Variation in the Prescription of Androgen Deprivation Therapy in Intermediate- and High-risk Prostate Cancer Patients Treated with Radiotherapy in the Netherlands, and Adherence to European Association of Urology Guidelines: A Population-based Study

Background: According to (inter-)national guidelines, (neo-)adjuvant and concurrent androgen deprivation therapy (ADT) in combination with external beam radiotherapy (EBRT) is optional for intermediate-risk prostate cancer (PCa) patients and is the recommended standard treatment for high-risk PCa patients. Objective: The aim of this study is to provide insight into the prescription of ADT in intermediate- and high-risk PCa patients treated with EBRT in the Netherlands, and to evaluate adherence to European Association of Urology guidelines and factors affecting prescription. Design, setting, and participants: All intermediate- and high-risk PCa patients between October 2015 and April 2016 were identified through the population-based Netherlands Cancer Registry. Variation in the prescription of ADT in patients with EBRT was evaluated. Multivariable multilevel logistic regression analyses were performed to determine the probability of ADT and to examine the role of patient-, tumour-, and hospital-related factors. Results and limitations: Overall, 29% of patients with intermediate-risk PCa received ADT varying from 3% to 73% between institutions. From the multivariable regression analysis, higher Gleason grade, magnetic resonance imaging, and computed tomography (CT)-positron-emission tomography/CT prior to radiotherapy appeared to be associated with increased prescription of ADT. Among high-risk patients, 83% received ADT, varying from 57% to 100% between departments. A higher prostate-specific antigen level, more advanced tumour stage, and a higher Gleason grade were associated with increased prescription. Conclusions: Less than one-third of intermediate-risk PCa patients treated with EBRT receive ADT. The variation in the prescription of ADT between different institutions is substantial. This suggests that the prescription is largely dependent on different institutional policies. The guideline adherence in high-risk PCa is fairly good, as the vast majority of patients received ADT as recommended. However, given the clear recommendations in the guidelines, adherence could be improved. Patient summary: In this review, we looked at the variation of hormonal treatment in intermediate- and high-risk prostate cancer patients. We found substantial variation between institutions