A CRM-Integrated ypT Staging System Improves Prognostic Stratification Following Neoadjuvant Therapy in Rectal Cancer
Wan-Hsuan Chow1, Chung-Han Ho2,3, Yi-Chen Chen2
1Department of Radiation Oncology, Chi Mei Medical Center, Tainan, Taiwan.
Journal of Cancer
|March 23, 2026
Summary
Integrating circumferential resection margin (CRM) status into the ypT stage improves prognostic accuracy for rectal cancer patients receiving neoadjuvant chemoradiotherapy (nCRT). This novel system enhances survival stratification for personalized treatment strategies.
Area of Science:
- Oncology
- Surgical Pathology
- Cancer Staging
Background:
- The ypT staging system alone has limited prognostic value post-neoadjuvant therapy for rectal cancer.
- Current staging primarily reflects tumor characteristics, necessitating improved prognostic tools.
Purpose of the Study:
- To develop and validate a novel staging system integrating circumferential resection margin (CRM) status with the ypT category.
- To enhance prognostic accuracy for rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT).
Main Methods:
- Analysis of 4,308 rectal adenocarcinoma patients treated with nCRT and surgery (2011-2021).
- CRM involvement defined as a margin ≤1 mm.
- Comparison of the proposed CRM-integrated ypT staging system with the AJCC TNM system using Harrell's c-statistic.
Main Results:
- CRM involvement (≤1 mm) was significantly associated with worse 5-year survival.
- A modified ypT classification integrating CRM status was established.
- The novel system showed superior prognostic discrimination compared to the AJCC classification (c-statistic: 0.756 vs. 0.752, P = 0.034).
Conclusions:
- Integrating CRM status into the ypT stage improves survival stratification for rectal cancer patients post-nCRT.
- This enhanced staging may guide more individualized postoperative treatment decisions.
