Adjuvant vaginal brachytherapy decreases the risk of vaginal recurrence in patients with stage I non-invasive uterine papillary serous carcinoma. A multi-institutional study.

OBJECTIVES: To investigate the impact of adjuvant vaginal brachytherapy on vaginal recurrence in stage I non-invasive uterine papillary serous carcinoma (UPSC).

METHODS: This is a retrospective multi-institutional study from 2000-2012. 103 patients who underwent surgical treatment with non-invasive stage IA UPSC were included.

RESULTS: 85% and 55% underwent staging lymphadenectomy and omentectomy respectively. 28.2% (29/103) developed recurrence. Vaginal, pelvic and extra-pelvic recurrences developed in 7.8% (8/103), 3.9% (4/103) and 16.5% (17/103) respectively. Among patients who were observed or received only chemotherapy, the rate of vaginal recurrence was 10.9% (7/64) compared to 2.6% (1/39) among those who received vaginal brachytherapy +/- chemotherapy (p=0.035). The rate of vaginal recurrence was not different between those who were observed and those who received only chemotherapy (9.3% vs. 14.3%, p=0.27). The 5-year progression free survival (PFS) and overall survival (OS) for the entire cohort were 88.3% and 90.6%. Patients who underwent surgical staging had longer PFS (p=0.001) and OS (p=0.0005) compared to those who did not. In multivariable analysis controlling for age, histology, chemotherapy, brachytherapy, and staging lymphadenectomy, only lymphadenectomy was an independent predictor of PFS (HR 0.28, 95% CI 0.11-0.71, p=0.0037) and OS (HR 0.27, 95% CI 0.10-0.71, p=0.0035). Neither chemotherapy nor brachytherapy were predictors of PFS or OS.

CONCLUSIONS: This is the largest study reported in stage I non-invasive UPSC. The majority of recurrences were extra-pelvic. Vaginal brachytherapy has a significant role in reducing the risk of vaginal recurrence and surgical staging was the only predictor of outcome. Therefore, both should be considered in these patients.