Research has shed plenty of light on what makes some people more susceptible to skin cancer — having fair skin or multiple moles, using tanning beds and getting too much unprotected sun exposure, for example. But you may be at increased risk for melanoma or non-melanoma skin cancer without knowing it if you have one of these four lesser-known risk factors.
1. Blue, green or hazel eyes
Fair skin increases the risk of skin cancer, especially melanoma, but so do light-colored eyes. “People with lighter-colored eyes and skin tend to lack the photoprotective mechanism provided by melanin, the pigment activated by UV light that darkens skin to help shield it from damage,” said Sean McGregor, DO, PharmD, a board-certified dermatologist at Water’s Edge Dermatology who specializes in high-risk skin cancer.
Light-eyed people also tend to have blond or red hair and fair skin, placing them low on the Fitzpatrick scale, a scale used to assess skin cancer risk based on skin type. The lower you fall on the scale, the greater your risk.
According to one study, people with genes tied to blue eyes also tend to have more freckles and moles in childhood, which could potentially increase the risk of melanoma in adulthood. Having 10 or more atypical moles (moles with irregular features — see the ABCDE signs) raises the risk of melanoma by a factor of 12.
2. A weakened immune system
Your immune system protects you from illness by recognizing and routing out bacteria and other microbes that can make you sick. It could also potentially recognize precancerous conditions such as actinic keratosis (AK) and head them off at the pass. AK is caused by sun exposure and often appears as dry, scaly, rough patches.
“We know that the immune system plays an important role in skin cancer,” said Dr. McGregor. “In someone with a compromised immune system, there is a loss of immune surveillance of tumor cells, allowing for the development of skin cancer.”
Skin cancer in someone with a weakened immune system tends to grow more quickly and is more likely to be fatal.
Taking a medication that suppresses the immune system increases the risk of skin cancer. Organ transplant recipients take immunosuppressants — often several different ones — for the rest of their lives to prevent organ rejection, which puts them at an especially high risk of developing skin cancer. On average, their risk is:
- 65 times higher than average for squamous cell carcinoma
- 10 times higher for basal cell carcinoma
- 3.6 times higher for melanoma
The degree of immune suppression necessary, and therefore the increase in skin cancer risk, varies with the organ transplanted. “People who’ve received a heart or lung transplant are at higher risk of skin cancer than those who’ve received a kidney or liver,” said Dr. McGregor.
Having other skin cancer risk factors, such a prior history of skin cancer or a lifetime of sun exposure, plays a role, too. “For example, a farmer who has worked outside their entire life, with a previous history of skin cancer, is potentially at a much higher risk of developing skin cancer earlier and/or more frequently,” said Dr. McGregor. The farmer might get skin cancer 10 months after a transplant (for example) versus 10 years.
Twenty years after an organ transplant, more than half of all transplant recipients will have developed a skin cancer.
4. Radiation treatment
Nonmelanoma skin cancers such as basal cell and squamous cell carcinoma are more likely to develop in areas of skin that received radiation treatment for lymphoma, breast cancer or another type of cancer. The increase in risk is more significant in people who undergo radiation therapy before the age of 20 and those who develop a side effect called radiation dermatitis, which may cause redness and peeling.
According to the American Academy of Dermatology, the increase in risk after radiation therapy persists for at least 40 years. The average time frame for developing skin cancer after radiation is 20 years.
What to do if you’re at increased risk
If you think you may be especially susceptible to skin cancer — whether it’s because you have a family history of skin cancer, you had a few blistering sunburns (all it really takes is one), you have fair hair, freckles and baby blues or greens or you’ve had an organ transplant — it’s essential to be vigilant about protecting your skin.
“The foundation of skin cancer prevention is sunscreen and sun-protective clothing,” said Dr. McGregor. Other key steps include checking your skin for changes, including changes in moles, and getting screened regularly.
“It’s important to come into the office to be screened for skin cancer,” said Dr. McGregor “The earlier we detect a potential malignancy, the better the prognosis.”
Article Written By: Maura Rhodes, a New Jersey-based writer and editor specializing in health and well-being.
Medical Review By: Sean McGregor, DO, PharmD