Abstract
Background: Neoadjuvant chemotherapy is generally recommended for locally advanced, potentially resectable thymic epithelial tumors. However, neoadjuvant chemoradiotherapy has been proposed as an alternative approach, potentially achieving higher complete resection rates. In this study, a retrospective analysis was conducted to compare the outcomes of neoadjuvant chemoradiotherapy (NCRT) and neoadjuvant chemotherapy (NCT). Methods: From 2009 to 2022, a total of 98 patients who underwent surgery following either NCRT (n = 30) or NCT (n = 68) for thymic epithelial tumors were included in this study. Propensity score matching was applied, resulting in two matched groups of 30 patients each. The primary endpoint was the comparison of complete (R0) resection rates between the groups. Results: In the matched cohort, the R0 resection rate was significantly higher in the NCRT group (93.3%) compared to the NCT group (73.3%; p = 0.038). The tumor regression grade was also significantly lower in the NCRT group (p = 0.002). However, no significant difference was observed in 5-year overall survival between the groups, either in patients with thymoma (100% for NCRT vs. 90.9% for NCT; p = 0.34) or thymic carcinoma (74.3% for NCRT vs. 63.2% for NCT; p = 0.82). For patients with initial local recurrence, both the 5-year overall survival and post-recurrence survival rates were 100%. Conclusions: The neoadjuvant chemoradiotherapy group demonstrated superior local control, as evidenced by improved tumor regression grades and complete resection rates. However, the absence of corresponding improvement in overall survival warrants further investigation with a larger patient cohort and a longer follow-up period.