Phase II trial of adjuvant pelvic radiation "sandwiched" between combination paclitaxel and carboplatin in women with uterine papillary serous carcinoma

Objective: To evaluate the safety and survival in women treated with adjuvant pelvic radiation "sandwiched" between six cycles of paclitaxel and carboplatin chemotherapy with completely resected UPSC. Methods: Surgically staged women with UPSC (FIGO stage 1-4) and no visible residual disease were enrolled. Treatment involved paclitaxel (175 mg/m ²) and carboplatin (AUC = 6.0-7.5) every 21 days for 3 doses, followed by radiation therapy (RT), followed by an additional 3 cycles of paclitaxel and carboplatin (AUC = 5-6). Survival analysis, using Kaplan-Meier methods, was performed on patients who completed at least 3 cycles of chemotherapy and RT. Results: A total of 81 patients were enrolled, of which 72 patients completed the first 3 cycles of chemotherapy followed by prescribed RT. Median age was 67 years (range: 43-82 years). 59/72 (82%) had disease confined to the uterus and 13/72 (18%) had completely resected extra-uterine disease (stage 3 and 4). 65 (83%) completed the protocol. Overall PFS and OS for combined stage 1 and 2 patients was 65.5 ± 3.6 months and 76.5 ± 4.3 months, respectively. PFS and OS for combined stage 3 and 4 patients was 25.8 ± 3.0 and 35.9 ± 5.3 months, respectively. Three-year % survival probability for stage 1 and 2 patients was 84% and for stage 3 and 4 patients was 50%. Of the 435 chemotherapy cycles administered, there were 11(2.5%) G3/G4 non-hematologic toxicities. 26(6.0%) cycles had dose reductions and 37(8.5%) had dose delays. Conclusions: Compared to prior studies of single modality adjuvant therapy, RT "sandwiched" between paclitaxel and carboplatin chemotherapy is well-tolerated and highly efficacious in women with completely resected UPSC.