Distinctive Pathology Associated With Focal Stenosis of the Main Pancreatic Duct Secondary to Remote Trauma: A Long-term Complication of Seat Belt Pancreatitis.

The radiologic finding of focal stenosis of the main pancreatic duct is highly suggestive of pancreatic cancer. Even in the absence of a mass lesion, focal duct stenosis can lead to surgical resection of the affected portion of the pancreas. We present four patients with distinctive pathology associated with non-neoplastic focal stenosis of the main pancreatic duct. The pathology included stenosis of the pancreatic duct accompanied by wavy, acellular, serpentine-like fibrosis, chronic inflammation with foreign body-type giant cell reaction, and calcifications. In all cases, the pancreas toward the tail of the gland had obstructive changes including acinar drop-out and interlobular and intralobular fibrosis. Three of the four patients had a remote history of major motor vehicle accidents associated with severe abdominal trauma. These results emphasize that blunt trauma can injure the pancreas and that this injury can result in long-term complications, including focal stenosis of the main pancreatic duct. Pathologists should be aware of the distinct pathology associated with remote trauma and, when the pathology is present, should elicit the appropriate clinical history.

Hiatal hernia repair with transoral incisionless fundoplication versus Nissen fundoplication for gastroesophageal reflux disease: A retrospective study.

Background and study aims Concomitant hiatal hernia (HH) repair with transoral incisionless fundoplication (TIF) is a therapeutic option for patients with HH > 2 cm and gastroesophageal reflux disease (GERD). Data comparing this approach with laparoscopic Nissen fundoplication (LNF) are lacking. We performed an exploratory analysis to compare these two approaches' adverse events (AEs) and clinical outcomes. Patients and methods This was a multicenter retrospective cohort study of HH repair followed by LNF versus HH repair followed by TIF in patients with GERD and moderate HH (2-5 cm). AEs were assessed using the Clavien-Dindo classification. Symptoms (heartburn/regurgitation, bloating, and dysphagia) were compared at 6 and 12 months. Results A total of 125 patients with HH repair with TIF and 70 with HH repair with LNF were compared. There was no difference in rates of discontinuing or decreasing proton pump inhibitor use, dysphagia, esophagitis, disrupted wrap, and HH recurrence between the two groups ( P  > 0.05). The length of hospital stay (1 day vs. 2 days), 30-day readmission rate (0 vs. 4.3 %), early AE rate (0 vs. 18.6 %), and early serious AE rate (0 vs. 4.3 %) favored TIF (all P  < 0.05). The rate of new or worse than baseline bloating was lower in the TIF group at 6 months (13.8 % vs. 30.0 %, P  = 0.009). Conclusions Concomitant HH repair with TIF is feasible and associated with lower early and serious AEs compared to LNF. Further comparative efficacy studies are warranted.

Risk of Pancreatic Cancer in the Long-Term Prospective Follow-Up of Familial Pancreatic Cancer Kindreds.

BACKGROUND: A family history of pancreatic cancer is associated with increased pancreatic cancer risk. However, risk estimates for individuals in kindreds with an aggregation of pancreatic cancer (>1 relative) are imprecise because of small samples sizes or potentially impacted by biases inherent in retrospective data. OBJECTIVE: The objective of this study is to determine the age-specific pancreatic cancer risk as a function of family history using prospective data. METHODS: We compared pancreatic cancer incidence (n = 167) in 21 141 individuals from 4433 families enrolled in the National Familial Pancreatic Cancer Registry with that expected based on Surveillance Epidemiology and End Results data and estimated the cumulative probability of pancreatic cancer using competing risk regression. RESULTS: Familial pancreatic kindred members (kindreds with pancreatic cancer in 2 first-degree relatives [FDRs] or a pathogenic variant) had a standardized incidence ratio of 4.86 (95% confidence interval [CI] = 4.01 to 5.90), and sporadic kindred members (kindreds not meeting familial criteria) had a standardized incidence ratio of 2.55 (95% CI = 1.95 to 3.34). Risk in familial pancreatic cancer kindreds increased with an increasing number of FDRs with pancreatic cancer, with a standardized incidence ratio of 3.46 (95% CI = 2.52 to 4.76), 5.44 (95% CI = 4.07 to 7.26), and 10.78 (95% CI = 6.87 to 16.89) for 1, 2, and 3 or more FDRs with pancreatic cancer, respectively. Risk was also higher among individuals with a family history of young-onset (aged younger than 50 years) pancreatic cancer. CONCLUSION: Pancreatic cancer risk is strongly dependent on family history, including both the degree of relationship(s) and age of onset of pancreatic cancer in relatives. These risk estimates will help inform the design of early detection studies and the risk and benefit analysis of screening trials.

Novel DNA Methylation Biomarker Panel for Detection of Esophageal Adenocarcinoma and High-Grade Dysplasia.

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.

Gastric per-oral endoscopic myotomy (G-POEM) for the treatment of gastric sleeve stenosis: a feasibility and safety study.

BACKGROUND: Traditional endoscopic treatments have limited success in gastric sleeve stenosis (GSS). Gastric peroral endoscopic myotomy (G-POEM) could conceivably obliterate the twist/angulation that causes GSS through a tunneled stricturotomy. We report early outcomes of G-POEM for GSS treatment. METHODS: We retrospectively reviewed all patients with GSS treated with G-POEM at our center. The primary end point was clinical success, defined as symptom improvement with resumption of adequate oral intake, without requiring further intervention. RESULTS: 13 patients (mean age 43 ±â€Š10.9 years; 12 female) underwent G-POEM for predominantly helical (11/13, 85 %) GSS. Three (23 %) had concurrent sleeve leak and 10 (77 %) had prior GSS treatment. Two intraoperative complications occurred, with no deviation to the procedure; no major complications occurred. At median follow-up of 175 (interquartile range [IQR] 119-260) days, clinical success was achieved in 10 patients (77 %). Median Gastroparesis Cardinal Symptom Index score in responders decreased from 2.06 (IQR 1.5-2.8) to 0.39 (IQR 0.2-0.5). Three patients (23 %) required surgical revision. CONCLUSIONS: G-POEM was feasible and safe, and may provide an alternative option for those averse to undergoing surgical revision for treatment of GSS.

Age of diagnosis in familial Barrett's associated neoplasia.

The identification of hereditary cancer genes for esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE), may prove critical for the development of novel prevention and treatment strategies. Specifically, efforts for detecting BE and EAC susceptibility genes have focused on families with three or more affected members, since these individuals have an earlier age onset compared to non-familial individuals. Given that the use of BE may overestimate the likelihood of disease heritability, we evaluated the age of diagnosis in kindreds with a restricted definition including only confirmed high-grade dysplasia (HGD) or EAC. The Familial Barrett's Esophagus Consortium database was used to identify individuals with HGD and EAC. These individuals were subsequently split into three kindred groups: non-familial-a single affected family member, duplex-two affected family members, and multiplex-three or more affected family members. Age of cancer diagnosis and other risk factors were compared between individuals in these groups. The study included 441 non-familial, 46 duplex, and 13 multiplex individuals. There was a statistically significant difference for age of diagnosis for individuals in the multiplex families compared to the non-familial and duplex families (56.0 versus 64.3, 63.5; p = 0.049). There was no significant difference between demographic factors and other cancer risk factors between family types. The results of this study support a genetic basis for familial Barrett's associated neoplasia and evaluation of the genetic susceptibility to this disease should continue to focus on families with multiple (three or more) affected members.

Is transoral incisionless fundoplication (TIF) an answer to post-peroral endoscopic myotomy gastroesophageal reflux? A multicenter retrospective study.

BACKGROUND: The use of peroral endoscopic myotomy (POEM) for achalasia has a high incidence of post-procedural gastroesophageal reflux (GER). Transoral incisionless fundoplication (TIF) may be an ideal endoscopic treatment. We report our experience with the use of post-POEM TIF. METHODS: In this multicenter retrospective study, post-POEM patients with GER who underwent TIF were included. The study end points were: (i) technical success; (ii) safety; (iii) effectiveness (changes in symptoms, scores, proton pump inhibitor [PPI] use, pH studies). RESULTS: 12 patients underwent TIF after POEM, nine of whom had daily symptoms, with 91.7% requiring twice daily (BID) PPIs. Technical success was achieved in all patients. Two adverse events occurred. There were significant decreases in the percentage of patients on BID PPIs (P = 0.03), frequency of daily symptoms (P = 0.03), Reflux Severity Index questionnaire, and GERD Health-related Quality of Life scores (P = 0.03 and P = 0.003; n = 6). pH studies performed in seven of the patients showed a significant reduction in the mean DeMeester score (P = 0.05) and mean percentage acid exposure time (P = 0.04). CONCLUSION: Our experience suggests that TIF may be effective and safe in treating GER after POEM. Larger prospective trials are needed.

COVID-19 related pancreatic cancer surveillance disruptions amongst high-risk individuals.

BACKGROUND: COVID-19 pandemic-related disruptions to EUS-based pancreatic cancer surveillance in high-risk individuals remain uncertain. METHODS: Analysis of enrolled participants in the CAPS5 Study, a prospective multicenter study of pancreatic cancer surveillance in high-risk individuals. RESULTS: Amongst 693 enrolled high-risk individuals under active surveillance, 108 (16%) had an EUS scheduled during the COVID-19 pandemic-related shutdown (median length of 78 days) in the spring of 2020, with 97% of these procedures being canceled. Of these canceled surveillance EUSs, 83% were rescheduled in a median of 4.1 months, however 17% were not rescheduled after 6 months follow-up. Prior history of cancer was associated with increased likelihood of rescheduling. To date no pancreatic cancer has been diagnosed among those whose surveillance was delayed. CONCLUSIONS: COVID-19 delayed pancreatic cancer surveillance with no adverse outcomes in efficiently rescheduled individuals. However, 1 in 6 high-risk individuals had not rescheduled surveillance, indicating the need for vigilance to ensure timely surveillance rescheduling.

Risk factors for lymph node metastasis and survival of patients with nonampullary duodenal carcinoid tumors treated with endoscopic therapy versus surgical resection: analysis of the Surveillance, Epidemiology, and End Results program.

BACKGROUND AND AIMS: Endoscopic therapy (ET) has been used to treat nonampullary duodenal neuroendocrine tumors (NAD-NETs) ≤10 mm in size, but data on long-term outcomes are limited. In addition, management of 11- to 19-mm NAD-NETs is not well defined because of variable estimates of risk of metastasis. We aimed to determine the prevalence and risk factors of metastasis of NAD-NETs ≤19 mm and evaluate the long-term survival of patients after ET as compared with radical surgery. METHODS: The Surveillance Epidemiology and End Result database was used to identify 1243 patients with T1-2 histologically confirmed NAD-NETs ≤19 mm in size. Cancer-specific survival (CSS) and overall survival (OS) were calculated. RESULTS: Overall, 4.8% of cases had metastasis at the time of diagnosis, with lower prevalence in ≤10-mm lesions (3.1%) versus 11- to 19-mm lesions (11.7%, P < .001). The risk factors for metastases included invasion to the muscularis propria (odds ratio, 25.95; 95% confidence interval, 9.01-76.70), age <65 years (odds ratio, 1.93), submucosal involvement (odds ratio, 3.1), and 11 to 19 mm in size (vs ≤10 mm). In patients with well- to moderately differentiated T1-2N0M0 NAD-NETs ≤19 mm confined to the mucosa/submucosa who underwent ET or surgery, the 5-year CSS was 100%. The 5-year OS was similar between the ≤10-mm and 11- to 19-mm groups (86.6% vs 91.0%, P = .31) and the ET and surgery groups (87.4% vs 87.5%, P = .823). CONCLUSIONS: In NAD-NETs, invasion to the muscularis propria is the strongest risk factor for metastasis. In the absence of metastasis, in lesions with well/moderate differentiation and without muscle invasion, ET is adequate for NAD-NETs ≤10 mm and is a viable option for 11- to 19-mm lesions.

Targeting the Hedgehog Pathway Using Itraconazole to Prevent Progression of Barrett's Esophagus to Invasive Esophageal Adenocarcinoma.

OBJECTIVE: The aim of the study was to investigate whether inhibition of Sonic Hedgehog (SHH) pathway would prevent progression of Barrett's Esophagus (BE) to esophageal adenocarcinoma. BACKGROUND: The hedgehog signaling pathway is a leading candidate as a molecular mediator of BE and esophageal adenocarcinoma (EAC). Repurposed use of existing off-patent, safe and tolerable drugs that can inhibit hedgehog, such as itraconazole, could prevent progression of BE to EAC. METHODS: The efficacy of itraconazole was investigated using a surgical rat reflux model of Barrett's Metaplasia (BM). Weekly intraperitoneal injections of saline (control group) or itraconazole (treatment group; 200 mg/kg) were started at 24 weeks postsurgery. Esophageal tissue was harvested at 40 weeks. The role of the Hh pathway was also evaluated clinically. Esophageal tissue was harvested after 40 weeks for pathological examination and evaluation of the SHH pathway by immunohistochemistry. RESULTS: BM was present in control animals 29 of 31 (93%) versus itraconazole 22 of 24 (91%). EAC was significantly lower in itraconazole 2 of 24 (8%) versus control 10 of 31 (32%), respectively (P = 0.033). Esophageal SHH levels were lower in itraconazole vs control (P = 0.12). In esophageal tissue from humans with recurrent or persistent dysplastic BE within 24 months of ablative treatment, strong SHH and Indian Hedgehog expression occurred in distal BE versus proximal squamous epithelium, odds ratio = 6.1 (95% confidence interval: 1.6, 23.4) and odds ratio = 6.4 (95% confidence interval: 1.2, 32.8), respectively. CONCLUSION: Itraconazole significantly decreases EAC development and SHH expression in a preclinical animal model of BM. In humans, BE tissue expresses higher SHH, Indian Hedgehog, and bone morphogenic protein levels than normal squamous esophageal epithelium.

Comparable Cancer-Specific Mortality of Patients With Early Gastric Cancer Treated With Endoscopic Therapy vs Surgical Resection.

BACKGROUND & AIMS: Endoscopic therapy is used commonly for superficial gastric cancer with very low risk of metastasis to the lymph nodes. However, limited population-based studies from the West have evaluated long-term outcomes of patients who received endoscopic therapy vs surgery. METHODS: We used the Surveillance Epidemiology and End Results database to identify and compare features and outcomes of patients who underwent endoscopic therapy (n = 786) or surgery (n = 2577) for Tis or T1aN0M0 superficial gastric cancer, diagnosed from 1998 to 2014. Multivariate logistic regression was performed to identify factors associated with endoscopic therapy. Overall survival and gastric cancer-specific survival times were compared after we controlled for covariates. RESULTS: Use of endoscopic therapy increased from 15.1% of cases in 1998 to 2000 to 39.0% of cases in 2013 to 2014. Endoscopic therapy was used more frequently in patients who were older, female, or Caucasian, or with lesions that were located in the proximal stomach or were limited in depth (Tis vs T1a) and size, compared with surgery. The median follow-up time was 59 months (interquartile range, 31-102 mo). Percentages of 5-year overall and cancer-specific survival were 57% and 99% in the endoscopic therapy group and 76% and 95% in the surgery group. After we adjusted for clinical factors using a multivariate Cox proportional hazards model, we found no significant difference in gastric cancer-specific mortality between patients who received endoscopic therapy vs surgery (hazard ratio, 1.42; 95% CI, 0.91-2.23; P = .12). CONCLUSIONS: In an analysis of a large population database, we found an increased trend in endoscopic therapy for superficial gastric cancer compared with surgery from 1998 through 2014. Patients who received endoscopic therapy vs surgery had comparable long-term cancer-specific mortality.

Detection of Circulating Tumor DNA in Patients with Pancreatic Cancer Using Digital Next-Generation Sequencing.

Circulating tumor DNA (ctDNA) measurements can be used to estimate tumor burden, but avoiding false-positive results is challenging. Herein, digital next-generation sequencing (NGS) is evaluated as a ctDNA detection method. Plasma KRAS and GNAS hotspot mutation levels were measured in 140 subjects, including 67 with pancreatic ductal adenocarcinoma and 73 healthy and disease controls. To limit chemical modifications of DNA that yield false-positive mutation calls, plasma DNA was enzymatically pretreated, after which DNA was aliquoted for digital detection of mutations (up to 384 aliquots/sample) by PCR and NGS. A digital NGS score of two SDs above the mean in controls was considered positive. Thirty-seven percent of patients with pancreatic cancer, including 31% of patients with stages I/II disease, had positive KRAS codon 12 ctDNA scores; only one patient had a positive GNAS mutation score. Two disease control patients had positive ctDNA scores. Low-normal-range digital NGS scores at mutation hotspots were found at similar levels in healthy and disease controls, usually at sites of cytosine deamination, and were likely the result of chemical modification of plasma DNA and NGS error rather than true mutations. Digital NGS detects mutated ctDNA in patients with pancreatic cancer with similar yield to other methods. Detection of low-level, true-positive ctDNA is limited by frequent low-level detection of false-positive mutation calls in plasma DNA from controls.

A multimodality test to guide the management of patients with a pancreatic cyst.

Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.

Deleterious Germline Mutations Are a Risk Factor for Neoplastic Progression Among High-Risk Individuals Undergoing Pancreatic Surveillance.

PURPOSE: To compare the risk of neoplastic progression by germline mutation status versus family history without a known germline mutation (familial risk) among individuals with an increased risk for pancreatic cancer who are undergoing surveillance. METHODS: Of 464 high-risk individuals in the Cancer of the Pancreas Screening program at Johns Hopkins Hospital who were undergoing pancreatic surveillance, 119 had a known deleterious germline mutation in a pancreatic cancer susceptibility gene; 345 met family history criteria for pancreatic surveillance but were not known to harbor a germline mutation. We used next-generation sequencing to identify previously unrecognized germline mutations among these 345 individuals. We compared the development of pancreatic cancer, high-grade dysplasia, or clinically worrisome features, adjusting for competing mortality, among all germline mutation carriers with the risk of progression in a cohort without a known germline mutation. RESULTS: Fifteen (4.3%) of 345 individuals classified as having familial risk had a previously unrecognized pancreatic cancer susceptibility gene mutation (nine that involved ATM, two BRCA2, one BRCA1, one PALB2, one TP53, and one CPA1). The cumulative incidence of pancreatic cancer, high-grade dysplasia, or worrisome features on pancreatic imaging was significantly higher in the germline mutation risk group (n = 134) than in the familial risk group (n = 330 [for pancreatic cancer, hazard ratio, 2.85; 95% CI, 1.0 to 8.18; P = .05]). CONCLUSION: The cumulative incidence of pancreatic cancer is significantly higher among individuals with an identifiable deleterious germline mutation in a pancreatic cancer susceptibility gene than it is among individuals with a strong family history but no identified mutation. Gene testing of individuals who meet criteria for pancreatic surveillance on the basis of their family history may better define those most at risk for neoplastic progression.

Systems Biology Analyses Show Hyperactivation of Transforming Growth Factor-ß and JNK Signaling Pathways in Esophageal Cancer.

BACKGROUND & AIMS: Esophageal adenocarcinoma (EAC) is resistant to standard chemoradiation treatments, and few targeted therapies are available. We used large-scale tissue profiling and pharmacogenetic analyses to identify deregulated signaling pathways in EAC tissues that might be targeted to slow tumor growth or progression. METHODS: We collected 397 biopsy specimens from patients with EAC and nonmalignant Barrett's esophagus (BE), with or without dysplasia. We performed RNA-sequencing analyses and used systems biology approaches to identify pathways that are differentially activated in EAC vs nonmalignant dysplastic tissues; pathway activities were confirmed with immunohistochemistry and quantitative real-time polymerase chain reaction analyses of signaling components in patient tissue samples. Human EAC (FLO-1 and EsoAd1), dysplastic BE (CP-B, CP-C, CP-D), and nondysplastic BE (CP-A) cells were incubated with pharmacologic inhibitors or transfected with small interfering RNAs. We measured effects on proliferation, colony formation, migration, and/or growth of xenograft tumors in nude mice. RESULTS: Comparisons of EAC vs nondysplastic BE tissues showed hyperactivation of transforming growth factor-ß (TGFB) and/or Jun N-terminal kinase (JNK) signaling pathways in more than 80% of EAC samples. Immunohistochemical analyses showed increased nuclear localization of phosphorylated JUN and SMAD proteins in EAC tumor tissues compared with nonmalignant tissues. Genes regulated by the TGFB and JNK pathway were overexpressed specifically in EAC and dysplastic BE. Pharmacologic inhibition or knockdown of TGFB or JNK signaling components in EAC cells (FLO-1 or EsoAd1) significantly reduced cell proliferation, colony formation, cell migration, and/or growth of xenograft tumors in mice in a SMAD4-independent manner. Inhibition of the TGFB pathway in BE cell lines reduced the proliferation of dysplastic, but not nondysplastic, cells. CONCLUSIONS: In a transcriptome analysis of EAC and nondysplastic BE tissues, we found the TGFB and JNK signaling pathways to be hyperactivated in EACs and the genes regulated by these pathways to be overexpressed in EAC and dysplastic BE. Inhibiting these pathways in EAC cells reduces their proliferation, migration, and formation of xenograft tumors. Strategies to block the TGFB and JNK signaling pathways might be developed for treatment of EAC.

Constitutively Higher Level of GSTT2 in Esophageal Tissues From African Americans Protects Cells Against DNA Damage.

BACKGROUND & AIMS: African American and European American individuals have a similar prevalence of gastroesophageal reflux disease (GERD), yet esophageal adenocarcinoma (EAC) disproportionately affects European American individuals. We investigated whether the esophageal squamous mucosa of African American individuals has features that protect against GERD-induced damage, compared with European American individuals. METHODS: We performed transcriptional profile analysis of esophageal squamous mucosa tissues from 20 African American and 20 European American individuals (24 with no disease and 16 with Barrett's esophagus and/or EAC). We confirmed our findings in a cohort of 56 patients and analyzed DNA samples from patients to identify associated variants. Observations were validated using matched genomic sequence and expression data from lymphoblasts from the 1000 Genomes Project. A panel of esophageal samples from African American and European American subjects was used to confirm allele-related differences in protein levels. The esophageal squamous-derived cell line Het-1A and a rat esophagogastroduodenal anastomosis model for reflux-generated esophageal damage were used to investigate the effects of the DNA-damaging agent cumene-hydroperoxide (cum-OOH) and a chemopreventive cranberry proanthocyanidin (C-PAC) extract, respectively, on levels of protein and messenger RNA (mRNA). RESULTS: We found significantly higher levels of glutathione S-transferase theta 2 (GSTT2) mRNA in squamous mucosa from African American compared with European American individuals and associated these with variants within the GSTT2 locus in African American individuals. We confirmed that 2 previously identified genomic variants at the GSTT2 locus, a 37-kb deletion and a 17-bp promoter duplication, reduce expression of GSTT2 in tissues from European American individuals. The nonduplicated 17-bp promoter was more common in tissue samples from populations of African descendant. GSTT2 protected Het-1A esophageal squamous cells from cum-OOH-induced DNA damage. Addition of C-PAC increased GSTT2 expression in Het-1A cells incubated with cum-OOH and in rats with reflux-induced esophageal damage. C-PAC also reduced levels of DNA damage in reflux-exposed rat esophagi, as observed by reduced levels of phospho-H2A histone family member X. CONCLUSIONS: We found GSTT2 to protect esophageal squamous cells against DNA damage from genotoxic stress and that GSTT2 expression can be induced by C-PAC. Increased levels of GSTT2 in esophageal tissues of African American individuals might protect them from GERD-induced damage and contribute to the low incidence of EAC in this population.