Melanoma Found in Jimmy Carter’s Brain: How Can a Skin Cancer Develop Inside The Body?

Jimmy Carter, the 39th President of the United States, shared more details of his cancer diagnosis today (Aug. 20), explaining that he now has four spots of melanoma in his brain.

The melanoma was discovered after undergoing surgery to remove a tumor from his liver, according to reports from a news conference Carter spoke at in Atlanta at the Carter Center. After further treatment and investigation by doctors, they found that the melanoma was also in his brain.

Good Morning America reports that the 90-year-old Carter would undergo radiation for the first time today, and then have three more radiation treatments three weeks apart from each other.

Carter is being treated at Emory Healthcare in Atlanta. When he first received the diagnosis, he thought he had “just a few weeks left,” Sky News reports, but now he is “perfectly at ease with whatever comes.”

Melanoma is infamously dangerous because of its ability to spread when it’s at its later stages, according to the Melanoma Research Foundation. The cancer originates in the melanocytes, which are pigment-producing cells in the basal layer of the skin. When caught early, it’s often curable. However, symptoms usually do not arise until it’s in its later stages, which is also unfortunately when it’s more life-threatening, according to the Skin Cancer Foundation.

But how can a skin cancer end up in the brain? When melanoma grows, it can start invading cells that then “start to invade the blood vessels and it gets into the circulation,” explains Wafik S. El-Deiry, MD, PhD, FACP, Deputy Cancer Center Director for Translational Research and professor of medical oncology at Fox Chase Cancer Center. “So the melanoma cells can leave the skin, get into blood vessels, and eventually end up in various organs, as seems to be the case here.”

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El-Deiry, who has not treated Carter, notes that it’s not uncommon for metastatic melanoma to spread to the brain. The cancer usually starts small — perhaps as a slight change in the color or size of a mole. But the longer the changes go on, the “deeper it grows in the skin,” he explains to Yahoo Health.

Another important factor in Carter’s case: where the melanoma was found in his brain. While Carter has not mentioned specific cognitive symptoms yet, “knowing exactly where [the tumors are] are tells the clinicians a lot in terms of potential risk, and what might be expected,” El-Deiry says. “I think he probably knows the answer to that, but in any event, I think that in someone who doesn’t yet have symptoms and has melanoma that has spread to brain, the key would be to preserve his function for as long as possible … so he can do all the things he wants to do, without having side effects.”

Though Carter has not revealed specific details of all of the treatments he will undergo (or has already undergone), El-Deiry notes that there are a number of immune checkpoint therapies that have shown recent success in melanoma patients, as well as targeted therapies — part of “precision medicine” — that work specifically on people whose melanoma tumors have a specific gene mutation.

While Carter’s age in and of itself is not considered a contraindication for cancer treatment — El-Deiry notes he treated a man in his late-90s recently with chemotherapy, and he “did just fine” — “you kind of have to figure out what the goals are of the treatment and [remember that] the most important thing is to do no harm,” he says, and that might mean taking care to adjust dosages.

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