Epidemiological and therapeutic analyses of lung cancer patients in the Hokushin region: a retrospective hospital administrative database study

Abstract Objective This study was performed to validate the epidemiology, initial treatment, and clinical practice in lung cancer patients in the Hokushin region, Japan. Methods We surveyed retrospective data of newly diagnosed and registered lung cancer patients in 22 principal hospitals in Hokushin region linked with health insurance claims data for registered patients between 2016 and 2017. Results A total of 5503 lung cancer cases were newly diagnosed in Hokushin region during the study period. These patients consisted of 3677 (66.8%) men and 1826 (33.2%) women, with a median age of 72.2 years (range, 27 – 103 years). Diagnoses were small cell lung cancer in 512 (9.4%) cases, squamous cell carcinoma in 1083 (19.7%), and non-squamous non-small cell lung cancer in 3906 (70.9%). The population with stage I disease in Toyama prefecture (41.1%) was lower than in the other three prefectures associated with reduced selection of initial surgery therapy and increased frequencies of stage IV disease (33.2%) and best supportive care (18.6%). Initial chemotherapy for stage IV non-squamous NSCLC consisted of tyrosine kinase inhibitors in 39.3% of cases for EGFR and 4% of cases for ALK-positive non-squamous NSCLC, followed by platinum compounds (25.9%) non-platinum compounds (12.9%), and immune checkpoint inhibitors (10.2%). Carboplatin was the commonly prescribed first-line cytotoxic chemotherapeutic agent in 65.4% of patients under 75 years old and in 96.7% of patients over 75 years old. Conclusion This study revealed real-world data on epidemiological and treatment status in lung cancer in four prefectures in Hokushin region, Japan.