Potential role of leptin expression in hepatocellular carcinoma

Background: Obesity is associated with hepatocellular carcinoma (HCC). The association may result from the aberrant expression of adipokines. Aim: To explore the potential biological effect and prognostic value of leptin, one of the adipokines, in HCC. Methods: Immunohistochemistry was used to evaluate the expression of leptin in 68 patients with HCC. The expression of Ki-67 and microvessel density (MVD) of tumorous lesions in HCC were also analysed. The result of leptin expression was further correlated with Ki-67 expression, intratumour MVD, clinicopathological characteristics, overall survival and the postoperative use of medroxyprogesterone acetate (MPA). Results: High leptin expression was seen in 60.3% of patients with HCC and was significantly correlated with intratumour MVD (high v low; 59.2 (standard deviation 3.2) v 44.2 (19.5), p = 0.004), but not with Ki-67 expression. No marked correlation was seen between leptin expression and clinicopathological characteristics. However, using a multivariate Cox's proportional hazards model, leptin expression was a predictor for improved overall survival of patients with HCC (odds ratio 0.16; 95% confidence interval 0.03 to 0.87; p = 0.033). In addition, the Kaplan-Meier survival curve showed that high leptin expression was associated with a better survival in patients with HCC, treated postoperatively with MPA (p = 0.008, log rank test). Conclusion: High leptin expression was associated with an increased intratumour MVD and thus may be associated with HCC development. In addition, high leptin expression was a predictor for improved survival of patients with HCC, treated postoperatively with MPA.