1.Research of gene mutations and polymorphisms involved in the development of lung cancer, in particular of multiple lung adenocarcinoma. With the development of high-resolution CT in recent years, the discovery of small lung adenocarcinoma in the peripheral lung showing lepidic growth has increased. Such lesions occur frequently in female, non-smoker, and oriental as compared with traditional lung cancer, in which EGFR gene mutations are frequently found. Any environmental and genetic factors are not well established involved in the development of lung adenocarcinoma in such cases. We have investigated the genetic background of lung adenocarcinoma in non-smokers, especially of multiple adenocarcinoma in peripheral lung showing lepidic growth.

2.Association of DNA methylation abnormalities with prognosis and clinicopathological features and carcinogenesis of lung cancer and thymoma. DNA methylation is known to play an important role in carcinogenesis and cancer progression. We have quantitatively evaluated the methylation of the promoter region of a variety of the tumor suppressor genes and the genome-wide methylation rate of lung cancer and thymic tumors, and analyzed their association with carcinogenesis, prognosis and the therapeutic effect.

3.Detection of Epithelial-Mesenchymal transition of lung cancer cell and prognosis and therapeutic application. 　In recent years, with the development of lung preserved surgery, it has become necessary to evaluate the potential of lymph node metastasis based on the CT findings and pathological features of lung cancer. Epithelial-Mesenchymal transition (EMT) is seen during invasion and metastasis of cancer cells. We have evaluated the EMT using immunostaining and molecular techniques. Furthermore, we have studied molecular analysis focusing on the degeneration of the alveolar basement membrane during transition of preinvasive lesion (AAH, CIS) into invasive cancer.

4.Clarification of recurrence risk factors in adjuvant chemotherapy group, the study of polymorphism and genetic mutations involved in anticancer drug sensitivity. Today, doing adjuvant chemotherapy for patients with postsurgical stage IB or more and postsurgical stage IA tumor diameter greater than 2cm of non-small cell lung cancer after radical surgery has become the standard (lung cancer guidelines; Grade B). A detailed analysis to predict the benefit from adjuvant chemotherapy is not enough. In our department, we have been researching the molecular recurrence risk markers to determine the indications for treatment in the future. We are also cooperating with the department of respiratory medicine to analyze genetic mutation and polymorphisms which contribute to calculate their chemosensitivity in unresectable lung cancer cases and postoperative recurrence cases, and conducting research in order to establish a tailor-made treatment of lung cancer in the future.