BodyCompositionandProstateCancerRisk: ASystematicReviewofObservationalStudies

Abstract

Body composition parameters are not captured by measures of body mass, which may explain inconsistent associations between body weight and prostate cancer (PC) risk. The objective of this systematic review was to characterize the association between fat mass (FM) and fat-free mass (FFM) parameters and PC risk. A search of PubMed, Embase, and Web of Science identified case-control and cohort studies that measured body composition in relation to PC risk. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Thirteen observational studies wereincluded,ofwhich8werecase-controlstudies(n=1572cases,n=1937controls)and5wereprospectivecohortstudies(n=7854incident caseswithPC).TheNOSscorewas5.9±1.1forcase-controlstudiesand8.4±1.3forcohortstudies.Themostcommonbodycompositiontechnique was bioelectricalimpedance analysis (n=9studies),followedby DXA(n=2), computedtomography(n=2), airdisplacement plethysmography (n= 1), and MRI (n= 1). No case-control studies reported differences in %FM between PC cases and controls and no consistent differences in FM or FFM (in kilograms) were observed. Two out of 5 cohort studies reported that higher %FM was associated with lower PC risk. Conversely, 3 cohort studies reported a greater risk of being diagnosed with advanced/aggressive PC with higher FM (expressed in kilograms, %FM, or fat distribution). Two out of 4 studies (both case-control and cohort) found that higher abdominal adipose tissue was associated with increased PC risk.Inconclusion,althoughresultswereinconsistent,thereissomeevidencethatFMmaybenegativelyassociatedwithtotalPCriskbutpositively associated with the risk of advanced/aggressive PC; modest evidence suggests that abdominal adipose tissue may increase the risk of PC. Future workshould elucidate unique patterns of FMdistributionand PC riskto triagemen at riskfordeveloping PC. Thisstudyprotocolwas registeredin theInternationalProspectiveRegisterofSystematicReviews(PROSPERO)databaseasCRD42019133388