Avoidance of Overtreatment of Rectal Cancer by Selective Chemoradiotherapy: Results of the Optimized Surgery and MRI-Based Multimodal Therapy Trial

Abstract

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects. The aim of this study was to examine the selective application of nCRT based on patient risk profile, as determined by MRI, to find the optimal range between undertreatment and overtreatment. STUDY DESIGN: In this prospective multicenter observational study, nCRT before total mesorectal excision (TME) was indicated in high-risk patients with involved or threatened mesorectal fascia ( 1 mm), or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery. RESULTS:Of the 1,093 patients, 878 (80.3%) were treated according to the protocol, 526 patients (59.9%) underwent primary surgery, and 352 patients (40.1%) underwent nCRT followed by surgery. The 3-year locoregional recurrence (LR) rate was 3.1%. Of 604 patients with clinical stages II and III, 267 (44.2%) had primary surgery; 337 (55.8%) received nCRT followed by TME. The 3-year LR rate was 3.9%, without significant differences between groups. In patients with clinical stages II and III who underwent primary surgery, 27.3% were diagnosed with pathological stage I. CONCLUSIONS: The results justify the restriction of nCRT to high-risk patients with rectal cancer classified by pretreatment MRI. Provided that a high-quality MRI diagnosis, TME surgery, and standardized examination of the resected specimen are performed, nCRT, with its adverse effects, costs, and treatment time can be avoided in more than 40% of patients with stage II or III rectal cancer with minimal risk of undertreatment. (clinicaltrials.gov NCT325649) (

The Evolving Personalized Landscape of Colorectal Cancer Therapies

“…2020. 3 Summary: A standard treatment for locoregionally advanced rectal cancer involves neoadjuvant radiation and chemotherapy followed by surgery. Although nLCRT has been shown to decrease the risk of LR, some patients experience treatment-related side effects and may not benefit from it.…”

“…Although nLCRT has been shown to decrease the risk of LR, some patients experience treatment-related side effects and may not benefit from it. The aim of this prospective multicenter observational study 3 was to evaluate the selective omission of nLCRT, based on risk as determined by MRI. The study included patients with cT2-4, any cN, cM0 histologically confirmed rectal adenocarcinoma who were candidates for TME.…”

“…The Optimized Surgery and MRI-Based Multimodal Therapy (OCUM) group's trial was a prospective, multicenter observational study where lower-risk rectal cancer patients received primary surgery, reserving nLCRT for those with certain high-risk clinical features. 3 This trial adds to the growing body of literature suggesting that select rectal patients may be able to safely avoid radiation in favor of surgery alone. With the age of diagnosis disconcertingly trending younger, avoiding radiation therapy might help avoid fertility problems and other more universal late-effect concerns.…”

The combination of pre-neoadjuvant chemoradiotherapy inflammation biomarkers could be a prognostic marker for rectal cancer patients

“…Neoadjuvant chemoradiotherapy followed by radical resection is the standard treatment for stage III RC patients and stage II RC patients with high-risk factors 1 , 2 . While lymph node metastasis, vessel invasion, R1 or R2 resection, and high tumor stage are identified as unfavorable prognostic factors, patients with comparable risk elements have a wide variation of oncology outcomes 3 , 4 .…”

Gemeinsame Stellungnahme der Chirurgischen Arbeitsgemeinschaft Coloproktologie (CACP) der Deutschen Gesellschaft für Allgemein- und Viszeralchirurgie (DGAV) und der AG Gastrointestinal- und Abdominaldiagnostik der Deutschen Röntgengesellschaft (DRG) zur Standardisierung der präoperativen Ausbreitungsdiagnostik beim Rektumkarzinom mittels MRT

“…Dennoch wurden in der Gruppe der primär operierten Patienten 18 % der Karzinome pathologisch lediglich als T1-2N0 diagnostiziert [3]. In der OCUM-Studie wuchs trotz protokollgeführter MRT-Diagnostik dieser Anteil auf 27,3 % an [4].…”