The sequencing of chemotherapy, radiation, and surgery has been forefront in recent trials for locally advanced rectal cancer. But what if some patients need none of those? In this phase 2 trial, patients with stage II or III rectal adenocarcinoma that was mismatch repair deficient—the case for about 5-10% of all rectal tumors—received 6 months of neoadjuvant, single-agent dostarlimab, a PD-1 inhibitor, followed by planned standard chemoradiation and surgery. Here’s the kicker, those with a complete clinical response to dostarlimab continued with clinical observation without either chemoradiation or surgery…which happened in 12/12 patients with >6 months follow-up. Cue this New York Times headline. While a tiny study, it’s created understandable excitement surrounding the fact all 12 (100%) had no evidence of disease confirmed with MRI, PET, endoscopy, and biopsy with no need for scalpel, therapeutic rays nor cytotoxic chemo. | Cercek, N Engl J Med 2022
