Trends and Current Status in Anticancer Therapy for Older Patients with Non-Small Cell Lung Cancer in Japan, 2016–2021

Introduction: Anticancer therapy for non-small cell lung cancer in patients ≥ 75 years has evolved with accumulating evidence. Recent guidelines recommend that treatment decisions be based on functional status rather than age alone. However, disparities in treatment rates persist between those above and below 75 years. This study examined whether evidence supporting treatment in older patients influences implementation, comparing trends over time by age groups.Methods: A hospital-based cancer registry covering designated cancer centers was linked with a Diagnosis Procedure Combination database, which records all medical interventions at each facility, capturing approximately 50% of lung cancer cases in Japan. For patients ≥ 75 years with good performance status, the implementation rates of standard anticancer therapy were analyzed by disease stage in 2021 and trends from 2016 to 2021.Results: In 2021, all standard treatments, except oral molecular-targeted therapies for patients with unresectable cancer, were administered less frequently to those ≥ 75 years. Treatments with evidence established before 2016 were stable throughout the study period. Oral molecular-targeted therapies demonstrated no age-related differences, and adjuvant cytotoxic chemotherapy was less frequently administered to patients ≥ 75 years. In contrast, treatments validated in patients ≥ 75 years after 2016 demonstrated a significant trend towards higher implementation, approaching that in younger patients. However, immune checkpoint inhibitors, for which safety and efficacy in older patients remain uncertain, exhibited increasing divergence in implementation rates between age groups over time.Conclusion: Evidence supporting the efficacy and safety of therapies in individuals ≥ 75 years may influence treatment selection over time.