Lambert-Eaton myasthenic syndrome (LEMS) that’s not associated with cancer is associated with early onset of the disease, but it does not have an impact on the long-term survival of patients, according to researchers.
These findings are from a large-scale study conducted by Duke Myasthenia Gravis Clinic researchers. The team investigated the clinical characteristics and long-term survival of LEMS patients who were followed in the Duke clinic between January 1980 and December 2015.
Results of the study are the subject of a poster presentation at the 2018 American Academy of Neurology (AAN) Annual Meeting, April 21-27 in Los Angeles. The poster is titled “Lambert-Eaton Myasthenia With and Without Cancer: Clinical Characteristics and Long-term Survival.”
LEMS is an autoimmune disorder caused by the abnormal interaction between nerve cells and muscles. Overproduction and accumulation of antibodies will block the electrical signals of nerve cells, preventing muscles cells from receiving them.
The clinical data of 126 patients was collected from the Duke Myasthenia Gravis Clinic database and systematically reviewed.
About 44% of the patients were found to have cancer-associated LEMS, of whom 49% were females. Among the 71 cases without cancer, 58% were females. Patients without cancer were found to have earlier symptoms manifestation, with a mean onset age of 48, compared to 63 in the LEMS patients with cancer.
Significantly more patients with cancer-associated LEMS were found to have a history of smoking tobacco than those without cancer. Both groups of patients were found to have a similar incidence of secondary autoimmune disorders.
Patients without cancer were found to have similar survival rates at five, 10, 15, and 20 years compared to the general public, as reported in the 2013 National Vital Statistics Report. But when compared to the group of LEMS patients with cancer, a significant difference in survival probabilities was reported.
Smoking was not found to change the long-term survival of patients with LEMS who did not have cancer.
“Although virtually all patients with cancer had a history of smoking, a smoking history did not significantly affect long-term survival in LEM patients without cancer,” researchers wrote.
Results of the study indicate that “compared to LEM patients with cancer, a slightly higher proportion of those without cancer were female; they were also younger at onset, less likely to smoke tobacco, and had longer survival,” the team concluded.