New Data from DECIDE Study Show the Significant Role of DecisionDx®-Melanoma Test Results and Patient Preference in Decisions to Perform the Sentinel Lymph Node Biopsy (SLNB) Surgical Procedure

Study data also show that using certain DecisionDx-Melanoma test results in conjunction with current guidelines can reduce the number of SLNB procedures performed, particularly in patients with a low biological risk of metastasis

FRIENDSWOOD, Texas--(BUSINESS WIRE)-- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced new data from its prospective, multicenter DECIDE1 study in which DecisionDx®-Melanoma test results influenced 85% of clinicians’ decisions regarding the sentinel lymph node biopsy (SLNB) surgical procedure, demonstrating the role of the test’s results in guiding risk-aligned patient management decisions.

“Melanoma is an aggressive and deadly disease, thus any decisions on whether to forego a procedure like an SLNB cannot be taken lightly,” said J. Michael Guenther, M.D., surgical oncologist at St. Elizabeth Physicians in Edgewood, Kentucky. “The clinically actionable information that DecisionDx-Melanoma provides is precious to both doctors and patients. It enables me to have more productive conversations with my patients, so we can make shared, informed decisions about their overall care; this includes decisions on whether to pursue an SLNB if their risk of a positive sentinel lymph node is low.”

The data was presented during the 19th International Congress of the Society for Melanoma Research (SMR), held Oct. 17-20 in Edinburgh, United Kingdom, through a poster (# P- 037) titled, “Clinical use of the 31-gene expression profile for informing sentinel lymph node biopsies: a prospective, multicenter study.” The poster can be viewed here.

SLNB surgery is used to determine whether a patient’s melanoma has spread to the lymph node; the procedure has the potential for complications and returns a biopsy that is negative for metastatic spread in up to 88% of patients who undergo the procedure.2-3 DecisionDx-Melanoma is a gene expression profile risk stratification test designed to inform two clinical questions in the management of cutaneous melanoma: a patient’s individual risk of sentinel lymph node (SLN) positivity and a patient's personal risk of melanoma recurrence and/or metastasis. The test has been validated to identify patients who have less than a 5% risk of a positive SLN, indicating that these patients could safely forego the SLNB surgical procedure, and improve the yield of positive SLNBs by identifying patients more likely to have a positive SLNB result.4-5

Study highlights:

• The prospective, multicenter study included patients with invasive cutaneous melanoma (tumors staged as T1a (and at least one high-risk feature), T1b and T2) who were considering the SLNB surgical procedure.
• Clinicians received DecisionDx-Melanoma test results prior to making SLNB decisions and were asked which features influenced their decision on whether to perform the procedure. Potential influencing factors included patient preference, clinical and pathological features and DecisionDx-Melanoma results.
• The data showed that DecisionDx-Melanoma test results influenced 85% of SLNB decisions, and that DecisionDx-Melanoma test results and patient preference played a significant role in influencing the decision to undergo or forego SLNB.
  • When DecisionDx-Melanoma test results influenced for SLNB, the procedure was performed in 92% of the cases in the study; similarly, when the test result influenced against SLNB, the decision was made to forego SLNB in 70% of cases. This data indicates that the test’s results in conjunction with current guidelines can guide risk-aligned clinical decision-making regarding the SLNB surgical procedure.
• The use of DecisionDx-Melanoma test results in conjunction with current guidelines resulted in a significant reduction of SLNB procedures performed, most notably a 29% decrease in SLNBs performed for patients with a low-risk (Class 1A) test result, compared to SLNB decisions made based on a patient’s clinicopathologic risk factors alone (p