Geographic Variability, Time Trends and Association of Preoperative Magnetic Resonance Imaging with Surgical Outcomes for Elderly United States Men with Prostate Cancer: A Surveillance, Epidemiology, and End Results-Medicare Analysis

Purpose: Our goal was to assess patterns of adoption and population-level outcomes of prostate magnetic resonance imaging (MRI) and association with surgical outcomes across a sample of U.S. elderly. Materials and Methods: This population-based retrospective study used Surveillance Epidemiology, and End Results-Medicare linked data from 2003-2016 to identify men receiving prostatectomy for prostate cancer. We characterized the proportion of men receiving preoperative MRI in each year and in each hospital referral region (HRR). A 2-stage instrumental variable analysis was performed to assess the association of preoperative MRI with margin status, surgical complications and further cancer-directed therapies. Results: A total of 19,369 men received prostatectomy in 72 HRRs; the mean age was 70.2 years (SD 3.2). The proportion of men receiving a preoperative MRI increased from 2.9% to 28.2% over the study period and ranged from 0.0% to 28.8% in the different HRRs. In our instrumental variable analysis, preoperative MRI was associated with lower odds of positive surgical margin (OR 0.84, 95% CI 0.72-0.97, p=0.01) lower odds of blood transfusions at 30 and 90 days (OR 0.56, 95% CI 0.38-0.83, p=0.003 and OR 0.58, 95% CI 0.41-0.84, p=0.004) but higher odds of further treatments (OR 1.49, 95% CI 1.32-1.70, p <0.001). Conclusions: Given that a minority of men receive presurgical MRIs with marked geographic variability, the association of MRI with lower odds of positive surgical margin suggests that efforts to support the dissemination of prostate MRI may improve surgical outcomes-but may come with a tendency for more resourceintensive cancer care overall.