Castle Biosciences Study Validates DecisionDx-Melanoma’s Precision in Reducing Unnecessary SLNB Procedures
Event summary
- Prospective multicenter study published in Future Oncology confirms DecisionDx-Melanoma’s i31-SLNB test outperforms traditional staging criteria in identifying low-risk melanoma patients.
- Among 912 patients, those with <5% predicted SLN positivity by i31-SLNB had a 2.6% actual SLN positivity rate and 97.8% three-year recurrence-free survival.
- i31-SLNB demonstrated TN:FN ratios of 55:1 in T1–T2a patients and 73:1 in T1b–T2a subgroup, exceeding NCCN guideline benchmarks.
- Castle Biosciences to host investor webcast on March 23, 2026, to discuss findings.
The big picture
The study validates Castle Biosciences’ ability to reduce unnecessary sentinel lymph node biopsies (SLNB) in melanoma patients, aligning with broader trends in precision oncology. By integrating molecular insights with clinicopathologic features, DecisionDx-Melanoma’s i31-SLNB supports risk-aligned decision-making, potentially lowering healthcare costs and improving patient outcomes. The findings position Castle Biosciences as a leader in personalized melanoma diagnostics, with implications for other cancer diagnostic markets.
What we're watching
- Adoption Dynamics
- Whether the study results will accelerate physician adoption of DecisionDx-Melanoma’s i31-SLNB for early-stage melanoma patients.
- Regulatory Impact
- How NCCN and AJCC may incorporate these findings into future guideline updates for melanoma management.
- Competitive Positioning
- The pace at which Castle Biosciences can differentiate its test from other predictive gene expression profile tests in the market.
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