A type of skin cancer that was rare three decades ago has surged in the United States, a study in the Journal of the American Medical Association (JAMA) found.
The cancer known as cutaneous T-cell lymphoma became increasingly more common in the United States in the decades between 1973 and 2002, according to a study in the July issue of Archives of Dermatology, which is part of JAMA.
"The overall incidence increased each decade, was higher among blacks than whites and among men than women, increased substantially with age, and varied geographically," wrote the authors.
They say the cause is as yet unknown, but added the results of their study were alarming.
Cutaneous T-cell lymphoma can develop when cells of the lymph system (called T lymphocytes) become cancerous and affect the skin. It spreads slowly and can cause red patches on the skin. It is treatable but not curable.
A total 4,783 cases were identified in the 30-year period. That amounts to a rate of 6.4 per million persons and a total of 0.14 percent of all cancers and 3.9 percent of non-Hodgkins lymphomas, the data showed.
But the results varied across the country.
"The geographic differences in incidence are substantial even after controlling for race," said the study led by Vincent Criscione and Martin Weinstock of the VA Medical Center, Rhode Island Hospital, and Brown University, Providence, Rhode Island.
Access to doctors and other social-economic indicators such as levels of income and education appeared to affect the numbers of reported cases, the study found.
San Francisco in California reported the highest rise in the cases with 9.7 for every million among white and 10.8 for every million among African-Americans.
Iowa counted the lowest incidence with a rate of 3.7 per million for the whol population.