Abstract
BACKGROUND: We previously reported that TRIO pY2681, a novel prognostic biomarker for CRC, can be detected by polyclonal antibodies (pAb). We have now developed a novel monoclonal antibody (mAb) that recognizes TRIO pY2681. This study aims to assess the utility of immunohistochemical (IHC) staining using the TRIO pY2681 mAb as a prognostic marker for CRC in clinical practice. METHODS: IHC using TRIO pY2681 mAb was performed on surgical specimens from 357 CRC patients at Kyoto Medical Center and 320 at Kyoto University Hospital. Based on the results, we conducted a retrospective outcome analysis. RESULTS: TRIO pY2681 mAb exhibited significantly higher titers than pAb. In both cohorts of all stages, TRIO pY2681 IHC positivity correlated with shorter disease-specific survival (DSS) (HR, 1.67; 95% CI, 1.00-2.79; P = 0.046, and HR, 5.84; 95% CI, 2.26-15.1; P < 0.001) and relapse-free survival (RFS) (HR, 1.92; 95% CI, 1.15-3.22; P = 0.011, and HR, 4.36; 95% CI, 2.17-8.76; P < 0.001). The trend persisted in stage III. Multivariate analysis confirmed TRIO pY2681 IHC positivity as an independent prognostic factor for RFS. CONCLUSIONS: The novel TRIO pY2681 mAb identifies CRC patient subsets with poorer prognoses, enhancing prognostic precision in clinical settings.