By Jen Singer
Recent studies have suggested some surprising things (not beaming from the center of our solar system) that might increase your risk for skin cancer. We delved into the research on several of these, which we are sharing in a series of articles here. The first looked at drinking white wine. The second focused on commonly prescribed medications. This one looks at three common medical conditions and whether you should be concerned — or not.
It’s long been known that people who must take antirejection drugs to suppress the immune system after an organ transplant are at much higher risk for developing all types of skin cancers, especially squamous cell carcinoma (SCC). The drugs reduce the ability of the immune system to detect and defend against cancer.
Less well-known, though, is the increased risk of skin cancer in people who have an autoimmune disease. “The immune system has many purposes, but its fundamental tenet is to distinguish your own tissue from cancer,” explains Animesh Sinha, MD, PhD, Rita M. and Ralph T. Behling Professor of Dermatology at the University at Buffalo. When you have an autoimmune disease, the immune system mistakenly attacks healthy tissue instead of fighting disease. “In certain cases, just having an autoimmune disease may set you up for an increased risk for basal cell carcinoma (BCC) or SCC, the two most common types of skin cancer,” he says.
“In addition, the immunosuppressive and biologic medications prescribed to treat autoimmune diseases can suppress not only the offending aggressive autoimmune disease cells, but also large parts of the immune system, or even the entire immune system,” he explains. This may allow cancer cells to grow unchecked, as it can in transplant patients, too.
Autoimmune diseases linked to skin cancer include lupus, scleroderma, Sjögren’s syndrome and dermatomyositis. Women are more likely to have autoimmune diseases than men, and they typically start during childbearing years, from the teens through the 40s.
He adds that doctors and patients must weigh the risks and rewards of any treatment and monitor for side effects. “Even though the risk is small in most cases, it’s still important for patients on immunosuppressive therapy to be vigilant in looking for any lesions that do not heal and that bleed,” says Dr. Sinha. In addition to daily sun protection and monthly skin self-checks, he recommends that those with an autoimmune disease visit a dermatologist for a full-body skin exam every six to 12 months.
Endometriosis is a painful and frequently undiagnosed condition in which tissue that usually lines the uterus isn’t shed during the menstrual cycle but becomes trapped and grows elsewhere in the body. Women with a history of endometriosis have an increased risk for certain cancers, such as ovarian cancer and non-Hodgkin’s lymphoma, but is skin cancer among the risks?
A study of 100,000 French women published in Cancer Causes Control found that endometriosis is associated with an increased overall risk of skin cancer, especially melanoma. The scientists who conducted this study recognized genetic factors that are associated with both endometriosis and melanoma, including red hair, freckles and skin sensitivity to sun exposure. Several additional studies have suggested a positive association between endometriosis and melanoma. Yet other studies have shown no clear link. Those who have endometriosis as well as a family history of skin cancer may want to consult their dermatologists.
The human papillomavirus (HPV) has been linked to cancers that can be sexually transmitted, such as cervical, anal and oral cancer; as well as warts on the chest, arms, hands and feet. There are more than 150 different strains of HPV. Now researchers have discovered that 16 specific strains of HPV may promote skin cancer (along with exposure to UV radiation). An international team of researchers, led by Margaret R. Karagas, PhD, of Dartmouth Medical School, found that people with these types of the virus were more than one-and-a-half times as likely to develop SCC. The more of these types of HPV a person has, the higher the risk.
Though HPV is a common virus affecting nearly 80 million people, most people with HPV never develop symptoms or health problems. About 90 percent of infections go away on their own within two years. The American Cancer Society recommends that girls and boys start HPV vaccinations at age 11 or 12, completing the series by their 20s.
The study has led other researchers to investigate whether vaccinations for HPV could help prevent SCC skin cancers in adult patients who have a history of such cancers. A report published last year in JAMA Dermatology found that HPV vaccinations could reduce the number of both squamous cell and basal cell carcinomas diagnosed in patients with a history of skin cancer. Though the report covered just two patients, the results were remarkable: Both patients dramatically reduced their number of new SCCs and BCCs in the year after vaccination. More research is needed to determine if the HPV vaccine can help reduce the odds of developing skin cancer in the wider population.
Jen Singer is a health writer based near New York City.
Articles in this series: