Leptomeningeal Disease: A Rare Cancer Metastasis

The brain isn’t the part of the central nervous system where primary cancers spread.

Studies have shown that for up to 5% of people, cancer moves to the cerebrospinal fluid that surrounds the brain and spinal cord or to the brain and spinal cord lining (called the leptomeninges). The condition, known as leptomeningeal disease or leptomeningeal carcinomatosis, most commonly affects those with melanoma, lung cancer or breast cancer.

Because the cancer cells float freely in the cerebrospinal fluid, the disease quickly spreads throughout the central nervous system, leading to an approximate three-month survival rate after diagnosis.

“People have tumor cells in the brain, as well as the fluid and tissue that coat the brain and brainstem,” says Dr. Chetan Bettegowda, a Jennison and Novak Families Professor of Neurosurgery at Johns Hopkins Medicine in Baltimore.

Symptoms are similar to brain metastases but may also include facial or other muscle weakness or pain, difficulty swallowing, double vision and difficulty thinking clearly. The number of people developing leptomeningeal disease is increasing for the same reason that diagnoses of brain metastases are on the rise: People are living longer, giving cancer more time to spread. Doctors use MRIs and spinal taps (lumbar punctures), to make a diagnosis.

Treatments have been limited to radiation therapy to shrink tumors and intrathecal chemotherapy delivered directly into the spinal fluid through a small, quarter-sized port called an Ommaya reservoir implanted underneath the skin on the scalp. Less commonly, chemotherapy is injected into the fluid via a spinal tap procedure. These treatments, however, are considered palliative — they ease symptoms but won’t stop the disease. Clinical trials are underway to identify molecular changes to primary cancer cells that may signal a higher risk of leptomeningeal disease.

This new knowledge could lead to the use of targeted therapies to treat metastatic cancer and prevent it. Ongoing trials are also showing encouraging results of immunotherapy and certain targeted therapies.

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To read an in-depth story from CURE®’s most recent seasonal issue on the tremendous hope that surrounds emerging therapies for cancer that has spread to the brain, click here.