The addition of cell adhesion-linked gene expression variables to clinicopathologic variables improves the identification of patients with sentinel lymph node (SLN) metastases within 90 days of thin or intermediate-thickness melanoma diagnosis, a new study published online ahead of print in the Journal of Clinical Oncology has shown.
According to the study, fewer than 20% of patients with melanoma who undergo SLN biopsy are SLN positive. Therefore, researchers from Mayo Clinic in Rochester, MN, and Jacksonville, FL, as well as their colleagues at Hospital Roskilde in Copenhagen, Denmark, sought to identify new molecular risk factors associated with SLN positivity in patients with thin and intermediate-thickness melanoma.
Researchers used next-generation gene sequencing to identify gene mutations in a set of benign tumors, primary cutaneous melanomas, and in-transit melanoma metastases. Then, researchers validated their findings in a cohort of 146 melanomas.
Results showed that ITGB3, LAMB1, and TP53 expression were associated with SLN metastasis. Researchers found that a predictive model that included clinicopathologic variables, such as patient age, Breslow depth, and tumor ulceration, plus these molecular variables had significantly better predictive ability than a model that solely included clinicopathologic variables.
The study also demonstrated that false-positives occurred 22% of the time with the combination predictive model and false-negatives occurred 0% of the time.