Influence of tumor peroxisome proliferator-activated receptor gamma and delta expression on postoperative mortality of patients undergoing colorectal cancer surgery.

Purpose: To evaluate the influence of peroxisome proliferator-activated receptor gamma (PPAR gamma) and delta (PPAR delta) 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 gamma (> 2.0) or PPAR delta (> 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 gamma (> 2.0/ < or = 2.0) (odds ratio, 11.43; 95% C.I., 1.154-113.1; p = .0373), PPAR delta (> 1.0/ < or = 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 gamma and delta expression is useful for predicting postoperative mortality in patients undergoing CRC surgery.