Impact of adjuvant chemotherapy and pelvic radiation on pattern of recurrence and outcome in stage I non-invasive uterine papillary serous carcinoma. A multi-institution study.

OBJECTIVES: To determine the impact of adjuvant chemotherapy or pelvic radiation on risk of recurrence and outcome in stage IA non-invasive uterine papillary serous carcinoma (UPSC).

METHODS: This is a multi-institutional retrospective study for 115 patients with stage IA non-invasive UPSC (confined to endometrium) treated between 2000 and 2012. Kaplan-Meier and multivariable Cox proportional hazards regression modeling were used.

RESULTS: Staging lymphadenectomy and omentectomy were performed in 84% and 57% respectively. Recurrence was seen in 26% (30/115). Sites of recurrences were vaginal in 7.8% (9/115), pelvic in 3.5% (4/115) and extra-pelvic in 14.7% (17/115). Adjuvant chemotherapy did not impact risk of recurrence (25.5% vs. 26.9%, p=0.85) even in subset of patients who underwent lymphadenectomy (20% vs. 23.5%, p=0.80). These findings were consistent for pattern of recurrence. Among those who underwent lymphadenectomy, adjuvant chemotherapy did not impact progression-free survival (p=0.34) and overall survival (p=0.12). However among patients who did not have lymphadenectomy, adjuvant chemotherapy or pelvic radiation was associated with longer progression-free survival (p=0.04) and overall survival (p=0.025). In multivariable analysis, only staging lymphadenectomy was associated with improved progression-free survival (HR 0.34, 95% CI 0.12-0.95, p=0.04) and overall survival (HR 0.35, 95% CI 0.12-1.0, p=0.05). Neither adjuvant chemotherapy nor pelvic radiation were predictors of progression-free or overall survivals.

CONCLUSION: In stage IA non-invasive UPSC, staging lymphadenectomy was significantly associated with recurrence and outcome and therefore, should be performed in all patients. Adjuvant chemotherapy or pelvic radiation had no impact on outcome in surgically staged patients but was associated with improved outcome in unstaged patients.