The cancer known as cutaneous T-cell lymphoma became substantially more common in the United States between 1973 and 2002, according to a report in the July issue of Archives of Dermatology, one of the JAMA/Archives journals. The rates of the disease vary by race, sex and geographic area.

Cutaneous T-cell lymphoma occurs when certain cells of the lymph system (called T lymphocytes) become cancerous and affect the skin. The term covers several types of lymphoma, according to background information in the article. The nationwide rates of the disease were last documented in 1992.

Vincent D. Criscione, A.B., and Martin A. Weinstock, M.D., Ph.D., of the VA Medical Center, Rhode Island Hospital, and Brown University, Providence, R.I., used data from 13 cancer registries of the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute to describe incidence trends in cutaneous T-cell lymphoma from 1973 through 2002.

A total of 4,783 cases were identified in the 30-year period, a rate of 6.4 per million persons and a total of 0.14 percent of all cancers and 3.9 percent of non-Hodgkin's lymphomas. The overall incidence increased each decade, was higher among blacks than whites and among men than women, increased substantially with age, and varied geographically. The San Francisco registry had the highest rates - 9.7 per million white individuals and 10.8 per million black individuals - while the Iowa registry had the lowest, with 3.7 per million white individuals and 5.8 per million among blacks.

"The geographic differences in incidence are substantial even after controlling for race. Incidence is correlated with high physician density and several indexes of socioeconomic status such as median family income, percentage of the population with a bachelor's degree or higher and median home value," the authors write. "These geographic differences in incidence may be related, to some degree, by differences in access to medical care."

Changes and ambiguities in classifications and coding may be partially responsible for the increase in incidence over time, the authors note, as may improved detection and advances in medical technology. "An epidemiological investigation using population-based data is important to better understand this disorder," they conclude. However, "these data may be useful in planning public health strategies, identifying risk factors and understanding the etiology of this cancer so that it may some day be prevented."

Arch Dermatol. 2007;143(7):854-859
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This project was funded by a grant from the Cutaneous Lymphoma Foundation. Dr. Weinstock was supported by grants from the Department of Veterans Affairs, Office of Research and Development, Washington, D.C., and from the National Cancer Institute, Bethesda, Md.

Editorial: Patients Helping to Solve Disease's Mystery

Scientists have been attempting for 200 years to uncover the underlying causes of cutaneous T-cell lymphoma, and while the disease remains mysterious, dermatologists and patients have begun working together to understand it, writes Stuart R. Lessin, M.D., of the Fox Chase Cancer Center, Philadelphia, in an accompanying editorial.

"Many etiologic factors have been advanced and studied, but none have been conclusive," Dr. Lessin writes. "These have included occupational exposures, viruses (Epstein-Barr virus, human T-lymphotropic virus 1 and human herpesvirus 6) and bacteria (staphylococcal superantigens)."

"While the increased incidence of cutaneous T-cell lymphoma remains unexplained, it demonstrates the increasing importance of the role of the dermatologist to remain at the forefront of diagnosis and treatment" of the disease, Dr. Lessin continues.

Arch Dermatol. 2007;143(7):916-918
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Dr. Lessin serves as chairman of the Medical Advisory Board and as a member of the Board of Directors of the Cutaneous Lymphoma Foundation, the organization that funded the project that is the subject of this editorial.