National trends in the management of patients with positive surgical margins at the time of radical prostatectomy.

Abstract

111 Background: The optimal management approach for patients with positive surgical margins (PSM) at radical prostatectomy (RP) has not been definitively assessed. To better understand contemporary patterns of care, we sought to examine time trends and determinants of adjuvant therapy in a large national sample of men with prostate cancer (PCa) treated with RP. Methods: We queried the National Cancer Database (NCDB) to identify men with clinically-localized PCa diagnosed from 2010 to 2014 who had PSM at RP performed as initial primary definitive treatment. We used descriptive statistics to examine subsequent management strategies, assessed as no adjuvant therapy as part of the initial planned course of management, receipt of adjuvant radiation therapy (RT), and receipt of adjuvant RT in combination with androgen deprivation therapy (ADT). Binary logistic regression models were constructed to identify patient, tumor, and facility features associated with receipt of adjuvant therapy. Results: During the study period, we identified 44,523 patients with PSM. Of those, 5,179 (11.6%) men received any adjuvant RT (+/- ADT), while only 1,380 (3%) received adjuvant RT with ADT. Use of adjuvant RT did not change over the study period ( p= 0.61). On multivariable analysis men of uninsured status (p = 0.003), Medicaid insurance (p = 0.001), and patients treated in non-academic facilities (p < 0.001) were more likely to receive adjuvant RT. In addition, use of adjuvant RT was associated with higher pre-treatment PSA (p < 0.001), pathologic stage (p < 0.001) and Gleason grade group (p < 0.001), decreasing distance from the treatment center (p < 0.001), and shorter duration between diagnosis and RP (p < 0.001). Receipt of adjuvant ADT with RT was associated with clinical and pathologic features; however, not with sociodemographic factors. Conclusions: The majority of patients experiencing PSM at RP did not receive adjuvant RT, and rates of adjuvant therapy have remained stable over time. In addition to adverse clinical and pathologic features, sociodemographic and facility factors were significantly associated with receipt of adjuvant RT; however, the addition of ADT appears largely driven by disease characteristics.