Obesity is not associated with disease-free interval, melanoma-specific survival, or overall survival in patients with clinical stage IB-II melanoma after SLNB.

Background and objectives Clinicopathologic characteristics have prognostic value in clinical stage IB-II patients with melanoma. Little is known about the prognostic value of obesity that has been associated with an increased risk for several cancer types and worsened prognosis after diagnosis. This study aims to examine effects of obesity on outcome in patients with clinical stage IB-II melanoma. Methods Prospectively recorded data of patients with clinical stage IB-II melanoma who underwent sentinel lymph node biopsy (SLNB) between 1995 and 2018 at the University Medical Center of Groningen were collected from medical files and retrospectively analyzed. Cox-regression analyses were used to determine associations between obesity (body mass index> 30), tumor (location, histology, Breslow-thickness, ulceration, mitotic rate, SLN-status) and patient-related variables (gender, age, and social-economic-status [SES]) and disease-free interval (DFI), melanoma-specific survival (MSS), and overall survival (OS). Results Of the 715 patients, 355 (49.7%) were women, median age was 55 (range 18.6-89) years, 149 (20.8%) were obese. Obesity did not significantly affect DFI (adjusted hazard ratio [HR] = 1.40; 95% confidence interval [CI] = 0.98-2.00; p = 0.06), MSS (adjusted HR = 1.48;95%CI = 0.97-2.25; p = 0.07), and OS (adjusted HR = 1.25; 95% CI = 0.85-1.85; p = 0.25). Increased age, arm location, increased Breslow-thickness, ulceration, increased mitotic rate, and positive SLN-status were significantly associated with decreased DFI, MSS, and OS. Histology, sex, and SES were not associated. Conclusion Obesity was not associated with DFI, MSS, or OS in patients with clinical stage IB-II melanoma who underwent SLNB.