Thymic Carcinomas and Second Malignancies: A Single-Center Review

Abstract

Thymic carcinomas account for less than 0.01% of new cancer diagnoses annually and are more aggressive than thymomas. Autoimmune disorders have been associated with thymomas and only recently with thymic carcinomas. Second malignancies are well described after thymomas. The aim of this study was to analyze the incidence of second malignancies in patients with thymic carcinomas. All cases of thymic carcinomas were identified from the pathology archives of Indiana University. Histological materials were reviewed and further correlated with clinical data to identify incidence of second cancers in patients with thymic carcinomas. Histological material was available for review in 92 cases of thymic carcinoma. Clinical data were available for 85 patients. Fourteen of these (16.5%) patients had a second malignancy; these included small cell lung carcinoma, “testicular cancer”, embryonal carcinoma, seminoma, breast carcinoma (two cases), prostatic adenocarcinoma, Hodgkin’s lymphoma, thyroid carcinoma, bladder carcinoma (two cases), renal cell carcinoma, and melanoma. The latter could precede, be concurrent with, or follow the diagnosis thymic carcinoma. The incidence of second cancers in patients with thymic carcinomas is similar to that reported for thymomas. Abnormalities in immunological surveillance may be responsible for this high incidence of second malignancies in thymic tumors.

SEOM-GECP-GETTHI Clinical Guidelines for the treatment of patients with thymic epithelial tumours (2021)

“…However, a higher incidence of TETs has been reported in multiple endocrine neoplasia type 1 [ 6 ]. Similarly, in patients with TET, several studies have documented rates of second malignancies ranging from 8 to 31%, particularly thymomas [ 7 ]. The prognosis of TET correlates with the histological subtype, with a 5-year overall survival (OS) of ~ 80% and ~ 45% for T and TC, respectively [ 8 ].…”

Incidence of second malignancies in patients with thymic carcinoma and thymic neuroendocrine tumor

“…Previous studies have revealed the association between the incidence of second malignant tumors and thymoma (LeGolvan and Abell 1977 ; Gray and Gutowski 1979 ; Lewis et al 1987 ; Couture and Mountain 1990 ; Wilkins et al 1999 ; Welsh et al 2000 ); because thymic carcinoma and thymic NET are rare, there are few studies on second malignancies arising after diagnosis. Badve suggested that 14 of 85 patients had a second malignancy including embryonal carcinoma, prostatic adenocarcinoma, small cell lung carcinoma, bladder carcinoma, testicular cancer, and so on (Badve et al 2021 ). Hamaji found that the thymic carcinoma patients have a lower cumulative incidence of a second malignancy than thymoma patients.…”