To compare the prognosis of patients with scalp or neck (scalp/neck) melanomas with that of patients with melanomas at other sites in a large, population-based national data set controlling for known prognostic factors.
Retrospective cohort study using US cancer registries that constitute the Surveillance, Epidemiology, and End Results 13 Registries (SEER-13) database.
A total of 51 704 non-Hispanic white adults in the United States with a first invasive cutaneous melanoma reported during the period 1992 to 2003.
Main Outcome Measures
Kaplan-Meier survival estimates were used to compare melanoma-specific survival by anatomic site at 5 and 10 years. Multivariate Cox models were used to examine the hazard ratio (HR) of melanoma-specific death associated with scalp/neck melanoma compared with melanoma of the extremities after controlling for other variables.
The 5- and 10-year Kaplan-Meier survival probabilities for scalp/neck melanoma were 83.1% and 76.2%, respectively, compared with 92.1% and 88.7%, respectively, for melanoma of the other sites, including extremities, trunk, face, and ears (log-rank test; P < .001). In a multivariate Cox model, the patients with melanoma of the scalp/neck died of melanoma at 1.84 times (HR, 1.84; 95% confidence interval, 1.62-2.10) the rate of those with melanoma on the extremities, controlling for age, Breslow thickness, sex, and ulceration. Neither excluding cases of lentigo maligna and nodular melanoma nor controlling for lymph node involvement materially changed the HR for scalp/neck melanoma.
A notable survival difference remained between scalp/neck melanoma and melanoma of other sites even after adjustment for important prognostic factors. This finding has implications for screening and public health recommendations, and we urge physicians, physician assistants, nurses, and nurse practitioners to examine the scalp/neck carefully during routine skin examinations. Further studies are needed to understand the biological or environmental factors leading to survival differences by anatomic site.