[Gemcitabine long-term maintenance chemotherapy benefits patients with survival: a multicenter, real-world study of advanced breast cancer treatment in China].

Objective: This study collected a real-world data on survival and efficacy of gemcitabine-containing therapy in advanced breast cancer. Aimed to find the main reasons of affecting the duration of gemcitabine-base therapy in advanced breast cancer patients. Methods: Advanced breast cancer patients who received gemcitabine-base therapy from January 2017 to January 2019 were enrolled(10 hospitals). The clinicopathological data, the number of chemotherapy cycles and the reasons for treatment termination were collected and analyzed. To identify the reasons related with continuous treatment for advanced breast cancer and the factors which affect the survival and efficacy. Results: A total of 224 patients with advanced breast cancer were enrolled in this study, with a median age of 52 years (26-77 years), 55.4%(124/224) was postmenopausal. Luminal type were 83 cases, TNBC were 97 cases, and human epidermal growth factor receptor 2 (HER's-2) overexpression were 44. At the analysis, 224 patients who received the gemcitabine-based regimens were evaluated, included 5 complete reponse (CR), 77 partial response (PR), 112 stable disease (SD) and 27 progressive disease (PD). The objective response rate (ORR) was 36.6%(82/224). Seventy patients had serious adverse diseases, including leukopenia (9), neutrophilia (49), thrombocytopenia (15), and elevated transaminase (2). The median follow-up time was 41 months (26~61 months), and the median PFS was 5.6 months. The reasons of termination treatment were listed: disease progression were 90 patients; personal reasons were 51 patients; adverse drug reactions were 18 patients; completed treatment were 65 patients. It was found that progression-free survival (PFS) was significantly longer in patients receiving >6 cycles than that in patients with ≤6 cycles (8.2 months vs 5.4 months, HR=2.474, 95% CI: 1.730-3.538, P＜0.001). Conclusions: Gemcitabine-based regimen is generally well tolerated in the Chinese population and has relatively ideal clinical efficacy in the real world. The median PFS is significantly prolonged when the number of treatment cycles are appropriately increased.