The incidence and prognosis of thymic squamous cell carcinoma

Abstract

Background: Thymic carcinoma represents a rare type of malignant mediastinal tumor and has been the subject of controversy. Although independent prognostic factors related to thymic carcinoma have been investigated previously, few studies have focused specifically on the survival outcomes associated with thymic squamous cell carcinoma (TSCC). This study aims at presenting a survival analysis in this rare malignant disease at population level. Methods: We extracted the data of 216 patients with TSCC recorded from 1973 to 2015 from the Surveillance, Epidemiology, and End Results (SEER) database of the National Cancer Institute. The patients’ demographic features, clinical traits, and treatment factors were analyzed in order to identify prognostic factors, which correlate overall survival using the Kaplan–Meier method as well as a multivariate Cox regression model, for TSCC. Results: The majority of patients were male, Caucasian, married, and insured. Furthermore, 58.3%, 54.6%, and 59.7% of patients TSCC underwent surgery, radiotherapy, and chemotherapy respectively. In a multivariate analysis, age of diagnosis (hazard ratio [HR]: 1.022, 95% confidence interval [CI]: 1.003–1.040, P = .020), surgical treatment (HR: 0.282, 95% CI: 0.164–0.484, P = .000), and stage (regional vs distant HR: 0.532, 95% CI: 0.324–0.872, P = .013; localized vs distant HR: 0.297, 95% CI: 0.133–0.664, P = .003) correlated with increased overall survival, whereas adjuvant therapy, including chemotherapy and radiotherapy, did not correlate with survival. Among surgically treated patients, age of diagnosis and stage were associated with better overall survival, while chemotherapy and radiotherapy did not contribute significantly to overall survival. Conclusion: Surgery, age of diagnosis, and stage were associated with better overall survival among TSCC.

Identification of predictors of long‐term survival and prognostic outcomes in thymic squamous cell carcinoma: A real‐world study

“…The primary characteristics of TSCC patients in our study were that most were male, diagnosed when middle‐aged, and exhibited an insidious disease onset with rare comorbidity of MG. These characteristics were consistent with those found in other studies on TSCC patients 8,12,14 …”

“…These characteristics were consistent with those found in other studies on TSCC patients. 8,12,14 The Masaoka system is the most commonly used tool when staging TETs. However, the use of this system in assessing thymic carcinoma remains controversial.…”

“…This has the potential of inducing bias in the findings due to differences in the characteristics of the subtypes, resulting in misleading study conclusions 13 . We are only aware of three large‐scale studies that have examined the optimal treatments and prognostic factors associated with TSCC 8,12,14 . The results of these studies were inconsistent, leading to difficulties in clinical decision‐making.…”

“…13 We are only aware of three large-scale studies that have examined the optimal treatments and prognostic factors associated with TSCC. 8,12,14 The results of these studies were inconsistent, leading to difficulties in clinical decision-making.…”

Thymic epithelial tumours: histopathological classification and differential diagnosis

“…In the anterior mediastinum, thymic carcinomas are the fourth most common solitary lesions after thymomas, benign cysts, and lymphomas 91 . Like other carcinomas, they tend to occur in a slightly higher age group than thymomas (median age 54–65.5 years), but with a broad age range (12–96 years old) and a male predominance 52,90‐97 . They are usually invasive, with an aggressive course of disease, and often present at advanced stages (most patients presenting at TNM stage III, IVA, or IVB, with lymph node metastases in 1/3 at presentation), with a median time to death (3 years) considerably shorter than in thymomas 48,89‐92,97 .…”