[Measuring Financial Toxicity in Japanese Cancer Patients]

Financial toxicity (FT) has a negative impact on quality of life (QOL) and survival of patients with cancer. However, FT has not been well defined and unlike the Common Terminology Criteria for Adverse Events (CTCAE) for physical toxicities, valid methods to quantify FT have not been well established. Hence, further studies into the methods to properly measure and quantify the risks of FT are important. The COmprehensive Score for financial Toxicity (COST) score has been validated as a useful tool for measuring FT among patients with cancer in the US. However, the health insurance system in the US is unique and thus, COST score's feasibility and validity in other countries with public universal health care in place is unknown. Thus, we aimed to evaluate the feasibility of COST questionnaire as a tool to evaluate FT among patients with cancer in a different health care system of Japan where universal public health insurance system exists. We performed a prospective survey to ascertain the feasibility of using COST questionnaire (Japanese version) to evaluate FT in Japanese patients with advanced solid cancer who were receiving chemotherapy. The survey showed some Japanese patients experienced meaningful FT during chemotherapy.