JLCS medical practice guidelines for thymic tumors: summary of recommendations

The Guideline Committee of the Japan Lung Cancer Society (JLCS) for Thymic Tumors published the Medical Practice Guideline for Thymic Tumors in Japanese as Chapter 3 of the Medical Practice Guidelines for Lung Cancers according to evidence-based medicine in December 2016. This medical practice guideline is the first for thymic epithelial tumors in Japan, and comprises a set of recommendations covering clinical diagnosis, treatment and pathological diagnosis. Thymic epithelial tumors include thymoma, thymic carcinoma and thymic neuroendocrine tumor. The recommendations for clinical diagnosis concern detection of the symptoms, blood and serum tests according to clinical presentation, essential imaging for differential diagnosis and staging, and the necessity and methods of definitive diagnosis. The recommendations for treatment are dependent on tumor stage and recurrence status, and the treatment modalities included surgery, radiation therapy, chemotherapy and multimodality therapy. Those for pathological diagnosis deal with the handing methods of resected specimen and essential reporting contents for pathological diagnosis. Since data from large-scale analyses or clinical studies of thymic epithelial tumor are limited due to its low prevalence, the relevant recommendations and grading were based on available reported evidence and expert opinions as well as diagnostic methods and treatments commonly used in Japan. This report summarizes the recommendations concerning each topic addressed by this JLCS guideline for thymic tumors.