Risk Factors and Prevention

A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as sunbathing, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health-care choices.

The following factors may raise a person’s risk of developing melanoma:

Individual history. People with many moles or unusual moles called dysplastic nevi (flat, large moles that have irregular color and shape) have a higher risk of developing melanoma. About 50% of people with melanoma have dysplastic nevi. Also, people who have weakened immune systems or use certain medications that suppress immune function have a higher risk of developing skin cancer. In addition, people who have had one melanoma have an increased risk of developing additional new melanomas; overall, in the general population, 3% of people who develop one melanoma develop other new melanomas. People who have had a non-melanoma skin cancer also have a somewhat increased risk of developing melanoma.

Family history. Approximately 10% of people with melanoma have a family history of the disease. Therefore, it is recommended that close relatives (parents, brothers and sisters, and children) of a person with melanoma routinely have their skin examined. Changes in two genes (CDKN2A and CDK4) that may lead to melanoma have been identified. However, only a small number of families with melanoma have changes to these genes. Genetic testing for these two genes is only available through clinical trials (research studies). It is likely that other genes and environmental factors also affect risk of melanoma. Learn more about the genetics of melanoma.

Exposure to ultraviolet (UV) radiation. Ultraviolet B (UVB) radiation from the sun produces sunburn and plays a role in the development of both melanoma and non-melanoma skin cancer. Ultraviolet A (UVA) radiation penetrates skin more deeply and may also play a role in the development of both melanoma and non-melanoma skin cancer. People who live in areas with bright sunlight year-round or at high altitudes have a higher risk of developing skin cancer, as do those who spend a lot of time outside during the midday hours. People who use tanning beds, tanning parlors, or sun lamps have an increased risk of melanoma and other skin cancer. Even people who tan well increase their risk of melanoma with more sun exposure.

Fair skin. Less pigment (melanin) in the skin offers poorer protection against UV radiation. People with light hair and light-colored eyes who have skin that tans poorly or freckles, or those who burn easily, are two to three times more likely to develop melanoma.

Sunburn. According to many scientific studies, multiple, severe, blistering sunburns increase the risk of developing melanoma.

Prevention

Reducing exposure to UV radiation, particularly through sun exposure, lowers the risk of melanoma. This is important for people of all ages and is especially important for people who have an increased risk of melanoma. Sun damage builds up over time. Steps to reduce sun exposure, avoid sunburn, and help prevent many cases of melanoma include:

• Limiting or avoiding sun exposure between 10:00 AM and 4:00 PM
  
  
• Wearing sun-protective clothing, including a hat that shades the face, neck, and ears. Clothes made of fabric labeled with UPF (UV protection factor) may provide better protection. UV-protective sunglasses are also recommended.
  
  
• Using sunscreen with a sun protection factor (SPF) of 15 or higher throughout the year and reapplying it often, especially after heavy perspiration or being in the water
  
  
• Examining the skin regularly (examinations by a health-care professional and self-examinations)
  
  
• Avoiding use of sun lamps, tanning beds, and tanning salons