ABSTRACT
Background: Studies have indicated that there are two main pathogenetic pathways of colorectal cancer, chromosomal instability pathway and microsatellite instability (MSI) pathway. Aims: To investigate the expressions and clinical significance of mismatch repair protein (MMRP) and p53 protein in colorectal cancer. Methods: Immunohistochemical SP staining was used to detect the expressions of 4 MMRP and p53 protein in 276 colorectal cancer patients from Jan. 2013 to Dec. 2017 at Jiading Central Hospital of Shanghai, and their relationships with clinicopathological features were analyzed. The influence of MSI on survival rate of patients with colorectal cancer was analyzed. Results: The deficit of expression rate of MMRP was 13.0%. MSI was associated with histological type, TNM staging, Schistosomiasis infection (P0.05). The positivity expression rate of p53 was 44.9%, and the expression was correlated with histological type, TNM staging, lymph node metastasis, Schistosomiasis infection (P0.05). MSI was negatively correlated with p53 expression (r=-0.169,P<0.05). The 1-, 3-, 5-year survival rates in MSI group and MSS group were 100%, 97.2%, 83.1% and 96.7%, 81.9%, 38.9%, respectively, and the difference was statistically significant (χ2=12.582, P=0.001). Conclusions: MSI and p53 are closely related to the clinicopathological features of colorectal cancer, and have some values in predicting the degree of malignancy and prognosis of colorectal cancer. MSI is negatively correlated with p53 expression, which indicates that the two may participate in different stages of development and progress of colorectal cancer.