Rectal bleeding after radiation therapy for endometrial cancer

Background and purpose: The goals of this study were to determine the rate and risk factors of rectal bleeding (RB) after external beam radiotherapy and vaginal brachytherapy (EBRT +VB), and to compare these data to previously unreported RB rates from PORTEC-2 patients receiving EBRT or VB alone.

Materials and methods: Retrospective chart review identified 212 endometrial cancer patients receiving adjuvant EBRT+VB between 2006 and 2013. Patient-reported RB data were also obtained from PORTEC-2 patients randomized to EBRT (n=166) or VB (n=182). The two populations were compared using an RB scale of symptom severity.

Results: After a median 35months, 17.9% of EBRT+VB patients (n=38) experienced any RB with 1.9% (n=4) having bleeding requiring intervention. Age ⩽70years was the only predictor of RB (OR 2.8; 95% CI 1.1-8.7; p=0.027). Rates of patient-reported RB after EBRT were similar with 15.0% (n=25) having any RB and 0.6% (n=1) having "very much" bleeding. On regression analysis, any EBRT (either EBRT alone or EBRT+VB) increased the risk of RB compared to those who received VB alone (OR 3.0; p=0.0028; 95% CI 1.4-6.7). The rates of more severe RB were low and did not significantly differ between treatments.

Conclusions: Significant RB is rare after radiation. EBRT has higher rates of rectal bleeding than VB. The addition of VB to EBRT does not significantly alter bleeding rates.