31-gene expression profile test guides clinical management of melanoma adjuvant therapies

MIAMI BEACH, Fla. — The 31-gene expression profile test demonstrated accurate melanoma-specific survival predictions and may help guide clinicians in adjuvant therapy management, according to a poster presentation at South Beach Symposium.

Regardless of a negative sentinel lymph node biopsy (SLNB), 10% to 24% of patients will experience recurrence or metastasis with melanoma-specific survival rates ranging from 82% to 99%. Further, in the KEYNOTE-716 trial, researchers found adjuvant therapies to cause adverse events in 80% of patients with 18% discontinuing treatment.

“These data underpin a need for prognostic tools beyond clinicopathologic features to identify patients with high-risk tumor staging but low-risk tumor biology, or low-risk tumor staging but high-risk tumor biology, so that patients receive risk-aligned treatment,” Brian Martin, PhD, senior scientist at Castle Biosciences, and colleagues wrote in their poster.

Studies have shown that the 31-gene expression profile (GEP) test successfully predicts survival among patients with stage I to stage III cutaneous melanoma. In this study, researchers set out to demonstrate the performance of the 31-GEP to identify patients with high-risk tumor biology in an unselected, clinically tested cohort of patients with negative SLNB. SEER cancer registries linking melanoma cases were used to identify 3,271 patients who were tested with the 31-GEP between 2016 and 2018.

Using the 31-GEP, patients were categorized into classes based on their 3-year, predicted melanoma-specific survival, with class 1a being the most likely to survive and class 2b the least likely. Results showed class 1a patients had a 99.7% survival rate, class 1b/2a had a 97.8% survival rate and class 2b had a 91.8% survival rate (P < .001). In the subset of 311 patients with stage IIB to stage IIC disease, 0% of class 1a patients died from melanoma vs. 6.7% of class 2b patients.

According to the study, these results may guide clinicians in the assignment of adjuvant therapy to those that may benefit compared with those who may not, steering them away from potential adverse events. The authors also concluded that the 31-GEP is a significant predictor of melanoma-specific death, even while accounting for substage.

“Using the 31-GEP results to guide increased clinical management and surveillance for patients at high risk of melanoma-specific death may improve patient outcomes,” the authors wrote.