Assessing the ability of the Cancer and Aging Research Group tool to predict chemotherapy toxicity in older Japanese patients: A prospective observational study

The Cancer and Aging Research Group (CARG) prediction tool was designed in the United States to predict grade ≥ 3 chemotherapy-related adverse events (CRAE) in older patients. However, its usefulness among Japanese people, who have different sensitivities to anticancer drugs and life expectancy, remains unknown. We aimed to prospectively evaluate the utility of the CARG tool for predicting severe CRAE in older Japanese patients with cancer. Patients with solid tumors aged 65 years and older who commenced anticancer drug regimens from April 2018 to October 2020 were divided into three groups (low, medium, and high-risk) based on their CARG risk scores. Toxicity was prospectively observed by a pharmacist. The primary objective was to evaluate the correlation between the incidence of grade ≥ 3 CRAE and the CARG risk score. The secondary objective was to evaluate hematological and non-hematological toxicities. CRAE incidence was compared among the three groups using a closed testing procedure: (1) Cochran–Armitage test for trend and (2) chi-square test for paired comparison. The patients (N = 165) had a median age of 71 years (range: 65–89 years). CRAE in patients divided into low-, medium-, and high-risk groups, based on CARG risk scores, were 39%, 55%, and 82%, respectively (low vs high; p