School of Medicine, Nankai University, Tianjin, 300110, China.
Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, 300121, China.
BMC Cancer. 2023 Oct 20;23(1):1013. doi: 10.1186/s12885-023-11525-7.
Recent studies have shown that deficient mismatch repair (dMMR) rectal cancer may be related to treatment resistance, resulting in a worse prognosis than proficient MMR (pMMR) rectal cancer. The purpose of this study was to explore whether surgery plus other treatments (radiotherapy and chemotherapy) can bring more benefits to these patients than surgery alone.
A retrospective study of 168 patients with rectal adenocarcinoma who underwent total mesorectal excision was conducted using immunohistochemical methods to determine MMR status and a propensity score matching model to minimize potential confounding factors between subgroups of patients with different treatment regimens. Kaplan-Meier analysis, log-rank tests, and Cox regression models were used to assess overall survival (OS) and disease-free survival (DFS) in patient subgroups.
Only 6.9% (n = 168) of patients in the total cohort had dMMR rectal adenocarcinoma, and the most common cause of dMMR was a PMS2 deletion (103, 61.3%). The median DFS of the surgery alone group was 45.7 months (IQR, 40.9 to 77.8), and the median DFS of the surgery plus other treatment group was 43.9 months (IQR, 14.2 to 80.1). The surgery alone group was superior to the surgery plus other treatment group (HR, 0.16; 95% CI, 0.07 to 0.38; p = 0.005). There was no significant difference in OS (45.8 (IQR, 41.0 to 79.8) vs. 45.9 (IQR, 38.5 to 80.3)) between the two groups (HR, 0.57; 95% CI, 0.23 to 1.40; p = 0.263).
For patients with locally advanced dMMR rectal adenocarcinoma, compared with surgery alone, surgery plus other treatment options (radiotherapy and chemotherapy) do not grant long-term survival benefits but rather shorten DFS.
最近的研究表明，错配修复缺陷（dMMR）的直肠癌可能与治疗耐药有关，导致预后比错配修复完整（pMMR）的直肠癌更差。本研究旨在探讨手术加其他治疗（放疗和化疗）是否比单纯手术能给这些患者带来更多的益处。
采用免疫组织化学方法对 168 例接受全直肠系膜切除术的直肠腺癌患者进行回顾性研究，以确定 MMR 状态，并采用倾向评分匹配模型来最小化不同治疗方案患者亚组之间的潜在混杂因素。采用 Kaplan-Meier 分析、对数秩检验和 Cox 回归模型评估患者亚组的总生存（OS）和无病生存（DFS）。
在总队列中，仅有 6.9%（n=168）的患者存在 dMMR 直肠腺癌，最常见的 dMMR 原因是 PMS2 缺失（103，61.3%）。单纯手术组的中位 DFS 为 45.7 个月（IQR，40.9 至 77.8），手术加其他治疗组的中位 DFS 为 43.9 个月（IQR，14.2 至 80.1）。单纯手术组优于手术加其他治疗组（HR，0.16；95%CI，0.07 至 0.38；p=0.005）。两组间 OS 无显著差异（45.8（IQR，41.0 至 79.8）与 45.9（IQR，38.5 至 80.3）（HR，0.57；95%CI，0.23 至 1.40；p=0.263）。
对于局部晚期 dMMR 直肠腺癌患者，与单纯手术相比，手术加其他治疗选择（放疗和化疗）并不能带来长期生存获益，反而缩短了 DFS。
