Risk-Adapted Neoadjuvant Chemoradiotherapy in Rectal Cancer: Final Report of the OCUM Study.

Purpose: We investigated whether neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer can be restricted to those at high risk of locoregional recurrence (LR) without compromising oncological outcomes.

Patients And Methods: In a prospective multicenter interventional study, patients with rectal cancer (cT2-4, any cN, cM0) were classified according to the minimal distance between the tumor, suspicious lymph nodes or tumor deposits, and mesorectal fascia (mrMRF). Patients with a distance >1 mm underwent up-front total mesorectal excision (TME; low-risk group), whereas those with a distance ≤1 mm and/or cT4 and cT3 tumors in the lower rectal third received nCRT followed by TME surgery (high-risk group).

Selection of patients with rectal cancer for neoadjuvant therapy using pre-therapeutic MRI - Results from OCUM trial.

Purpose: No consensus is available on the appropriate criteria for neoadjuvant chemoradiotherapy selection of patients with rectal cancer. The purpose was to evaluate the accuracy of MRI staging and determine the risk of over- and undertreatment by comparing MRI findings and histopathology.

Method: In 609 patients of a multicenter study clinical T- and N categories, clinical stage and minimal distance between the tumor and mesorectal fascia (mrMRF) were determined using MRI and compared with the histopathological categories in resected specimen.

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

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.

MRI-Based Use of Neoadjuvant Chemoradiotherapy in Rectal Carcinoma: Surgical Quality and Histopathological Outcome of the OCUM Trial.

Background: Preoperative magnetic resonance imaging (MRI) allows highly reliable imaging of the mesorectal fascia (mrMRF) and its relationship to the tumor. The prospective multicenter observational study OCUM uses these findings to indicate neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

Methods: nCRT was indicated in patients with positive mrMRF (≤ 1 mm) in cT4 and cT3 carcinomas of the lower rectal third.

Session 1: The surgeon as a prognostic factor in colon and rectal cancer?

The impact of quality of surgery, colorectal surgical specialization, training and expertise has been far greater on survival outcomes than adjuvant and neoadjuvant therapies. The review of the evidence by Professor Martling and expert discussion addresses the evidence base and the crucial importance of the surgeon as a prognostic factor, and how this has been relatively neglected in comparison to other resources invested in improving the treatment of colorectal cancer.