Clinical characteristics and prognosis of primary thymic adenocarcinoma: A single-center retrospective analysis.

Background: Primary thymic adenocarcinoma (PTAC) is an extremely rare disease with a poor prognosis. In the present study, we sought to analyze the clinical characteristics and prognostic factors of patients with PTAC.

Methods: A total of 14 patients with PTAC treated at our center from January 2000 to January 2019 were included in this study. We retrospectively collected information on sex, age, history of smoking, family history of cancer, comorbidities, symptoms, imaging tests, serum tumor marker levels, tumor, node, metastasis (TNM) staging, and treatment records. Follow-up information was obtained by telephone interviews or outpatient clinic visit. Univariate and multivariate Cox regression analyses were performed to investigate the clinicopathological factors associated with survival.

Results: Among 14 patients with PTAC, there were five males and nine females, with an average age of 48.7 ± 9.3 years. A total of 23.1% of the patients had a history of smoking. The clinical symptoms of the patients were nonspecific and seven patients had elevated levels of serum tumor markers. Surgery was performed for nine patients, among which only four received R0 resection. The median survival time of the 14 patients was 16.0 months, and the 1-, 3- and 5-year survival rates were 57.1%, 35.7% and 21.4%, respectively. TNM stage was identified as an independent prognostic factor for PTAC patients (the median survival time of stage I-IIIA vs. stage IV was 44.0 months vs. 9.0 months, p = 0.002).

Conclusions: PTAC is highly aggressive malignancy with poor prognosis. Surgical treatment is feasible, but R0 resection is challenging. TNM staging is significantly associated with patient survival.