Castle Biosciences, Inc., a company improving health through innovative tests that guide patient care, today announced new data further demonstrating the performance of DecisionDx-Melanoma and i31-SLNB to provide improved risk prediction of sentinel lymph node (SLN) positivity, compared to using T-stage factors alone, in patients with cutaneous melanoma.

The data will be shared in a poster presentation at the Society of Surgical Oncology (SSO) 2022 International Conference on Surgical Cancer Care, being held in Dallas and virtually, March 9-12, 2022.

“While the sentinel lymph node biopsy (SLNB) surgical procedure is a common technique in determining possible tumor metastasis, our current criteria for biopsy may be overestimating a person’s risk of having a positive node. This means we may be doing more sentinel node biopsies than necessary; and while we certainly don’t want to miss any lymph node metastases, we also don’t want to do procedures unnecessarily,” said study author Joseph Bennett, M.D., Chief of Surgical Oncology and Director of the Melanoma and Sarcoma Multidisciplinary Clinic at ChristianaCare Helen F. Graham Cancer Center & Research Institute, Newark, Del. “The study data show that DecisionDx-Melanoma has the ability to more accurately stratify risk for melanoma patients, which can help guide risk-aligned discussions about which patients should be offered the SLNB procedure and which can forgo it, based on their personal, biologic risk of a positive SLN. We expect that by using DecisionDx-Melanoma and i31-SLNB in addition to standard criteria, we can avoid doing SLNB procedures in many low-risk patients without missing melanoma metastases.”

The poster, titled “Integrating the 31-gene expression profile test with clinical and pathologic features can provide personalized precision estimates for sentinel lymph node positivity,” evaluated the performance of DecisionDx-Melanoma’s proprietary i31-SLNB algorithm in predicting the risk of SLNB positivity in 156 melanoma patients with known SLN outcomes at the ChristianaCare Helen F. Graham Cancer Center & Research Institute.

In the study, the DecisionDx-Melanoma test outperformed T-stage in identifying patients with low-risk tumors who could forgo SLNB, with an Area Under the Curve (AUC) of 0.89 versus 0.78 for T-stage in patients with T1-T2 tumors, indicating that DecisionDx-Melanoma provides improved predictions compared to those of the T-stage system. Additionally, the test accurately identified all patients with T1-T2 tumors who had a low risk (<5%) of SLN positivity (all of whom had negative SLNB results) with 100% negative predictive value, 100% sensitivity and significantly improved specificity compared to T-stage (37.5% vs. 2.5% for T-stage). Using T-stage alone, only two patients (T1a with no other high-risk tumor features) were accurately identified as low risk (<5%) of SLN positivity.

“The results of the study demonstrate that DecisionDx-Melanoma, with its proprietary i31-SLNB algorithm, can allow for more precise and personalized management of melanoma patients and improve patient selection for the SLNB surgical procedure, thus potentially enabling a reduction in unnecessary healthcare costs,” said Derek Maetzold, president and chief executive officer of Castle Biosciences.

Source: Company Press Release