Sentinel Lymph Node Drainage Can Be Used to Test For Marker of Melanoma Relapse Risk Interview with:

Héctor Peinado PhDMicroenvironment and Metastasis LaboratoryMolecular Oncology ProgramSpanish National Cancer Research CenterMadrid, Spain

Dr. Peinado

Héctor Peinado PhD
Microenvironment and Metastasis Laboratory
Molecular Oncology Program
Spanish National Cancer Research Center
Madrid, Spain What is the background for this study? What are the main findings? 

Response: In this study we detected for the first time BRAF mutation by liquid biopsy in melanoma stage III patients that underwent lymphadenectomy. We obtained a novel biofluid from the drainage implanted 24-48 hours post-lymphadenectomy, called exudative seroma, and profiled BRAF mutation in circulating free DNA and extracellular vesicles.

Those patients positive for BRAF mutation in the seroma had increased risk of relapse, therefore we believe that this technique identifies patients at risk of relapse by identifying residual disease.

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Melanoma: Study Examines Metastases in Nonhottest Sentinel Nodes Interview with:
Lyn McDivitt Duncan, MD
Professor of Pathology, Harvard Medical School
Chief, Dermatopathology Unit and
Su Luo, MD Dermatology Resident
Massachusetts General Hospital
Boston, MA 02114

Medical Research: What is the background for this study? What are the main findings?

Response: We studied 475 patients with cutaneous melanoma diagnosed at the Massachusetts General Hospital (MGH) who also had a sentinel lymph node biopsy procedure performed.  There is a practice gap in the sentinel lymph node biopsy procedure ranging from removal of one “sentinel” lymph node to removing the hottest lymph node and any lymph nodes with radioactive tracer of 10% or more of the hottest lymph node’s counts (with an average of three lymph nodes removed).  At the MGH we use this latter method.  We examined the sentinel lymph nodes in each case to determine whether the positive cases with microscopic melanoma metastases had metastases only in the most radioactive, or “hottest”, node or whether tumor was also present in the less hot nodes. We found that in 19% of positive cases there were metastases present only in the less hot nodes. We also performed survival analysis and showed that the less hot nodal positive cases are of equivalent prognostic significance.  We found that removal of only the hottest lymph node would have led to under-staging of 19% of patients with melanoma.

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