Understanding Active Surveillance for Prostate Cancer.

PURPOSE To assess how active surveillance for prostate cancer is apportioned across specialties and how testing patterns and transition to treatment vary by specialty. METHODS We used a 20% national sample of Medicare claims to identify men diagnosed with prostate cancer from 2010 through 2016 initiating surveillance (N = 13,048). Patients were assigned to the physician responsible for the bulk of surveillance care based on billing patterns. Freedom from treatment was assessed by specialty of the responsible physician (urology, radiation oncology, medical oncology, and primary care). Multinomial logistic regression models were used to examine associations between specialty and treatment patterns. RESULTS Urologists were responsible for surveillance in 93.7% of patients in 2010 and 96.2% of patients in 2016 (P for trend = .01). Testing patterns varied by specialty. For example, patients of medical oncologists had more frequent prostate-specific antigen testing compared with patients of urologists (1.85 v 2.39 tests per year, respectively; P < .01). Three years after diagnosis, a significantly smaller proportion of patients managed by radiation oncologists (64.3%) remained on surveillance compared with patients managed by other physicians (75.8%-79.5%; P < .01). Although radiation was the most common treatment among all men who transitioned to treatment, a disproportionate percentage of patients followed by radiation oncologists (28.9%) ultimately underwent radiation compared with patients followed by other physicians (15.1%-15.4%; P < .01). CONCLUSION Nontrivial percentages of patients on active surveillance are managed by physicians outside of urology. Given the interspecialty variations observed, efforts to strengthen the evidence underlying surveillance pathways and to engage other specialties in guideline development are needed.