Abstract
BACKGROUND: Thymic epithelial tumors (TETs) are rare tumors and the provided care is not standardized. This study describes the population of TET patients in the Netherlands, diagnosed between 2017 and 2023, registered by the Dutch Cancer Registry (NKR). The aim of this study was to analyze changing care patterns for TET patients and differences between high- and low-volume centers regarding surgery and outcome. METHODS: All patients with a new diagnosis of TET between 2017 and 2023 were selected from the NKR database. Data on patient characteristics, staging, treatment and survival were collected and analyzed. Chi-squared test and log-rank test was used to determine differences between high- and low-volume centers. High-volume center was defined as >10 TET surgeries a year. RESULTS: In total, 965 patients were included. The crude incidence rate of TETs was 7.3/1,000,000. This was 6.1/1,000,000 for thymoma and 1.2/1,000,000 for thymic carcinoma. The mean age was 62.1 years with SD 13.2 and the male:female ratio was 1.15. Surgery was performed in 721 (74.7%) patients, 154 (16%) patients had radiotherapy and 163 (16.9%) patients had chemotherapy. The most commonly used chemotherapy regimen consisted of doxorubicin with cyclophosphamide and cisplatin. In 90 patients no treatment was given for various reasons. Surgery was performed in 25 centers throughout the Netherlands; two were high-volume centers. The number of incomplete resections (R1 and R2) was significantly lower in high-volume centers (9.8%) than in low-volume centers (17.4%) (P=0.02) (Table 1). Survival was significantly higher when resection was complete (P=0.01). Median survival was not reached, 5-year survival was 89% in R0, 82% in R1 and 73% in R2 resections. CONCLUSIONS: This study describes the population of TET patients in the Netherlands and changing care patterns. The number of incomplete resections was significantly lower in high-volume hospitals compared to low-volume. Moreover, complete resection was associated with improved survival. Therefore, centralization of TET care is recommended.