Adjuvant carboplatin and paclitaxel chemotherapy followed by radiotherapy in high-risk endometrial cancer: A retrospective analysis.

Abstract

e17115 Background: It remains unclear which is the best chemotherapy (CT) regimen and what is the role of adding radiotherapy (RT) to adjuvant CT in high-risk endometrial cancer. Methods: We performed a retrospective analysis of the patients (pts) with high-risk endometrial cancer (endometrioid histology stages III-IVA or carcinossarcoma/ clear cells/ serous histology stages I-IVA) treated with adjuvant carboplatin (AUC 5) and paclitaxel (175 mg/m2), every 3 weeks, for 6 cycles, followed by RT (conformal external beam radiotherapy to pelvic or pelvic and paraortic fields with 45Gy-54Gy plus weekly vaginal brachytherapy with 20Gy in 4 fractions). Pts were treated from 2010 to 2016 at a Brazilian public cancer center. Medical records were reviewed for demographic, clinicopathologic and outcome information. Data was analyzed for overall survival (OS), disease-free survival (DFS), prognostic factors and toxicity. The Kaplan-Meier method was used for survival analysis and Cox proportional hazard model for prognostic factors. Results: 146 consecutive pts were evaluated. Median age was 62 years (range 35-81). Most patients had ECOG 0-1 (98%), endometrioid (53%) or serous histology (26%), grade 3 tumor (57%) and FIGO stage III (77%). Median follow-up was 26.5 months. The OS rates were 85% (95% CI 75 – 91%) in 3 years and 73% (95% CI 58 – 84%) in 5 years. Factors that significantly affected OS in a multivariate analysis were FIGO stage (p = .009), pelvic lymphadenectomy (yes vs no, p = .023) and positive peritoneal cytology (yes vs no, p = .002). 3-year and 5-year DFS rates were 79% (95% CI 70 – 86%) and 68% (95% CI 52 – 80%), respectively. The initial site of recurrence was limited to the pelvis in 3% of the pts, within the abdomen in 1% and extra-abdominal in 11%. Grade 3/4 AEs occurred in 47% of the pts and were mainly hematologic toxicity (43%). There were only 3 cases of febrile neutropenia and 4 cases of hospitalization due to toxicity. Conclusions: Our data suggests that adjuvant carboplatin and paclitaxel, followed by RT, in high-risk endometrial cancer is safe and effective. Low rates of pelvic recurrence were observed, which might be explained by the addition of RT to adjuvant CT.