Obesity and Prostate Cancer: A Focused Update on Active Surveillance, Race, and Molecular Subtyping.

CONTEXT: In 2012, we published a detailed review on obesity and prostate cancer. Since then, new studies have brought further understanding regarding the role of obesity in selecting active surveillance candidates, and differing associations between obesity and prostate cancer as a function of race and molecular subtype of prostate cancer.

OBJECTIVE: To review new manuscripts on these new concepts for which there were limited data before 2012.

EVIDENCE ACQUISITION: A PubMed search from July 2012 to March 2016 was performed using the terms "prostate cancer" and "obesity". Of 450 articles, we included 15 related to these three topics.

EVIDENCE SYNTHESIS: Among men on active surveillance or candidates for active surveillance, multiple studies suggest that the risk of upgrading is higher for obese men. No study has shown long-term oncologic differences, and the risk of prostate cancer mortality remains low. One study suggested that the link between obesity and prostate cancer risk is stronger among black men; however, other studies found that obesity is correlated with aggressive disease regardless of race. Two studies found that the associations between obesity and prostate cancer (ie, fewer low-grade cancers and yet more aggressive cancers) was limited to men with TMPRSS2-ERG-positive tumors.

CONCLUSIONS: The past 4 yr has seen much new work on the obesity-prostate cancer link. If confirmed in other studies, these findings provide novel insights into not only the link between obesity and prostate cancer but also prostate cancer biology in general.

PATIENT SUMMARY: While their outcomes may be slightly worse, obese men with localized prostate cancer should not be discouraged from active surveillance. Early studies suggest there may be subtypes of patients in whom obesity is more strongly linked to aggressive disease.