# Should minimally invasive surgery be the standard approach for early-stage thymoma? A 20-year experience

## TL;DR

This study examines whether minimally invasive surgery is as effective as open surgery for early-stage thymoma, finding it has fewer complications but possibly higher recurrence risks.

## Contribution

The study provides a 20-year analysis of surgical approaches for early-stage thymoma, comparing outcomes between minimally invasive and open surgery.

## Key findings

- Minimally invasive surgery is associated with lower blood loss, fewer complications, and shorter hospital stays compared to open surgery.
- The recurrence risk appears slightly higher with minimally invasive surgery, though the difference is not statistically significant.
- The use of minimally invasive surgery for thymoma has increased significantly over the past two decades.

## Abstract

Minimally invasive surgery (MIS) has become the prevailing technique for resecting early-stage thymoma; however, studies evaluating the oncologic impact of this evolution are lacking. This study aimed to characterize the transition from open surgery to MIS and to evaluate outcomes.

This was a retrospective, single-institution review of resections performed for pathologic TNM stage I-II thymomas between January 2000 and September 2023. The relationships between factors and recurrence were quantified using competing risk regression before and after applying overlap propensity score weights.

A total of 296 patients were identified, including 118 who underwent open surgery and 178 who underwent MIS (25 with video-assisted thoracic surgery and 153 with robotic-assisted thoracic surgery). Open surgery composed the vast majority of cases (92.3%) performed between 2000 and 2009, compared to 26.7% between 2010 and 2023 (P < .0001). Median blood loss (125 mL vs 25 mL; P < .0001), tumor dimension (6.5 cm vs 4.1 cm; P < .0001), rate of major complications (35% vs 16%; P = .003), and length of stay (LOS; 4 days vs 2 days; P < .0001) were significantly greater in the open surgery cohort. Eighteen patients developed recurrence (open, n = 12; MIS, n = 6). Univariable analyses revealed that World Health Organization class (P < .001), higher TNM (P = .043) and Masaoka-Koga stage (P = .017), and R1/R2 resection (P < .001) were associated with a greater risk of recurrence. Overlap propensity score weighting revealed a cumulative incidence of recurrence at 5 years of 5.1% (95% confidence interval [CI], 0.97%-9.2%) for open surgery (n = 47) compared to 7.1% (95% CI, 2.0%-12.9%) for MIS (n = 47), a non-statistically significant difference.

MIS has become the principal approach for resecting early-stage thymoma over the last 2 decades. MIS is associated with a lower complication rate and shorter LOS but may be associated with a higher risk of recurrence in certain situations. Larger studies to evaluate the appropriate role of MIS are warranted.