Castle Biosciences Study Validates DecisionDx-Melanoma’s Accuracy in Predicting Low SLN Positivity
Event summary
- Castle Biosciences presented data from a 912-patient study at the SSO 2026 Annual Meeting, confirming DecisionDx-Melanoma’s i31-SLNB test accurately predicts sentinel lymph node (SLN) positivity.
- Patients with less than 5% predicted risk had a 2.6% actual SLN positivity rate, aligning with NCCN guidelines recommending against SLNB for such low-risk patients.
- The study found that patients with high-risk i31-SLNB results (>10% risk) were 13.2 times more likely to be SLN-positive.
- DecisionDx-Melanoma’s integrated algorithm combines a 31-gene expression profile with clinicopathologic factors to provide personalized risk assessments.
The big picture
The study reinforces Castle Biosciences’ leadership in precision risk assessment for melanoma, addressing a critical need for more accurate SLNB decision-making. As oncology shifts toward personalized medicine, tests like DecisionDx-Melanoma could reduce unnecessary procedures while improving patient outcomes. The integration of molecular and clinicopathologic data represents a growing trend in diagnostic innovation, particularly in cancer care.
What we're watching
- Clinical Adoption
- Whether the study results will accelerate adoption of DecisionDx-Melanoma among clinicians for SLNB decision-making.
- Regulatory Alignment
- How NCCN and other guidelines may evolve to incorporate DecisionDx-Melanoma’s risk stratification thresholds.
- Competitive Positioning
- The pace at which Castle Biosciences can differentiate its test from other predictive gene expression profile tests in the melanoma space.
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