Influence of Tumor Peroxisome Proliferator-Activated Receptor γ and δ Expression on Postoperative Mortality of Patients Undergoing Colorectal Cancer Surgery

Abstract

Purpose: To evaluate the influence of peroxisome proliferator-activated receptor γ (PPAR γ) and δ (PPAR δ) expression on postoperative mortality of patients with colorectal cancer (CRC). Methods: Optimal cutoff values were determined for each relative expression ratio (RER) (RER = PPAR expression of tumor/PPAR expression of normal mucosa) of PPAR, and patients were divided into two groups as follows (PPAR staging): patients with elevated RERs of PPAR γ (> 2.0) or PPAR δ (> 1.0) were termed Group H, and patients showing none of these elevated RERs of PPARs were termed Group L. Prognostic significance was analyzed by univariate and Kaplan–Meier analyses. Results: In total, 26 CRC patients were studied. Univariate analysis revealed that PPAR γ (> 2.0/ ≤ 2.0) (odds ratio, 11.43; 95% C.I., 1.154–113.1; p =. 0373), PPAR δ (> 1.0/ ≤ 1.0) (odds ratio, 15.00; 95% C.I., 1.503–149.7; p =. 0210) and PPAR staging (H/L) (odds ratio, 63.00; 95% C.I., 4.956–800.8; p =. 0014) were significant predictors of postoperative mortality. Kaplan–Meier analysis revealed that the survival curve of patients with CRC was clearly divided by PPAR staging (log rank test, p <.0001). Conclusions: Evaluation of PPAR γ and δ expression is useful for predicting postoperative mortality in patients undergoing CRC surgery.

Keywords:

• Colorectal cancer
• Postoperative mortality
• PPAR γ
• PPAR δ
• PPAR staging
• Predictor