Castle Biosciences has announced that the largest long-term real-world study of 31-gene expression profiling (31-GEP) to date has validated the use of the firm’s 31-GEP test for melanoma, the DecisionDx-Melanoma test.
The study, results from which have now been published in JCO Precision Oncology, aimed to examine the effect of 31-GEP testing through the DecisionDx-Melanoma test on survival outcomes and to validate the prognostic ability of the test at the population level. Using a cohort from the National Cancer Institute’s SEER (Surveillance, Epidemiology, and End Results) program registries of over 4,500 cutaneous melanoma (CM) patients who received the DecisionDx-Melanoma test at their physician’s discretion and 9,000 matched CM patients who did not receive the test, the research team determined that the 31-GEP test effectively stratified patients with CM by their risk of death.
Three years into the study, patients identified as having the highest risk by the 31-GEP test had a 30 times higher melanoma-specific death rate compared to patients identified by the test as having the lowest risk. Furthermore, the results showed that not only was DecisionDx-Melanoma effective at predicting patients’ melanoma-specific survival, but it was also effective at predicting overall survival.
The study findings support results from a recently published study which showed that patients who received routine imaging guided by high-risk 31-GEP test scores had earlier diagnoses of recurrence with decreased tumor burdens, which in turn led to better clinical outcomes for the patients.
In providing significant and accurate survival outcome data, the test could help healthcare providers make more personalized clinical management decisions for patients with CM, the authors noted in the study, resulting in better patient outcomes: “31-GEP testing was associated with a 29% lower MSS [melanoma-specific survival] mortality and 17% lower overall mortality compared with untested patients.”
Cutaneous melanoma is the fifth most common cancer in the U.S. Current staging has difficulty distinguishing melanomas that are small but aggressive, which contributes to the nearly 40% CM mortality rate of patients initially diagnosed with stages I or II of the disease. 31-GEP testing, which examines the activity of 31 genes in melanoma tumor tissue, allows for better prediction of which tumors are likely to be aggressive, regardless of size.
“Management decisions for melanoma patients, such as referrals for sentinel lymph node biopsy or frequency and intensity of surveillance, are guided by a patient’s risk of disease recurrence or metastasis, and improvements in the accuracy of risk prediction can inform these decisions,” said Dr. Matthew Goldberg, senior vice president of Castle Biosciences, in a statement. “The independent risk-stratification provided by DecisionDx-Melanoma has already been demonstrated in numerous retrospective and prospective studies. This large study of real-world, unselected, clinically tested patients who received our test as part of their ongoing melanoma care further supports these findings.”
