Study Demonstrates Significant and Risk-Appropriate Clinical Impact of DecisionDx-Melanoma Test Results on Patient Management Decisions

Results published in Journal of Drugs in Dermatology

Friendswood, TX – May 15, 2017 – Castle Biosciences, Inc., a provider of molecular diagnostics to improve cancer treatment decisions, today announced the publication of results from a study evaluating the clinical impact of its gene expression profile (GEP) test DecisionDx®-Melanoma. The test uses tumor biology to provide an individual risk of recurrence in cutaneous (skin) melanoma patients.

The paper titled, “Impact of a 31-gene Expression Profiling Test for Cutaneous Melanoma on Dermatologists’ Clinical Management Decisions,” was recently published in the Journal of Drugs in Dermatology. In the study, researchers found that the DecisionDx-Melanoma test had a significant and risk-appropriate impact on management decisions for patients with melanoma, while remaining within the context of established guidelines. These data were previously presented at the Society for Melanoma Research 2016 Congress, which was held in Boston, MA from November 6–9, 2016.

Study Details
In the study, 169 physicians were presented with clinical validity evidence for the DecisionDx-Melanoma test showing prognostic accuracy in prospectively planned multicenter studies. The physicians were then provided with descriptions of six clinical vignettes for cutaneous melanoma (CM) patients representing those commonly evaluated in high-volume dermatology practices. The respondents were asked how a Class 1 (low-risk) and Class 2 (high-risk) test result, in addition to traditional clinicopathologic features, would affect their clinical recommendations. Respondents were also asked to provide the Breslow thickness (ranging from 0.7-1.5mm in 0.1mm increments) at which they would change management with and without the information provided by the DecisionDx-Melanoma test.

Study Results

  • The overall results indicate that the use of the GEP test, in conjunction with standard staging factors, significantly impacts CM patient management according to individual risk and within the context of current established practice guidelines;
  • Without a DecisionDx-Melanoma test result, a majority of respondents indicated a Breslow thickness of 1.0 mm as the thickness at which they would recommend a patient for sentinel lymph node biopsy (SLNB), oncology referral and imaging (62%, 57%, and 55%, respectively), reflecting adherence to current management guidelines;
  • For a Class 1 (low-risk) outcome, the initial Breslow thickness used to guide these clinical recommendations was changed for 23%, 18% and 19% of cases, respectively. These changes were risk-appropriate with the inflection point changed to an increased Breslow thickness in a majority of cases;
  • For a Class 2 (high-risk) outcome, the initial Breslow thickness used to guide these clinical recommendations was changed for 47%, 50% and 47% of cases, respectively. These changes were risk-appropriate with the inflection point changed to a decreased Breslow thickness in a majority of cases (95%, 84% and 97%, respectively).
  • Also for a Class 2 outcome, a significantly larger number of physicians recommended imaging in all cases and SLNB in all cases where the procedure wasn’t already recommended in accordance with guidelines, compared to a Class 1 outcome (p<0.005).

“It is critical that management and follow-up recommendations for patients with cutaneous melanoma are tailored to individual risk, yet current staging methods are often unable to precisely stratify different risk groups that may have markedly different outcomes,” noted study co-author Darrell Rigel, M.D., M.S., Clinical Professor at New York University School of Medicine. “These results demonstrate that information on tumor biology can impact clinical decisions in a significant, risk-appropriate manner.”

The publication may be accessed at:

About DecisionDx-Melanoma
The DecisionDx-Melanoma test uses tumor biology to provide a prediction of individual risk of melanoma recurrence beyond traditional factors. 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 three independent, prospective studies including 510 patients. The consistent high performance and accuracy demonstrated in these studies, which combined have included 1200 patients, provides confidence in disease management plans that incorporate DecisionDx-Melanoma test results. Clinical impact has been demonstrated in a multi-center and single-center study showing that test results add additional patient-specific prognostic information to complement traditional staging tools. More information about the test and disease can be found at

About Castle Biosciences
Castle Biosciences is a molecular diagnostics company dedicated to helping patients and their physicians make the best possible treatment and follow-up care decisions based on the individual molecular signature of their tumor. The Company currently offers tests for patients with cutaneous melanoma (DecisionDx®-Melanoma; and uveal melanoma (DecisionDx®-UM and DecisionDx®-PRAME;, with development programs in other underserved cancers. Castle Biosciences is based in Friendswood, TX (Houston), and has laboratory operations in Phoenix, AZ. More information can be found at

DecisionDx-UM, DecisionDx-Melanoma and DecisionDx-PRAME are the trademarks of Castle Biosciences, Inc. Any other trademarks are the property of their respective owners.

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