Total thymectomy is oncologically superior to partial thymectomy in patients with thymic carcinoma: insights from a multicenter real-world data analysis.

Background: Although total thymectomy has been the standard surgical approach for thymic epithelial tumors, an increasing number of recent reports suggest that partial thymectomy for early-stage thymomas may yield outcomes comparable to those of total thymectomy. However, whether partial thymectomy is a viable alternative for thymic carcinoma remains unclear.

Materials and methods: A total of 106 patients with thymic carcinoma underwent curative intended resection at 19 institutions between January 2010 and December 2021. Excluding 14 patients with incomplete resection, 92 patients with thymic carcinoma who underwent total (n = 73) or partial thymectomy (n = 19) were compared. Overall survival (OS) and recurrence-free survival (RFS) were analyzed using Kaplan-Meier curves and Cox proportional hazard models. Overlap weighting was applied to adjust for potential confounding factors.

Results: Among patients with clinical-stage I disease, 79.3% were upstaged to stage II or higher postoperatively. Unadjusted analyses revealed no statistically significant differences in OS and RFS between the total and partial thymectomy groups, although a trend toward poorer outcomes in the partial thymectomy group was observed. After overlap weighting, partial thymectomy was associated with significantly poorer OS (p = 0.0027) and higher recurrence risk (p < 0.0001). Early postoperative recurrence occurred more frequently in the partial thymectomy group.

Conclusion: Partial thymectomy was associated with significantly worse survival and recurrence outcomes in thymic carcinoma. Given the limitations of preoperative diagnosis, total thymectomy should remain the preferred surgical approach for undiagnosed thymic epithelial tumors to achieve optimal oncologic control and minimize the risk of recurrence.