New research outlines key features linked to amelanotic melanoma.

The findings, which appear in JAMA Dermatology, may help improve detection of this type of melanoma, which is more likely to be diagnosed at advanced stages because it falls outside of the “ABCDE” guidelines.

The researchers analyzed the characteristics of 178 patients with this disease drawn from a study of 2,995 melanoma patients enrolled in The Genes, Environment, and Melanoma study. The international study enrolled patients from 1998 to 2004.

People who lacked moles on their backs, who had many freckles, and “sun-sensitive” features – including red hair, light-colored eyes and an inability to tan -- had higher odds of developing amelanotic melanoma, the researchers found. In addition, people who previously had this disease were at higher risk, as were people who had variants of the MC1R gene that are linked to red hair.

“If patients have these traits, they need to be more carefully screened,” says the study’s senior author Nancy E. Thomas, MD, PhD, a University of North Carolina Lineberger Comprehensive Cancer Center member, the Irene & Robert Alan Briggaman Distinguished Professor and chair in the UNC School of Medicine Department of Dermatology. “We hope this helps raise awareness for the potential for amelanotic melanoma in this group.”

Amelanotic melanoma is linked to worse survival because it’s more likely to be diagnosed at a later stage, Thomas says. “We have identified phenotypic traits that will trigger doctors and patients to pay attention not just to pigmented lesions, but also to these pink spots.”

About 2 to 8 percent of melanomas are amelanotic, studies have shown. These skin cancers are seen predominately in white patients, and develop as pink growths.

In addition to Thomas, other authors include: Steven Vernali; Weston T. Waxweiler; Patrick M. Dillon; Peter A. Kanetsky; Irene Orlow; Li Luo; Klaus J. Busam; Anne Kricker; Bruce K. Armstrong; Hoda Anton-Culver; Stephen B. Gruber; Richard P. Gallagher; Roberto Zanetti; Stefano Ross; Lidia Sacchetto; Terence Dwyer; Anne E. Cust; David W. Ollila; Colin B. Begg; and Marianne Berwick.

The study was supported by the National Cancer Institute, National Institute of Environmental Health Sciences, and University of Sydney Medical Foundation Program. Individual researchers were supported by the National Health and Medical Research Council and Cancer Institutes of New South Wales.

PHOTO CAPTION: Nancy E. Thomas, MD, PhD, is a UNC Lineberger member, the Irene & Robert Alan Briggaman Distinguished Professor and chair in the UNC School of Medicine Department of Dermatology.