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

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.