Leptomeningeal metastases: cancer in the membranes around the brain and spinal cord

The brain and spinal cord are covered by protective membranes called the meninges. The innermost layers are the leptomeninges, and Cancer Research UK says leptomeningeal metastases mean cancer cells have spread to these layers. The condition goes by several other names, including leptomeningeal disease, leptomeningeal carcinomatosis, carcinomatous meningitis and neoplastic meningitis, all of which describe the same problem.

Cancer cells can reach the meninges by travelling in the bloodstream from a cancer elsewhere in the body, or by spreading from a secondary cancer that has already developed in the brain, according to Cancer Research UK. It is therefore a type of secondary cancer, also called metastasis, which Cancer Research UK explains means that cancer cells broke away from the primary cancer and spread to another part of the body, and that the secondary cancer is made up of the same type of cells as the primary.

Cancer Research UK says between 5 and 10 out of every 100 people (5 to 10%) with solid tumours might develop leptomeningeal metastases, and that it is most common in people with breast or lung cancer or melanoma skin cancer. In people with blood cancer it says 5 to 15 out of every 100 (5 to 15%) might develop them.

It adds that you could talk to your cancer specialist or specialist nurse if you are worried about this.

Because the membranes cover both the brain and the spinal cord, symptoms are varied. Cancer Research UK lists the following, and, as with other secondary brain and spinal problems, many of them have other more common causes.

• Headaches, feeling sick (nausea) and vomiting.

• Changes to sight such as double vision or loss of sight, and hearing changes.

• Confusion, mood and behaviour changes.

• Weakness, facial drooping and seizures (fits).

• Pain in the lower back, legs or neck.

• Changes to the way you walk, and numbness or weakness of one or both legs and the bottom.

• Problems passing urine or stools.

If you are having cancer treatment or follow-up, use the emergency contact number your cancer team gave you for new neurological symptoms rather than waiting for a routine appointment. Cancer Research UK recommends telling your doctor or nurse about any symptoms of secondary brain cancer such as headaches, seizures, weakness, speech or vision changes. For a seizure, sudden severe headache, loss of consciousness, new weakness on one side or sudden loss of control of the bladder or bowel, call 999 or go to A&E.

Cancer Research UK says leptomeningeal metastases can be difficult to diagnose. They might show up on an MRI scan, or cancer cells might be found in fluid taken from the spine by a lumbar puncture. In a lumbar puncture a needle goes through the skin into the small of the back and into the space around the spinal cord to take a sample of the fluid that circulates around the brain and spinal cord.

For secondary brain cancer more generally, Cancer Research UK lists a physical examination to test muscle strength, eyes and reaction times, a CT scan, an MRI scan and sometimes a biopsy.

Cancer Research UK says your treatment depends on where the cancer started and that the aim is usually to control the growth of the cancer and relieve symptoms. It says doctors are still looking at which treatments work best, including which treatments best enter the cerebrospinal fluid (CSF), the clear fluid surrounding the brain and spinal cord.

Cancer Research UK says your individual outlook depends on many factors, including whether the cancer has spread to more than one part of the body, how quickly it is growing and how it responds to treatment. It says treatment might control the cancer cells in the meninges for some months, and with newer targeted cancer drugs possibly more than a year for certain cancers.

It acknowledges that it is difficult for doctors to predict someone's outlook and that this uncertainty can be hard to deal with. Asking your specialist what they would expect in your situation, and what the plan is if treatment does not work, can help.

Cancer Research UK says it can be difficult to cope with leptomeningeal metastases and that your doctor and cancer nurse specialist are your best source of information. They can tell you about local cancer support groups and groups that offer practical help, and talking to others in a similar situation or to those close to you can help. Some people decide to try counselling. Cancer Research UK also runs an information nurse service and the Cancer Chat online forum.

Leptomeningeal disease is managed by your oncology team on the NHS, with other specialists involved as needed. Some people also take a private oncology opinion to discuss options or trials. Intrathecal chemotherapy, targeted drugs and radiotherapy are the same treatments in both sectors; the practical differences are speed of access and which team coordinates the plan. Ask who your key worker is and who to call out of hours.