Hematologic toxicity of radium-223 in elderly patients with metastatic Castration Resistant Prostate Cancer: a real-life experience

BACKGROUND: Treatment with radium-223 has been shown to increase survival and to delay skeletal events related to bone metastases of patients with metastatic Castration Resistant Prostate Cancer (mCRPC). This treatment has also proved to be well tolerated, and hematological toxicity, in particular anemia, represents the most represented adverse event. MATERIALS AND METHODS: We evaluated the hematologic toxicity of Ra-223 treatment in a real-life experience of 38 patients from two Italian cancer centers, with bone metastases from mCRPC. The main endpoint of the study was the evaluation of the efficacy and tolerability of treatment with radium-223, with greater reference to hematological toxicity (especially anemia) as the cause of interruption of treatment, specifically in the elderly patient. RESULTS: From August 2016 to October 2017, a total of 38 consecutive nonselected patients, 20 of them aged >75 years, with mCRPC symptomatic bone metastases, were enrolled for radium-223 at standard doses. Hematologic adverse events were recorded more frequently (72.4% with AE), and 36.8% had anemia. The most frequent cause of treatment discontinuation due to AEs was anemia [8/10 patients (80%)], followed by thrombocytopenia (2 patients) and neutropenia (1 patient). Hematologic AEs were more represented in elderly patients with greater disease burden and previously treated with docetaxel. CONCLUSIONS: Anemia is the most represented AE related to radium-223 treatment in elderly patients with greater disease burden and previously treated with docetaxel, besides representing the main reason for interruption of treatment. Correct patient selection, appropriate timing, and adequate supportive care are elements that could facilitate successful treatment with radium-223, preventing premature interruption of the same. The results of this experience support the opportunity to propose treatment with radium-223 mostly in patients in the earliest stages.