Prognostic Factors in Thymic Cancer: Insights From a Systematic Literature Review

OBJECTIVES: Thymic cancer, a rare malignancy originating from the thymus gland, poses unique challenges in terms of diagnosis, treatment, and prognosis. Despite its rarity, the incidence of thymic cancer has been steadily increasing in recent years, necessitating a comprehensive understanding of prognostic factors to guide clinical decision-making and improve patient outcomes. The current systematic literature review (SLR) aims to provide a holistic overview of prognostic factors associated with thymic cancer outcomes.

METHODS: Electronic databases such as Embase^® and Medline^® were searched using a combination of relevant keywords related to prognosis and thymic cancer. Articles published in the last ten years in the English language that were specific to the United States and investigated prognostic factors in thymic cancer were included. Two independent reviewers collected data, and a third independent reviewer performed a quality check. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to ensure methodological rigor.

RESULTS: Three relevant studies were identified after screening 725 citations. Findings revealed that in the multivariable analysis, complete resection (N=2 studies) and radiation therapy (N=1) were positively associated with prolonged overall survival (OS). While the presence of lymph nodes (N=2), advanced disease stage (N=2), larger tumor size (N=1), and distant metastasis (N=1) negatively correlated with OS. Pathologic stage IVa (vs. I/II/IIa/IIb), radiation therapy (no vs. yes), and female gender were associated with shortened recurrence-free survival. Larger tumor size was also associated with worsened disease-specific survival.

CONCLUSIONS: Complete resection and radiation therapy improved survival, while advanced disease stage, larger tumor size, and distant metastases worsened outcomes in thymic cancer patients. Although this SLR provides valuable insights into prognostic factors in thymic cancer in the US, the identified data paucity underscores the imperative need for further well-designed studies to comprehensively elucidate the complex landscape of thymic cancer prognosis.