Neoadjuvant chemoradiotherapy with or without PD-1 inhibitors in MMR−proficient non−metastatic rectal cancer: a meta-analysis of randomized controlled trials

Among patients with pMMR non-metastatic rectal cancer, adding PD-1 inhibitors to standard nCRT improves pCR-most markedly when combined with short-course radiotherapy-with no statistically significant increase detected in high-grade neoadjuvant toxicity or major surgical morbidity. These randomized data support progression to confirmatory phase III trials to define optimal sequencing, regimen standardization and long-term oncologic and functional outcomes.<b>Systematic Review Registration</b>: https://www.crd.york.ac.uk/prospero/<b>, identifier 420251137668.</b>