Purpose: Obesity has been associated with a higher risk of progression following radical prostatectomy (RP). Obese men have higher serum leptin, a hormone produced by adipocytes, which has also been shown to be an in vitro prostate cancer growth factor. We examined whether serum leptin correlates with advanced pathological findings at RP.
Materials and methods: Preoperative serum from 225 men treated with RP between 1998 and 1999 was examined for serum leptin. Multivariate logistic regression analysis was used to determine whether serum leptin was predictive of extraprostatic extension (pT3a).
Results: Serum leptin highly correlated with body mass index (Spearman r = 0.602, p <0.001). Serum leptin was not associated with total or percent free prostate specific antigen (PSA), biopsy or prostatectomy Gleason score, age or height. On multivariate analysis with total and percent free PSA, clinical stage, age, biopsy Gleason score, body mass index, serum leptin, and height as variables considered for entry into the model, serum PSA (p = 0.009), clinical stage (p = 0.019) and serum percent free PSA (p = 0.041) were the only variables predictive of extraprostatic extension. Serum leptin was not significantly associated with pathological stage (pT3a).
Conclusions: In the current study of predominantly white men with mainly low risk disease there was no statistically significant association between serum leptin and pathological stage (pT3a) at RP. In this cohort serum leptin was not a good biomarker for predicting advanced stage at RP.