Utilization and predictors of expectant management among elderly men with low-and intermediate-risk localized prostate cancer in U.S. urological practice.

INTRODUCTION: Expectant management (EM) reduces overtreatment in low-risk but not intermediate-risk localized prostate cancer (PCa). We assessed the use and predictors of EM to understand its uptake in U.S. practice.
METHODS: Using the U.S. SEER-Medicare database, we conducted a retrospective cohort study of men 66 years and older diagnosed with low-risk (N=25,506) or intermediate-risk (N=25,597) localized PCa between 2004 - 2011 and followed through December 31, 2012. We defined EM as no definitive therapy (DT) and at least one prostate-specific antigen (PSA) test or re-biopsy 4 - 12 months post diagnosis; or receiving DT after PSA testing or re-biopsy 7 - 12 months after diagnosis. We performed separate analyses for low-risk and intermediate-risk groups using multiple logistic regressions.
RESULTS: For men diagnosed with PCa in 2004-2011, EM increased from 22% to 43% in the low-risk group and from 15% to 18% in the intermediate-risk group. In the low-risk group, EM increased with patients' age (adjusted odds ratio [aOR] = 1.26 for 71-75 years; 2.21 for 76-80 years; 6.33 for older then 80, p<0.0001, compared to 66-70 years). EM uptake was higher among men with comorbidities (aOR=1.29), and residing in the Pacific region (aOR=0.56, compared to the East Coast).
CONCLUSIONS: In U.S. practice, the utilization of EM steadily increased in low-risk PCa and remained low in the intermediate-risk group over time. While patients with advanced age or comorbidities were more likely to receive EM, its use varied substantially by geographic region. Our findings bring attention to the presence of multiple barriers for EM implementation.