By Matthew Reiss, MSE, PhD, Manager, Precision Medicine & Navigation, GO2 for Lung Cancer  

Hearing that cancer has spread to the brain or spinal cord can be a frightening, but very real outcome for many people living with lung cancer. While exact statistics are hard to pin down, recent studies suggest that about 10-40% of lung cancer patients’ cancer will spread to the brain or central nervous system.  

One rare form of spread, called leptomeningeal disease (LMD), can be especially confusing because it is unfamiliar and often hard to explain in simple terms. But better understanding what LMD is and how it may be treated can help you advocate for yourself in conversations with your healthcare team. 

What is leptomeningeal disease?

To understand leptomeningeal disease, it can help to picture how the brain and spinal cord are protected. In the body, these structures are wrapped in a thin layer of tissue called the meninges. Inside these layers flows a clear liquid called cerebrospinal fluid (CSF), which helps to cushion and nourish the brain and spinal cord. 

Leptomeningeal disease occurs when cancer cells, such as those from the lungs, travel to, and start growing in, the meninges or in the CSF surrounding the brain and spinal cord.  

How is LMD different from other brain metastases?

Many people have heard how cancer can sometimes spread from the lungs by travelling through the bloodstream to the brain, where it can begin to grow. These are called brain metastases or brain mets. Brain mets are not brain cancer, but rather lung cancer that has spread to the brain. 

Leptomeningeal disease is different. While brain mets usually form as a solid tumor(s) in the brain itself, LMD involves the lining and fluid around the brain and spinal cord. Instead of a single or multiple solid tumor masses, LMD can look more like a thin coating or a pattern of streaking around/within these structures, possibly affecting many areas at once. This can make LMD harder to see on a scan and more challenging to diagnose 

Because of this, symptoms of LMD can vary widely, and no 2 people experience LMD the same way. Often, symptoms include:  

  • Headaches 
  • Nausea 
  • Changes in thinking or mood 
  • Double vision 
  • Weakness 
  • Difficulty walking 
  • Back pain 
  • Numbness 

This also makes LMD more difficult to diagnose. Often, an LMD diagnosis is confirmed by collectively considering the results of MRI scans, spinal fluid tests, and other clinical exams. 

How common is LMD in lung cancer?

Leptomeningeal disease is not common, but it is a possibility to be aware of for individuals living with lung cancer. 

For individuals with non-small cell lung cancer (NSCLC), LMD is very rare: 

  • Studies show that LMD occurs in about 3-5% of individuals living with NSCLC. 
  • It is more common in people with mutations or changes in genes such as EGFR, ALK, and ROS1. 

LMD is more common, but still rare, in people living with small cell lung cancer (SCLC): 

  • About 2% of individuals with SCLC have signs of LMD at diagnosis. 
  • About 10% of individuals with SCLC have developed LMD after 2 years. 

You may also sometimes hear people say that LMD diagnoses are becoming more common. While true, many researchers believe LMD is being diagnosed more often today, not only because of better scanning technology, but also because new treatments are allowing people to live long enough with lung cancer for rarer complications like LMD to occur. 

Even though it’s uncommon, knowing the basics of LMD can help people better recognize symptoms early and get connected with a specialist. 

The importance of seeing a specialist

Because LMD is complex, it is very helpful to work with clinicians who have experience treating it. Your doctor may refer you to a: 

  • Neuro-oncologist – a doctor specializing in cancers found in the brain and nervous system 
  • Medical oncologist with LMD experience 
  • Radiation oncologist – a doctor specializing in the use of radiation to treat cancer in areas such as the brain and spine 

These experts work with your current healthcare team and can often open the door to more treatment options or clinical trials to help manage the cancer.   

Treating LMD can also be complex. Sometimes treatments that work well in one part of the body do not work the same way or as effectively in the brain or CSF.  If this happens to you or your loved one, it’s completely normal to feel overwhelmed. You can always ask your care team to slow down, repeat information, or clarify anything. Asking questions is an important way to advocate for yourself. 

Current treatment approaches for LMD

Overall, the goals of treatment for people with LMD are usually to slow or control further spread of the cancer, protect quality of life, and relieve troublesome symptoms such as pain, nausea, or nerve issues. 

Exactly which treatment someone receives for LMD is highly personalized, but there are several commonly used approaches: 

  • Targeted or systemic (whole-body) treatments: For some people who have certain genetic changes, targeted therapies or immunotherapies can be effective ways to treat LMD. For others who do not have genetic changes that can be targeted, traditional chemotherapy is often used. 
  • Radiation therapy: Targeted radiation may also be used to treat the specific areas of LMD that are likely causing symptoms. For others, radiation may be used more widely along the brain or spinal cord to treat LMD over a large region. 
  • Intrathecal therapy: In some cases, medicines such as chemotherapy are delivered directly into the spinal fluid through a small device or spinal tap. This approach allows the treatment to better access the protected part of the body where LMD is occurring, although this approach is not appropriate for everyone. 
  • Supportive and palliative care: This approach includes medicines and services that focus on symptom relief, mobility, and emotional support for people with LMD, rather than treating the LMD directly. Supportive and palliative care should be offered alongside other treatment approaches. 
  • Emerging approaches: While LMD remains a serious diagnosis, there is real progress being made in clinical trials to find new and better ways to treat LMD and improve long-term outcomes. Talk to your healthcare team about whether a clinical trial for LMD may be right for you. 

Closing thoughts

Leptomeningeal disease is complicated, and it is normal to have questions. If you or someone you care about has been told they have leptomeningeal disease related to lung cancer, reach out to your care team, ask about a referral to an expert, and feel comfortable asking questions related to your treatment options. Clear information is empowering and can help you advocate for the best possible care.  

If you’d like to learn more about LMD and its treatments, have questions, or need support, please contact our free HelpLine at 1-800-298-2436 or email support@go2.org.