Abstract
PURPOSE: A combined chemotherapy of taxane and platinum, with or without anthracycline, has been used as a standard first-line regimen. The purpose of this study was to investigate the effectiveness of second-line chemotherapy for treatment of advanced or recurrent endometrial carcinoma previously treated with a combined chemotherapy of taxane and platinum, with or without anthracycline. METHODS: During the 2000-2008 study period, 723 patients were diagnosed with endometrial cancer at the Departments of Obstetrics and Gynecology of the Osaka University and the Osaka Rosai Hospitals, Osaka, Japan. The subset of these cases that eventually required treatment by second-line chemotherapy was retrospectively analyzed. RESULTS: Response rate to second-line chemotherapy was 25%. Treatment-free interval (TFI) of ≥ or <6 months was demonstrated to be significantly associated with the response to second-line chemotherapy (P = 0.0026), progression-free survival (P = 0.0003) and overall survival (P = 0.025). The second-line chemotherapy similar to the first-line regimen was ineffective in all the 7 cases (100%) whose TFI was shorter than 6 months. Multivariate analysis showed that TFI was the most significantly important factor predicting the effectiveness of second-line chemotherapy (the adjusted hazard ratio of TFI on PFS and OS: 3.482, 95% CI, 1.641-7.388, P = 0.0012, and 2.341, 95% CI, 1.034-5.301, P = 0.042, respectively). CONCLUSIONS: Our present study provides, for the first time, evidence that the majority of refractory or recurrent diseases, if they occur within 6 months of a first-line chemotherapy using taxane and platinum with or without anthracycline, are non-responsive to the current regimens of second-line chemotherapy.