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University of Iowa News Release

June 16, 2003

Reduced Body Hair Growth May Lead To Pigmented Lesions And Melanoma

A recent study by University of Iowa researchers indicates that Caucasian men with diminished body hair growth may be at a greater risk for developing some pigmented lesions that may progress into malignant melanoma, or skin cancer.

The study found an inverse relationship between the density of body hair growth and the number of pigmented lesions. The finding is consistent with the researchers' hypothesis that in the absence of normal body hair growth, melanocytes (cells that produce melanin, a dark pigment) in hair follicles may develop into pigmented lesions. For the study, a pigmented lesion was classified as a darkly pigmented spot at least three millimeters in diameter. Joanne Tobacman, M.D., UI assistant professor (clinical) of internal medicine, led the study.

"The study reflects the hypothesis that some pigmented lesions may arise from the melanocytes of the hair follicles rather than just the melanocytes in the skin," Tobacman said. "The research may help us to think about new ways of treating malignant melanomas."

The study participants included 10 patients with a history of malignant melanoma and 22 control patients without a cancer history. The participants in the study were all Caucasian males of similar height, age and weight, and of similar socioeconomic, occupational, ethnic and sun exposure backgrounds. Tobacman and co-investigator Duane Whitaker, M.D., UI professor of dermatology, determined hair density and lesion counts at nine body sites for each participant.

The investigators found a significant inverse relationship between body hair density and pigmented lesions in the melanoma patients for the chest, upper back, upper arm and forearm, all common sites for melanoma development. The melanoma patients had a higher number of pigmented lesions, on average, than the control group at each site on their body (e.g. chest, leg) and had many more pigmented lesions overall.

These findings may have an impact on future research and treatment of melanoma, Tobacman said. The study reported that the presence of a hair associated with a pigmented lesion might help distinguish the lesion as benign (non-cancerous). The study also indicated that avoiding medications that may cause hair loss may help prevent the development of lesions, although more research is needed.

"It would be interesting if we could develop clinical trials with a drug like minoxidil, which is used to increase hair growth, and see if it would have any impact on melanomas," Tobacman said.

Another co-investigator of the study was Bridget Zimmerman, Ph.D., director of the UI Biostatistics Consulting Center. The study results were published in the February 2003 issue of Melanoma Research.

University of Iowa Health Care describes the partnership between the UI Roy J. and Lucille A. Carver College of Medicine and UI Hospitals and Clinics and the patient care, medical education and research programs and services they provide. Visit UI Health Care online at

STORY SOURCE: University of Iowa Health Science Relations, 5139 Westlawn, Iowa City, Iowa 52242-1178

MEDIA CONTACT: Becky Soglin, 319-335-6660, Writer: Jessie Rolph

PHOTO: A photo of Dr. Joanne Tobacman is available for downloading at