DecisionDx®-Melanoma Can Identify Melanoma Patients with Low Risk of Sentinel Lymph Node Positivity Who May Safely Forego Biopsy Surgery, New Independent Study Affirms

Using the DecisionDx-Melanoma test to guide sentinel lymph node biopsy (SLNB) surgery decisions could have significantly reduced the number of unnecessary SLNBs by 33% for patients with T1-T2 melanoma tumors

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of a new study further demonstrating that DecisionDx-Melanoma can precisely predict sentinel lymph node (SLN) positivity risk to help guide risk-aligned SLNB decisions, potentially reducing the number of unnecessary procedures and increasing the SLNB positivity yield if the procedure is performed. The paper, published in the World Journal of Surgical Oncology and titled “Integrating the melanoma 31-gene expression profile test with clinical and pathologic features can provide personalized precision estimates for sentinel lymph node positivity: an independent performance cohort,” is available here. 

“While SLNB is a common procedure used to determine possible tumor metastasis, our current criteria for biopsy may be overestimating a person’s risk of having a positive node, meaning we are probably performing more surgeries than necessary,” said lead author Joseph Bennett, M.D., MBA, surgical oncologist and system chief of surgery at LifeBridge Health in Baltimore, Maryland. “By using the DecisionDx-Melanoma test to accurately stratify patient risk and help guide these important decisions and discussions with patients, we can avoid doing SLNB procedures in low-risk patients without missing melanoma metastases.”

“Our DecisionDx-Melanoma test has significant clinical utility in helping to rule-out and rule-in SLNB procedures, as this study showed,” added Derek Maetzold, president and chief executive officer of Castle Biosciences. “And as demonstrated by data we shared earlier this year from our ongoing prospective, multicenter DECIDE study, patients with low-risk DecisionDx-Melanoma results whose providers use the test to help guide decisions to avoid SLNB surgery still experience good outcomes.”1

The DecisionDx-Melanoma test integrates a patient’s tumor biology with their personal clinicopathologic factors to help answer the likelihood of SLN positivity and risk of recurrence in patients with melanoma. Current National Comprehensive Cancer Network (NCCN) guidelines suggest foregoing SLNB when the likelihood of finding a positive SLN is less than 5%, to consider SLNB when between 5-10% and to offer the surgery when the likelihood is above 10%. This study evaluated the performance of DecisionDx-Melanoma in predicting the risk of SLN positivity in 156 melanoma patients with known SLN outcomes at the ChristianaCare Helen F. Graham Cancer Center & Research Institute.

In the study, none of the patients (0/30) considered low-risk by the DecisionDx-Melanoma test (less than 5% predicted risk of SLN positivity) had a positive SLN, compared to a 31.9% SLN positivity rate (30/94, p