Thymic Cancer

Epidemiology: Thymus cancers are rare heterogeneous group of malignancies that account for an incidence of 1.5 cases/100,000 each year in the US. In accordance with the SEER database, 13,586 new cases were reported with thymus cancer in the US, for the years 2001–2015 [1]. The number of new cases for different subtypes of thymic cancer in the US, for the years 2001–2015, include thymoma (9041 cases, 66.3% of total thymic cancers), thymic carcinoma (2772 cases, 20.4% of total thymic cancers), thymic neuroendocrine tumors (TNET) (481 cases, 3.5% of total thymic cancers), and other types of tumors (1319 cases, 9.7% of total thymic cancers) [1]. The cumulative SEER 5-year survival rates of thymoma, thymic carcinoma, and thymic NET were 90%, 55%, and 28–75%, respectively [2]. The peak incidence for thymus cancers was observed in the age group of 70–74 years (1.06 cases/100,000) [1]. The peak incidence was reported at a slightly younger age group in thymic NET (60–74-year-old age group) when compared to thymic carcinoma (70–74 years of age) and thymoma (70–79 years of age) [1]. The median age of diagnosis was 65.5 years during 2009–2015 (range include 16–96 years of age) [3]. In the US, thymic cancers occur more often in males (66%) compared to females (34%) [3].