New Study May Help Refine Sentinel Node Biopsy Decisions for Melanoma Patients
Source: Moffitt Cancer Centre, October 2024
A new study presented at the Society for Melanoma Research annual meeting could influence how early-stage melanoma patients are selected for sentinel node biopsy, a surgical procedure often used to determine if melanoma has spread to the lymph nodes. The MERLIN_001 trial was designed to evaluate whether a new gene expression profile test could help doctors more accurately predict which patients are at low risk of lymph node involvement, potentially sparing them from unnecessary surgery.
Sentinel node biopsy is a common staging procedure for patients with melanoma, especially those with tumors that are at least 0.8 millimeter thick as measured under the microscope. Current guidelines routinely recommend the procedure for patients with a 10% or greater risk of lymph node metastasis, and in many centers including Moffitt Cancer Center, most healthy patients with at least a 5% risk of having melanoma in their sentinel node are considered for the surgery. But whether the threshold used is 5% or 10%, that still means that most patients who undergo the sentinel node biopsy procedure won’t be found to have cancer in their lymph nodes. So, surgeons and researchers have been looking for better ways to predict who truly needs to undergo the surgery.
The test that was evaluated in the MERLIN_001 trial, called the CP-GEP (Clinicopathologic and Gene Expression Profile) test, was developed specifically to identify patients with either a low risk or a high risk of having a sentinel node metastasis, but a large study was needed to see if the CP-GEP test could identify patients’ risk precisely enough to be clinically useful. The test combines two clinical factors – the primary melanoma tumor’s thickness and the patient’s age – with genetic information from the patient’s tumor biopsy.