Objective: Despite recent advances in the treatment of recurrent ovarian cancer, little evidence exists describing the benefit of third- line chemotherapy. The present authors previously reported that the treatment-free interval (TFI) after second-line chemotherapy may predict a survival benefit of third-line chemotherapy, however the length of TFI was uncertain due to limited cases. In this study, the authors evaluated the length of TFI, which is correlated with the effectiveness of third-line chemotherapy and a prognostic factor of third-line chemotherapy.
Materials and methods: The authors reviewed the medical records of 85 women with recurrent ovarian cancer who received third-line chemotherapy after a paclitaxel/carboplatin (PC) regimen as first-line chemotherapy.
Results: The response rate [complete response (CR) + partial response (PR)] and clinical benefit rate [(CBR): CR + PR + stable disease (SD)] during the TFI after second-line chemotherapy for 0-3 months, 3-6 months, and 6-12 months and ≥ 12 months were 9.8%, 0%, 0%, 43.8% and 15.7%, 50%, 66.7%, and 93.8%, respectively. The median overall survival (OS) from the onset of third-line chemotherapy was longer for TFI ≥ 3 months than for TFI 0-3 months (795 days vs. 281 days, p < 0.001). Finally, according to univariate (HR = 0.256; p < 0.001) and multivariate (HR = 0.264; p < 0.001) analyses, TFI was the independent significant prognostic factor for OS.
Conclusions: TFI less than three months after second-line chemotherapy may predict little survival benefit of third-line chemotherapy.