Skin Cancer Facts

April 12, 1999
News Office: Alice Trinkl, Lordelyn P. del Rosario (415) 502-6397

Skin cancer is the most common form of cancer in the United States, with about 1 million new cases diagnosed each year. In fact, half of all new cancers are skin cancers, according to Janellen Smith, a dermatologist at the Cancer Center at UCSF Medical Center at Mount Zion and a UCSF assistant clinical professor of dermatology.

The most serious type of skin cancer -- malignant melanoma -- will kill about 7,300 people this year, according to the American Academy of Dermatology.

"Skin cancers, including melanoma, can be more easily treated if detected early," Smith said. "Yet most Americans don't know the warning signs of melanoma and only a third examine their skin for signs of skin cancer."

Other skin cancer facts, from the American Cancer Society and the American Academy of Dermatology, include:

  • About 75 percent of the all skin cancers will be basal cell carcinoma and 20 percent will be squamous cell carcinoma. Both basal cell carcinoma and squamous cell carcinoma, two types of nonmelanoma skin cancer, have a better than 95 percent cure rate if detected and treated early. About 1,900 people will die of nonmelanoma skin cancer in 1999.
  • Melanoma accounts for about 4 percent of skin cancer cases, but 79 percent of skin cancer deaths.
  • The number of new cases of melanoma diagnosed in the United States is increasing. Since 1973, the rate of new cases of melanoma diagnosed has doubled from six per 100,000 to 12 per 100,000.
  • Melanoma is more common than any non-skin cancer among people between 25 and 29 years old.

Some common questions about malignant melanoma include:

Q. What is malignant melanoma?
A. Malignant melanoma is a very serious skin cancer characterized by the uncontrolled growth of pigment-producing tanning cells. Melanomas may suddenly appear without warning and are found most frequently on the upper back of men and women and on the legs of women, but can occur anywhere on the body.

Q. Is melanoma a serious disease?
A. Yes. In later stages, malignant melanoma spreads to other organs and may result in death. But if detected in the early stages, melanoma usually can be treated successfully.

Q. What causes melanoma?
A. Excessive exposure to ultraviolet radiation of the sun is the most important preventable cause of melanoma. Other possible causes include genetic factors and immune system deficiencies. Malignant melanoma also has been linked to past sunburns and sun exposure at younger ages.

Q. What does malignant melanoma look like?
A. Melanoma generally begins as a mottled, light brown to black flat blemish with irregular borders. Blemishes are usually at least a quarter of an inch in size and may turn shades of red, blue and white, crust on the surface and bleed. They frequently appear on the upper back, torso, lower legs, head and neck. A changing mole, a new mole or a mole that is different or "ugly" or begins to grow requires prompt medical attention.

Q. Can melanoma be cured?
A. When detected early, surgical removal of thin melanoma can cure the disease in most cases. Early detection is essential. Dermatologists recommend a regular self-examination of the skin to detect changes in its appearance, especially changes in existing moles or blemishes. Additionally, patients with risk factors should have a complete skin examination annually. Anyone with a changing mole should be examined immediately.

Q. Can melanoma be prevented?
A. Yes. Because overexposure to ultraviolet light is thought to be a primary cause of malignant melanoma, dermatologists recommend the following precautions:

  • Avoid "peak" sunlight hours -- 10 a.m. to 3 p.m. -- when the sun's rays are most intense.
  • Apply a sunscreen with a sun protection factor of at least 15, apply 15 to 30 minutes before going outdoors and reapply every two hours, especially when playing, gardening, swimming or doing any other outdoor activities.
  • Wear protective clothing, including a hat with a wide brim and long-sleeved shirts and pants during prolonged periods of sun exposure.

In an effort to raise awareness about skin cancer and self-examination, the UCSF Department of Dermatology -- along with the American Academy of Dermatology, San Francisco Dermatology Society, and the American Cancer Society -- will sponsor a free skin cancer screening from 9 a.m. to 1 p.m., Saturday, May 15, at the UCSF/Mount Zion Medical Office Building, 1701 Divisadero St., third floor. For more information about the screening or to make an appointment call (415) 353-7800.