Differences in toxicity and outcome associated with circadian variations between patients undergoing daytime and evening radiotherapy for prostate adenocarcinoma.

This retrospective study tested the hypothesis that disease control and treatment-related toxicity in patients undergoing high-dose radiotherapy (HDRT) for prostate cancer varies in a circadian manner.

Patients with localized prostate adenocarcinoma receiving HDRT (median 78 Gy) to the prostate and involved seminal vesicle(s) without elective pelvic irradiation were divided into a daytime treatment (before 5 PM) group (n = 267) and evening treatment (after 5 PM) group (n = 142). Biochemical failure (Phoenix definition), acute and late gastrointestinal (GI) and genitourinary toxicities (Common Terminology Criteria for Adverse Events version 4), biochemical failure-free survival (BFFS) and freedom from late toxicity were assessed. Analyses were performed by binary logistic regression and Cox proportional hazard regression. The median follow-up was 68 months, and 75% of patients were ≥70 years old. Evening HDRT was significantly associated with worse freedom from ≥grade 2 late GI complications (hazard ratio = 2. 96; p < 0. 001). The detrimental effect of evening HDRT was significant in patients older than 70 years old (p < 0. 001) but not in younger patients (p = 0. 63). In a subgroup of propensity score-matched cohort with T2b-T3 disease (n = 154), the 5-year BFFS was worse in the evening group than the daytime group (72% vs. 85%, hazard ratio = 1. 95, p = 0. 05). Our study indicates that evening HDRT may lead to more GI complications, especially in older patients, and worse BFFS in patients with T2b-T3 disease.

Chronobiology international. 2016 Jan 28 [Epub ahead of print]

Feng-Ming Hsu, Wei-Hsien Hou, Chao-Yuan Huang, Chia-Chun Wang, Chiao-Ling Tsai, Yu-Chieh Tsai, Hong-Jeng Yu, Yeong-Shiau Pu, Jason Chia-Hsien Cheng

a Division of Radiation Oncology, Department of Oncology , National Taiwan University Hospital , Taipei , Taiwan. , b Department of Radiation Oncology , City of Hope Cancer Center , Duarte , California , USA. , c Department of Urology , National Taiwan University College of Medicine , Taipei , Taiwan. , a Division of Radiation Oncology, Department of Oncology , National Taiwan University Hospital , Taipei , Taiwan. , a Division of Radiation Oncology, Department of Oncology , National Taiwan University Hospital , Taipei , Taiwan. , d Division of Medical Oncology, Department of Oncology , National Taiwan University Hospital , Taipei , Taiwan. , c Department of Urology , National Taiwan University College of Medicine , Taipei , Taiwan. , c Department of Urology , National Taiwan University College of Medicine , Taipei , Taiwan. , a Division of Radiation Oncology, Department of Oncology , National Taiwan University Hospital , Taipei , Taiwan.

PubMed