Objective:

To determine if thymectomy is equally effective and safe in young and elderly patients with non-thymomatous myasthenia gravis (MG).

Background:

The efficacy of thymectomy in non-thymomatous MG was demonstrated by positive results from the pivotal MGTX trial in MG patients aged <50 years. However, the MGTX trial included only 17 myasthenic patients aged ≥50 years, thus limiting the generalization of its results in the older population. 

Design/Methods:

Electronic medical records were retrospectively searched for non-thymomatous MG patients undergoing thymectomy between the years of 1999-2022 at our institution. Data including antibody status, Myasthenia Gravis Foundation of America (MGFA) classification prior to surgery, treatments at time of surgery, clinical improvement, reduction in immunosuppression, MG exacerbations, post-operative complications, and development of cancer or autoimmune diseases following surgery were collected.

Results:

The study identified 79 MG patients; 45 were <50 years (mean=31.7 years; range=18-39 years) and 34 were ≥50 years (mean=60.3 years; range=50-69 years) at time of thymectomy. The median follow-up time post-thymectomy was 6 years in patients aged <50 years and 3.2 years in the group ≥50 years. Between the two age groups, post-thymectomy, there was no difference in percentage of patients with improved MGFA classification (p=0.48), reduction in corticosteroid dose (p=0.75), timing of earliest corticosteroid reduction (p=0.68), reduction in number of MG therapies (p=0.53), MG exacerbation (p=0.52), postoperative complications (p=0.87), diagnosis of cancer (p=0.57), or autoimmune disease (p=0.13). MG-activity of daily living score was available (median 1, range = 1-10) at the last visit for 28 patients in the elderly group, with 15 of 28 (53.6%) achieving a statue of minimal symptomatic expression.   

Conclusions:

The efficacy and safety of thymectomy in elderly patients with non-thymomatous MG is similar to that of their younger counterparts. These findings support the use of thymectomy in the management of elderly patients with MG.