AG

AA

bst

ract

s

FIGURE 1: (A) Cross-sectional view using VLE of a segment of BE previously treated withRFA. (B) Neosquamous epithelium is characterized by a layered structure that is absent in(C) specialized intestinal metaplasia. Measurements of NSE thickness (red double arrow)were taken at four quadrants (Q1-4) along each centimeter of the pre-RFA BE segment.Quadrants that contained both NSE and SIM were excluded from measurement (gray rectan-gle involving Q2 and Q3).

Mo1925

Cellular Senescence and P16ink4a Immunohistochemistry Predicts Responseto Radiofrequency Ablation (RFA) for Barrett's Esophagus (BE) With High-grade Dysplasia (HGD)Joshua D. Penfield, Cadman L. Leggett, Marlys Anderson, Lori S. Lutzke, Tsung-Teh Wu,Alan R. Zinsmeister, Prasad G. Iyer, Kenneth K. Wang

BACKGROUND: Cellular senescence is a state of permanent cell growth arrest that occursas a response to neoplastic stimuli and appears to prevent progression of neoplasia. Thepresence of markers of senescence in BE with HGD prior to ablative therapy may predictresponse to RFA, as escape from senescence promotes aggressive behavior of dysplastic cells.As identification of senescence in paraffin-embedded tissue is difficult to achieve withstandard methods, we chose biomarkers that were compatible. We hypothesized that therewould be a difference in senescence biomarkers and stem cells between patients whoresponded and those who did not respond to RFA. AIM: To evaluate whether senescencebiomarkers can predict response to RFA by using immunohistochemistry against the tumorsuppressor protein p16INK4a, the nuclear DNA damage response marker γ-H2Ax and theintestinal stem cell marker LGR5 in biopsy tissue from BE patients with HGD prior to RFA.METHODS: All patients referred for untreated BE with HGD were reviewed. Patients withpre-RFA esophageal biopsies, two RFA treatment sessions and surveillance biopsies 3 monthspost-RFA were identified. From this group, patients were selected as either persistent HGD[non-responders (NR)] or neosquamous re-epithelialization [responders (R)]. Pre-RFA tissuewas then stained with p16INK4a, γ-H2Ax and LGR5. Slides were reviewed by an experiencedGI pathologist blinded to the status of the patients. An intensity-weighted scoring systemwas used. RESULTS: Forty five patients (R:25, NR:20) fulfilled inclusion criteria. Baselinecharacteristics are shown in table 1. Using a logistic model to predict RFA response, meancell count of γ-H2Ax (R:110 vs. NR:76, p.0.05) and LGR5 (R:10 vs. NR:13, p.0.05) werenot significantly associated with response to RFA. Decreased intensity of p16INK4a in pre-RFA tissue was associated with persistent HGD post-RFA (OR=2.78, 95% CI 1.16-6.66; p=0.02). CONCLUSION: In our cohort of patients, p16INK4a intensity was associated withRFA response as patients with decreased expression of this tumor suppressor protein onpre-RFA tissue were more likely to have persistent HGD post-RFA. This is likely due to adecreased senescence response in pre-RFA tissue that promotes resistance to ablation.Table 1: Patient demographics

Figure 1: A) and B) Representative images of p16INK4a immunohistochemistry on pre-RFAbiopsy tissue from patients with subsequent complete neosquamous re-epithelialization post-RFA. C) and D) Representative images of p16INK4a on pre-RFA biopsy tissue from patientswith subsequent persistent HGD post-RFA.

S-696AGA Abstracts

Mo1926

Effects of Vitamin D Supplementation on Barrett's EsophagusLinda C. Cummings, Joseph Willis, Gregory S. Cooper, Beth Bednarchik, SanfordMarkowitz, Amitabh Chak

Background: Vitamin D directly or indirectly controls genes that regulate proliferation,apoptosis, and differentiation. We have previously reported that calcitriol, the active formof vitamin D, inhibits the growth of esophageal adenocarcinoma cell lines. Vitamin Ddeficiency is also associated with insulin resistance and increased risk for esophageal cancer.The goals of this study were to assess the effects of vitamin D supplementation on Barrett'sesophagus (BE) patients with or without dysplasia. We hypothesized that vitamin D supple-mentation may have beneficial effects including improvement of dysplasia and insulin resis-tance in BE. Methods: Patients with long-segment or short-segment BE with or without highgrade dysplasia (HGD) were treated with vitamin D3 (cholecalciferol) 50,000 internationalunits weekly for 2 weeks (HGD) or 12 weeks (no dysplasia or low grade dysplasia). BEbiopsies and blood samples were obtained before and after vitamin D3 supplementation.Biopsies were stained with hematoxylin and eosin and reviewed by an expert pathologistblinded to study arm. Serum 25-hydroxyvitamin D, insulin, and glucose levels were assessedto characterize vitamin D status and to estimate insulin resistance (IR) by the HomeostaticModel Assessment (HOMA). Results: Among the first 10 evaluable study subjects, 7 hadBE with no or low grade dysplasia and 3 had high grade dysplasia. 6 patients had long-segment BE and 4 had short-segment. The mean age was 65.6 years (standard deviation,9.6 years); 3 women and 7 men were enrolled. Baseline serum 25-hydroxyvitamin D levelsranged from 14.1 ng/mL (deficient) to 60.9 ng/mL (sufficient) with a median level of35.4 ng/mL. Median baseline HOMA-IR was 4.27. After vitamin D supplemention, 25-hydroxyvitamin D levels rose significantly (p, 0.001) with a median increase of 35.2 ng/mL among patients with no or low grade dysplasia. Among patients with HGD with 2 weeksof supplementation, 2 had small increments in serum 25-hydroxyvitamin D levels of 13.3and 14.2 ng/mL, while no change occurred in 1 patient. On pathologic review, regressionto low grade dysplasia after vitamin D supplementation occurred in 2 of 3 HGD subjects.There was no significant change in insulin resistance after vitamin D supplementation.Vitamin D supplementation was well tolerated. Conclusion: Regression to low grade dysplasiaoccurred in 2 of 3 high grade dysplasia subjects. Baseline Vitamin D status of BE patientswas generally sufficient. Treatment with 12 weeks of vitamin D supplementation resultedin marked increases in serum 25-hydroxyvitamin D levels compared with 2 weeks. Thesechanges occurred independent of effects on insulin resistance. These findings support thehypothesis that vitamin D supplementation may have beneficial effects in Barrett's esophagusand warrant further investigation.

Mo1927

Complete Remission of Intestinal Metaplasia After One RadiofrequencyAblation SessionBashar J. Qumseya, Waseem J. David, Edgar C. Aranda-Michel, Lois L. Hemminger,Michael B. Wallace, Herbert C. Wolfsen

Background: Radiofrequency ablation (RFA) is the most commonly used for treatment ofBarrett's esophagus (BE) with the goal of achieving complete remission from intestinalmetaplasia (CRIM). Endoscopic mucosal resection (EMR) is used in conjunction with RFAto remove nodular and other suspicious areas. Impact of EMR on CRIM is uncertain withpotential to improve CRIM by removal of nodular/thick tissue which is difficult to ablateby RFA, but also potential to worsen RFA by inducing stenosis and altered esophagealgeometry. Aims: To assess the effect of one treatment with RFA with/without EMR on therate of CRIM among patients with BE. Methods: This was a retrospective, observationalstudy using large RFA database in a tertiary referral center. The primary outcome was therate of CRIM after the first RFA session compared between patients who had RFA alone vs.RFA with EMR. A secondary outcome was the achievement of complete remission fromdysplasia (CRD) downgrade in pathology from baseline. Chi-square or Fisher's exact testswhere used to assess differences between proportions. Multivariable logistic regression analy-sis was used to assess the association between the primary outcome (CRIM) and predictorvariables. Results: 215 patients underwent RFA for BE between May 2005 and June 2012.Of those 23% (49) has nondysplastic BE (NDBE), 6.5% (14) were indefinite for dysplasia(IFD), 29% (63) has low-grade dysplasia (LGD), 36% (77) had high-grade dysplasia (HGD),and 5.5% (12) had adenocarcinoma (AC). Most patients (91%) were males. Half of allpatients (50%) had a history of ever having EMR. However, a minority of patients (11%)had EMR to remove nodules within 3 months of initiating RFA. Pathology on follow upEGD based on baseline pathology is summarized in Figure 1. Overall 36% [29-42%] achievedCRIM after one RFA treatment. Among 166 patients with BE and dysplasia, 46% (76)achieved complete remission of dysplasia (CRD) after one session of RFA. In a univariateanalysis there was no significant difference in the rate of CRIM after the first RFA betweenpatients who had RFA with EMR or RFA alone (50% vs. 34%, p=0.17). In a multivariablelogistic regression analysis when controlling for age, gender, and BE length, RFA with EMRshowed a trend toward more CRIM (OR 2.5 [0.96 - 6.6], p=0.06) when compared to RFAalone, but this did not achieve statistical significance. Conclusion: Many patients can achieveCRIM after one RFA treatment. Use of EMR to remove nodules before RFA may be associatedwith higher rates of CRIM after RFA. Larger studies are needed to confirm this association.