Limited thymectomy as a potential alternative treatment option for early-stage thymoma: A multi-institutional propensity-matched study

Abstract

Objectives: For early-stage thymoma, complete thymectomy has classically been regarded as the standard treatment protocol. However, several studies have shown that limited thymectomy may be an alternative treatment option for thymoma. This study compared perioperative outcomes, survival, and recurrence rates between patients undergoing limited thymectomy and complete thymectomy.

Materials and methods: Between January 2000 and December 2013, a total of 762 patients underwent thymectomy for stage I or II thymomas at four institutions participating in the Korean Association for Research on the Thymus. Patients were divided into two groups: limited thymectomy group (n=295) and complete thymectomy group (n=467). Comparative clinicopathological, surgical, and oncological features were reviewed retrospectively.

Results: The median follow-up time was 49 months (range: 0.2-189 months). A propensity score-matching analysis, based on seven variables (age, sex, surgical approach, tumor size, WHO histological type, Masaoka-Koga stage, and adjuvant radiotherapy), was performed using 141 patients selected from each group. The 5- and 10-year freedom-from-recurrence rates in the limited thymectomy group were 96.3% and 89.7%, respectively, and those in the complete thymectomy group were 97.0% and 85.0%, respectively. No significant differences in these rates were observed between groups (p=0.86). A multivariate Cox regression analysis showed that overall survival and freedom-from-recurrence rates did not significantly differ by surgery extent (p=0.27, 0.66, respectively). Perioperative outcomes were better in the limited thymectomy group.

Conclusion: Limited thymectomy was not inferior to complete thymectomy with respect to recurrence, and had better perioperative outcomes. Limited thymectomy may be a viable treatment option for early-stage thymoma.

Keywords: Complete thymectomy; Limited thymectomy; Recurrence; Thymectomy; Thymoma; Thymomectomy.