Background: Although most patients with cutaneous melanoma (CM) will have a negative sentinel lymph node biopsy (SLNB), up to 20%-30% of these patients will recur. The 31-gene expression profile (31-GEP) test has been prospectively validated to identify patients at low (Class 1A), intermediate (Class 1B/2A), and high (Class 2B) risk of SLN positivity and recurrence.
Methods: DECIDE is a prospective, multicenter study to assess the effect of 31-GEP testing on SLNB performance rates in patients with T1-T2 tumors considering SLNB and to study long-term outcomes. Here, we assessed outcomes in patients with a Class 1A 31-GEP result (n = 130).
Results: Of Class 1A patients, 63 had an SLNB, with a 3.2% SLN positivity rate (2/63). No Class 1A patients, regardless of SLN status, experienced a recurrence (2-year median follow-up).
Conclusions: These results are consistent with previous studies that showed the 31-GEP can identify patients at low risk of SLN positivity and recurrence.
© 2025 Castle Biosciences Inc and The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.