Sun Exposure and Cancer Risk
Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 23, 2012
While there may be some benefit to soaking up the sun's rays, such as synthesis of vitamin D within our bodies, there are also many harmful side effects of sun exposure. Most of us know that exposure to ultraviolet (UV) rays, either by natural sunlight or tanning beds, can lead to skin cancer. In addition, these rays can also result in other forms of skin damage such as premature aging, wrinkles, loss of skin elasticity, dark patches (lentigos, sometimes called age spots or liver spots), and pre-cancerous skin changes (such as dry, scaly, rough patches called actinic keratoses). The sun's UV rays also increase a person's risk of cataracts and can suppress the skin's immune system. Although dark-skinned people are less likely to develop skin cancer than light-skinned people, skin cancers can develop in any population. In darker skinned individuals, skin cancers develop most often in areas that are not exposed to sun (the foot, under nails, genitals).
Skin cancer is the most common of all cancer types. According to the American Cancer Society (ACS), more than 2 million skin cancers are diagnosed each year in the U.S. (more than prostate, breast, lung, colon, uterus, ovaries, and pancreas cancers combined) and the number of cases has been steadily increasing over the past few decades.
The good news is that you can do a lot to protect yourself from damaging UV rays and to detect skin cancer early. Start by practicing sun safety, including using a broad spectrum sunscreen (protects against UVA & UVB rays) every day, avoiding peak sun times (10am-4pm, when the rays are strongest) and wearing protective clothing such as hats, sunglasses and long sleeved shirts.
Performing a skin check for suspicious skin lesions doesn't require any x-rays or blood tests -- just your eyes and a mirror. Examine your skin regularly so you become familiar with any moles or birthmarks. If a mole has changed in any way, including a change in size, shape, or color, has developed scaliness, bleeding, or oozing, or has become itchy or painful, or you develop a sore that will not heal, you should have a healthcare provider examine the area. If you have many moles, it may be helpful to make note of moles using pictures or a mole map. SkinCancerNet has a helpful guide to performing a skin exam.