High vs. Standard Radiotherapy Dose in Locally Advanced Rectal Adenocarcinoma Patients Treated With Neoadjuvant Long Course Chemoradiotherapy: A Population-based Study

Anticancer Res. 2022 Feb;42(2):1143-1150. doi: 10.21873/anticanres.15578.

Abstract

Background/aim: Locally advanced rectal cancer (LARC) patients are often treated with neoadjuvant long course chemoradiotherapy (NLCCRT) using 45-50.4 Gy conventional fractionated radiotherapy (CFRT). The role of radiotherapy dose escalation is unclear.

Patients and methods: We identified LARC patients diagnosed from 2011 to 2016 and treated with NLCCRT using CFRT at high dose (54-60 Gy) or standard dose (45-50.4 Gy). In the primary analyses, we used propensity score (PS) weighting to balance the observable potential confounders. The hazard ratio (HR) of death and other endpoints were compared. We also evaluated these outcomes in supplementary analyses via an alternative approach.

Results: Our primary analysis included 459 patients. The HR of death when high dose was compared with standard dose was 0.62 (p=0.51). There were also no statistically significant differences in other endpoints or in the supplementary analyses.

Conclusion: Overall, survival of LARC patients treated with NLCCT in CFRT was not significantly different between high or standard dose.

Keywords: Conventional fractionated radiotherapy; chemoradiotherapy; locally advanced rectal cancer; neoadjuvant long course; population-based; radiotherapy dose escalation.

MeSH terms

  • Adenocarcinoma / mortality
  • Adenocarcinoma / pathology
  • Adenocarcinoma / therapy*
  • Adolescent
  • Adult
  • Aged
  • Chemoradiotherapy / methods*
  • Cohort Studies
  • Disease Progression
  • Dose Fractionation, Radiation
  • Drug Administration Schedule
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoadjuvant Therapy / methods
  • Neoplasm Invasiveness
  • Radiotherapy Dosage
  • Rectal Neoplasms / mortality
  • Rectal Neoplasms / pathology
  • Rectal Neoplasms / therapy*
  • Retrospective Studies
  • Standard of Care
  • Survival Analysis
  • Taiwan / epidemiology
  • Time Factors
  • Young Adult