People with scalp or neck melanomas die at nearly twice the rate of people with melanoma elsewhere on the body, including the face or ears, researchers at the University of North Carolina at Chapel Hill have found.
The analysis of 51,704 melanoma cases in the US confirms that survival rates differ depending on where skin cancer first appears. Those with scalp or neck melanomas die at a rate 1.84 times higher than those with melanomas on the extremities, after controlling for the possible influences of age, gender, tumor thickness and ulceration.
Nancy Thomas, the study's senior author, recommends that physicians pay special attention to the scalp when examining patients for signs of skin cancer. "Only 6% of melanoma patients present with the disease on the scalp or neck, but those patients account for 10% of melanoma deaths. That's why we need to take extra time to look at the scalp during full-skin examinations."
The study helps address a controversy among cancer researchers: whether scalp and neck skin cancer is more lethal primarily because it's diagnosed later than other melanomas.
"That was the thinking of a lot of people in the field," Thomas said. But the analysis indicates that the presence of the melanoma on the scalp or neck, in itself, is an indicator of a poorer prognosis.
"We think there's something different about scalp and neck melanomas," Thomas said. "This gives us directions for research to look at tumor cell types in those areas at the molecular level and to see if there are differences. I'm interested in identifying the mutations that drive malignancy."
Melanomas on the extremities or on the face or ears had the best prognosis. The five-year melanoma-specific survival rate for patients with scalp or neck melanomas was 83%, compared with 92% for patients with melanomas at other sites. The 10-year survival rate was 76% for scalp or neck melanomas and 89% for other melanomas.
The results appear in the April issue of the journal Archives of Dermatology.