Epidemiological and Therapeutic Analyses in Lung Cancer Patients Over 80 Years Old in the Hokushin Region: A Retrospective Hospital Administrative Database Study

Little is known about annual clinical practice in patients with lung cancer over 80 years old. In this analysis, we found several differences in treatment pattern between patients < 80 and > 80 years old. Propensity score matching analysis including sex, stage, and comorbidities indicated that age over 80 years itself is significantly related to the choice of no treatment. Objective: This study was performed to validate the epidemiology, initial treatment, and clinical practice in lung cancer patients < 80 and > 80 years in Hokushin region, Japan. Methods: We retrospectively surveyed data of 5481 newly diagnosed and registered lung cancer patients (4311 [78.7%] < 80 years; 1170 [21.3%] > 80 years ) in 22 principal hospitals in Hokushin region linked with health insurance claims data between 2016 and 2017. Stage, initial treatment, and clinical practice were compared between the 2 groups. Results: The distributions of clinical stage I/II/III/IV/unknown were 2535/387/654/1371/111 in non-small cell lung cancer (NSCLC) and 37/32/114/237/3 in SCLC. Initial surgery for stage I NSCLC was performed in 90.0% and 60.2% of cases in the < 80 and > 80 years groups, respectively. Rates of treatment with best supportive care (BSC) for stage IV disease were significantly higher in the > 80 than the < 80 years group (NSCLC:58.9% vs. 18.7%; SCLC: 42.3% vs. 6.8%, respectively), regardless of the presence/absence of comorbidities. Propensity score matching showed that age > 80 years itself was significantly related to choice of BSC in patients with lung cancer. The ratio of initial cytotoxic chemotherapy for NSCLC was low (49.9%) but that of biomarker-based therapy including tyrosine kinase inhibitors and immune checkpoint inhibitors (50.0%) was significantly higher in the > 80 than < 80 years group (70.2% vs. 29.8%, respectively). Conclusion: There are several differences in treatment pattern between patients < 80 and > 80 years. Age > 80 years may be related to BSC choice in patients with lung cancer.