The impact of mismatch repair status on accuracy of clinical staging in stage II/III rectal cancer in daily practice

作者：R.A. Lunenberg, Ingrid A. Franken, Manon N.G.J.A. Braat, Marloes A.G. Elferink, Frederieke H. van der Baan, Miriam Koopman, Geraldine R. Vink, Martijn Intven, Femke P C Sijtsma, Jeanine M.L. Roodhart · 发表于：European Journal of Cancer · 年份：2025 · DOI：10.1016/j.ejca.2025.116117 · 被引用次数：2 · 研究领域：Colorectal Cancer Surgical Treatments、Genetic factors in colorectal cancer、Colorectal Cancer Screening and Detection

BACKGROUND: Accurate clinical staging of rectal cancer (RC) is critical for guiding neoadjuvant treatment decisions. In colon cancer, mismatch repair deficient (dMMR) tumours have shown a higher risk of overstaging, but the impact of mismatch repair (MMR) status on staging accuracy in RC remains unclear. This study assessed the accuracy of clinical T and N staging compared to pathological staging in dMMR versus proficient MMR (pMMR) RC patients in the Netherlands. METHODS: Data from 2908 patients diagnosed with stage II/III RC between 2015 and 2022, treated with upfront surgery or short-course radiotherapy (SCRT) followed directly by surgery, and with known MMR status (50 dMMR, 2858 pMMR) were obtained from the Netherlands Cancer Registry. Discrepancies between clinical and pathological T and N stage and TNM risk category were classified as over-, under-, or correctly staged. RESULTS: T stage was overstaged in 47.8 % of dMMR tumours versus 37.1 % of pMMR tumours, while understaging was similar (6.5 % vs 7.5 %). N stage overstaging was more frequent in dMMR (34.7 %) than in pMMR tumours (21.6 %), while understaging was less frequent in dMMR (2.0 %) than in pMMR (18.1 %). TNM risk category was overstaged in 34.0 % of dMMR versus 23.8 % of pMMR tumours, while understaging occurred in 12.0 % vs 23.7 %, respectively. CONCLUSIONS: In RC patients treated with upfront surgery or with SCRT followed directly by surgery, pMMR tumours were more prone to clinical understaging, while dMMR ...