Impact of external beam pelvic radiotherapy of endometrial carcinoma: A focus on chronic digestive toxicity

Abstract

Purpose: The standard treatment for endometrial cancer is surgery, although depending on the risk factors, adjuvant radiation therapy may also be given. It is proposed for high-risk carcinomas for which an improvement in progression-free survival though not overall survival has been shown. However, despite the development of radiotherapy treatments with intensity modulation and image guidance, adjuvant radiation therapy remains toxic to the digestive system. We aimed to investigate the incidence of digestive toxicity and the presence of any predictive factors.

Materials and methods: Data were retrospectively collected from patients treated with adjuvant radiotherapy for endometrial carcinoma at the Institut de cancérologie de Lorraine and centre hospitalier Émile-Durkheim between January 2010 and October 2016 and analyzed to identify factors associated with chronic digestive toxicity.

Results: One hundred and thirty-nine patients received a total dose of 50Gy fractionated into 25 sessions, five per week for five weeks. The median follow-up after irradiation completion was 38 months. The incidence of gastrointestinal and rectal toxicity in all patients treated with pelvic irradiation for endometrial carcinoma was 11.1% (95% confidence interval [95%CI]: 5.4-19%) for grade 3-4 and 25.6% (95%CI: 17.0-34.9%) for grade 2-4. No factor was found to be significantly predictive of chronic digestive toxicity. At five years, the overall survival was 74.3%, (95%CI: 65.3-81.4%), progression-free survival was 69.6% (95%CI: 60.1-77.3%) and incidence of pelvic recurrence was 7.9% (95%CI: 3.8-13.9%).

Conclusion: Our results confirmed that pelvic radiotherapy can induce a relatively high rate of digestive toxicity but failed to identify relevant factors able to predict it.

Keywords: Adjuvant radiotherapy; Cancer de l’endomètre; Digestive toxicity; Endometrial carcinoma; Radiothérapie adjuvante; Toxicité digestive.