The Impact of Different Adjuvant Management Strategies on Survival Endpoints in Women with Early Stage Uterine Serous Carcinoma

Abstract

To determine the impact of adjuvant chemotherapy, radiation treatment, combined modality treatment, and observation on survival and recurrence outcomes in women with early stage uterine serous carcinoma (USC). After IRB study approval, our prospectively-maintained database for women with endometrial carcinoma was queried for women with 2009 International Federation of Gynecology and Obstetrics (FIGO) stages I-II USC based on WHO pathologic definition who underwent adequate surgical staging between 1/1991 and 4/2017 followed by adjuvant management [observation, radiation therapy (RT), chemotherapy (CT), or combination treatment (CRT)]. Chi-squared tests were performed to compare differences in outcome by type of adjuvant management. Recurrence-free (RFS), disease-specific (DSS), and overall survival (OS) were assessed by Kaplan-Meier and log-rank tests. Univariate and multivariate analyses (MVA) were performed to identify statistically significant predictors of survival endpoints. We identified 171 women who met our inclusion criteria. The median follow-up time was 70.5 months. 75% of the study cohort were with stage IA, 13% stage IB and 12% with stage II. All women underwent pelvic lymph node dissection with a median number of dissected lymph nodes of 14. Omentectomy was performed in 61% of patients. Adjuvant RT was utilized in 56% of women (65 with vaginal brachytherapy alone, 10 with pelvic RT and 21 with combination). Most commonly used chemotherapy was carboplatin and paclitaxel with a median number of cycles of 6 5-year RFS was 73% for those received CRT, 84% for RT alone, 68% who received CT alone and 55% for those who were observed (p = 0.13). 5-year DSS was 81%, 94%, 71% and 60%, respectively (p = 0.02). 5-year OS was 76%, 70%, 60% and 56%, respectively (p = 0.11). On MVA of OS and DSS, higher percentage of myometrial invasion, presence of lower uterine segment involvement, positive peritoneal cytology, and receiving chemotherapy alone/observation were independent predictors of worse outcomes. The independent predictor of worse RFS on MVA was the presence of positive peritoneal cytology. In this cohort of women with early stage uterine serous carcinoma who underwent surgical staging, adjuvant radiation treatment with or without chemotherapy is associated with improved survival and trended towards improved recurrence rates.