Rectal bleeding after radiation therapy for endometrial cancer

Area of Science:

• Gynecologic Oncology
• Radiation Oncology
• Clinical Outcomes Research

Background:

• Endometrial cancer treatment often involves radiation therapy, including external beam radiotherapy (EBRT) and vaginal brachytherapy (VB).
• Rectal bleeding (RB) is a potential side effect of these treatments.
• Understanding the incidence and risk factors of RB is crucial for patient care.

Purpose of the Study:

• To determine the rate and risk factors of rectal bleeding (RB) following combined external beam radiotherapy and vaginal brachytherapy (EBRT+VB).
• To compare RB rates in patients receiving EBRT+VB with those receiving EBRT or VB alone, using data from the PORTEC-2 trial.
• To identify predictors of RB in endometrial cancer patients treated with adjuvant radiation.

Main Methods:

• Retrospective chart review of 212 endometrial cancer patients treated with adjuvant EBRT+VB (2006-2013).
• Utilized patient-reported RB data from PORTEC-2 trial participants randomized to EBRT (n=166) or VB (n=182).
• Compared RB incidence and severity between treatment groups using a standardized symptom scale.

Main Results:

• After a median follow-up of 35 months, 17.9% of EBRT+VB patients experienced RB, with 1.9% requiring intervention.
• Age ⩽70 years was a significant predictor of RB (OR 2.8; p=0.027).
• External beam radiotherapy (EBRT), alone or combined with VB, was associated with higher RB rates compared to VB alone (OR 3.0; p=0.0028).

Conclusions:

• Significant rectal bleeding is rare following radiation therapy for endometrial cancer.
• External beam radiotherapy is associated with a higher risk of rectal bleeding than vaginal brachytherapy.
• The addition of vaginal brachytherapy to external beam radiotherapy does not significantly increase rectal bleeding rates.