Abstract
BACKGROUND: Non-small-cell-lung cancer (NSCLC) medication use and guideline adherence remain unclear. We investigated treatment patterns and adherence among Japanese patients with NSCLC. RESEARCH DESIGN AND METHODS: We analyzed treatment patterns and guideline adherence by age and histology in ≥ 20-year-olds with stage IV NSCLC treated between 2016-2018 using diagnostic procedure combination data. Logistic regression analysis evaluated the impact of various factors on guideline adherence. RESULTS: We included 9,722 patients. In < 75-year-olds with nonsquamous NSCLC, first-to third-line treatments comprised 31.8% platinum combination therapy, 26.3% immune checkpoint inhibitors, and 62.5% cytotoxic chemotherapy. In ≥ 75-year-olds, first-line and second-line molecular targeted therapies represented 46.6% and 35.6%, whereas third-line cytotoxic chemotherapy represented 42.3%. In squamous NSCLC, first-line platinum combination therapy was predominant (69.7% and 47.7% for < 75-and ≥75-year-olds). The most common second-line and third-line therapies were immune checkpoint inhibitors (48.6% and 50.8% for < 75-and ≥75-year-olds) and cytotoxic chemotherapy (62.5% and 55.2% for < 75-and ≥75-year-olds), respectively. The highest guideline adherence (90%) was in < 75-year-olds with squamous NSCLC. Age, histology, activities of daily living, and cumulative hospitalizations over the past 18 months influenced treatment adherence. CONCLUSION: New NSCLC drug introduction increased regardless of age, suggesting prognosis improvement. More efficient drug application and broader guideline dissemination are required.