Combination versus sequential paclitaxel plus gemcitabine as first-line chemotherapy for women with metastatic breast cancer: a prospective randomized phase II study

Paclitaxel (T) plus gemcitabine (G) is an active concomitant combination for the treatment of metastatic breast cancer (MBC). However, the efficacy of sequential administration of these two drugs is unclear. This randomized phase II study was conducted to evaluate the efficacy of T and G administered either as a concomitant or as a sequential regimen in patients with MBC. Patients with MBC (n=66) were randomized to either receive 6 cycles of concomitant T and G or 4 cycles of T followed by 4 cycles of G, as first line chemotherapy. With no progression, the arms would switch to maintenance with paclitaxel. Progression free survival (PFS) was defined as the primary endpoint; secondary endpoints were the overall response rate (ORR), overall survival (OS), and toxicity. In total, 33 patients were randomized to the concomitant or sequential arms. Patient characteristics were well balanced. The median number of chemotherapy cycles was 6 for the concomitant arm and 8 for the sequential arm. No significant difference was observed in terms of PFS, ORR, and OS. Only 13 (39.4%) patients progressed in the sequential arm. Although there was no significant difference between the two arms (p=0.056),the sequential arm had a remarkable trend of longer PFS than the concomitant arm. Toxicities were manageable and similar in both arms.The incidence of neutropenia was significantly higher in the concomitant arm (90.9%) than in the sequential arm (60.6%). Grade 3 or 4 neutropenia was not significantly different between the two arms. Concomitant and sequential treatment with paclitaxel and gemcitabine had no significant difference in terms of PFS.