Friendswood – October 12, 2026 -- Management recommendations changed in line with TissueCypher risk classifications for 96% of patients in a multi-center Barrett's esophagus cohort, according to data Castle Biosciences (Nasdaq: CSTL) is presenting at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting in Nashville, Oct. 9-14.
The company is presenting three studies: two case reports and one multi-center cohort study. All three examine whether the molecular test adds risk information beyond histopathology.
TissueCypher and clinicopathologic scoring agreed only slightly in the multi-center cohort
The cohort study (P5192) compared TissueCypher with the Progression in Barrett's (PIB) clinicopathologic approach and found only slight agreement (Cohen's κ = 0.04). TissueCypher classified 83% of patients as low risk and 17% as intermediate/high risk. The PIB score classified 31% as low risk and 69% as intermediate/high risk.
Under guideline-informed management, most patients would have been recommended surveillance every three years using the PIB approach. Guided by TissueCypher results, physicians recommended a longer five-year surveillance window for 38 patients and endoscopic eradication therapy (EET) for eight. Five of those eight had non-dysplastic Barrett's esophagus (NDBE) but intermediate or high TissueCypher risk, with no dysplasia detected on biopsy.
High-risk result led to repeat endoscopy six months later and uncovered missed dysplasia
In the first case report (P3056), a patient with NDBE received a high-risk TissueCypher result, indicating a 62% probability of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC) within five years. Guidelines generally recommend surveillance endoscopy every three to five years for NDBE. Instead, a repeat endoscopy six months after the initial exam identified previously missed prevalent HGD. The patient then underwent EET with radiofrequency ablation (RFA).
Test result prompted RFA within two months in a case of conflicting biopsy findings
The second case report (P5296) involved a patient whose biopsies were classified successively as NDBE, low-grade dysplasia and indefinite for dysplasia (IND). TissueCypher testing of the IND biopsy returned a high-risk result, indicating a 47% five-year probability of progression to HGD or EAC. Interventional endoscopy with RFA followed two months after the IND diagnosis, and biopsies confirmed previously undetected HGD. After RFA and subsequent cryotherapy, follow-up biopsies confirmed complete eradication of the patient's intestinal metaplasia.
"Endoscopic biopsy findings do not always tell the whole story," said study author Virendra Joshi, M.D., of Emory University School of Medicine, who said the test adds objective molecular risk information to standard pathology.
Castle schedules Oct. 13 product theater at Booth 117
The test analyzes protein biomarkers and tissue architecture in routine endoscopic biopsy samples to produce an individualized five-year probability of progression to HGD or EAC. Posters P3056 (Oct. 12) and P5192 and P5296 (both Oct. 13) are in Exhibit Halls A-D at Music City Center. On Oct. 13, 1:15-1:45 p.m. Central time, Castle will host a product theater featuring patient ambassador Johnny Walker, Mark Amorosino, M.D., of Gastro Health, and David Forcione, M.D., of Baptist Health.