It is important to know early warning signs so that cancerous growths are found before they spread. The signs include a skin growth that changes in size, color, thickness or texture. Exams with a trained medical worker are also important. See a doctor if a mole bleeds, is bigger than six millimeters or you feel like rubbing it. If one or more of the warning signs are present, a doctor should examine you immediately.

Knowing what your skin looks like will help you recognize any changes. Some experts suggest taking pictures of moles and dating the images to compare over time.

DOUG JOHNSON: Treatment of skin cancer depends on the kind, size, position on the body and depth of the growth, or tumor. Other considerations are the patient's age and general health. An operation to remove the cancerous cells can cure melanoma if the cancer has not spread.

Doctors use drugs to treat melanoma when it has already spread. They also may use radiation to kill cancer cells and reduce the size of cancerous growths. In addition, doctors now use treatments like gene therapy or remove affected fingers or toes. They also may use immunotherapy -- getting the body's immune system to fight the cancer.

Last month, researchers reported that an experimental drug improved survival in a study of melanoma patients. The drug, ipilimumab, worked by helping the body's natural defenses to fight cancer. Patients getting the drug lived on average for ten months compared to six months for those not getting it. Drug-maker Bristol-Myers Squibb hopes to get permission to sell ipilimumab by the end of the year.