Primary melanoma location on the scalp is an important risk factor for brain metastasis: a study of 1,687 patients with cutaneous head and neck melanomas

BACKGROUND: Primary cutaneous head and neck melanomas (HNM) are reported to be associated with a higher incidence of brain metastasis than trunk and limb melanomas (TLM). In this study, the incidence of brain metastases in patients with HNM and risk factors for the development of brain metastases were analyzed.

METHODS: From a large, prospectively-collected database, 1,687 HNM patients and 8,793 TLM patients who presented with American Joint Committee on Cancer (AJCC) stage I and II disease were identified. Survival was assessed using the Kaplan-Meier method and multivariate Cox regression analysis. Independent risk factors were determined by binary logistic regression analysis.

RESULTS: The incidence of brain metastases 5 years after diagnosis of HNM was 6.7 % compared with 4.7 % for brain metastases from TLM (p = 0.003). Patients with scalp melanomas were most likely to develop brain metastases (12.7 %). Independent risk factors for brain metastasis in patients with HNM were Breslow thickness, ulceration, and scalp location.

CONCLUSION: Patients with primary scalp melanomas had a much higher incidence of brain metastasis than patients with melanomas on other head and neck sites, who in turn had a higher incidence than patients with melanomas on sites elsewhere on the body. More intensive monitoring of patients with scalp melanomas, who are at particularly high risk of brain metastasis, might lead to earlier discovery of metastatic disease in the brain, offering the prospect of earlier intervention and better outcomes.