Purpose: Elderly melanoma patients are known to have lower survival rates than younger patients with melanoma. Paradoxically, a few recent studies have shown a lower frequency of sentinel lymph node (SLN) positivity in older individuals. This is the first analysis of a large national sample to examine the relationship between SLN metastasis and melanoma death across all age groups.
Methods: The U.S. Surveillance Epidemiology and End Results (SEER) Databases were queried to examine SLN biopsy and mortality outcomes in 158,813 melanoma cases reported from 2003 to 2011, the most current data available in SEER.
Results: In bivariate analyses of the 47,577 cases with coded tumor depths and nodal surgery, increasing age varied directly with melanoma death and inversely with SLN positivity, for tumor depths >1 mm (P < 0.001). In multivariate regression analyses, 60-79 year-olds were more likely to die of melanoma compared with 20-39 year-olds [odds ratio (OR) 1.83, 95 % confidence interval (CI) 1.64-2.05], but they were less likely to be SLN-positive (OR 0.62, 95 % CI 0.57-0.68). The inverse association between melanoma mortality and SLN positivity was most pronounced at the extremes of age.
Discussion: The finding that increasing age is associated with a higher incidence of melanoma death but a lower incidence of SLN metastasis highlights the need for further study into age-related differences in melanoma biology, immunological surveillance, and host response. It also questions whether the 5- and 10-year survival rates associated with the current melanoma staging system should be stratified by age to predict outcomes more accurately for melanoma patients.