Abstract：【Objective】To investigate the expression of mismatch repair proteins (MMRP) and p53 in patients with colorectal cancer and their clinicopathological significance.【Methods】 Ninety-eight patients with colorectal cancer were included. According to the presence or absence of MMRP expression, they were divided into the dMMR group (n=20) and the pMMR group (n=78). According to p53 expression, they were divided into the p53-positive group (n=72) and the p53-negative group (n=26). General clinical data were compared between groups, and Spearman correlation analysis was performed to evaluate the relationships among MLH1, PMS2, MSH2, and MSH6 within the MMRP family.【Results】 Tumor diameter was larger in the pMMR group than in the dMMR group. The proportions of high differentiation, TNM stage Ⅲ~Ⅳ, intravascular tumor thrombus, and lymph node metastasis were higher in the pMMR group compared with the dMMR group, with statistically significant differences (P<0.05). In the p53-positive group, the proportions of male patients and TNM stage Ⅰ~Ⅱ were higher than those in the p53-negative group (P<0.05). Among the 20 patients in the dMMR group, MLH1 loss was observed in 6 cases, PMS2 in 7 cases, MSH2 in 3 cases, and MSH6 in 2 cases; MLH1 combined with PMS2 loss was found in 1 case, and MSH2 combined with MSH6 loss was shown in 1 case. MLH1 was significantly positively correlated with PMS2, and MSH2 with MSH6 (both P<0.05).【Conclusion】 Loss of MMRP expression is significantly associated with clinicopathological features such as tumor diameter and degree of differentiation in colorectal cancer patients. p53 positivity is significantly associated with patient gender and TNM stage.
2025, Vol. 42 
