Surgical outcomes of 215 patients with thymic epithelial tumors: A single-center experience.

Objectives: To evaluate the oncological prognosis and neurological outcomes for patients with thymic epithelial tumors (TETs) after thymectomy.

Methods: Consecutive patients with TETs who underwent thymectomy at Beijing Hospital from January 2011 to December 2018 were retrospectively enrolled into the study. Clinical, pathological, and perioperative data was collected. Patients were followed-up by telephone interview and outpatient records. Statistical analyses were performed using SPSS version 19.0.

Results: A total of 215 patients (115 men and 100 women) were included in this study of which 133 patients (61.9%) had TETs associated with myasthenia gravis (MG), and 82 patients (38.1%) had thymic tumors without MG. A total of 194 (90.2%) patients were successfully followed-up. The median follow-up period was 42 months. The five-year overall survival (OS) rate was 88.6%. MG was the first cause of death for patients with MG (6/10). Prognosis in MG patients was similar to those without MG. Multivariate Cox regression analysis demonstrated that TNM stage III + IV was an independent risk factor for OS. Incomplete resection and younger age were risk factors for tumor recurrence. For patients with MG, the cumulative complete stable remission (CSR) rate increased with the postoperative follow-up period, and the five-year CSR rate was 44.7%. Univariate Cox analysis indicated that age, preoperative MG duration and preoperative medication might correlate with CSR. Multivariate Cox analysis only indicated older age as a negative factor of achieving CSR.

Conclusions: MG had little influence on OS and tumor recurrence of thymic tumors. The new TNM staging system was an independent prognostic factor. Incomplete resection and younger age were risk factors for tumor recurrence. Older age was a negative factor of achieving CSR for thymoma patients with MG after extended thymectomy.

Key Points: Significant findings of the study MG was not a prognostic factor for thymic tumors. The new TNM staging system was useful for prediction of prognosis. Incomplete resection and younger age were risk factors for tumor recurrence. Older age led to a lower probability of achieving CSR for thymomatous MG. What this study adds This study had a relatively large sample size of patients with thymic epithelial tumors in a single center. We evaluated not only the oncological prognosis, but also neurological outcomes after thymectomy, which was a more comprehensive assessment of surgical effect for thymic epithelial tumors.