I am sorry for your lost Marsha, and for the misdiagnosis one year ago. The fact that she was diagnosed with this disease means that the original cancer was in a far advanced stage. This disease has been happening more often and is more unrecognized than ever. Noticed that no one knew anything until a spinal tap was performed.
The most common cancers involving leptomeningeal metastastis are breast cancer, lung cancer and melanomas, and now, because of dose-intense infusional combination chemotherapies, even ovarian cancer is more common.
Unfortunately, cancer cells are too small to find on any scans unless they have grown into a lump. There can still be cancer cells in the body even though scans may have indicated that all the cancer had gone. Recent studies have shown that the chemo drug Taxol produces the greatest release of circulating tumor cells.
Leptomeningeal metastasis (Lepteomeningeal Carcinomatous or Carcinomatous Meningitis) is a condition caused by cancer cells getting into the thin sheets of body tissue that surround and protect the brain and spine. These sheets are called the meninges. Meningitis means inflammation of the meninges. Carcinomatous just means acting like a cancer. Most people are familiar with the type of meningitis caused by an infection, but with carcinomatous meningitis, it is the cancer cells in the meninges that cause the inflammation, not an outside infection.
Cancer cells do not always develop into an active secondary tumor when they have spread to a new site. Sometimes they stay inactive for many years. Even after a cancer appears to have been successfully treated, some cancer cells may still be elsewhere in the body. No one knows why some cancer cells stay inactive or what triggers them to form a secondary cancer.
Tumor cells reach the meninges by hematogenous (blood) spread or by direct extension from pre-existing lesions and are then disseminated throughout the neuroaxis by the flow of the cerebrospinal fluid. Patients present with signs and symptoms from injury to nerves that traverse the subarachnoid space, direct tumor invasion into the brain or spinal cord, alterations in blood supply to the nervous system, obstruction of normal cerebrospinal fluid (CSF) flow pathways or general interference with brain function.
Secondary cancers from a primary cancer can develop in different parts of the body, including the brain or spine. Cancer cells do not always develop into an active secondary tumor when they have spread to a new site. Sometimes they stay inactive for many years. So, even after a cancer appears to have been successfully treated, some cancer cells may still be elsewhere in the body. No one knows why some cancer cells stay inactive or what triggers them to form a secondary cancer.
Diagnosis is most commonly made by lumbar puncture, although the CSF cytology is persistently negative in about 10% of patients with leptomeningeal carcinomatosis. Radiology studies may reveal subarachnoid masses, diffuse contrast enhancement of the meninges or hydrocephalus without a mass lesion.
The condition is very difficult to treat. The main aim is to help control symptoms and not cure the disease. Chemotherapy injected into the spinal fluid (via Ommya Reservoir in the brain) or radiotherapy to the brain are both treatments for Carcinomatous meningitis. Some patients respond to these treatments, but the prognosis is generally poor. There are no set guidelines for treating this condition as oncologists don't really know which treatments work best.
Without treatment, the median survival of patients is 4 - 6 weeks and death occurs from progressive neurologic dysfunction. Oncologists have been looking at using different combinations of chemotherapy drugs to treat Leptomenigeal Carcinomatous secondary to the primary cancer (Chemosensitivity Testing may help in this process). They found that giving both chemotherapy injected into the bloodstream and chemotherapy given directly into the spinal fluid may improve the outlook for some people. However, current available therapies are toxic though, and provide limited benefits.