SUO 2017: BMI is Not a Risk Factor for Active Surveillance Progression
On another end, obesity and metabolic syndrome, having been associated with worse cancer outcomes across many malignancies, has been associated with higher risk disease, high rates of progression and worse outcomes in prostate cancer.
The authors of this study wanted to study the impact of obesity (BMI specifically) on the risk of PCa progression in men on AS followed by MRI and MRI-TRUS FBx. However, this question obviously has significant limitations and this analysis must be taken with caution.
This was a retrospective review on a prospectively maintained database of all men who underwent MRI-TRUS FBx at a single institution between January 2007 to May 2015. Patients who enrolled on AS were stratified by BMI into normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), and obese (BMI ≥ 30.0).
Of the 204 men enrolled, 51 (25%) were normal weight, 101 (49.5%) were overweight, and 52 (25.5%) were obese. Of note, while patients in all 3 groups were similar in terms of age and PSA, patients has significantly larger prostate size in the obese group compared to the overweight and normal weight groups (69.8 g vs 57.5 g vs. 43.6 g, respectively).
The overall rate of progression was 32.8%, where progression was defined as pathologic progression on a subsequent biopsy or progression to treatment. Of the patients who progressed, 18 (26.9%) were normal weight, 32 (15.7%) were overweight and 17 (25.4%) were obese. On multivariate analysis, BMI was not a risk factor for AS progression, HR=1.00 (p=0.99, 95% CI=0.95-1.06).
Based on this single institutional series, the authors state that in patients diagnosed by FBx, obesity does not confer an additional risk of progression on AS. However, as there is no evidence of higher progression risk using systematic biopsy alone, it would seem this conclusion reaches too far… while obesity has been associated with higher progression rates, it is not necessarily due to the technique of biopsy.
Presented by: Kareem Rayn, BS
Co-Authors: Joseph A. Baiocco BS, Abhinav Sidana MD, Sam A. Gold BS, Graham R. Hale BS, Jonathan Bloom MD, Vladmir Valera Romero MD/PhD, Baris Turkbey MD, Peter Choyke MD, Bradford Wood MD and Peter Pinto MD
Affiliation: National Cancer Institute, National Institutes of Health, Bethesda, MD
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC