What is LEMS?
LEMS stands for Lambert-Eaton Myasthenic Syndrome. It is a rare neuromuscular disorder that affects how nerves and muscles work together.
LEMS happens when your immune system attacks healthy nerve cells by mistake. This affects the way nerves and muscles communicate, making it harder to move your muscles as you normally would.
How is LEMS related to SCLC?
LEMS can develop when your immune system is also fighting a type of lung cancer called small cell lung cancer (SCLC). About 3 out of every 100 people with SCLC also have LEMS.
- Symptoms of LEMS may show up before, during, or after a cancer diagnosis—even 5 or more years apart.
- Sometimes it is hard for doctors to diagnose LEMS because SCLC can cause the same symptoms, like feeling tired and weak.
- If you have both lung cancer and LEMS, LEMS can get worse faster.
What can LEMS look like?
The most common symptoms of LEMS are muscle weakness, especially in the legs and hips, and fatigue (tiredness). Other symptoms of LEMS are shown in the diagram below.
Keep a daily journal of your symptoms, how you feel, and note if everyday tasks get harder. Bring this to your appointments so your care team can better understand what you’re going through.
How can I get tested for LEMS?
Doctors use a few different tests to find out if you have LEMS. These tests help them understand how your nerves and muscles are working and check for signs your immune system may be involved.
The 3 most common tests are:
A physical exam
Your doctor will check your strength, reflexes, and other signs of muscle weakness.
A blood test
This checks for certain antibodies that are often found in people with LEMS.
A nerve and muscle test
(called an “electrodiagnostic test”) – This shows how well your nerves send signals to your muscles.
What should I do if I think I have LEMS?
If you think you might have symptoms of LEMS, it’s important to talk with your healthcare team.
LEMS can improve with cancer treatment, but there are also specific medications that can help treat the symptoms of LEMS. Treatments include:
- Amifampridine (FDA-approved) – helps nerves talk to muscles better, improving strength. In clinical trials, it helped people with LEMS get stronger, and most side effects were manageable. Read more about the FDA approval here.
- Acetylcholinesterase inhibitors – help boost nerve signals.
- Intravenous immunoglobulin (IVIG) – helps calm down the immune system.
What questions should I ask my oncology team about LEMS?
- I’m having trouble with [list your symptoms, other changes, or concerns with daily activities]. Could it be LEMS? Remember to keep a daily journal to keep track of your symptoms.
- What tests can check for LEMS? Which test would be right for me? Does my insurance cover the testing I need?
- What happens if my test for LEMS comes back positive, which shows I do have LEMS?
- What happens if my test is negative?
The Lung Cancer Research Foundation is here to help
If you have any questions about this information, or are looking for resources or other assistance, you can reach out to LCRF’s Lung Cancer Support Line. When you contact the support line, you will connect with a Licensed Clinical Social Worker who will talk through your specific needs and what resources are available to you. You can call us toll-free at (844) 835-4325 or email support@LCRF.org.
This complimentary resource is provided with support from Catalyst Pharmaceuticals.