Mustafa Al-Kharsan1, Samantha Colgan1, Andrew Heim1, Long Davalos1, Matthew Varon1, Constantine Farmakidis1, Omar Jawdat1, Jeffrey Statland1, Mamatha Pasnoor1, Mazen Dimachkie1
1Neuromuscular Division, University of Kansas Medical Center
Objective:
To evaluate the risk of extrathymic malignancy in adult patients with MG who have undergone thymectomy, compared to those with MG who did not undergo the procedure at our institution.
Background:
International treatment guidelines recommend thymectomy for myasthenia gravis (MG) patients with acetylcholine receptor (AChR) antibodies under 50 years old, regardless of thymic abnormalities. However, a recent study published in the New England Journal of Medicine raised concerns about potential negative outcomes following thymectomy in adults, including increased risks of all-cause mortality, cancer, and autoimmune diseases.
Design/Methods:
We obtained IRB approval to conduct a retrospective observational analysis investigating the risk of extrathymic malignancy in MG patients who underwent thymectomy at our institution, compared to those who did not have the procedure. We datamined the Healthcare Enterprise Repository for Ontological Narration database at our institution to identify all adult patients with MG between 2012 and 2024. The primary outcome was the frequency of extrathymic malignancy in both groups. We also will compare malignancy frequency pre-thymectomy and post-thymectomy within the thymectomy group.
Results:
We identified 225 MG thymectomy cases and 225 matched MG non-thymectomy patients and present partial analysis. The baseline demographics for the thymectomy group are 60% female, mean age at diagnosis is 43 years, mean follow up duration is 14 years, mean age at thymectomy is 50 years, and pre-thymectomy malignancy is 6% and post-thymectomy new malignancy is 5%. The baseline demographics for the non-thymectomy group are 59% female, mean age at diagnosis is 50 years, mean follow up duration is 13 years, and overall malignancy is 11%. Further data abstraction and analysis are ongoing and will be presented at the annual AAN 2025 meeting.
Conclusions:
We anticipate this monocentric dataset will provide insight into the potential long-term risk of extrathymic malignancy in MG patients undergoing thymectomy.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.