Masatsugu Hamaji1, Takashi Sozu2, Ryunosuke Machida3, Shun-Ichi Watanabe4, Kazuo Yoshida5, Shinichi Toyooka6, Masayuki Tanahashi7, Kazuya Kondo8, Hirotoshi Horio9, Meinoshin Okumura10, Hiroshi Date1. 1. Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 2. Department of Information and Computer Technology, Faculty of Engineering, Tokyo University of Science, Tokyo, Japan. 3. Biostatistics Division, Center for Research Administration and Support, National Cancer Center, Tokyo, Japan. 4. Department of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan. 5. Department of Thoracic Surgery, Shinshu University School of Medicine, Nagano, Japan. 6. Department of Thoracic, Breast and Endocrinological Surgery, Okayama University Graduate School of Medicine Dentistry and Pharmaceutical Sciences, Okayama, Japan. 7. Division of Thoracic Surgery, Respiratory Disease Center, Seirei Mikatahara General Hospital, Shizuoka, Japan. 8. Department of Oncological Medical Services, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan. 9. Department of Thoracic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan. 10. National Hospital Organization Toneyama Hospital, Osaka, Japan.
Abstract
OBJECTIVES: To identify risk factors associated with extrathymic malignancy-related mortality after thymic epithelial tumour resection. METHODS: The Japanese Association for Research on the Thymus database registered the records of 2835 patients collected from 32 Japanese institutions from 1991 to 2010. The cumulative incidence function of death due to extrathymic malignancies or recurrence was calculated, with other causes of death as competing risks. Relevant risk factors associated with extrathymic malignancy-related deaths in patients with thymoma were evaluated using the Fine and Gray model. RESULTS: In total, 2701 patients were eligible for the analysis (thymoma, 2374; thymic carcinoma, 273; thymic neuroendocrine tumour, 54). The median follow-up period was 4.6 years. The cumulative incidence function of death due to extrathymic malignancies at 10 years was 2.2% (3.2% due to recurrence) in patients with thymoma, 1.6% (38.6% due to recurrence) in patients with thymic carcinoma and 0% (36.6% due to recurrence) in patients with thymic neuroendocrine tumour. In the multivariable analysis, age (every 10 years) at thymectomy [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.53-3.14; P < 0.001], male gender (HR 2.62, 95% CI 1.19-5.77; P = 0.017) and previous malignancies (HR 3.09, 95% CI 1.18-8.11; P = 0.022) were significant factors for death due to extrathymic malignancies after thymectomy. CONCLUSIONS: Continued management and early detection of extrathymic malignancies may improve survival of patients with thymoma who are male, of advanced age, or have previous malignancies. Prospective studies are required to further investigate the management of extrathymic malignancies.
OBJECTIVES: To identify risk factors associated with extrathymic malignancy-related mortality after thymic epithelial tumour resection. METHODS: The Japanese Association for Research on the Thymus database registered the records of 2835 patients collected from 32 Japanese institutions from 1991 to 2010. The cumulative incidence function of death due to extrathymic malignancies or recurrence was calculated, with other causes of death as competing risks. Relevant risk factors associated with extrathymic malignancy-related deaths in patients with thymoma were evaluated using the Fine and Gray model. RESULTS: In total, 2701 patients were eligible for the analysis (thymoma, 2374; thymic carcinoma, 273; thymic neuroendocrine tumour, 54). The median follow-up period was 4.6 years. The cumulative incidence function of death due to extrathymic malignancies at 10 years was 2.2% (3.2% due to recurrence) in patients with thymoma, 1.6% (38.6% due to recurrence) in patients with thymic carcinoma and 0% (36.6% due to recurrence) in patients with thymic neuroendocrine tumour. In the multivariable analysis, age (every 10 years) at thymectomy [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.53-3.14; P < 0.001], male gender (HR 2.62, 95% CI 1.19-5.77; P = 0.017) and previous malignancies (HR 3.09, 95% CI 1.18-8.11; P = 0.022) were significant factors for death due to extrathymic malignancies after thymectomy. CONCLUSIONS: Continued management and early detection of extrathymic malignancies may improve survival of patients with thymoma who are male, of advanced age, or have previous malignancies. Prospective studies are required to further investigate the management of extrathymic malignancies.