Thymoma resection and myasthenia gravis: what is the neurological outcome in patients older than 65 years?

ABSTRACT

To increase the neurological results in patients older than 65 years with myasthenia gravis after thymectomy, we retrospectively analysed this outcome in a large bicentric cohort of patients with myasthenia gravis (MG)years, for which surgery was indicated for a concurrent thymoma. From 1/2000 to 2/2022, 502 patients underwent thymectomy for thymic epithelial tumours (TETs) in two high-volume Institutions (167aged more than 65 years). Among them, 66 patients were affected by TET and MG, representing our final study group. The mean age for MG onset was 68.3 ± 6 years.At surgery, the Osserman score 2 was the most diffuse in our cohort (43, 65.1%), followed by 1 (20, 30.3%). In 11 cases, the MG diagnosis coincided with thymoma diagnosis. In the other cases, the interval between MG diagnosis and surgery was 1.7 years ± 1.9. The most common surgical approach was sternotomy (41,62.1%), followed by RATS (14,21.2%). The most frequent TNM stage was T1N0 (75.7%) and most patients had WHO type-B tumour. After radical thymectomy, 58 patients (88%) reported a significant neurological improvement. According to MGFA-PIS, after surgery we had 4 (6%) complete stable remission, 11 (16.7%) pharmacological remission, 43 (65.2%) minimal manifestation, 2 (3%) worsening/death for MG, and 5 (7.6%) unchanged. No association was found between neurological outcome and age of MG onset, kind of pharmacological therapy before surgery, surgical approach (sternotomy vs others), tumour dimension, the ITMIG stage and the preoperative Osserman score. For MG and thymoma-afftected patients over 65 years, thymectomy seems to be an effective treatment to improve neurological symptoms. We suggest to set up clinical trials to explore the neurological efficacy of mini-invasive thymectomy in clinically selected MG patients aged over 65 years.