Newly Published Study Shows DecisionDx-Melanoma Prognostic Test Accurately Identified Risk for Patients with Melanoma of the Head and Neck
Friendswood, TX – February 7, 2019 – Castle Biosciences, Inc., a skin cancer diagnostics company providing personalized genomic information to improve cancer management decisions, today announced the publication of a study highlighting the ability of the DecisionDx®-Melanoma test to accurately determine risk of metastasis in patients with melanoma of the head and neck. Results from the study demonstrated that the DecisionDx-Melanoma test can provide independent information about recurrence risk in patients with tumors of the head and neck region, and can improve the evaluation of prognosis when used in combination with sentinel lymph node (SLN) status, especially in patients with a negative SLN biopsy. The study was published in the journal Head and Neck.
Melanoma tumors in the head and neck region are associated with lower SLN positivity rates compared to tumors located on the trunk or extremities. There is also a higher rate of recurrence among SLN-negative patients with melanoma of the head and neck. Thus, improved methods for determining prognosis in patients with head or neck melanoma are needed.
“Tumors of the head and neck region can pose clinical challenges for traditional prognostic methods such as the SLN biopsy procedure,” said lead author Brian Gastman, M.D., Cleveland Clinic Lerner Research Institute, Cleveland, Ohio. “In this study, the DecisionDx-Melanoma test accurately and independently determined prognosis for patients with melanoma of the head and neck. Importantly, the test can complement traditional AJCC staging methods and SLN status to identify high-risk patients who could potentially benefit from more aggressive surveillance and earlier therapeutic intervention at a time when these treatments can be more effective.”
Study Details and Key Findings:
- 157 patients with Stage I, II or III melanoma of the head or neck had a median age of 65 years and median Breslow thickness of 1.6 mm. The median time to recurrence was 1.4 years and the median follow-up time was 7.1 years for patients who did not experience recurrence.
- The DecisionDx-Melanoma test was performed to determine molecular class for each patient, with a Class 1A result indicating the lowest 5-year risk of metastasis and a Class 2B result indicating the highest risk.
- Patients who were identified as Class 1A (lowest risk) by the DecisionDx-Melanoma test had higher recurrence-free (RFS), distant metastasis-free (DMFS) and melanoma-specific survival (MSS) rates compared to those in the SLN-negative group (80%, 83% and 98% compared to 65%, 69% and 89%, respectively).
- Patients identified as Class 2B (highest risk) by the DecisionDx-Melanoma test had 5-year RFS, DMFS and MSS rates of 25%, 33% and 61%, respectively, which closely aligned with those of the SLN-positive group (20% RFS, 28% DMFS and 61% MSS, respectively).
- The DecisionDx-Melanoma test demonstrated better sensitivity for identifying recurrence (74%), distant metastasis (74%) and melanoma-specific mortality (88%) than SLN biopsy alone (41%, 40% and 52%, respectively).
- Similarly, the negative predictive values (NPV) for identifying recurrence (76%), distant metastasis (78%) and melanoma-specific mortality (96%) were superior to those for node positivity (64%, 67% and 90%, respectively).
- When results from the DecisionDx-Melanoma test were combined with nodal status, the combination showed a sensitivity for RFS of 81%, DMFS 80% and MSS 88%, similar to those for the DecisionDx-Melanoma test alone but substantially improved over sensitivity for SLN biopsy alone.
- Cox multivariate analysis comparing the DecisionDx-Melanoma Class 2 result to American Joint Committee on Cancer (AJCC) Stage IIB and above showed that both classifications were significant predictors of recurrence and distant metastasis (p≤0.006 for both endpoints), but only the Class 2 result was significant for melanoma-specific death (p=0.005).
The full published study results can be accessed at the Head and Neck website.
The DecisionDx-Melanoma test uses tumor biology to predict individual risk of melanoma recurrence and sentinel lymph node positivity independent of traditional factors and has been studied in over 2,900 patients. Using tissue from the primary melanoma, the test measures the expression of 31 genes. The test has been validated in three multi-center studies that have included 690 patients and have demonstrated consistent results. Performance has also been confirmed in five prospective studies including over 780 patients. The consistent high performance and accuracy demonstrated in these studies, which combined have included over 1,470 patients, provides confidence in disease management plans that incorporate DecisionDx-Melanoma test results.
Prediction of the likelihood of sentinel lymph node positivity has also been validated in two prospective multicenter cohorts that included over 1,400 patients. Impact on patient management plans for one of every two patients tested has been demonstrated in multi-center and single-center studies. More information about the test and disease can be found at www.SkinMelanoma.com.
About Castle Biosciences
Castle Biosciences is a skin cancer diagnostics company dedicated to helping patients and their physicians make more informed decisions about treatment and follow up care based on the individual molecular signature of the patient’s tumor. The Company currently offers tests for patients with cutaneous melanoma (DecisionDx®-Melanoma, DecisionDx®-CMSeq; www.SkinMelanoma.com) and uveal melanoma (DecisionDx®-UM, DecisionDx®-PRAME and DecisionDx®-UMSeq; www.MyUvealMelanoma.com), with programs in development for other underserved cancers, the most advanced of which is focused on patients with cutaneous squamous cell carcinoma. Castle Biosciences is based in Friendswood, Texas (Houston) and has laboratory operations in Phoenix, Arizona. More information can be found at www.CastleBiosciences.com.
DecisionDx-Melanoma, DecisionDx-CMSeq, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are the trademarks of Castle Biosciences, Inc. Any other trademarks are the property of their respective owners.
Derek Maetzold, President and CEO