Inter-prefectural and urban–rural regional disparities in lung cancer surgery: a Japanese nationwide population-based cohort study from 2017 to 2019

Purpose To investigate regional disparities in lung cancer surgery in Japan. Methods The annual incidence of lung cancer, lung cancer surgery, and the number of board-certified thoracic surgeons in Japan during 2014–2019 were investigated using a national open database. Lung cancer surgeries were categorized by procedure (wedge resection, segmentectomy, lobectomy, pneumonectomy) and approach (open, thoracoscopic). Disparities in 47 prefectures and urban–rural disparities during 2017–2019 were evaluated using the Gini coefficient and an unpaired t-test. Correlation was assessed using Pearson’s correlation method. Results The national annual average incidences of lung cancer and lung cancer surgery were 121,106 and 50,959, respectively, in 2014–2019. The use of the thoracoscopic approach increased over time in all procedures, except pneumonectomies. The Gini coefficients of lung cancer, thoracoscopic surgery, and board-certified thoracic surgeons indicated low inequality across prefectures; however, those of open surgery indicated high inequality. Open surgery was more common in urban areas than in rural areas. The number of thoracoscopic surgeries and board-certified thoracic surgeons by prefecture were moderately correlated. Conclusion The thoracoscopic approach is becoming more common in lung cancer surgery, with little inter-prefectural regional disparity in the incidence of lung cancer, thoracoscopic surgeries, or the number of board-certified thoracic surgeons.