Tumor-infiltrating mast cells in colorectal cancer as a poor prognostic factor.

The purpose of this study is to investigate the clinical/prognostic significance of tumor-infiltrating mast cells (TIMs) in patients with colorectal cancer (CRC). TIM infiltration in 325 stage I to III CRC specimens was detected by immunohistochemistry. The optimal cutpoint of TIM density was assessed by the X-tile program. TIM infiltration in CRC was significantly higher than in normal colorectal tissues. According to the X-tile program, the cutpoint for high TIM infiltration in CRC was determined when TIM density was more than 8.0 per high-power field. Correlation analysis between TIM density and clinicopathological variables demonstrated that TIM infiltration was significantly associated with gender, nodal status, and American Joint Committee on Cancer stage. Multivariate Cox regression analysis showed that high TIM infiltration was a risk factor for both overall survival and disease-free survival. Taken together, high TIM infiltration can be an independent and useful biomarker for predicting the poor survival of patients with CRC.