What is an appropriate second-line regimen for recurrent endometrial cancer? Ancillary analysis of the SGSG012/GOTIC004/Intergroup study

Abstract Purpose: We previously reported that the concept of "platinum sensitivity" could be applied to recurrent endometrial cancer. We conducted an ancillary analysis to determine an appropriate second-line regimen for patients who received a platinum agent as first-line chemotherapy. Methods: We extracted and reanalyzed data of patients treated with doxorubicin and cisplatin (AP), paclitaxel and carboplatin (TC), or docetaxel and carboplatin (DC) as first- and second-line chemotherapies from the SGSG012/GOTIC004/Intergroup study. Results: We identified 216 patients: 38 received AP as first-line chemotherapy, of which 36 received TC or DC (Tax-C) as second-line chemotherapy; and 178 received Tax-C as first-line chemotherapy, of which 51 received AP and 127 received Tax-C as second-line chemotherapy. Median progression-free survival (PFS) and overall survival (OS) after second-line chemotherapy decreased in the order of Tax-C followed by Tax-C (10 and 48 months, respectively), AP followed by Tax-C (9 and 23 months, respectively), and Tax-C followed by AP (3 and 12 months, respectively). Median PFS and OS after second-line chemotherapy for platinum-resistant patients receiving Tax-C as first-line chemotherapy were longer in Tax-C than in AP (7 and 23 vs. 3 and 10 months, respectively) as second-line chemotherapy [hazard ratio (HR) 3.255, 95 % confidence interval (CI) 1.908-5.555, p < 0.0001; HR 3.179, 95 % CI 1.835-5.507, p < 0.0001, respectively]. Median PFS and OS after second-line chemotherapy for platinum-sensitive patients receiving Tax-C as first-line chemotherapy were almost equivalent to those receiving Tax-C or AP as second-line chemotherapy. Conclusions: For platinum-resistant recurrent endometrial cancer patients, Tax-C may be preferred over AP as second-line chemotherapy.