The effects of body mass index on pretreatment characteristics, treatment choice, and response to treatment of intermediate- and high-grade prostate cancer.

Abstract

142 Background: The relationship between obesity and prostate cancer outcomes remains unclear. A retrospective cohort study was performed to determine the effect of body mass index (BMI) on patients with intermediate to high-grade prostate cancer. Methods: Our retrospective study cohort included 1077 men from the South Texas Veteran’s Healthcare System Tumor Registry diagnosed with Gleason 7-10 prostate cancer in 1998-2008 and treated with either radical prostatectomy (RP), radiation therapy (RT) or hormone therapy (HT). Mean follow up was 4.6 ± 2.7 years. Patients were stratified into four groups on the basis of their BMI at the time of prostate cancer diagnosis (<25, 25-30, 30-35 or >35). Statistical analysis included Kruskal-wallis test and Pearson’s Chi-square test. Results: There was an inverse relationship between PSA and BMI at diagnosis; however, we found no difference in Gleason score at diagnosis. There was a difference in the primary treatment modality chosen between the BMI groups. Primary treatment modality decision was likely influenced by PSA at diagnosis, among other pre-treatment characteristics. Patients with a BMI >35 were significantly less likely to undergo RP. However, after controlling for age, primary treatment modality, Gleason score, pre-treatment PSA and diabetes diagnosis, there was no difference in overall mortality. Conclusions: Patients with an increasing BMI have a lower PSA at diagnosis, are less likely to receive RP but do not have significantly worse overall survival.