Skin cancer is the most commonly diagnosed form of cancer in the United States. Skin cancer is divided into two main categories - melanoma and non-melanoma. Non-melanoma skin cancers are far more common, and less dangerous, than melanoma skin cancer. The two most common forms of non-melanoma skin cancer are basal cell carcinoma, which begins in the skin's lowest layer, and squamous cell carcinoma, which occurs in the higher layers of the skin.

People with dark skin are less likely to develop skin cancer because they have a higher amount of melanin in their skin. Melanin is a dark brown pigment that provides color to the skin and the hair. It also filters out ultraviolet (UV) radiation from sunlight. The more melanin that is produced in a person's body, the darker the skin and the more protected an individual is from cancer-causing UV rays. For instance, dark-skinned black people have a natural sun protection factor (SPF) of more than 13, a level lighter-skinned people can achieve by wearing sunscreen. Darker-skinned people also filter twice the amount of UV rays as white-skinned individuals.

Although people with dark skin are less likely to develop skin cancer, the condition appears to be more dangerous in these populations. Research from the University of Cincinnati suggests that dark-skinned people, including blacks, Asians, Hispanics and Native Americans, are much more likely to die from skin cancer than white people.

"There's a perception that people with darker skin don't have to worry about skin cancer, but that's not true," explains Dr. Hugh Gloster, lead author of the study, in a press release. "Minorities do get skin cancer, and because of this false perception most cases aren't diagnosed until they are more advanced and difficult to treat."

"Unfortunately," he adds, "that translates into higher mortality rates."

The researchers analyzed clinical data collected over the past 50 years by medical centers in North America, Asia and Africa to establish which features of skin cancer occur exclusively in dark skin. The rates of basal and squamous cell carcinomas and melanomas remained relatively constant in black people, while they increased between 5 and 8 percent in white people. However, black patients have a much lower survival rate for skin cancer.

The researchers also discovered that blacks were 8.5 times more likely to develop squamous cell carcinoma on areas shielded from the sun (e.g., the palms, toes, mucous membranes) than on areas regularly exposed to the sun (e.g., nose, ears, back of the hands). This suggests that UV radiation plays less of a role in the development of squamous cell carcinoma in minorities than it does in whites.

These findings are significant because they stress the importance of teaching skin cancer prevention methods and skin self-examination techniques to minorities.

Details of the study were provided by the University of Cincinnati in a press release. The research was presented at the summer meeting of the American Academy of Dermatology in San Diego, California.

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