The comparison of predictive factors regarding prognoses and invasion of thymic neuroendocrine tumors preoperatively and postoperatively

Abstract

Background: Thymic neuroendocrine tumors (TNT), in the anterior mediastinum, are extremely rare diseases which have significantly poor prognoses. Studies have rarely provided conclusive evidence of the prognostic factors of TNT. Standard therapies have been controversial.

Methods: TNT patients (n=173) were enrolled from Surveillance, Epidemiology and End Results database (SEER). Univariate and multivariate analyses were utilized to evaluate predictive factors of prognoses. Logistic regression analysis was used to assess the plausible correlation between histological grade, and cancer invasion. Stratification analysis was used to evaluate the effectiveness of adjuvant therapies.

Results: According to our analysis, local Masaoka stage, surgery, radiotherapy, and non-chemotherapy predicted better overall survival (OS) (P<0.05, for all) in 173 TNT patients. We found that the higher the histological grade of the tumor, the greater the rate of metastasis (P<0.05). The focus was on 125 surgically treated patients, who were females with poor prognostic factors of OS, upgraded histological grade, and advanced Masaoka stage (P<0.01, for all). The effectiveness of radiotherapy treatments had discrepancies at different clinical stages. In the local stage, radiotherapy caused significantly worse OS (P=0.011), while in the advanced stage, patients demonstrated significantly better OS with this treatment (P=0.028). Chemotherapy caused worse OS, primarily, in females (P=0.028).

Conclusions: Surgery, Masaoka stage, and adjuvant treatments were prognostic factors. With surgically treated TNT, gender, histological grade, and Masaoka stage predicted significantly worse OS. Chemotherapy decreased female patients' OS. Radiotherapy significantly promoted advanced and local advanced patients' OS; however, it decreased local stage patients' OS. Predicted TNT invasiveness significantly correlated with histological grade.

Keywords: Chemotherapy; neuroendocrine tumors (NETs); prognoses; radiotherapy; surgery.

Figure 1

Overall survival curves of TNT according to: (A) male and female patients; (B) patients in different clinical stages; (C) patients with and without surgery; (D) patients with and without chemotherapy. TNT, thymic neuroendocrine tumors.

Figure 2

Postoperative survival curves. (A,B) Postoperative survival curves with or without radiotherapy in clinical stage I (A) and II–IV (B); (C,D) postoperative survival curves with or without chemotherapy for male (C) and female (D) patients.