Mismatch repair system and p53 expression in patients with T1 and T2 colorectal cancer: predictive role of lymph node metastasis and survival.

Background: The aim of this study was to evaluate the predictive role of the mismatch repair (MMR) system and p53 expression for lymph node metastasis and long-term survival in patients with T1 and T2 colorectal cancer.

Methods: A total of 543 patients with T1 or T2 colorectal cancers who underwent radical surgery with regional lymphadenectomy from December 2007 to December 2009 were analyzed. Predictive factors for lymph node metastasis and prognostic factors were analyzed.

Results: During the median follow-up period of 4 years, the 5-year disease-free survival rate for patients without lymph node metastasis was 94.8%, which was significantly higher than that for those with lymph node metastases (85.2%; P < 0.001). On multivariate analysis, gender, tumor location, N category, lymphatic invasion, vascular invasion, and perineural invasion were independent prognostic factors for disease-free survival; however MMR defect, p53 expression, and microsatellite instability (MSI) were not. The presence of lymphatic invasion, vascular invasion, and tumor budding were independent predictors of lymph node metastasis.

Conclusions: In patients with T1 or T2 colorectal cancer, lymphatic invasion, vascular invasion, and tumor budding were predictive of lymph node metastasis; however, MMR defect, p53 expression, and MSI were not predictive.