Perioperative outcomes and long-term survival in clinically early-stage thymic malignancies: video-assisted thoracoscopic thymectomy versus open approaches

Background: Video-assisted thoracoscopic surgery (VATS) theoretically offers advantages over open thymectomy for clinically early-stage (Masaoka-Koga stage I and II) thymic malignancies. However, longterm outcomes have not been well studied. We compared the postoperative outcomes and survival from a cohort study based on the database of the Chinese Alliance for Research in Thymomas (ChART). Methods: Between 1994 and 2012, data of 1,117 patients having surgery for clinically early-stage (Masaoka-Koga stage I and II) tumors were enrolled for the study. Among them, 241 cases underwent VATS thymectomy (VATS group), while 876 cases underwent open thymectomy (Open group). Univariate analyses were used to compare the clinical character and perioperative outcomes between the two groups. And multivariate analysis was performed to determine the independent predictive factors for long-term survival. Results: Compared with the Open group, the VATS group had higher percentage of total thymectomy (80.5% vs. 73.9%, P=0.028), resection rate (98.8% vs. 88.7%, P=0.000) and less recurrence (2.9% vs. 16.0%, P=0.000). Five-year overall survival was 92% after VATS and 92% after open thymectomy, with no significant difference between the two groups (P=0.15). However, 5-year disease free survival were 92% in VATS group and 83% in Open group (P=0.011). Cox proportional hazards model revealed that WHO classification, Masaoka-Koga stage and adjuvant therapy were independent predictive factors for overall survival, while surgical approach had no significant impact on long-term outcome. Conclusions: This study suggests that VATS thymectomy is an effective approach for clinically early-stage thymic malignancies. And it may offer better perioperative outcomes, as well as equal oncological survival.