Daily symptom monitoring commonly leads to treatment modification in older adults receiving treatment for metastatic prostate cancer (mPC)

82 Background: Treatment options for older adults with mPC expanded significantly in recent years but commonly include chemotherapy with Docetaxel (Chemo), androgen receptor-axis-targeted therapies (ARAT), and Radium-223 (Ra-223). Symptom burden associated with Chemo, ARAT, and Ra-223 is frequently observed and often leads to treatment modification, especially in older men. The objective of this study is to explore how often, and which moderate to severe symptoms during treatment for mPC and triggered follow-up, lead to treatment delay and/or dose reduction. Methods: Men aged 65+ with mPC starting standard dose (n=24) or reduced dose (n=1) Chemo, standard dose (n=41) or reduced dose (n=1) ARATs, or Ra223 (n=12) from two tertiary cancer centres in Toronto, Canada, were enrolled in a prospective cohort study. Participants self-reported symptoms daily using the Edmonton Symptom Assessment Scale (ESAS) for 3-4 weeks either through a web-based interface or phone calls. ESAS scores of >4 were followed by ‘triggered’ detailed questionnaires. The oncology care team was informed of reportable events based on scores of triggered questionnaires and patients were advised to call their care team. Clinical and treatment data were abstracted from electronic patient records and descriptive analysis was used. Results: 52/79 participants (66%) reported 345 moderate to severe symptoms that merited triggered questionnaires (table) with an adherence of 83%. Tiredness (n=74), appetite (n=49), insomnia (n=49), and pain (n=48) were the most frequently reported symptoms. 28 patients reported high scores on triggered questionnaires that led to informing the oncology care team and 79% of these patients were contacted by the care team, or an appointment with the Most Responsible Physician was scheduled. Moderate to severe symptom reporting resulted in treatment modification for 9 patients, Chemo (n=5), ARAT (n=3), and Ra-223 (n=1). Conclusions: Daily monitoring identified clinically relevant symptoms and actionable concerns. Informing care teams of reportable adverse events resulted in contacting patients and ultimately in treatment modification in a considerable number of patients. [Table: see text]