Cross-Sectional Study on MRI Restaging After Chemoradiotherapy and Interval to Surgery in Rectal Cancer: Influence on Short- and Long-Term Outcomes

Robin Detering,Dutch Snapshot Research Group ,Corrie A M Marijnen,Wernard A A Borstlap,Lisa Broeders,Linda Hermus,Willem A Bemelman,Henderik L Van Westreenen,Regina G H Beets-Tan,Pieter J Tanis

doi:10.1245/s10434-018-07097-7

Abstract

BackgroundThe time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic resonance imaging (MRI) and its impact on timing of surgery, and, second, to evaluate the impact of timing of surgery after chemoradiotherapy (CRT) on short- and long-term outcomes.MethodsPatients were selected from a collaborative rectal cancer research project including 71 Dutch centres, and were subdivided into two groups according to time interval from the start of preoperative CRT to surgery (< 14 and ≥ 14 weeks).ResultsFrom 2095 registered patients, 475 patients received preoperative CRT. MRI restaging was performed in 79.4% of patients, with a median CRT–MRI interval of 10 weeks (interquartile range [IQR] 8–11) and a median MRI–surgery interval of 4 weeks (IQR 2–5). The CRT–surgery interval groups consisted of 224 (< 14 weeks) and 251 patients (≥ 14 weeks), and the long-interval group included a higher proportion of cT4 stage and multivisceral resection patients. Pathological complete response rate (n = 34 [15.2%] vs. n = 47 [18.7%], p = 0.305) and CRM involvement (9.7% vs. 15.9%, p = 0.145) did not significantly differ. Thirty-day surgical complications were similar (20.1% vs. 23.1%, p = 0.943), however no significant differences were found for local and distant recurrence rates, disease-free survival, and overall survival.ConclusionsThese real-life data, reflecting routine daily practice in The Netherlands, showed substantial variability in the use and timing of restaging MRI after preoperative CRT for rectal cancer, as well as time interval to surgery. Surgery before or after 14 weeks from the start of CRT resulted in similar short- and long-term outcomes.

Highlights

The time interval between CRT and surgery in rectal cancer patients is still the subject of debate
After exclusion of patients with metastasis (n = 92), patients who received additional preoperative chemotherapy (n = 3) and patients with unknown start date of CRT (n = 114), 475 patients remained for inclusion in the present analysis
The median time interval between the start of CRT and surgery was 14 weeks (IQR 12–16) (Fig. 1). Based on this median time interval, patients were subdivided into two groups: 224 patients with a short interval and 251 patients with a long interval

Summary

Introduction

The time interval between CRT and surgery in rectal cancer patients is still the subject of debate. The aim of this study was to first evaluate the nationwide use of restaging magnetic resonance imaging (MRI) and its impact on timing of surgery, and, second, to evaluate the impact of timing of surgery after chemoradiotherapy (CRT) on short- and long-term outcomes. Patients were selected from a collaborative rectal cancer research project including 71 Dutch centres, and were subdivided into two groups according to time interval from the start of preoperative CRT to surgery (\ 14 and C 14 weeks). MRI restaging was performed in 79.4% of patients, with a median CRT–MRI interval of 10 weeks (interquartile range [IQR] 8–11) and a median MRI–surgery interval of 4 weeks (IQR 2–5). The CRT– surgery interval groups consisted of 224 (\ 14 weeks) and 251 patients (C 14 weeks), and the long-interval group

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