A Multicenter, Randomized Controlled Phase II Study of Short-Course Radiotherapy Followed by Sequential PD-1 Inhibitor and FOLFOX Chemotherapy Versus Long-Course Chemoradiotherapy for High-Risk Locally Advanced pMMR/MSS Lower Rectal Adenocarcinoma (STAR Trial)

This study adopts a prospective randomized controlled design to evaluate the efficacy and safety of short-course radiotherapy followed by sequential PD-1 inhibitor and FOLFOX chemotherapy versus conventional regimens in high-risk locally advanced pMMR/MSS lower rectal adenocarcinoma, aiming to provide high-level evidence supporting a novel treatment paradigm.