 3. Other non-hematological toxic effects did not significantly differ between two groups.

Conclusion: nab-Paclitaxel is an effective antitumor drug in NST of breast cancer, especially for TNBC and HER2+ tumors, in terms of pCR. Exchange of nab-Paclitaxel for conventional taxanes could significantly improve pCR rate with reasonable toxicities.

Clinical trial information: 1.Lancet Oncol.2016,17:345-56.; 2.J Clin Oncol.2016,34(suppl; abstract 502).; 3.J Clin Oncol.2015,33(suppl; abstract 136).

Citation Format: Zong Y, Wu J, Shen K. Nanoparticle albumin-bound paclitaxel as neoadjuvant chemotherapy of breast cancer: A meta-analysis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-16-29.