Former President Jimmy Carter revealed recently that the cancer doctors had found in his liver during an exam in May had spread to his brain. The doctors diagnosed the cancer as melanoma, a skin cancer, but they didn’t know the exact source. The doctors removed a malignant tumor along with about a tenth of Carter’s liver in early August, according to reports by Tribune Newspapers. Later, scans found the four spots on his brain. They did not find cancer in his pancreas, though pancreatic cancer killed four Carter family members. Carter said he will undergo treatment, though this cancer in late stages has a poor prognosis. He told reporters that he was "at ease" with what comes and wasn't in much pain. Dr. Charles Park, a neurosurgeon at Mercy Medical Center in Baltimore, who has not treated the former president, answers questions about melanoma in the brain.
Melanoma is skin cancer, so how often does it end up in the brain?
About 10 percent [of the time]. It’s very common. It goes through the skin and lymph nodes or blood stream to spread to other parts of the body.
Who is likely to have such metastasis?
Patients who present with brain metastasis have advanced stage of melanoma.
How is a melanoma brain tumor diagnosed?
It’s diagnosed by brain imaging studies, such as CT and MRI. MRI is a better study with higher sensitivity and specificity. Sometimes, the initial presentation is intracerebral hemorrhages, as these tumors are more likely to bleed, and neurosurgeons may find the tumor when evacuating the blood clot.
Melanoma is considered treatable if caught early, so does such spread mean the cancer is late stage and less treatable?
That is correct. As with all the other cancers, early detection gives the best prognosis. The prognosis of patients with brain metastasis are very poor and the goal should be palliative and comfort care.
What are the treatments?
Radiation and chemotherapy.
Although melanomas are not very sensitive to radiation, it is the main stay of treatment. There are two forms of radiation: whole brain and stereotactic radiosurgery. Whole brain is the treatment where the whole brain is radiated. In stereotactic radiation, the multiple small beams delivered to the target area from many different angles, such that all the beams intersect at the tumor and the normal brain gets very little radiation. Whole brain radiation takes up to 20 treatments where as the stereotactic radiation treatment is typically done in one setting.
Traditional chemotherapy is used but the advances in the immunotherapy are promising. In immunotherapy, the immune system is enhanced such that cancer cells can no longer evade body’s own immune system.