Trends and current status of general thoracic surgery in Japan revealed by review of nationwide databases.

Nationwide databases of cases treated for thoracic disease have been established by several academic associations in Japan, which contain information showing trends and current status in regard to surgical treatment. The Japanese Association of Thoracic Surgery (JATS), Japanese Association of Chest Surgery (JACS), Japan Lung Cancer Society (JLCS), Japanese Respiratory Society (JRS), and Japan Society for Respiratory Endoscopy (JSRE) have maintained databases of lung cancer cases treated in Japan. In 1986, the number of general thoracic surgery cases was 15,544, which increased to 75,306 in 2013. Furthermore, the number of lung cancer operations performed in 2013 was 37,008, occupying 49.1% of all general thoracic operations. Also, the proportions of adenocarcinoma, female patients, aged patients, stage I disease, and limited resection procedures are increasing in lung cancer surgery cases. While the 5-year overall post-operative survival rate of lung cancer patients was 47.8% in those undergoing surgery in 1989, it was 69.6% in those of 2004, which means 22% increase during 15 years. JATS, JACS, and the Japanese Association for Research of the Thymus (JART) have maintained retrospective databases of thymic epithelial tumor cases. The number of mediastinal tumors surgically treated is also increasing and was 4,780 in 2013, among which thymoma was the most prevalent. The Japanese Association for Lung and Heart-Lung Transplantation has developed a prospective nationwide database of lung transplantation cases in Japan, which contains clinical data for 466 patients who received lung transplantation or heart-lung transplantation from 1998 to 2015. Nationwide databases are currently being utilized for clinical studies and will also contribute to international projects related to the Union for International Cancer Control (UICC) tumor, node, and metastasis (TNM) classification system.