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117 citation(s) found for "G Iyer, Prasad".

S0389 Comparison of the Risk Factor Profile of Adenocarcinomas of the Esophagogastric Junction (EGJ) and Non-Junctional Esophageal Adenocarcinomas (EAC): A National Database Study
Alaber, Omar , Chandar, Apoorva K., Codipilly, Don C. , Thota, Prashanthi N. , Iyer, Prasad G. , Chak, Amitabh

American Journal of Gastroenterology | October 24, 2020 | Volume: 115 | Issue: 1 | Pages: S193-S193

10.14309/01.ajg.0000703604.23774.df Get It

S0362 Central Obesity Perturbs Esophageal Epithelial Barrier Function by Down-Regulating Desmosomes
Gibbens, Ying , Lansing, Ramona, Johnson, Michele R., Blevins, Christopher H. , Priyan, Harshith, Katzka, David A. , Iyer, Prasad G.

American Journal of Gastroenterology | October 24, 2020 | Volume: 115 | Issue: 1 | Pages: S178-S178

10.14309/01.ajg.0000703496.02616.ab Get It

S0348 Long-Term Outcomes and Predictors of Survival in Patients Undergoing Barrett’s Esophagus Surveillance
Hanada, Yuri , Hoefnagel, Sanne , Linn, Bryan, Mangels-Dick, Tiffany, Ghosh, Prithwish , Iyer, Prasad G. , Buttar, Navtej , Song, Louis Wong Kee, Wang, Kenneth K.

American Journal of Gastroenterology | October 24, 2020 | Volume: 115 | Issue: 1 | Pages: S171-S171

10.14309/01.ajg.0000703440.25420.10 Get It

Risk Factor Profiles Can Distinguish Esophageal Adenocarcinoma From Barrett's Esophagus
Sawas, Tarek , Dilmaghani, Saam , Dhaliwal, Lovekirat , Wang, Kenneth K. , Iyer, Prasad G. , Katzka, David A.

American Journal of Gastroenterology | October 15, 2020 | Volume: 116 | Issue: 1 | Pages: 198-201

10.14309/ajg.0000000000001001 | PMID 33065588 Get It

INTRODUCTION: It is assumed that screening risk factors for Barrett's esophagus (BE) and prevalent esophageal adenocarcinoma (EAC) are the same. METHODS: A matched case-control study comparing risk factors between EAC and BE was performed. RESULTS: In 1,356 patients (678 with EAC and 678 with BE), heartburn (52.7%), diabetes, hyperlipidemia, hypertension, nonalcoholic steatohepatitis, and metabolic syndrome were less common in EAC (52.7, 29.2, 45.7, 48.2, 12, and 28.5%, resp.) compared with BE (84.5, 37.6, 82.2, 64.6, 18.4, and 44.1%, P < 0.01). Mean alanine aminotransferase and HgA1c levels were also significantly lower in EAC compared with BE. DISCUSSION: Optimal strategies for screening for prevalent EAC may be different than that for BE.
Utilisation of artificial intelligence for the development of an EUS-convolutional neural network model trained to enhance the diagnosis of autoimmune pancreatitis
Marya, Neil B. , Powers, Patrick, Chari, Suresh T. , Gleeson, Ferga C. , Leggett, Cadman L. , Dayyeh, Barham K. Abu , Iyer, Prasad G. , Majumder, Shounak , Pearson, Randall K., Petersen, Bret T. , Rajan, Elizabeth , Sawas, Tarek , Vege, Santhi Swaroop, Chen, Shigao , Long, Zaiyang , Hough, David M., Mara, Kristin C. , Levy, Michael J. , Abu Dayyeh, Barham K , Iyer, P G , Majumder, Shounak , Sawas, T , Vege, Santhi S, Mara, Kristin, Mara, Kristin C , Leggett, Cadman L , Chari, Suresh T , Marya, Neil B. , Chandrasekhara, Vinay , Storm, Andrew C. , Vege, Santhi Swaroop , Levy, Michael J.

Gut | October 7, 2020 | Volume: 70 | Issue: 7 | Pages: 1335-1344

10.1136/gutjnl-2020-322821 | PMID 33028668 Get It

Objective The diagnosis of autoimmune pancreatitis (AIP) is challenging. Sonographic and cross-sectional imaging findings of AIP closely mimic pancreatic ductal adenocarcinoma (PDAC) and techniques for tissue sampling of AIP are suboptimal. These limitations often result in delayed or failed diagnosis, which negatively impact patient management and outcomes. This study aimed to create an endoscopic ultrasound (EUS)-based convolutional neural network (CNN) model trained to differentiate AIP from PDAC, chronic pancreatitis (CP) and normal pancreas (NP), with sufficient performance to analyse EUS video in real time. Design A database of still image and video data obtained from EUS examinations of cases of AIP, PDAC, CP and NP was used to develop a CNN. Occlusion heatmap analysis was used to identify sonographic features the CNN valued when differentiating AIP from PDAC. Results From 583 patients (146 AIP, 292 PDAC, 72 CP and 73 NP), a total of 1 174 461 unique EUS images were extracted. For video data, the CNN processed 955 EUS frames per second and was: 99% sensitive, 98% specific for distinguishing AIP from NP; 94% sensitive, 71% specific for distinguishing AIP from CP; 90% sensitive, 93% specific for distinguishing AIP from PDAC; and 90% sensitive, 85% specific for distinguishing AIP from all studied conditions (ie, PDAC, CP and NP). Conclusion The developed EUS-CNN model accurately differentiated AIP from PDAC and benign pancreatic conditions, thereby offering the capability of earlier and more accurate diagnosis. Use of this model offers the potential for more timely and appropriate patient care and improved outcome.
Multifocal Cryoballoon Ablation for Eradication of Barrett's Esophagus-Related Neoplasia: A Prospective Multicenter Clinical Trial
Rosenblum, Michael , Dumot, John A. , Chak, Amitabh , Iyer, Prasad G. , Khara, Harshit S. , Corbett, F Scott , McKinley, Matthew , Shin, Eun Ji , Waxman, Irving , Infantolino, Anthony, Tofani, Christina , Samarasena, Jason , Chang, Kenneth J. , Wang, Bingkai , Goldblum, John R. , Voltaggio, Lysandra , Lightdale, Charles J. , Shaheen, Nicholas J. , Iyer, Prasad, Canto, Marcia Irene , Trindade, Arvind J. , Abrams, Julian A , Diehl, David L. , Montgomery, Elizabeth Anne

American Journal of Gastroenterology | October 2, 2020 | Volume: 115 | Issue: 11 | Pages: 1879-1890

10.14309/ajg.0000000000000822 | PMID 33156107 Get It

INTRODUCTION: Ablation of Barrett's esophagus (BE) is the preferred approach for the treatment of neoplasia without visible lesions. Limited data on cryoballoon ablation (CBA) suggest its potential clinical utility. We evaluated the safety and efficacy of CBA in a multicenter study of patients with neoplastic BE. METHODS: In a prospective clinical trial, 11 academic and community centers recruited consecutive patients with BE of 1–6 cm length and low-grade dysplasia, high-grade dysplasia (HGD), or intramucosal adenocarcinoma (ImCA) confirmed by central pathology. Patients with symptomatic pre-existing strictures or visible BE lesions had dilation or endoscopic mucosal resection (EMR), respectively, before enrollment. A nitrous oxide cryoballoon focal ablation system was used to treat all visible columnar mucosa in up to 5 sessions. Study end points included complete eradication of all dysplasia (CE-D) and intestinal metaplasia (CE-IM) at 1 year. RESULTS: One hundred twenty patients with BE with ImCA (20%), HGD (56%), or low-grade dysplasia (23%) were enrolled. In the intention-to-treat analysis, the CE-D and CE-IM rates were 76% and 72%, respectively. In the per-protocol analysis (94 patients), the CE-D and CE-IM rates were 97% and 91%, respectively. Postablation pain was mild and short lived. Fifteen subjects (12.5%) developed strictures requiring dilation. One patient (0.8%) with HGD progressed to ImCA, which was successfully treated with EMR. Another patient (0.8%) developed gastrointestinal bleeding associated with clopidogrel use. One patient (0.8%) had buried BE with HGD in 1 biopsy, not confirmed by subsequent EMR. DISCUSSION: In patients with neoplastic BE, CBA was safe and effective. Head-to-head comparisons between CBA and other ablation modalities are warranted (clinicaltrials.gov registration NCT02514525).
Methylated DNA Markers of Esophageal Squamous Cancer and Dysplasia: An International Study
Qin, Yi , Bamlet, William R. , Ravindran, Adharsh, Buglioni, Alessia , Cao, Xiaoming , Albert, Paul S. , Kim, Sungduk , Etemadi, Arash , Sotoudeh, Masoud , Smyrk, Thomas C. , Katzka, David A. , Topazian, Mark , Ahlquist, David A. , Iyer, Prasad G. , Bamlet, William R , Foote, Patrick H. , Slettedahl, Seth W , Mahoney, Douglas W. , Malekzadeh, Reza , Abnet, Christian C , Katzka, D A , Topazian, Mark D , Dawsey, Sanford M. , Ahlquist, David, Kisiel, John B , Qin, Y , Taylor, William R. , Slettedahl, Seth W. , Hu, Nan , Taylor, Philip R. , Malekzadeh, Reza , Abnet, Christian C. , Kisiel, John B.

Cancer Epidemiology, Biomarkers & Prevention | September 18, 2020 | Volume: 29 | Issue: 12 | Pages: 2642-2650

10.1158/1055-9965.epi-20-0616 | PMID 32948633 Get It

Abstract Background: Discovery of methylated DNA markers (MDM) of esophageal squamous cell carcinoma (ESCC) has sparked interest in assessing these markers in tissue. We evaluated MDMs in ESCC from three geographically and ethnically distinct populations, and explored the feasibility of assaying MDMs from DNA obtained by swallowed balloon devices. Methods: MDMs were assayed in ESCC and normal tissues obtained from the populations of United States, Iran, and China, and from exfoliative cytology specimens obtained by balloons in a Chinese population. Areas under the receiver operating curve (AUC) of MDMs discriminating ESCC from normal tissues were calculated. Random forest prediction models were built, trained on U.S. cases and controls, and calibrated to U.S.-only controls (model 1) and three-country controls (model 2). Statistical tests were used to assess the relationship between dysplasia and MDM levels in balloons. Results: Extracted DNA from 333 ESCC and 322 normal tissues was analyzed, in addition to archival DNA from 98 balloons. For ESCC, model 1 validated in Iranian and Chinese tissues with AUCs of 0.90 and 0.87, and model 2 yielded AUCs of 0.99, 0.96, and 0.94 in tissues from the United States, Iran, and China, respectively. In Chinese balloons, MDMs showed a statistically significant trend of increasing levels with increasing grades of dysplasia (P &lt; 0.004). Conclusions: MDMs accurately discriminate ESCC from normal esophagus in tissues obtained from high- and low-incidence countries. Preliminary data suggest that levels of MDMs assayed in DNA from swallowed balloon devices increase with dysplasia grade. Larger studies are needed to validate these results. Impact: MDMs coupled with minimally invasive collection methods have the potential for worldwide application in ESCC screening.
Abstract 2593: Inhibition of COX1/2-driven thromboxane A2 pathway suppresses Barrett's esophagus and esophageal adenocarcinoma development
Wang, Qiushi , Ma, Weiya, Wang, Keke , Chang, Xiaoyu , Johnson, Michele L., Bai, Ruihua , Bode, Ann M. , Foster, Nathan R. , Iyer, Prasad G. , Zhang, Tianshun , Falk, Gary W. , Dong, Zigang

Cancer Research | September 4, 2020 | Volume: 80 | Issue: 16_Supplement | Pages: 2593-2593

10.1158/1538-7445.am2020-2593 Get It

Abstract Barrett's esophagus (BE), a complication of gastroesophageal reflux disease (GERD), predisposes patients to esophageal adenocarcinoma (EAC). Reliable biomarkers for early detection and discovery of potential drug targets are urgently needed for improved BE and EAC patient outcomes. In this study, COX2 and TBXAS are highly expressed in BE and EAC patients accompanied by a pronounced elevation of circulating TXA2 levels in patient biopsy samples. Acetylsalicylic acid (ASA) suppressed BE and EAC growth by targeting the TXA2 pathway in a esophagoduodenostomy mouse model of reflux. Additionally, biopsies from patients showed that ASA substantially decreased serum TXA2 levels, resulting in reduced inflammation in a window opportunity clinical trial. Overall, this study establishes the importance of the COX1/2-driven TXA2 pathway in BE and EAC pathophysiology and lays the groundwork for introducing a TXA2-targeting strategy for EAC prevention and early detection. ASA targets the TXA2 pathway and suppresses BE and EAC. Citation Format: Tianshun Zhang, Qiushi Wang, Wei-Ya Ma, Keke Wang, Xiaoyu Chang, Michele L. Johnson, Ruihua Bai, Ann M. Bode, Nathan R. Foster, Gary W. Falk, Prasad G. Iyer, Zigang Dong. Inhibition of COX1/2-driven thromboxane A2 pathway suppresses Barrett's esophagus and esophageal adenocarcinoma development [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2593.
Accurate Nonendoscopic Detection of Barrett's Esophagus by Methylated DNA Markers: A Multisite Case Control Study
Iyer, Prasad G. , Johnson, Michele L., Lansing, Ramona, Maixner, Kristyn, Hemminger, Lois L., Cayer, Frances K., Yab, Tracy C. , Devens, Mary E., Broderick, Brendan T., McGlinch, Maria, Giakomopoulos, Maria, Allawi, Hatim T. , Smyrk, Thomas C. , Wang, Kenneth K. , Katzka, David A. , Wolfsen, Herbert C. , Burke, James A. , Ahlquist, David A. , Lansing, Ramona L, Maixner, Kristyn A, Slettedahl, Seth W. , Mahoney, Douglas W. , McGlinch, Maria C, Berger, Calise K. , Foote, Patrick H. , Taylor, William R. , Burke, James A., Kisiel, John B.

American Journal of Gastroenterology | June 19, 2020 | Volume: 115 | Issue: 8 | Pages: 1201-1209

10.14309/ajg.0000000000000656 | PMID 32558685 Get It

INTRODUCTION: Nonendoscopic Barrett's esophagus (BE) screening may help improve esophageal adenocarcinoma outcomes. We previously demonstrated promising accuracy of methylated DNA markers (MDMs) for the nonendoscopic diagnosis of BE using samples obtained from a capsule sponge-on-string (SOS) device. We aimed to assess the accuracy of these MDMs in an independent cohort using a commercial grade assay. METHODS: BE cases had ≥ 1 cm of circumferential BE with intestinal metaplasia; controls had no endoscopic evidence of BE. The SOS device was withdrawn 8 minutes after swallowing, followed by endoscopy (the criterion standard). Highest performing MDMs from a previous study were blindly assessed on extracted bisulfite-converted DNA by target enrichment long-probe quantitative amplified signal (TELQAS) assays. Optimal MDM combinations were selected and analyzed using random forest modeling with in silico cross-validation. RESULTS: Of 295 patients consented, 268 (91%) swallowed the SOS device; 112 cases and 89 controls met the pre-established inclusion criteria. The median BE length was 6 cm (interquartile range 4–9), and 50% had no dysplasia. The cross-validated sensitivity and specificity of a 5 MDM random forest model were 92% (95% confidence interval 85%–96%) and 94% (95% confidence interval 87%–98%), respectively. Model performance was not affected by age, gender, or smoking history but was influenced by the BE segment length. SOS administration was well tolerated (median [interquartile range] tolerability 2 [0, 4] on 10 scale grading), and 95% preferred SOS over endoscopy. DISCUSSION: Using a minimally invasive molecular approach, MDMs assayed from SOS samples show promise as a safe and accurate nonendoscopic test for BE prediction.
PTU-055 Comparative cost-effectiveness of gastroesophageal reflux disease (GORD) centric and population based barrett’s oesophagus (BO) screening
Sami, Sarmed S. , Rosedahl, Jordan K., Katzka, David A. , Ahlquist, David A. , Moriarty, James P. , Borah, Bijan J. , Kisiel, John B. , Wang, Kenneth , Iyer, Prasad

Posters | May 8, 2020 | Volume: No volume available | Issue: No issue available | Pages: A142.1-A142

10.1136/gutjnl-2019-bsgabstracts.268 Get It