Background: Though efforts have been made toward standardizing access to quality cancer care in Japan, there are still geographical and institutional disparities in the level of cancer care availability. We investigated the utilization of cyclin-dependent kinase 4/6 inhibitors plus endocrine therapy (CDK4/6i+ET) as first-line (1 L) treatment for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) in Japan.
Research design and methods: This cross-sectional survey included physicians who had treated ≥3 1 L patients with HR+/HER2- ABC in the past year.
Results: Of 41,695 physicians invited, 300 were included in the analysis. The mean percentage share of CDK4/6i+ET and ET monotherapy was 38.3% and 42.2%, respectively. Common challenges facing CDK4/6i+ET prescription were adverse reaction management, prohibitive cost, and a preference for ET monotherapy for treating elderly patients. Key solutions included reducing the burden of adverse reaction management, improving financial support, and preparing educational videos for medical staff.
Conclusions: The study concluded that CDK4/6i+ET is not well established as a 1 L option in Japan as of 2022. More effective ways of creating awareness and supportive tools are needed for CDK4/6i+ET to be adopted as standard of care in Japan.
Trial registration number: UMIN000050760.
Keywords: Breast cancer; CDK4/6 inhibitors; Japan; endocrine therapy; web-based survey.
A new combination treatment (CDK4/6i + ET) was approved for a type of advanced breast cancer and recommended by the treatment guidelines. However, we do not know how often they use it in Japan. To find out, we surveyed 300 doctors in Japan. We found that this treatment is prescribed 38.3% of the time. This means it is not the most common choice. Most doctors who use this are happy with it. However, they find some difficulties. These include dealing with side effects, high costs, and hesitating to use the new treatment for the elderly. To make this treatment more popular, we need to help doctors manage side effects better, provide financial support to patients, and teach medical staff about it. Raising awareness about this treatment can also help more doctors use it. Thus, while the treatment is good and many doctors like it, some challenges must be fixed. By focusing on these areas, we can make this treatment more common and help more patients in Japan.