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Skin Cancer Facts

What is the skin?

The skin is the largest organ of the body. It has many functions, such as:

  • Covering the internal organs and protecting them from injury
  • Serving as a barrier to germs such as bacteria
  • Preventing the loss of too much water and other fluids
  • Helping control body temperature
  • Protecting the rest of the body from ultraviolet (UV) rays
  • Helping the body make vitamin D

How many people get skin cancer?

Skin cancer is the most common of all cancers. About 3.5 million cases of basal and squamous cell skin cancer are diagnosed in this country each year. Melanoma, a more dangerous type of skin cancer, will account for more than 73,000 cases of skin cancer in 2015.

What are basal and squamous cell skin cancers?

These types of skin cancer start in the basal cells or squamous cells of the skin, which is how they get their names. These cells are found in the outer layer of the skin.

Most basal and squamous cell cancers develop on sun-exposed areas of the skin, like the face, ears, neck, lips, and the backs of the hands.

Basal cell cancers tend to grow slowly and rarely spread to other parts of the body. Squamous cell cancers are more likely to grow into deeper layers of skin and to spread, although this is still not common.

Both basal cell and squamous cell skin cancers can be cured if found and treated early – when they are small and have not spread. But either type can cause problems if it is left untreated.

You can learn more about these skin cancers in our document Skin Cancer: Basal and Squamous Cell.

What is melanoma skin cancer?

Melanoma is a cancer that begins in the melanocytes – the cells that make the brown skin pigment known as melanin, which gives the skin its color. Melanin helps protect the deeper layers of the skin from the harmful effects of the sun.

Melanoma can start on nearly any part of the skin, even in places that are not normally exposed to the sun, such as the genital or anal areas. Though melanoma most often affects the skin (including under the nails), it can also start in other parts of the body, such as in the eyes or mouth.

Melanoma is almost always curable when it’s found in its very early stages. Although melanoma accounts for only a small percentage of skin cancers, it’s much more likely to grow and spread to other parts of the body, where it can be hard to treat. Because of this, melanoma causes most skin cancer deaths, accounting for nearly 10,000 of the more than 13,000 skin cancer deaths each year.

You can learn more in our document Melanoma Skin Cancer.

Other types of skin cancer

There are many other types of skin cancer, such as Merkel cell carcinoma, skin lymphoma, Kaposi sarcoma, skin adnexal tumors, and sarcomas. These are all much less common than basal or squamous cell cancers or melanomas.

What are the risk factors for skin cancer?

Risk factors for skin cancer include:

  • Too much exposure to ultraviolet (UV) radiation (from sunlight or tanning beds and lamps)
  • Pale skin (easily sunburned, doesn’t tan much or at all, natural red or blond hair)
  • Exposure to large amounts of coal tar, paraffin, arsenic compounds, or certain types of oil
  • You or members of your family have had skin cancers
  • Multiple or unusual moles
  • Severe sunburns in the past
  • Weakened immune system
  • Older age (although melanomas can also occur in younger people)

What are the signs and symptoms of skin cancer?

Skin cancer can be found early, and both people and their doctors play important roles in finding skin cancer. If you have any of these symptoms, see a doctor:

  • Any change on your skin, especially in the size or color of a mole, growth, or spot, or a new growth (even if it has no color)
  • Scaliness, roughness, oozing, bleeding, or a change in the way an area of skin looks
  • A sore that doesn’t heal
  • The spread of pigmentation (color) beyond its border, such as dark coloring that spreads past the edge of a mole or mark
  • A change in sensation, such as itchiness, tenderness, or pain

To see some examples of different types of skin cancers, visit our Skin Cancer Image Gallery.

Can skin cancer be prevented?

The best ways to lower your risk of skin cancer are to avoid long exposure to intense sunlight and practice sun safety. You can still exercise and enjoy the outdoors while using sun safety at the same time. Here are some ways to be sun safe:

  • Seek shade, especially in the middle of the day (between 10 am and 4 pm) when the sun’s rays are strongest. Teach children the shadow rule: if your shadow is shorter than you, the sun’s rays are at their strongest.
  • Follow the Slip! Slop! Slap!® and Wrap! rules:
  • Slip on a shirt: Cover up with protective clothing to guard as much skin as possible when you’re out in the sun. Choose comfortable clothes made of tightly woven fabrics that you can’t see through when held up to a light.
  • Slop on sunscreen: Use sunscreen and lip balm with broad spectrum protection and a sun protection factor (SPF) of 30 or higher. Apply a generous amount of sunscreen (about a palmful) to all areas of unprotected skin. Reapply every 2 hours and after swimming, toweling dry, or sweating.
  • Slap on a hat: Cover your head with a wide-brimmed hat, shading your face, ears, and neck. If you choose a baseball cap, remember to protect your ears and neck with sunscreen.
  • Wrap on sunglasses: Wear sunglasses with 100% UVA and UVB absorption to protect your eyes and the surrounding skin.
  • Sunscreen doesn’t protect from all UV rays, so don’t use sunscreen as a way to stay out in the sun longer.
  • Follow these practices to protect your skin even on cloudy or overcast days. UV rays can travel through clouds.
  • Avoid other sources of UV light. Tanning beds and sun lamps are dangerous. They damage your skin and can cause cancer.

What is the American Cancer Society doing about skin cancer?

  • Education: The Society delivers high quality health information to the public so that people can make informed personal decisions. Examples include: printed materials; media coverage; community-based outreach programs; and free, nationwide services such as www.cancer.org and our 24-hour cancer information center at 1-800-227-2345.
  • Advocacy: With the help of grassroots volunteers in communities across the country, the Society advocates with lawmakers at both the state and federal levels to enact responsible health policies and increase funding for research, testing, and treatment coverage. The ACS Cancer Action Network (the Society’s non-profit, non-partisan advocacy affiliate) has asked the FDA to review how it regulates tanning beds to reflect their known dangers in increasing skin cancer risk, and supports legislation banning minors from using indoor tanning beds.
  • Service: The Society works to improve quality of life for people living with cancer through a variety of support services and programs helping patients and families cope with the disease.
  • Society also collaborates with many nationwide organizations to promote skin cancer prevention, education, and sun-safe policies.


Last Medical Review: 04/13/2015
Last Revised: 04/13/2015