Utility of radiation therapy for early-stage uterine papillary serous carcinoma.

Objective: Early-stage uterine papillary serous carcinoma (UPSC) has a poor prognosis and high recurrence rate. While adjuvant chemotherapy is generally recommended, the role of radiation is uncertain. We examined the association between vaginal brachytherapy and whole pelvic radiation and survival in women treated with and without adjuvant chemotherapy.

Methods: The National Cancer Data Base was used to identify women with stage I-II UPSC treated between 1998 and 2012. Trends in use of chemotherapy, brachytherapy, and external beam radiation over time were examined. The association between these treatments and mortality were examined using multivariable Cox proportional hazards models.

Results: A total of 7325 patients were identified. Overall, 2779 (37.9%) received chemotherapy. The use of vaginal brachytherapy increased from 7.2% in 1998 to 29.1% in 2012 (P<0.0001), while use of external beam radiation decreased from 18.2% to 11.7% over the same period (P<0.0001). Use of chemotherapy was associated with a 22% reduction in mortality (HR=0.78; 95% CI, 0.69-0.88). While brachytherapy was associated with decreased mortality (HR=0.67; 95% CI, 0.57-0.78), use of external beam radiation was not associated with survival (HR=1.03; 95% CI, 0.92-1.17). Stratified by stage, use of chemotherapy was associated with decreased mortality for women with stage IB and II tumors, but not for stage IA neoplasms. Vaginal brachytherapy was associated with reduced mortality for stage IA and II neoplasms.

Conclusion: For women with early-stage UPSC, chemotherapy is associated with improved survival. Vaginal brachytherapy was also associated with improved survival, however, there was little benefit to use of external beam radiation.