Purpose: To evaluate the clinical impact of biweekly liver function tests (LFTs) during the first 3 months of abiraterone therapy in veterans with prostate cancer.
Background: Abiraterone monitoring recommendations include biweekly LFTs for 3 months, then monthly based on concerns of early hepatoxicity in a limited number of patients. Veterans at the Richard L. Roudebush Veterans Affairs Medical Center (RLRVAMC) appear to tolerate abiraterone without clinically significant hepatoxicity despite stringent monitoring. There appears to be an opportunity to improve patient satisfaction/ quality of life and decrease cost to the healthcare system.
Methods: Patients were included in this retrospective chart review if abiraterone was initiated through the RLRVAMC between May 2014 and July 2018. Exclusion criteria were discontinuation within three months due to rising prostate-specific antigen or adverse drug events unrelated to hepatotoxicity, prior abiraterone exposure, and management outside RLRVAMC. Primary outcome was incidence and severity of LFT changes. Secondary outcomes included incidence and cause of dose reduction and death. Descriptive statistics analyzed outcomes. Severity of toxicity was classified according to common terminology criteria for adverse events (CTCAE) version 5.
Results: Ninety patients were included. Across three months of treatment, 24 (26.7%), 2 (2.2%), 0, and 2 (2.2%) patients experienced maximum CTCAE grade 1, 2, 3, and 4 LFT changes, respectively. Two patients experienced grade 3 or 4 LFT changes, both with previous therapy modifications due to grade 1 or 2 LFT changes and acute illness. Therapy modifications for any reason occurred in 4.4% of patients, all due to acute illness, general tolerability concerns, or grade 1 or 2 LFT changes. Four patients experienced death. No deaths were considered directly related to abiraterone.
Implications: Need for week 10 laboratory monitoring may be determined based on patient specific criteria. Reduction in laboratory monitoring may increase patient satisfaction/quality of life and decrease unnecessary costs to the healthcare system. Patients initiated on abiraterone through the RLRVAMC will receive monthly monitoring starting at week eight in the absence of baseline risk factors for hepatoxicity, grade 2 or worsening grade 1 changes during the first two months of therapy, or new grade 1 changes identified at week eight of therapy
