Prognostic variables in patients with thick melanomas. Analysis of 362 cases

Melanoma epidemiological and prognostic studies are based on Caucasian populations, in whom the predominant subtype is superficially-spreading melanoma and in whom thin melanomas (Breslow < 3 mm) predominate. Mexican patients show a predominance of thick melanomas (Breslow ≥ 3 mm), and the acral subtype is the most common. There are no publications on prognostic factors in thick melanomas. We hypothesize that we will identify factors that determine the prognosis in this group of patients.

To identify clinical-pathological factors associated with the prognosis of patients with thick melanomas in the Mexican population.

Data on melanomas with Breslow > 3 mm were collected from 2010 to 2015. The prognostic influence of various clinical-pathological factors was analyzed.

The most common subtypes were acral melanoma in 271 patients (74.9 %) and nodular melanoma in 49 (13.5 %). Median Breslow thickness was 7 mm. 56.6 % of the patients had lymph node metastases (clinical stage [CS] III), 269 (74.3 %) had ulceration, and surgical margins were positive in 15 (4.1 %). Elevated neutrophil: lymphocyte ratio (≥ 2) was found in 188 (51.9 %). The variables associated with lower overall survival were CS (p < 0.001), Breslow thickness (p = 0.044), ulceration (p = 0.004), mitotic activity (p < 0.001), < 2-cm margin (p < 0.001) and an increased neutrophil: lymphocyte ratio (p = 0.037). In the multivariate analysis, the factors associated with overall survival were CS, mitotic activity, and surgical margin.

In patients with thick melanomas, overall survival is influenced by mitotic activity, a positive margin, and clinical stage.