Purpose: Body size has been hypothesized to affect the risk of prostate cancer (PCa). However, previous studies have provided conflicting results, in that some show positive associations, whereas others indicate inverse associations or null findings. To further understand this we examined the effects of weight, height, body mass index and lean body mass (LBM) on PCa risk and aggressiveness in a sibling based case-control study.
Materials and methods: A total of 439 cases were recruited at major medical institutions in Cleveland, Ohio and Detroit, Michigan, and 479 unaffected brothers were recruited as controls. Conditional logistic regression with robust variance estimation was used to evaluate the association between body size and PCa.
Results: Higher LBM was inversely associated with PCa, especially in men with more aggressive disease or a later age at onset. Comparing those above and below the 25th percentile showed an OR of 0.49 (95% CI 0.28 to 0.84) and 0.28 (95% CI 0.14, 0.56), respectively. Similar inverse patterns were observed for weight. No noteworthy associations were observed between PCa and height or body mass index.
Conclusions: These observations suggest that PCa may be affected by LBM.