Treatment Interval between Neoadjuvant Chemoradiotherapy and Surgery in Rectal Cancer Patients: A Population-Based Study

Abstract

Background Neoadjuvant chemoradiation therapy (CRT) has been widely implemented in the treatment of rectal cancer patients, but optimal timing of surgery after neoadjuvant therapy is unclear. The purpose of this study was to evaluate the effects of prolonged intervals between long-course CRT and surgery in rectal cancer patients.MethodsData on all rectal cancer patients diagnosed between 2006 and 2011 were retrieved from the population-based Netherlands Cancer Registry; the main outcome parameters were pathologic complete response (pCR) and overall survival (OS). Outcomes were reported separately for patients with early tumors (ETs; N = 217) and locally advanced rectal cancer (LARC; N = 1073). Patients were divided into 2-week interval groups according to treatment interval, ranging from 5–6 to 13–14 weeks. Kaplan–Meier curves, and logistic regression and Cox regression models were used for data analysis.ResultsNo significant difference in pCR rate was observed for ET patients according to treatment interval. Compared with a treatment interval of 7–8 weeks, pCR rates in LARC patients were higher after 9–10 weeks (18.4 %; odds ratio [OR] 1.56, 95 % CI 1.03–2.37) and 11–12 weeks of treatment interval (20.8 %; OR 1.94, 95 % CI 1.15–3.26). Treatment interval did not influence OS in ET or LARC patients.ConclusionsTreatment intervals of 9–12 weeks between surgery and CRT seem to improve the chances of pCR in LARC patients, without an effect on OS. The length of treatment interval did not affect outcomes in patients with ET. The ongoing search for minimally invasive surgery drives the need for exploration of factors that improve pathologic response.Electronic supplementary materialThe online version of this article (doi:10.1245/s10434-016-5294-0) contains supplementary material, which is available to authorized users.

Oncological results of extended resection for locally advanced rectal cancer: the value of postirradiation MRI in predicting local recurrence

“…The pCR rate of 5% in the present study is less than the 10–27% rate reported in larger series which included T2 and T3 rectal cancers and T4 tumours not needing MVR . Also the interval of 6–8 weeks between the end of CRT and surgery may have influenced the pCR rate, since an interval of 9–12 weeks results in a higher rate of achieving a pCR . There is contrary evidence to suggest that the pathological response decreases again after 9–10 weeks .…”

Randomized controlled trial of 8 weeks’ vs 12 weeks’ interval between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer

“…A meta‐analysis of 13 studies and 19 652 patients published in 2017 revealed similar sphincter preservation rates between shorter and longer interval groups (relative risk 0.99, P = 0.743) . Similarly, in a Dutch study, sphincter preservation rate did not significantly differ in longer interval groups ranging between 5 and 14 weeks ( P = 0.393) . Briefly, the recently published data show no beneficial effect of longer intervals on sphincter preservation .…”

Meta-analysis of the effect of extending the interval after long-course chemoradiotherapy before surgery in locally advanced rectal cancer

“…). A total of 26 publications, including four RCTs and 25 445 patients with rectal cancer were eligible for inclusion ( Table ). Twenty‐four of the 26 studies (22 650 patients) reported the primary endpoint of pCR based on the predefined wait interval and were included in the qualitative and quantitative analysis for this outcome variable; 15·9 per cent (1522 of 9551) and 11·3 per cent (1481 of 13 099) had achieved pCR in the extended and classical intervals respectively.…”