Purpose: To evaluate practice patterns of planned post-operative radiation therapy (RT) among men with positive surgical margins (PSM) at radical prostatectomy.
Methods: We identified 43,806 men within the National Cancer Database with pathologic node-negative prostate cancer diagnosed in 2010 through 2014 with PSM. The primary endpoint was receipt of planned (RT) within a patient's initial course of treatment. We examined post-RP androgen deprivation therapy (ADT) with RT as a secondary endpoint. We evaluated patterns of post-operative management and characteristics associated with planned post-prostatectomy RT.
Results: Within 12 months of RP, 87.0% received no planned RT, 8.5% RT alone, 1.3% ADT alone, and 3.1% RT with ADT. In a multivariable logistic regression model, planned RT use was associated with clinical and pathologic characteristics as estimated by surgical Cancer of the Prostate Risk Assessment (CAPRA-S) category (intermediate versus low, OR = 2.87, 95% CI 2.19-3.75, P < 0.001; high versus low, OR = 10.23, 95% CI 7.79-13.43, P < 0.001), treatment at community versus academic centers (OR = 1.24, 95% CI 1.15-1.34, P < 0.001), shorter distance to a treatment facility (OR = 0.97 for each 10-mile, 95% CI 0.96-0.98, P < 0.001), and uninsured status (OR = 1.39, 95% CI 1.10-1.77, P = 0.005). The odds of receiving planned RT were lower in 2014 versus 2010 (OR = 0.76, 95% CI 0.68-0.85, P < 0.001). There was no significant change in the use of ADT with RT. High versus low CAPRA-S category was associated with the use of ADT in addition to RT (OR = 5.13, 95% CI 1.57-16.80, P = 0.007).
Conclusion: The use of planned post-prostatectomy RT remained stable among patients with PSM and appears driven primarily by the presence of other adverse pathologic features.
Keywords: Adjuvant therapy; Androgen deprivation therapy; Positive surgical margins; Prostate cancer; Radiation therapy; Radical prostatectomy.