Gemcitabine (G) and cisplatin (C) as first-line treatment of metastatic breast cancer (MBC): Results of phase II trial.

Abstract

273 Background: G has been studied in combination with a variety of agents known to be active in cancer. G has a mild toxicity profile. GC is active in various advanced tumors. Splitting of C dose (D 1 + d8) is better tolerated and can be a good alternative to once a cycle in pts with advanced breast cancer. This phase II trial evaluates G (1000 mg/m2) C (35 mg/ m2) d1+8 repeated every 21 d in the 1st-line treatment of metastatic breast cancer (MBC). The primary objective of the study was to determine the objective tumor response rate (ORR) of 1st-line GC in patients with metastatic breast cancer.The one-stage design tested the null hypothesis that the true response rate for this population should be equal to 50% for efficacy. Overall survival (OS), time to progression (TTP) and toxicity were evaluated. Methods: 70 female MBC pts with the median age of 49.8 ys (range 29.6-80.0) were enrolled. Tumor assessment was performed every other cycle by standard criteria including CT or MRI. 67 pts received a total of 310 cycles GC, out of these 54 pts were evaluable for efficacy. Results: Complete and partial responses were observed in 7/54 (13.0%) and 19/54 (35.2%) evaluable pts, respectively with an overall response of 48.2%. Disease stabilization was noticed in 19/54 (35.2%) pts. Progression was observed in 5/54 (9.3%) pts. TTP was 33.9 weeks (95% CI, 23.9-48.0). OS was 84.0 weeks (95% CI, 58.6-119.3). 1-year overall survival rate was 68.4% (95% CI, 53.6-79.3%). Hematological toxicity G4 was neutropenia in 14.9% (10/67), and no G4 thrombocytopenia. Hypotension G4 (1.5%) was the only severe non-hematological toxicity. Conclusions: GC in the first-line treatment of MBC, demonstrated a substantial overall response rate and had a good toxicity profile. GC is a suitable option for first-line MBC in selected pts.