HE PREVALENCE OF OBESITY IN the United States has dramatically increased in the past decade. 1 Increased body mass index (BMI) has been linked to death from colon, breast, and many other cancers. 2 Although there are biological bases for increased risk of certain cancers in obese persons, 3 delayed diagnosis may provide an explanation for advanced stage of disease and poor outcome. Obesity presents technical problems for cancer detection, since adiposity may hinder physical examination and interfere with imaging and ancillary tests. 4 Likewise, obesity may negatively affect early diagnosis through assessment of serum concentrations of soluble tumor markers. For example, recent evidence suggests that prostate cancer screening may be adversely affected by increased BMI. 5 In the United States, most prostate cancer cases are diagnosed by needle biopsy of the prostate prompted by a high serum prostate-specific antigen (PSA) concentration. The ability to accurately detect prostate cancer can be compromised by any factor that decreases PSA concentration in the circulation. Multiple studies have found that obese men have lower PSA con-Author Affiliations are listed at the end of this article.

IMPORTANCE Black men are more likely to die of prostate cancer than white men. In men with similar stages of disease, the contribution of biological vs nonbiological differences to this observed disparity is unclear. OBJECTIVE To quantify the association of black race with long-term survival outcomes after controlling for known prognostic variables and access to care among men with prostate cancer. DESIGN, SETTING, AND PARTICIPANTS This multiple-cohort study included updated individual patient-level data of men with clinical T1-4N0-1M0 prostate cancer from the following 3 cohorts: Surveillance, Epidemiology, and End Results (SEER [n = 296 273]); 5 equal-access regional medical centers within the Veterans Affairs health system (VA [n = 3972]); and 4 pooled National Cancer Institute-sponsored Radiation Therapy Oncology Group phase 3 randomized clinical trials (RCTs [n = 5854]). Data were collected in the 3

The percentage of obese men undergoing RP in our data set doubled in the last 10 years. Obesity was associated with higher-grade tumors, a trend toward increased risk of positive surgical margins, and higher biochemical failure rates among men treated with RP. A BMI > or = 35 kg/m(2) was associated with a higher risk of failure than a BMI between 30 and 35 kg/m(2).