Prognostic Value of Body Mass Index in Korean Patients with Castration-Resistant Prostate Cancer

PURPOSE: We investigated the correlation between body mass index (BMI) and the prognosis of castration-resistant prostate cancer (CRPC) in patients who received docetaxel treatment. MATERIALS AND METHODS: A retrospective study was conducted of 55 patients who were diagnosed with CRPC and received docetaxel treatment between 2003 and 2009 at our institution. Patients with a normal or lower BMI (<23.0 kg/m(2)) were categorized as group I and patients with an overweight or greater BMI (≥23.0 kg/m(2)) were categorized as group II. Clinicopathological features and survival rates were evaluated by using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: On the basis of BMI, 27 patients (49.1%) belonged to group I and 28 (50.9%) patients belonged to group II. Mean follow-up periods were 30 months and 34.2 months, respectively (p=0.381). There were no significant differences between the two groups in terms of age, prostate-specific antigen (PSA), Gleason score, Eastern Cooperative Oncology Group Performance Status, hemoglobin level, alkaline phosphatase level, distant metastasis, radiation treatments, or performance of radical prostatectomy (p>0.05). In the univariate analysis for predicting survival rates, BMI (p=0.005; hazard ratio [HR], 0.121), logPSA (p=0.044; HR, 2.878), and alkaline phosphatase level (p=0.039; HR, 8.582) were significant factors for prediction. In the multivariate analysis, BMI (p=0.005; HR, 0.55), logPSA (p=0.008; HR, 7.836), Gleason score (p=0.018; HR, 6.434), hemoglobin (p=0.006; HR, 0.096), alkaline phosphatase level (p=0.005; HR, 114.1), and metastasis to the internal organs (p=0.028; HR, 5.195) were significant factors for prediction. CONCLUSIONS: Better effects on the cancer-specific survival rate were observed in cases with higher BMI.