Inadomi, John M.

INTRODUCTION: The adjunctive use of p53 immunohistochemistry has been proposed as a potential tool to improve risk stratification in Barrett's esophagus (BE) with conflicting results. We performed a systematic review and meta-analysis to evaluate the performance of p53 in predicting progression to advanced neoplasia (high-grade dysplasia [HGD] and esophageal adenocarcinoma [EAC]) among patients with BE. METHODS: We searched multiple databases for studies that evaluated the use of aberrant p53 in esophageal biopsies among patients with BE and reported progression rates to HGD/EAC. The outcomes were p53 test characteristics and incidence and risk ratio (RR) for progression to HGD/EAC in patients with and without aberrant p53 using random effects models. RESULTS: Among the 27 included studies, the proportion of patients with aberrant p53 expression at baseline was 20% (95% CI: 14%, 27%). The rate of progression with and without aberrant p53 was 8 per 100 person-years (95% CI: 6, 11) and 0.3 per 100 person-years (95% CI: 0.1, 0.6), respectively. Compared with patients without aberrant p53 expression, those with aberrant p53 had a higher risk for progression to HGD/EAC in cohort studies (RR = 10.2 [95% CI: 6.9, 15.0]) and case control studies (RR = 3.3 [95% CI: 2.5, 4.4]). The sensitivity for progression for non-dysplastic Barrett's esophagus and low-grade dysplasia/indefinite for dysplasia was 42% and 77% and specificity was 96% and 76%, respectively. DISCUSSION: While aberrant p53 expression has been associated with an increased risk of progression to advanced neoplasia in patients with BE undergoing surveillance, the diagnostic characteristics are suboptimal precluding uniform clinical adoption. Prospective studies with standardized grading protocols are needed to determine whether p53-guided surveillance strategies can meaningfully improve patient outcomes.

Abstract Purpose: Current endoscopy-based screening and surveillance programs have not been proven effective at decreasing esophageal adenocarcinoma (EAC) mortality, creating an unmet need for effective molecular tests for early detection of this highly lethal cancer. We conducted a genome-wide methylation screen to identify novel methylation markers that distinguish EAC and high-grade dysplasia (HGD) from normal squamous epithelium (SQ) or nondysplastic Barrett's esophagus (NDBE). Experimental Design: DNA methylation profiling of samples from SQ, NDBE, HGD, and EAC was performed using HM450 methylation arrays (Illumina) and reduced-representation bisulfate sequencing. Ultrasensitive methylation-specific droplet digital PCR and next-generation sequencing (NGS)-based bisulfite-sequencing assays were developed to detect the methylation level of candidate CpGs in independent esophageal biopsy and endoscopic brushing samples. Results: Five candidate methylation markers were significantly hypermethylated in HGD/EAC samples compared with SQ or NDBE (P < 0.01) in both esophageal biopsy and endoscopic brushing samples. In an independent set of brushing samples used to construct biomarker panels, a four-marker panel (model 1) demonstrated sensitivity of 85.0% and 90.8% for HGD and EACs respectively, with 84.2% and 97.9% specificity for NDBE and SQ respectively. In a validation set of brushing samples, the panel achieved sensitivity of 80% and 82.5% for HGD and EAC respectively, at specificity of 67.6% and 96.3% for NDBE and SQ samples. Conclusions: A novel DNA methylation marker panel differentiates HGD/EAC from SQ/NDBE. DNA-methylation–based molecular assays hold promise for the detection of HGD/EAC using esophageal brushing samples.