LOS ANGELES — Only 6% of patients with melanoma present with the disease on the scalp or neck, but these patients account for 10% of melanoma deaths, Anne M. Lachiewicz reported in a poster presentation at the annual meeting of the Society for Investigational Dermatology.
Patients with scalp/neck melanomas died at nearly twice the rate of patients with melanomas on extremities, the face, or the ears in a retrospective study of 51,704 melanoma cases, said Ms. Lachiewicz, a medical student at the University of North Carolina, Chapel Hill.
Full-skin examinations should include a careful look at the scalp. Five-year survival for the patients in the study with scalp/neck melanomas was 83%, compared with 92% for patients with melanomas at other sites. Ten-year survival rates were 76% with scalp-neck melanomas and 89% with other melanomas.
Compared with other melanomas, scalp/neck melanomas increased the risk for death by 92% after controlling for the effects of age, sex, melanoma thickness, ulceration, lymph node status, and extent of ultraviolet light exposure.
The data came from 13 Surveillance Epidemiology and End Results (SEER) Registries that cover 14% of the U.S. population in 11 states. Ms. Lachiewicz and her associates looked at cases of first invasive melanoma among non-Hispanic white adults during 1992–2003.
Patients with scalp/neck melanomas generally were older (mean age 59 years) than patients with other melanomas (mean age 55 years), and they were more likely to be male (74% vs. 54%, respectively). At diagnosis, melanomas of the scalp/neck were thicker (0.7 mm) than melanomas at other sites (0.6 mm) and more likely to be ulcerated, nodular, or lentigo maligna subtypes. Lymph-node involvement was more common in patients with scalp/neck melanoma.
“They're clearly presenting later” in the scalp/neck group, Ms. Lachiewicz said.
Melanomas on the extremities or on the face or ears had the best prognosis after controlling for factors other than anatomic location. Melanomas on the trunk carried an intermediate risk, with a 26% greater risk of death compared with melanomas on extremities.
Besides location on the scalp/neck or trunk, other independent predictors of poor prognosis included older age, greater lesion thickness, male sex, ulceration, and positive lymph nodes.
The age-adjusted incidence rate for melanoma using the SEER data was 25 per 100,000 people. The mean age at diagnosis was 56 years, and the median lesion thickness was 0.64 mm. Males comprised 56% of patients.
The anatomic sites at diagnosis included 18% on the neck or head (of which 6% were scalp or neck and 12% were face or ears). Another 34% of lesions were on the trunk, 43% on an extremity, and 4% were unclassified or on overlapping sites. Five percent of patients had ulcerated melanomas, and 6% had melanoma in their lymph nodes.
These results could inform public health messages concerning melanoma. Emphasizing partner skin exams and educating hairdressers may help catch scalp melanomas earlier, she suggested.
Five-year survival associated with scalp/neck melanomas was 83%, compared with 92% for those at other sites. MS. LACHIEWICZ
If hairdressers were trained, it could help catch scalp melanomas earlier. Courtesy Anne M. Lachiewicz/UNC Dermatology