Prevalence of sentinel lymph node evaluation in patients with thick primary cutaneous melanoma.

Abstract

e19013 Background: Sentinel lymph node biopsy (SLNB) was developed for intermediate thickness melanoma. Its use for thick cutaneous melanoma is controversial. We aimed to report on clinical and pathologic factors associated with the overuse of SLNB for thick primary cutaneous melanoma. Methods: The Surveillance, Epidemiology, and End Results database was queried for patients who underwent surgery for thick primary cutaneous melanoma (known Breslow thickness > 4.00 mm) from 2004 to 2008. We excluded patients with mucosal melanoma, those without a biopsy-proven diagnosis, those diagnosed at autopsy, patients whose lymph node evaluation was unknown or other than SLNB “yes” or SLNB “no”. We used multivariate logistic regression models to predict use of SLNB. Covariates examined included: age sex, race/ethnicity, Breslow depth, tumor histology, tumor location, and ulceration status. Likelihood of undergoing sentinel lymph node biopsy was reported as odds ratios (OR) with 95% confidence intervals (CI); significance was set at p ≤ 0.05. Results: Among 1,981 patients with thick cutaneous melanoma, 1,158 (58.2%) received a SLNB. On multivariate analysis, patients with primary melanomas of the arm (OR 2.07, CI 1.56-2.75; p<0.001), leg (OR 2.40, CI 1.70-3.40; p<0.001) and trunk (OR 1.82, CI 1.38-2.40; p<0.001) had an increased likelihood of receiving a SLNB, as did those with desmoplastic histology (OR 1.47, CI 1.11-1.96; p=0.008). Conclusions: A significant number of patients with thick melanomas receive a SLNB, even though this procedure was not developed for this patient population. We have identified predictors associated with the use of SLNB. These include: arm, leg and trunk primary sites and desmoplastic histology. Further research to assess whether use of SLNB in this population is detrimental or beneficial is needed.