Higher body mass index (BMI) at baseline (per 5 kg/m<sup>2</sup> HR 0.75; 95% CI, 0.61-0.91; <i>P</i><sub>heterogeneity</sub> = 0.02) and updated BMI over time (per 5 kg/m<sup>2</sup> HR 0.86; 95% CI, 0.74-1.00; <i>P</i><sub>heterogeneity</sub> = 0.07) were associated with a reduced risk of ERG-positive disease only.<b>Conclusions:</b> Our results indicate that anthropometrics may be uniquely associated with <i>TMPRSS2:ERG</i>-positive prostate cancer; taller height may be associated with greater risk, whereas obesity may be associated with lower risk.<b>Impact:</b> Our study provides strong rationale for further investigations of other prostate cancer risk factors that may be distinctly associated with subtypes.
Epidemiologic evidence shows that obesity is associated with a greater risk of aggressive prostate cancer (PCa) and PCa-specific mortality and this is observed mainly in men with the <i>TMPRSS2-ERG</i> gene fusion.
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.