New Study Shows That TissueCypher® Changed Management at an Expert Surgery Center in 90% of Patients With Non-Dysplastic Barrett's Esophagus

FRIENDSWOOD, Texas, Sept. 28, 2026 /PRNewswire/ -- Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, today announced the publication of a study showing that its TissueCypher^® Barrett's Esophagus Test helped guide risk-aligned management decisions for patients with non-dysplastic Barrett's esophagus (NDBE). In the study, clinicians changed their management recommendations 90% of the time after receiving TissueCypher results, including escalating management for all patients with intermediate- or high-risk results and de-escalating management for 84% of those with low-risk results.

The study, titled "The Tissue Systems Pathology Test Guides Physician Recommendations for Patients With Non-Dysplastic Barrett's Esophagus: A Case Series From a Gastrointestinal Surgery Center," was published in Foregut: The Journal of the American Foregut Society and is available here.

"All patients in this study had the same non-dysplastic Barrett's diagnosis, but TissueCypher showed that their risk of progression differed," said study author Caitlin C. Houghton, M.D., board-certified foregut surgeon at Keck Medicine of the University of Southern California (USC) in Los Angeles. "The test results helped us tailor management to each patient's individual risk — whether that meant closer surveillance or endoscopic eradication therapy for patients with intermediate- or high-risk results, or a longer surveillance interval for those with low-risk results. Ultimately, TissueCypher can help us detect patients at increased risk who may benefit from earlier surveillance or treatment and avoid unnecessary procedures for patients at lower risk."

Barrett's esophagus (BE) is a precancerous condition that can progress to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). Patients with NDBE represent the majority of those undergoing surveillance for BE and are generally considered to have a low risk of progression. However, traditional clinicopathologic factors alone may not reliably distinguish the subset of patients with NDBE who are at elevated risk of progression, highlighting the need for more precise risk stratification. To assess TissueCypher's clinical utility in this population, the study evaluated 30 patients with NDBE who received testing as part of their clinical care at Keck Medical Center of USC.

Key Study Findings:

• TissueCypher identified higher-risk patients within NDBE: The test classified 17% of patients as intermediate or high risk for progression to HGD/EAC within five years and 83% of patients as low risk.
• Intermediate- or high-risk results supported escalated management: Management plans were escalated for all patients with intermediate- or high-risk TissueCypher results, including endoscopic eradication therapy for four patients and shorter-interval surveillance for one.
• Lower-risk results supported de-escalated management: Management was de-escalated for 84% of patients with low-risk TissueCypher results, including extending surveillance intervals or no longer recommending endoscopic eradication therapy.
• Test results changed management or increased confidence: TissueCypher results changed management recommendations or increased physicians' confidence in their plans for 97% of patients.

Findings from the study were also presented on Sept. 27 at the American College of Surgeons Clinical Congress 2026 in Washington, D.C.

Presentation details:

• Title: The Tissue Systems Pathology Test Impacts Clinician-recommended Management Decisions for Patients with Non-dysplastic Barrett's Esophagus
• Presenter: Katie M. Galvin, M.D., Keck School of Medicine of USC
• Session: QS101-1 | Quick-Shots I - Station 1: Bariatric/Foregut

About TissueCypher Barrett's Esophagus Test
TissueCypher is a precision medicine test designed and extensively validated to predict a patient's personalized risk of progression from Barrett's esophagus (BE) to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). Indicated for patients with non-dysplastic BE, indefinite for dysplasia or with low-grade dysplasia, TissueCypher's five-year risk assessment is designed to help physicians tailor care to each patient's risk of developing HGD or EAC.

Backed by more than 17 peer-reviewed publications and studied in biopsies from more than 8,000 patients, TissueCypher has been shown to be the strongest independent predictor of progression compared with traditional histopathological risk assessment. Using an AI-derived spatialomics approach, the test identifies molecular signatures that often precede the development of dysplasia, which can enable earlier identification, treatment, and management of patients at increased risk of cancer. TissueCypher is designed to integrate seamlessly into routine endoscopic practice by analyzing standard esophageal pinch biopsies, delivering actionable insights without requiring additional procedures. Learn more at CastleBiosciences.com/TissueCypher.

About Castle Biosciences
Castle Biosciences (Nasdaq: CSTL) is a leading diagnostics company improving health through innovative tests that guide patient care. With a primary focus in dermatologic and gastroenterological disease, we develop personalized, clinically actionable solutions that help improve disease management and patient outcomes.

We put people first—empowering patients and clinicians and informing care decisions through rigorous science and advanced molecular tests that support more confident treatment planning. To learn more, visit www.CastleBiosciences.com and connect with us on LinkedIn, Instagram, Facebook and X. 

DecisionDx-Melanoma, DecisionDx-CMSeq, i31-SLNB, i31-ROR, DecisionDx-SCC, MyPath Melanoma, AdvanceAD-Tx, TissueCypher, Esopredict, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are trademarks of Castle Biosciences, Inc.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the "safe harbor" created by those sections. These forward-looking statements include, but are not limited to, statements concerning: TissueCypher's ability to (i) predict a patient's personalized risk of progression from Barrett's esophagus to high-grade dysplasia or esophageal adenocarcinoma, (ii) help clinicians tailor surveillance and management decisions to each patient's individual risk profile, (iii) enable earlier identification and management of patients at increased risk of cancer, and (iv) help reduce uncertainty for patients. The words "believe," "can," "may" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements that we make. These forward-looking statements involve risks and uncertainties that could cause our actual results to differ materially from those in the forward-looking statements, including, without limitation: subsequent study or trial results and findings may contradict earlier study or trial results and findings or may not support the results obtained in these studies, including with respect to the discussion of our tests in this press release; actual application of our tests may not provide the aforementioned benefits to patients; and the risks set forth under the heading "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2025, and our subsequent Quarterly Reports on Form 10-Q, each as filed or to be filed with the SEC, and in our other filings with the SEC. The forward-looking statements are applicable only as of the date on which they are made, and we do not assume any obligation to update any forward-looking statements, except as may be required by law.

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SOURCE Castle Biosciences, Inc.