Intermediate-term oncologic outcomes of patients with large-sized early-stage thymomas after robotic thymectomy: a single-institute experience

Background:

Data on oncologic outcome of patients with large thymomas undergoing robotic thymectomy are limited. This study aims to investigate the safety and efficacy of robotic thymectomy in patients with a large-sized early-stage thymoma, compared to those with a small-sized one.

Material and method:

Patients with an early-stage thymoma who underwent robotic thymectomy between January 2003 and December 2017 were retrospectively reviewed for inclusion and categorized into two groups for further analyses: large-sized thymoma (LST) group (≥4 cm) and small-sized thymoma (SST) group (< 4 cm). The main outcomes were perioperative outcomes and intermediate-term oncologic outcomes.

Result:

Eighty-one patients (43 women and 38 men) with an early-stage thymoma (35 Masaoka-Koga stage I and 46 stage II) were eligible for inclusion. The median size of the tumor was 6.2 (4 – 13.8)cm for the LST group (n = 39) and 2.9 (1 – 3.7)cm for the SST group (n = 42). The median follow-up period was 40 (12 – 155) months (LST, 30 [12 – 154]; SST, 51.5 [12 – 155]). There were no significant differences between the two groups in terms of the patients' characteristics, surgical margin status and perioperative morbidity and mortality. No recurrence was identified in the entire cohort, but two patients died of non-thymoma associated conditions (myasthenia gravis crisis and myocardial infarction respectively). The estimated 5-year overall survival rate was 96.1% for the entire cohort, there were no significant differences between the two groups (LST, 100%; SST, 93.3%).

Conclusion:

The perioperative and intermediate-term oncologic outcomes of patients with an early-stage thymoma of 4 cm and larger after robotic thymectomy are similar to that of those with an early-stage thymoma smaller than 4 cm.