Skin cancer: Ethnic skin not immune

San Francisco - Physicians need to stress behavior modification to prevent skin cancer in their non-Caucasian patients. This population is not immune to sun-related skin problems.

"When it is diagnosed in ethnic patients, it is usually at a more advanced stage. Patients tend to have a worse prognosis and higher mortality and morbidity," he tells Dermatology Times.

Not considered a problem

"Physicians don't typically look for skin cancers in these patients," explains Dr. Gloster, who is an associate professor of dermatology and director of dermatology surgery at the University of Cincinnati.

"At the same time, these patients think of themselves as immune from getting skin cancers. Public education campaigns, for the most part, have not targeted ethnic populations because it's not thought of as a big problem for them. Physicians should be conducting regular skin exams of these patients and encouraging self-examination as well," Dr. Gloster says.

Some pre-existing conditions such as pigmented lesions, chronic inflammation, burn scars or physical or thermal trauma can increase the risk of blacks developing a condition like squamous cell carcinoma, he says.

Research study

A study published in the Journal of the American Academy of Dermatology retrospectively reviewed 163 black patients who had 176 squamous cell carcinomas of the skin. The lesions were about 20 percent more common than basal cell carcinomas in blacks of the same patient population. The mortality rate was 18.4 percent.

Another study published in 2002 found that nearly half of the total 35 subjects with squamous cell carcinoma had lesions on their legs with features that were atypical. The study concluded that looking for cutaneous changes such as mottled pigmentation might help physicians make the diagnosis of squamous cell carcinoma.

Melanoma is more common among Caucasians, with the age-adjusted incidence being 18.9 per 100,000 in the United States, compared to (per 100,000) 4.01 in the Hispanic population, 2.02 in the American Indian/Alaskan Native population, 1.46 in the Asian or Pacific Islander population and 1.02 among blacks. Melanoma and basal cell carcinoma are seven times less frequent in Hispanics than in Caucasians.

Non-sun exposed areas

When melanoma does occur in blacks, Asians or Hispanics, it mainly occurs in non-sun-exposed areas such as palms, soles, fingers, toes, subungual area and mucous membranes. By contrast, it occurs on the trunk of the body in Caucasian men and on the legs of Caucasian women. Acral melanoma, which is usually diagnosed at a later stage and shows poorer survival than melanomas that occur at other sites, is more common in blacks, Asians or Hispanics.

"Physicians should watch out for any pigmentation that grows under the nails or palms, or the genitals," says Dr. Gloster. "When they are diagnosed, they are thicker and more advanced. They occur in areas where you would not look for melanoma. If it is caught early, it can be cured for the most part through excision. If it is advanced, it can spread to the lymph nodes and other organs."

Basal cell carcinoma

Basal cell carcinoma that occurs in blacks is related to intense ultraviolet exposure. One study published in the Journal of the American Academy of Dermatology found that response to therapy was effective in 14 cases where lesions were largely asymptomatic and hyperpigmented and were diagnosed as benign before the biopsy.