AUDIE CORNISH, HOST:
Elizabeth Buchbinder is a doctor at the Dana-Farber Cancer Institute. She specializes in melanoma or skin cancer, and she joins me now. Dr. Buchbinder, welcome to the program.
ELIZABETH BUCHBINDER: Thanks - great to be here.
CORNISH: So speaking in general terms, what's the prognosis for someone in Jimmy Carter's position? And I guess specifically, what we want to talk about - how age can affect that prognosis.
BUCHBINDER: Absolutely. So it's really interesting with melanoma 'cause about five years ago, I would've said he has a prognosis of somewhere between six months to a year. But over the last five years, the treatments in melanoma have just exploded with really, really exciting new treatments that have changed that to a point that we actually don't have a good estimate yet in terms of long-term prognosis will be.
The biggest thing that's really affecting that is new therapies that are called immunotherapies, which actually work on the patient's immune system. And the reason that that affects prognosis so much is that although they don't work for everybody, for those people they work for, they can lead to these very durable responses with patients actually living for many, many years after their diagnosis, even with cancer as widespread as former president Carter's.
So it actually is very exciting time. And the nice thing about these treatments is unlike some of our older treatments like chemotherapy, these new therapies seem to be working regardless of age. And preliminary data suggests that even in patients as old as 90, it's still safe to give them and appropriate to give them and that they can lead to very nice responses.
CORNISH: So help us understand here. We heard that former President Carter - his treatment will call for radiation and a new class of checkpoint inhibitors, a new class of drug. Are we talking about the same thing? What do they do?
BUCHBINDER: Yes, we are. So immune checkpoint inhibitors are a type of immune therapy. And what they do is kind of turn off the off switch on the immune system. So our immune system is very tightly regulated to make sure that it only attacks things that are foreign to our body and it doesn't attack our own organs. And when this goes wrong, it leads to things like rheumatoid arthritis or Type 1 diabetes.
And so there's these very close checks and balances or checkpoints that help keep the immune system under control, but these checkpoints can also be manipulated by cancer in order to turn off the immune system and make it so that the cancer is kind of camouflaged. So what these treatments do is they block that off switch so that the immune system then comes back on, recognizes the cancer and attacks it and potentially either destroys it entirely or keeps it from growing and really keeps it under control.
CORNISH: You know, for our listeners, they're probably wondering how common this form of cancer is. What can you tell us about what's known?
BUCHBINDER: Yeah. So skin cancer, as a whole, is the most common form of cancer. But melanoma's only 2 percent of skin cancer. And the issue is that melanomas, although they fall in that group of skin cancers, most other skin cancers are relatively benign. They get removed. They may come back locally, but it's unlikely they're going to spread, whereas even the thinnest melanoma carries some risk of actually getting into the bloodstream and spreading elsewhere in the body.
CORNISH: Is there anything that surprised you about today's announcement or how President Carter discussed how he's dealt with it?
BUCHBINDER: From what I've read and heard, it's actually not an infrequent way that we see patients. They're often initially seem, and nobody sees a spot on their skin. There isn't a clear spot that this came from, and yet, they've developed disease elsewhere in their body. And so we actually think of these cases as patients having an unknown primary melanoma. And in some ways, these patients seem to do better, and it probably ties back to the whole activation of the immune system and that perhaps the immune system has actually gotten rid of the original melanoma already so that it's more likely to then recognize the cancer elsewhere in the body
CORNISH: Elizabeth Buchbinder, thank you so much for speaking with us.
BUCHBINDER: Oh, absolutely. Thank you.
CORNISH: Dr. Elizabeth Buchbinder - she's a melanoma specialist at the Dana-Farber Cancer Institute and an instructor at Harvard Medical School. Transcript provided by NPR, Copyright NPR.