Patient-related risk factors for late rectal bleeding after hypofractionated radiotherapy for localized prostate cancer: a single-center retrospective study

Tae Gyu Kim,Yun Gyu Song,Haeyoung Kim,Sung Min Kong,Daehyeon Cho,Dong-Soo Ryu,Seung Chan Jeong,Tae Hee Oh,Hyoun Wook Lee,Jun Young Kim,Byungdo Park,Jieun Oh,Kwang Min Kim,Hyoun Soo Lee,Jung Won Lee

doi:10.1186/s13014-022-01998-4

Abstract

BackgroundSeveral studies have reported patient-related risk factors for late rectal bleeding following conventionally fractionated radiotherapy for prostate cancer. We investigated patient-related risk factors for late rectal bleeding after hypofractionated radiotherapy.MethodsA total of 231 patients with local or locally advanced prostate cancer treated with hypofractionated radiotherapy (70 or 67.2 Gy in 28 fractions) were evaluated retrospectively. All patients received intensity-modulated radiotherapy with daily image guidance. The relationships between late rectal bleeding and risk factors like diabetes, hypertension, cirrhosis, and anticoagulant use were analyzed.ResultsDuring a median follow-up of 23 months, the crude rates of grade ≥ 1, grade ≥ 2, and grade ≥ 3 late rectal bleeding were 23.8%, 16.9%, and 9.5%, respectively. Cirrhosis and anticoagulant use predicted an increased risk of grade ≥ 3 rectal bleeding in multivariable analyses (hazard ratio [HR] 14.37, 95% confidence interval [CI] 3.09–66.87, P = 0.001, and HR 2.93, 95% CI 1.14–7.55, P = 0.026, respectively). The non-anticoagulant group had a significantly superior 5-year freedom from grade ≥ 3 bleeding compared to the anticoagulant group in a propensity-weighted log-rank analysis (88.0% vs. 76.7%, P = 0.041). A receiver operating characteristic curve analysis revealed that rectal bleeding was minimized in the anticoagulant group if the equivalent dose at fractionation of 2 Gy (EQD2) V77 Gy of the rectum was < 4.5% or if the EQD2 V8.2 Gy was < 71.0%.ConclusionsPatients taking anticoagulants or those with cirrhosis had a significantly higher risk of severe late rectal bleeding than other patients after hypofractionated radiotherapy for prostate cancer in the present study. The bleeding risk could be lowered by minimizing hotspots in patients taking anticoagulants.

Highlights

Several studies have reported patient-related risk factors for late rectal bleeding following convention‐ ally fractionated radiotherapy for prostate cancer
The theoretical background for hypofractionated radiotherapy is that prostate cancer has a low α/β value, which means that using large doses per fraction increases the therapeutic effect [6,7,8]
Chronic proctitis, which can occur after curative radiotherapy for local or locally advanced prostate cancer, is a major problem that has a profound effect on a patient’s quality of life

Summary

Introduction

Several studies have reported patient-related risk factors for late rectal bleeding following convention‐ ally fractionated radiotherapy for prostate cancer. We investigated patient-related risk factors for late rectal bleeding after hypofractionated radiotherapy. Chronic rectal symptoms include rectal bleeding, loose stools, urgency, pelvic pain, and tenesmus, with intermittent bleeding being the most common. It occurs a median of 8 to 12 months after the end of radiotherapy, and the incidence rate is 2%–20% in studies of patients with pelvic malignancies who have received external beam radiotherapy or brachytherapy [9, 10]

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Conclusion