The skin is a place where cancer cells can grow and multiply, where it’s possible to catch it before it spreads and, most importantly, where patients may not realize they have the disease until it’s too late.
And that is a very bad thing.
“You know, I can think of maybe 100 people in this country that have cancer that are still alive,” says Livia Naveira, M.D., chief of the Division of Cancer Genetics at Children’s Hospital Boston.
“The vast majority of people who do have cancer are not even aware of it.”
“But they are dying.”
What is the role of the immune system?
There’s a huge body of literature that suggests the immune response is important in the prevention and treatment of cancer.
When a tumor cells invade the body, the immune systems’ protective mechanisms respond by boosting the production of cytokines, which signal to cells in the body that they’re attacking the cancer.
Those cytokines help kill off the cancer cells, and then the immune cells can continue to fight the cancer until it is gone.
But when a patient has skin cancer, it’s likely that the immune responses are weakened or absent.
“It’s not a simple thing to understand,” says Dr. Naveiro.
“So I think there’s a lot of research that’s just been done on this.”
In fact, studies have found that skin cancer is far more common in people who have immune deficiencies.
The reason, Dr. Klima says, is that a person with an immune deficiency will have less of the cytokine production needed to fight cancer.
That’s because the immune cell production has to take in the specific molecules needed to protect the cells from other invaders, like viruses.
The result: a more aggressive immune response.
“And so if you have a chronic immune deficiency, you’re not going to have a normal immune response,” she says.
And the less the immune defense system is active, the more it can be destroyed by other cells.
“This is a real problem,” says Meryl Siegel, M and D, MSc, director of the Center for Immunology and Cancer Research at Harvard Medical School.
“There’s no cure for cancer.
But this is the first time we have a real disease model that looks at the impact of this and that really tells us that there are many different factors that can cause the immune deficiency and this is a significant one.”
Skin cancer may seem like an easy target, but its importance is not.
In fact the immune dysfunction is thought to be a cause of nearly 70% of all cancers.
That means that one in five Americans are at risk for developing skin cancer at some point in their lives.
The exact number of cases has been estimated at 1,800 to 1,900 per year.
And many people with skin cancer are unaware of the problem.
“We can’t really tell a patient from a non-cancer patient,” Dr. Siegel says.
“I think most people will have the appearance of cancer, but they may not know what they have.
And we really have to find a way to tell them.”
What are the most common cancers?
About a quarter of all skin cancers are melanoma, an aggressive form of skin cancer.
Another 10% are basal cell carcinoma, a type of skin cell that develops in the pancreas, and 2% are nonmelanoma skin cancers (NSCs).
All three types are extremely common.
“What we see with skin cancers is that the number of people that are diagnosed increases with each additional type of cancer,” says Jodi D’Agostino, MPh., a dermatologist and director of dermatology at the University of Florida.
“They’re more prevalent in people with less aggressive cancers.
And so you see a doubling of skin cancers that are non-melanomas, in men and in women, with each doubling of melanoma.”
In men, NSCs are more common and more aggressive than basal cell cancers.
“A lot of people think NSCs [nonmelanotic skin cancer] is more common, but it’s actually less common in men than in women,” says Naveiras.
In the United States, more than 70% are diagnosed with basal cell or nonmelanaemic skin cancer and about a quarter are diagnosed at some time with NSCs.
About 10% of those patients are treated with oral chemotherapy, a drug that destroys melanocytes.
About 25% of people with NSC are treated by a combination of oral and topical chemotherapy, called selective serotonin reuptake inhibitors (SSRIs).
But that doesn’t mean all patients with NSAs are treated well.
“In terms of the treatments that are available, it varies greatly from state to state,” says Siegel.
“People with NSDs in the U.S. are given a lower dose of an SSRI that may not be as effective, and patients with these tumors are