Increased number of forkhead box P3+ tumor-infiltrating lymphocytes correlates with high preoperative albumin level and better survival in patients with stage II or III colorectal cancer.

Tumor-infiltrating lymphocytes (TILs) that test positive for forkhead box P3 (FOXP3) and elevated preoperative serum albumin levels have been positively associated with survival in colorectal cancer (CRC). This study aimed to investigate correlations among FOXP3+ TILs, preoperative serum albumin, overall survival, and other clinicopathological features of CRC patients. Surgical specimens from 340 stage II-III CRC patients were stained immunohistochemically for the presence of FOXP3+ TILs. Serum albumin levels were determined using an automatic biochemistry analyzer. Associations between various clinicopathological features and patient survival were analyzed via a Cox proportional hazards regression model. The correlation between FOXP3+ TILs and preoperative serum albumin was assessed using Pearson's correlation analysis. Survival curves were constructed by the Kaplan-Meier method. A high FOXP3+ TIL density (>15/five high-power fields), elevated preoperative serum albumin (≥35 g/L), and proximal colon carcinoma were significantly associated with better survival, and high FOXP3+ TIL number and elevated preoperative serum albumin were independent predictors of better survival. The correlation between the number of FOXP3+ TILs and preoperative serum albumin level was significant but neither of these correlated with gender, age, tumor size, tumor differentiation, mucinous tumor, T4 stage, postoperative chemotherapy, or tumor location. Our findings suggest that increased FOXP3+ TILs and high preoperative serum albumin levels are independent prognostic markers for improved survival in CRC patients. Furthermore, the number of FOXP3+ TILs correlates with preoperative serum albumin levels in these patients.