Top Line: The management of locally advanced rectal cancer has become extremely nuanced over the past few years.
The Study: Here is an excellent multidisciplinary consensus from the American Radium Society delving into the very nuanced subject or when and when not to radiate locally-advanced rectal cancer. Most clear-cut omission cases are proximal tumors with no risk factors on MRI (clear CRM, limited T3 depth, no EMVI) supported by prospective studies such as QuickSilver and OCUM suggesting surgery alone achieves local control with 95-97% of cases. Other node-positive or slightly-more high-risk tumors in proximal or mid-rectum may receive neoadjuvant chemo alone following a good initial response per PROSPECT, FOWARC, and CONVERT if a patient is motivated to minimize impact on future sexual function at the expense of neuropathy. Then there’s upfront immunotherapy for the minority of patients with MMR-deficient tumors. Conversely, upfront chemoradiation followed by chemotherapy as a total neoadjuvant approach remains the standard for low rectal tumors or those in any location with high-risk features (threatened CRM ≤1 mm, T4, EMVI, lateral pelvic nodes). And don’t forget adjuvant radiation for unanticipated high-risk pathologic features at surgery such as T4b disease or involved margins.
TBL: This review arms you with all the know-how to sound informed and judicious at your next multi-disciplinary rectal tumor board discussion. | Tchelbi, Int J Radiat Oncol Biol Phys 2026
The Study: Here is an excellent multidisciplinary consensus from the American Radium Society delving into the very nuanced subject or when and when not to radiate locally-advanced rectal cancer. Most clear-cut omission cases are proximal tumors with no risk factors on MRI (clear CRM, limited T3 depth, no EMVI) supported by prospective studies such as QuickSilver and OCUM suggesting surgery alone achieves local control with 95-97% of cases. Other node-positive or slightly-more high-risk tumors in proximal or mid-rectum may receive neoadjuvant chemo alone following a good initial response per PROSPECT, FOWARC, and CONVERT if a patient is motivated to minimize impact on future sexual function at the expense of neuropathy. Then there’s upfront immunotherapy for the minority of patients with MMR-deficient tumors. Conversely, upfront chemoradiation followed by chemotherapy as a total neoadjuvant approach remains the standard for low rectal tumors or those in any location with high-risk features (threatened CRM ≤1 mm, T4, EMVI, lateral pelvic nodes). And don’t forget adjuvant radiation for unanticipated high-risk pathologic features at surgery such as T4b disease or involved margins.
TBL: This review arms you with all the know-how to sound informed and judicious at your next multi-disciplinary rectal tumor board discussion. | Tchelbi, Int J Radiat Oncol Biol Phys 2026