Preoperative chemoradiotherapy for rectal cancer and impact on outcomes – A population-based study

Abstract

Background and purposePreoperative (chemo)radiotherapy ((C)RT) for rectal cancer is, in Norway, restricted to patients with cT4-stage or threatened circumferential resection margin. This nationwide population-based study assessed the use of preoperative (C)RT in Norway and its impact on treatment outcomes. Patients and methodsData from The Norwegian Colorectal Cancer Registry were used to identify all stage I–III rectal cancers treated with major resection (1997–2011: n=9193). Cumulative risk of local recurrence, distant metastasis, and relative survival was estimated for patients in 2007–2011 (n=3179). Multivariate regression-models were used to compare outcomes following preoperative (C)RT and surgery versus surgery alone. ResultsThe proportion of patients given preoperative (C)RT increased from 5% to 49% during 1997–2011. Preoperative (C)RT was associated with reduced risk of local recurrence (hazard ratio (HR)=0.55; 95% CI=0.29–1.04) and a tendency of improved survival (excess HR=0.75; 95% CI=0.52–1.08) with significant effects in patients aged ≥70years (local recurrence: HR=0.35; 95% CI=0.13–0.91; survival: excess HR=0.58; 95% CI=0.35–0.95). ConclusionsThis study indicates that when use of preoperative (C)RT is restricted to selected high-risk rectal cancers, preoperative (C)RT is associated with improved local recurrence, and possibly improved survival, when studied on a population-based level.