It seems that those who have melanoma on their scalp or neck are less likely to survive for five or ten years when compared to those who have melanoma at other sites.
Melanoma is a malignant tumor of melanocytes, which are found predominantly in skin but also in the bowel and the eye.
It is one of the rarer types of skin cancer but causes the majority of skin cancer related deaths.
"Understanding the role of anatomic site in melanoma survival is important for public health messages on skin awareness and sun protection," the researchers said.
"Moreover, because the role of screening in melanoma is considered important for early detection, it is useful to clarify those characteristics with prognostic significance," they added.
In the study, Anne M. Lachiewicz, M.P.H., of the University of North Carolina School of Medicine, Chapel Hill, and colleagues analyzed data from U.S. cancer registries for 51,704 individuals first diagnosed with melanoma between 1992 and 2003.
Of those, 43 percent had melanomas on their arms or legs, 34 percent on the trunk, 12 percent on the face or ears, 6 percent on the scalp or neck and 4 percent at an unspecified site.
Survival rates were lower among those with scalp and neck melanoma than among those with melanoma at other sites both five years and 10 years after diagnosis.
"Fourteen percent of those with scalp/neck melanoma and 44 percent of those with melanomas at unknown sites died compared with only 6 percent of those with extremity [arm or leg] melanoma, 8 percent with trunk melanomas and 6 percent with face/ear melanomas," the authors write.
After controlling for other factors-including age, tumor thickness and sex-patients with melanoma on their neck or scalp died at 1.84 times the rate of those with melanoma on their arms or legs.
"The reason for worse survival among patients with scalp/neck melanomas is unclear," the authors write.
The blood supply and lymphatic drainage systems serving these areas are rich and complex, which may make it easier for melanoma cells to penetrate and circulate. In addition, such patients are more likely to have cancer that spreads into their brain than those with melanoma on their arms, legs or trunk. Finally, the skin lesions may be hidden by hair and therefore diagnosed later than those at other sites.
"The recognition that scalp/neck location is associated with poorer melanoma survival has implications for screening and public health recommendations," the authors conclude. "We suggest that all full-skin examinations and future screening studies include a careful inspection of the scalp/neck," the researchers said.
The study is published in the Archives of Dermatology, one of the JAMA/Archives journals.