Factors predicting recurrence in thymic epithelial neoplasms

Abstract

Objectives: Thymic epithelial neoplasms (TENs) represent a heterogeneous group of rare thoracic malignancies. We analysed the clinicopathological features, survival outcomes, risk factors, and patterns of recurrence in patients undergoing resection.

Methods: Records were reviewed for adult patients with TEN who underwent resection from 2006 to 2019. Survival rates were assessed using the Kaplan-Meier method. Univariable and multivariable analyses were performed using the log-rank test and Cox proportional hazards model.

Results: A total of 100 patients were analysed (51 females, median age 58 years). Thymoma was the most common histology (n = 92), followed by thymic carcinoma (n = 5) and thymic neuroendocrine tumour (n = 3). Stage II (Masaoka) tumours were most common (n = 51), followed by stage I (n = 27). World Health Organization B2/B3 was the most prominent histological subtype (n = 34). Complete resection (R0) was achieved in 91 patients: 86/92 thymoma, 4/5 thymic carcinoma and 1/3 neuroendocrine tumour. The most common treatment modality was surgery alone in 72 patients, followed by surgery and radiation therapy in 24, and adjuvant chemoradiotherapy in 3 patients. Only one patient with thymic carcinoma received neoadjuvant chemotherapy. The 10-year overall and disease-free survival rates were 86.6% and 83.9%, respectively. Recurrence was most common in neuroendocrine tumours (3/3). Risk factors for recurrence identified on multivariable analyses were: R1/2 resection (hazard ratio 9.30; 95% confidence interval 1.82-36.1), TEN subtype (hazard ratio 8.08; 95% confidence interval 1.24-34.6), and presence of lymphovascular invasion (hazard ratio 9.56; 95% confidence interval 2.56-25.8).

Conclusions: Complete resection remains critical in patients with TEN. Incomplete resection, high-risk histology, and lymphovascular invasion highlight the need for effective adjuvant modalities. Given the rarity of these diseases, emphasis must be placed on collaborative research conducted on TEN.

Keywords: Adult; Masaoka classification; Prognosis; Recurrence; Thymic cancer; Thymic neoplasms; Thymoma; Treatment outcome; World Health Organization classification.