A comparison study of thymectomy outcomes in young and older patients with non-thymomatous myasthenia gravis.

INTRODUCTION: The pivotal MGTX trial demonstrated that thymectomy improves outcomes in non-thymomatous myasthenia gravis (MG) while lessening the need for immunotherapy in patients aged 50 and under. However, only 17 patients aged 50 years or older were included, limiting the results' generalizability in older patients. Several recent studies have generated conflicting results. The goal of this study was to determine if thymectomy is similarly efficacious and safe in young (< 50 years) and older (≥ 50 years) patients with non-thymomatous MG. METHODS: Electronic medical records were retrospectively searched for patients diagnosed with MG that underwent thymectomy in the absence of thymoma between the years 1999-2022 at our institution. Data collected included Myasthenia Gravis Foundation of America (MGFA) classification, MG-Activities of Daily Living (MG-ADL) score, surgical approach, post-operative complications, reduction in immunosuppression, and MG exacerbation rates. RESULTS: A total of 79 patients with MG were identified; 45 in the young group and 34 in the older group. Between the groups, post-thymectomy, there was no difference in percentage of patients with improved MGFA classification (p=0.48), corticosteroid reduction (p=0.75), postoperative complications (p=0.87), cancer diagnoses (p=0.57) or autoimmune diagnoses (p=0.13). Rates of MG exacerbation (p=0.22), rescue therapy during post-thymectomy follow-up (p=0.29), MG-ADL score (p=0.84), and percentage of patients achieving minimum symptom expression at final follow-up (p=0.31) were also no different. CONCLUSIONS: In our patients, the safety and efficacy of thymectomy in those aged 50 or older with non-thymomatous MG appear comparable to that of their younger counterparts. These findings provide some support to the use of thymectomy in the management of older patients with MG.