Identification of MKI67, TPR, and TCHH Mutations as Prognostic Biomarkers for Patients With Defective Mismatch Repair Colon Cancer Stage II/III

BACKGROUND: Stage II/III disease is the most predominant form of colorectal cancer, accounting for approximately 70% of cases. Furthermore, approximately 15% to 20% of patients with stage II/III disease have deficient mismatch repair or microsatellite instability-high colorectal cancer. However, there are no identified significant prognostic biomarkers for this disease. OBJECTIVE: To identify prognostic markers for patients with deficient mismatch repair/microsatellite instability-high colon cancer stage II/III. DESIGN: Retrospective study design. SETTING: The study was conducted at a high-volume colorectal center, the Cancer Hospital, Chinese Academy of Medical Sciences. PATIENTS: Patients diagnosed with stage II/III deficient mismatch repair/microsatellite instability-high colon cancer who underwent curative surgery at the Cancer Hospital at the Chinese Academy of Medical Sciences between July 2015 and November 2018 were included. MAIN OUTCOME MEASURES: The primary outcome measure was the influence of differentially mutated genes on progression-free survival. RESULTS: The retrospective deficient mismatch repair/microsatellite instability-high cohort involved 32 patients and The Cancer Genome Atlas-microsatellite instability-high cohort involved 45 patients. Patients with deficient mismatch repair/microsatellite instability-high colon cancer had higher mutational frequencies of MKI67, TPR, and TCHH than patients with microsatellite stable colon cancer. MKI67, TPR, TCHH, and gene combination were significantly correlated with prognosis. The biomarker mutation-type colon cancer group had a higher risk of recurrence or death than did the wild-type group. Moreover, biomarker mutation-type tumors had more mutations in the DNA damage repair pathway and tumor mutational burden than did biomarker wild-type tumors. LIMITATIONS: This study was limited by its retrospective nature. CONCLUSIONS:MKI67, TPR, and TCHH may serve as potential diagnostic and prognostic biomarkers for deficient mismatch repair/microsatellite instability-high colon cancer stage II/III. )