Abstract 3505: Opioid use in Veterans with metastatic castration-resistant prostate cancer
Authors: Rasmussen Kelli M. , Yong Christina , Patil Vikas , Li Catherine , Sauer Brian C. , Halwani Ahmad 
Published: September 2020

Abstract
Rationale: Describe the real-world practice patterns of opioids in Veterans with metastatic castration-resistant prostate cancer.
Background: Pain is one of the most common and debilitating symptoms of metastatic castration-resistant prostate cancer (mCRPC); it is associated not only with decreased quality of life but also shorter overall survival. Current guidelines recommend opioid therapy for alleviating pain in adult cancer patients, however, administration of opioids may have adverse effects including constipation, nausea, and respiratory depression. Previous studies have reported that long-term use of opioids in advanced cancer patients may contribute to increased healthcare utilization, morbidity, and mortality.6 However, few studies have examined the use of opioids in patients with advanced prostate cancer. This study examines current opioid practice patterns in mCRPC patients treated in the Veterans Health Administration (VHA).
Methods: Patient information from the Veterans Affairs (VA) Central Registry System and the VA Corporate Data Warehouse was used to identify patients who were diagnosed with prostate cancer and later developed mCRPC, defined as (1) radiologic evidence of metastasis obtained from radiology reports using a natural language processing algorithm; (2) evidence of rising prostate-specific antigen (PSA); (3) evidence of ongoing androgen deprivation consisting of a serum testosterone level of ≤ 50 ng/dL. Patient demographics, disease characteristics, treatment practices, and survival outcomes were extracted and have been previously presented. Opioid medications (including both oral and intravenous) used during 1L treatment were identified and included codeine, fentanyl, hydromorphone, methadone, morphine, oxycodone, tramadol, and hydrocodone.
Results: From 2006 to 2015, 120,374 patients were diagnosed with and treated for prostate cancer in the VHA, with 3,637 developing mCRPC. Of these patients 1,590 (44%) patients received first-line (1L) therapy, 1,143 (31%) received second-line (2L) therapy, and 590 (16%) received third-line (3L) therapy. The most frequently used treatments, regardless of treatment line were abiraterone, docetaxel, and enzalutamide. All mCRPC patients (1,590, 100%)–regardless of therapy–were treated with at least one opioid during their disease course. The opioids most frequently prescribed opioids during 1L therapy included: oxycodone (686, 43%), hydrocodone (679, 43%), and morphine (661, 42%). During 2L therapy morphine (361, 32%) became the most frequently used opioid, followed by oxycodone (352, 31%) and hydrocodone (287, 25%). Morphine (192, 33%), oxycodone (165, 28%), and hydrocodone (145, 25%) were the most frequently used opioids during 3L therapy.
Discussion: Our findings suggest there is high utilization of opioids in mCRPC patients treated in the VHA. Further efforts will examine whether opioid use impacts overall survival in Veterans with advanced prostate cancer.
Conclusions: There is a significant need for determining the most appropriate method of integrating opioid therapy to reduce pain in patients with mCRPC.
Citation Format: Kelli M. Rasmussen, Christina Yong, Vikas Patil, Catherine Li, Brian C. Sauer, Ahmad Halwani. Opioid use in Veterans with metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3505.