Evaluation of brachytherapy and external beam radiation therapy for early stage, node-negative uterine carcinosarcoma

There is limited evidence to guide treatment decision making for patients with early stage uterine carcinosarcoma (UCS) regarding the use of pelvic external beam radiation therapy (RT) vs. vaginal brachytherapy (BT) after hysterectomy. We analyzed a population-based database to compare survival outcomes after adjuvant BT vs. pelvic external beam RT for patients with Stages I-II UCS.

We searched the Surveillance, Epidemiology, and End Results registry to identify a cohort of patients with International Federation of Gynecology and Obstetrics I/II UCS diagnosed during 1998-2010, who received a total hysterectomy and for whom radiotherapy type was known. χ(2) tests were used to test associations between patient characteristics and radiotherapy type. Overall and cancer-specific survival, measured from date of diagnosis, were summarized within each covariate. Cox proportional hazards models were used to model the impact of RT type on survival while adjusting for other factors.

A total of 1581 subjects were identified, including 803 (50.8%) no radiotherapy; 636 (40.2%) external beam radiotherapy ± BT; and 142 (9.0%) BT alone. The use of BT alone increased from 4.5% in 1988-1999 to 12.5% in 2005-2010. Multivariate models of overall and cause-specific survival showed that radiotherapy type was not associated with survival after adjustment for other covariates.

For patients with Stages I-II UCS, adjuvant radiotherapy type did not influence survival after hysterectomy. This study addresses an existing evidence gap and identifies a trend toward increasing utilization of BT alone. Prospective trials are warranted to provide high-quality evidence to guide adjuvant therapy decisions for these patients.