Abstract
PURPOSE: Contemporary tumor-directed therapies for metastatic castration-resistant prostate cancer (mCRPC) are approved to prolong life, but their effects on symptoms such as pain are less well understood as a result of the lack of analytically valid assessments of pain prevalence and severity, clinically meaningful definitions of therapeutic benefit, and methodologic standards of trial conduct. This study establishes pain characteristics in the mCRPC population using a PRO measure. MATERIALS AND METHODS: Patients with prostate cancer participated in an anonymous survey at five US comprehensive cancer centers in the Prostate Cancer Clinical Trials Consortium that incorporated the Brief Pain Inventory (BPI), analgesic use, and interference with daily activities. Prevalence and severity of cancer-related pain and analgesic use were tabulated according to castration-resistant status and exposure to docetaxel chemotherapy. RESULTS: Four hundred sixty-one patients with prostate cancer participated, of whom 147 had mCRPC involving bone (61% [89 of 147] docetaxel exposed, 39% [58 of 147] docetaxel naive). Pain of any level was more common among docetaxel-exposed versus docetaxel-naive patients with mCRPC (70% [62 of 89] v 38% [22 of 58], respectively; P<.001). BPI score≥4 was reported by 38% (34 of 89) of docetaxel-pretreated and 24% (14 of 58) of docetaxel-naive patients with mCRPC; 40% of these patients with pain intensity≥4 reported no current narcotic analgesic. CONCLUSION: Pain prevalence and severity were higher in patients with prior docetaxel exposure. Analgesics were underutilized. These results provide a method for estimating accruals along the disease continuum, and for enabling design of trials appropriately powered to assess pain.