Tissue Systems Pathology Test Objectively Risk Stratifies Barrett's Esophagus Patients With Low-Grade Dysplasia.

INTRODUCTION: Low-grade dysplasia (LGD) is the best predictor of neoplastic progression in Barrett's esophagus (BE). Most LGD cases are downstaged to nondysplastic (ND) BE on expert pathologist review, which is prone to interobserver variation and not widely available. Recent studies indicate that a risk prediction assay (TissueCypher) risk stratifies patients with NDBE for neoplastic progression. We aimed to investigate whether this risk prediction assay predicts neoplastic progression in BE patients with LGD. METHODS: A blinded, retrospective cohort study was derived from the screening cohort of a randomized controlled trial of SURveillance vs RadioFrequency ablation for BE patients with LGD. Hematoxylin and eosin and p53 immunohistochemistry slides from the first endoscopy with LGD were independently reviewed by 3 expert pathologists and tested by the risk prediction assay. Revision diagnoses of NDBE were considered low risk, although indefinite for dysplasia, and LGD were considered high risk for progression. RESULTS: A total of 155 BE patients (123 men), mean age 61 ± 10 years, were analyzed. Thirty-four patients (22%) progressed to high-grade dysplasia/esophageal adenocarcinoma (median time 2.4 years) and 121 did not progress (median high-grade dysplasia/esophageal adenocarcinoma-free surveillance 7.9 years). The risk prediction assay sensitivity was 68% vs 76% for the 3 pathologists, and specificity was 79% vs 64%-77.0% for the pathologists. The assay detected 50%-56% of progressors that were downstaged to NDBE by the pathologists. DISCUSSION: The risk prediction assay provided significant risk stratification in BE patients with LGD and identified progressors that the experts downstaged to NDBE. This objective assay provides an effective solution to the lack of standardization of expert pathology review of LGD.

Independent Validation of a Tissue Systems Pathology Assay to Predict Future Progression in Nondysplastic Barrett's Esophagus: A Spatial-Temporal Analysis.

INTRODUCTION: An automated risk prediction assay has previously been shown to objectively identify patients with nondysplastic Barrett's esophagus (NDBE) who are at increased risk of malignant progression. To evaluate the predictive performance of the assay in 76 patients with NDBE of which 38 progressed to high-grade dysplasia/esophageal adenocarcinoma (progressors) and 38 did not (nonprogressors) and to determine whether assessment of additional (spatial) levels per endoscopy and/or multiple (temporal) time points improves assay performance. METHODS: In a blinded, nested case-control cohort, progressors and nonprogressors were matched (age, sex, and Barrett's esophagus length). All random biopsy levels from the baseline endoscopy (spatial samples) and all available previous endoscopies back to 10 years before progression (temporal samples) were assayed. Because the 1:1 ratio of progressors to nonprogressors does not reflect the real-world Barrett's population, negative and positive predictive values were adjusted for prevalence. RESULTS: Seventy-six patients (58 men), mean age of 63 ± 9 years, were studied. A high-risk score was associated with a prevalence-adjusted annual progression rate of 6.9%. The assay identified 31% of progressors when assessing a single biopsy level from the baseline endoscopy. Sensitivity increased to 50% and 69% in spatial and temporal analyses, respectively, while specificity remained at 95%. DISCUSSION: The assay identified a significant subset of NDBE patients who progress at a rate comparable with published estimates for expert-confirmed low-grade dysplasia. Assessing additional spatial and temporal biopsies increased the predictive accuracy, allowing for identification of most future progressors. Additional studies will evaluate the predictive performance of the assay in low-prevalence settings.

Systematic review with meta-analysis: risk factors for thiopurine-induced leukopenia in IBD.

BACKGROUND: Thiopurine-induced leukopenia, a frequently observed and potentially life-threatening adverse event, complicates the clinical management of IBD patients. AIM: To assess risk factors for thiopurine-induced leukopenia in IBD. METHODS: MEDLINE, EMBASE, BIOSIS and Cochrane library were searched for studies reporting at least one risk factor for thiopurine-induced leukopenia. Pooled odds ratio (OR) was calculated for each potential risk factor using a random effects model. Studies that were not eligible for meta-analysis were described qualitatively. RESULTS: Seventy articles were included, 34 (11 229 patients) were included in meta-analyses. A significantly higher thiopurine-induced leukopenia risk was found for TPMT (OR 3.9, 95% [CI] 2.5-6.1) and for NUDT15 R139C (OR 6.9, 95% CI 5.2-9.1), G52A (OR 3.2, 95% CI 1.3-7.9) and 36_37ins/delGGAGTC variant carriers (OR 5.6, 95% CI 2.8-11.4). A potential association between high 6-thioguanine nucleotides (6-TGN) or 6-methylmercaptopurine (6-MMP) levels and leukopenia was observed, since most studies reported higher metabolite levels in leukopenic patients (6-TGN: 204-308 (Lennard method) and 397 (Dervieux method), 6-MMP: 4020-10 450 pmol/8 x 108 RBC) compared to controls (6-TGN: 170-212 (Lennard method) and 269 (Dervieux method), 6-MMP: 1025-4550 pmol/8 x 108 RBC). CONCLUSIONS: TPMT and NUDT15 variants predict thiopurine-induced leukopenia. High 6-TGN and 6-MMP levels might induce leukopenia, although exact cut-off values remain unclear. Potential preventive measures to reduce the risk of thiopurine-induced leukopenia include pre-treatment TPMT and NUDT15 genotyping. Routine thiopurine metabolite measurement might be efficient, yet cut-off levels must be validated in advance.