J. Lizalek1, C. Dougherty1, J. Mammen1 1University Of Nebraska College Of Medicine, Surgical Oncology, Omaha, NE, USA
Introduction:
The management of early-stage melanoma typically includes sentinel lymph node (SLN) biopsy for prognostic and treatment planning purposes. While the minimum necessary number of SLNs has been determined for patients with breast cancer, it has not been delineated in melanoma. The current study evaluates risk factors for SLN positivity and the number of SLNs that should be removed for appropriate staging.
Methods:
The National Cancer Database Participant User File from 2018-2020 was queried for patients with clinical node-negative subjects who underwent SLN biopsy. Descriptive statistics were obtained. ANOVA statistical analyses performed.
Results:
5,142 melanoma patients were identified from 2018-2020 that had lymph node positivity on SLN biopsy, out of 32,516. The median age of positive patients was 62. The male-to-female ratio was 1.50. One-way ANOVA revealed that there was a statistically significant difference in positivity rate between at least two groups (F(9, 32514)=39.9, p=<0.001) for primary melanoma site. One-way ANOVA also showed a statistically significant difference (F(7, 32514)=24.18, p=<0.001) by age groups with positivity decreasing with age. SLN positivity rate increases with the number of SLNs examined until plateauing at 3 SLNs (Figure 1). There was no statistical difference between positivity for 3 SLNs and larger numbers of SLNs examined.
Conclusion:
SLN positivity for patients with melanoma is dependent on primary melanoma location and age. SLN positivity increases with the number of SLNs examined until it plateaus at 3 lymph nodes, suggesting that surgeons should remove a minimum of 3 SLNs for the optimal staging patients with melanoma.
