METHODS: The study used a multi-centered recruitment protocol targeting men scheduled for prostate biopsy. Men without prostate cancer at biopsy served as controls (n=1057). Prostate cancer cases were classified as having Gleason 6 (n=402), Gleason 7 (n=272), or Gleason 8-10 (n=135) cancer. BIA and body size measures were ascertained by trained staff prior to diagnosis, and clinical and comorbidity status were determined by chart review. Analyses utilized multivariable linear and logistic regression.
RESULTS: Body size and composition measures were not significantly associated with low-grade (Gleason 6) prostate cancer. In contrast, BMI, WC, FM, and FFM were each significantly associated with an increased risk of Gleason 7 and Gleason 8-10 prostate cancer. Furthermore, BMI and WC were no longer associated with Gleason 8-10 (ORBMI=1.039 (1.000, 1.081), ORWC=1.016 (0.999, 1.033), continuous scales) with control for total body FFM (ORBMI=0.998 (0.946, 1.052), ORWC=0.995 (0.974, 1.017)). Furthermore, increasing FFM remained significantly associated with Gleason 7 (ORFFM = 1.030 (1.008, 1.052)) and Gleason 8-10 (ORFFM = 1.044 (1.014, 1.074)) after controlling for FM.
CONCLUSION: Our results suggest that associations between BMI and WC with high-grade prostate cancer are mediated through the measurement of total body FFM. It is unlikely that FFM causes prostate cancer, but instead provides a marker of testosterone and IGF1 activities involved with retaining lean mass as men age.
Fowke JH, Motley SS, Concepcion RS, Penson DF, Barocas DA. Are you the author?
Reference: BMC Cancer. 2012 Jan 18;12(1):23.