The influence of body mass index on the survival of patients with melanoma. A cross-sectional study of 707 patients

Introduction Obesity has been linked with an increased incidence of melanoma; however, there are few data about its impact on melanoma prognosis. We aimed to determine if there is an association between body mass index (BMI) and overall survival (OS) in 707 patients with melanoma. Material and methods A retrospective study of 707 patients with melanoma collected consecutively from 2005 to 2015 with a diagnosis of melanoma, who were been diagnosed and treated in our institution and who had clinical follow-up was carried out. Survival analysis was performed comparing patients according to their BMI. Results In a multivariate analysis, factors influencing the 5-year OS were a positive margin (HR = 3.475, 95% CI: 1.829-6.600), the clinical-stage (HR = 2.565, 95% CI: 2.020-3.257, per switch to the upper stage), ulceration (HR = 3.475, 95% CI: 1.829-6.600), and BMI (HR .905, p = 0.018 for the overweight group; HR = 0.663, p = 0.021 for obesity grade I). Conclusions Patients who had a BMI between 25 and 34.9 kg/m2 had better survival.