Increased UCP1 mRNA expression of perirenal fat predicts a poor prognosis of clear cell renal cell carcinoma / 中华内分泌外科杂志

ABSTRACT

Objective:To evaluate the effect of uncoupling protein 1 (UCP1) expression of perirenal fat on the prognosis of clear cell renal cell carcinoma (ccRCC) .Methods:From Feb. 2013 to Oct. 2013 and Mar. 2015 to Oct. 2015, 98 patients with ccRCC who underwent retroperitoneal laparoscopic radical nephrectomy were analyzed. UCP1 mRNA of perirenal fat around tumor was detected by RT-qPCR. Preoperative Computed tomography (CT) images were used to evaluate the thickness and adhesiveness of perirenal fat. According to the UCP1 mRNA value, the patients were divided into high UCP1 group (42 cases) and low UCP1 group (56 cases) . The general clinical data, perirenal fat thickness and adhesiveness were compared, and Kaplan Meier curve was used to evaluate the difference of progression free survival (PFS) between the two groups. Univariate and multivariate Cox analysis were used to determine the potential independent prognostic factors of PFS.Results:In the high UCP1 group, the renal fat thickness, the ratio of fat adhesion, the ratio of Ⅲ to Ⅳ in Fuhrman grade and the ratio of >T2 in T stage were higher than those in the low UCP1 group[ (13.84±2.41) vs (10.75±1.99) , 42.86% vs 16.07%, 28.57% vs 8.93%, 21.43% vs. 5.36%; P=0.000, P=0.003, P=0.011, P= 0.037]. During the follow-up period (median, 62.0 months) , 15 cases (12 cases of high UCP1 group, 3 case of low UCP1 group) developed tumor progression. Kaplan Meier curve showed that PFS of high UCP1 group was worse than that of low UCP1 group (71.43% vs 94.64%, P=0.001) . Cox regression analysis showed that high UCP1 expression and high T stage were significantly correlated with low PFS ( β=1.334, RR=3.796, 95% CI=1.009-14.280, P= 0.048; β=2.886, RR=17.930, 95% CI=5.538-58.047, P=0.000) . Conclusions:The increased UCP1 expression of perirenal fat may be an independent risk factor of tumor progression in ccRCC. Combined with the assessment of browning of perirenal adipose tissue may be helpful for risk stratification of ccRCC patients after surgery.