Individuals with melanoma on their scalp or neck appear less likely to survive for five or 10 years than those with melanoma at other sites, according to a report in the April issue of Archives of Dermatology, one of the JAMA/Archives journals.
Melanoma rates continue to increase while rates for most other cancers decline, according to background information in the article. The significance of tumor location in determining cancer prognosis has been debated for decades, the authors note. “Understanding the role of anatomic site in melanoma survival is important for public health messages on skin awareness and sun protection,” they write. “Moreover, because the role of screening in melanoma is considered important for early detection, it is useful to clarify those characteristics with prognostic significance.”
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 (83.1 percent vs. 92.1 percent) and 10 years (76.2 percent vs. 88.7 percent) 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.
Source: JAMA and Archives Journals
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