Body mass index is not a prognostic marker for prostate-specific antigen failure and survival in Dutch men treated with brachytherapy

Level of Evidence 4 OBJECTIVE To examine the relationship between body mass index (BMI) and biochemical recurrence (BCR), cancer-specific (CSS) and overall survival (OS) in men treated with permanent prostate brachytherapy (PPB), as there is limited information on the affect of obesity on treatment outcomes for prostate cancer. PATIENTS AND METHODS In all, 1530 patients with clinically localized prostate cancer who underwent PPB were studied. Clinical and pathological data were retrospectively obtained from medical records. The BMI was classified as normal (< 25 kg/m2), overweight (25-30 kg/m2) and obese (>= 30 kg/m2). BCR was defined as a rise in PSA levels of >= 2 ng/mL after the nadir had been reached. The cause of death was determined for each deceased patient. Patients with metastatic prostate cancer who died of any cause were classified as prostate cancer deaths. RESULTS In all, 617 (40%) patients were classified as having a normal weight, 754 (49%) overweight and 159 (10%) were obese. The Kaplan-Meier 8-year risk of BCR (95% confidence interval) was 33.3% (27.2-39.4), 29.2% (23.5-34.9) and 29.3% (12.4-46.2) for patients with a BMI of < 25 kg/m2, 25-30 kg/m2 and >= 30 kg/m2, respectively. The 8-year CSS was 88.2% (83.1-93.3), 88.6% (83.7-93.5) and 90.6% (79.9-101.4) and the 8-year OS was 70.1% (63.6-76.6), 72.9% (66.6-79.2) and 81.8% (69.3-94.3) for these three groups, respectively. Multivariate proportional hazard regression analyses of BMI and established prognostic factors for BCR confirmed the absence of any prognostic value of BMI on BCR, CSS and OS. CONCLUSIONS BMI did not appear to have any prognostic value for BCR, CCS or OS in patients with clinically localized prostate cancer treated with PPB.