Locally advanced rectal cancer with dMMR/MSI-H may be excused from surgery after neoadjuvant anti-PD-1 monotherapy: a multiple-center, cohort study

作者：Renfang Yang, Tina Wu, Jiehai Yu, Xinyi Cai, Guoyu Li, Xiangshu Li, Weixin Huang, Ya Zhang, Yuqin Wang, Xudong Yang, Yongping Ren, Ruixi Hu, Qing Feng, Peirong Ding, X. Zhang, Yunfeng Li · 发表于：Frontiers in Immunology · 年份：2023 · DOI：10.3389/fimmu.2023.1182299 · 被引用次数：28 · 研究领域：Cancer Immunotherapy and Biomarkers、Colorectal Cancer Surgical Treatments、Genetic factors in colorectal cancer

Objective: Examine patients with locally advanced rectal cancer (LARC) with deficient mismatch repair (dMMR) or microsatellite instability-high (MSI-H) who received neoadjuvant immunotherapy (nIT), and compare the outcomes of those who chose a watch-and-wait (WW) approach after achieving clinical complete response (cCR) or near-cCR with those who underwent surgery and were confirmed as pathological complete response (pCR). Methods: LARC patients with dMMR/MSI-H who received nIT were retrospectively examined. The endpoints were 2-year overall survival (OS), 2-year disease-free survival (DFS), local recurrence (LR), and distant metastasis (DM). The efficacy of programmed cell death protein-1 (PD-1) inhibitor, immune-related adverse events (irAEs), surgery-related adverse events (srAEs), and enterostomy were also recorded. Results: Twenty patients who received a PD-1 inhibitor as initial nIT were examined. Eighteen patients (90%) achieved complete response (CR) after a median of 7 nIT cycles, including 11 with pCR after surgery (pCR group), and 7 chose a WW strategy after evaluation as cCR or near-cCR (WW group). Both groups had median follow-up times of 25.0 months. Neither group had a case of LR or DM, and the 2-year DFS and OS in each group was 100%. The two groups had similar incidences of irAEs (P=0.627). In the pCR group, however, 2 patients (18.2%) had permanent colostomy, 3 (27.3%) had temporary ileostomy, and 2 (18.2%) had srAEs. Conclusion: Neoadjuvant PD-1 blockade ha...