A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment.

Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss.

Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation.

After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ(2) test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight.

Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC.Prostate Cancer and Prostatic Diseases advance online publication, 19 July 2016; doi:10.1038/pcan.2016.28.

Prostate cancer and prostatic diseases. 2016 Jul 19 [Epub ahead of print]

M A Liss, J M Schenk, A V Faino, L F Newcomb, H Boyer, J D Brooks, P R Carroll, A Dash, M D Fabrizio, M E Gleave, P S Nelson, M L Neuhouser, J T Wei, Y Zheng, J L Wright, D W Lin, I M Thompson

Department of Urology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA., Fred Hutchinson Cancer Research Center, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA., Stanford University, Stanford, CA, USA., University of California at San Francisco, San Francisco, CA, USA., University of Washington, Seattle, WA, USA., Eastern Virginia Medical School, Norfolk, VA, USA., University of British Columbia, Vancouver, BC, Canada., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, Seattle, WA, USA., University of Michigan, Ann Arbor, MI, USA., Fred Hutchinson Cancer Research Center, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA., Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA., Department of Urology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA.