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Mark Johnston, MD, Gastroenterology, Lancaster, PA, Penn Medicine Lancaster General Hospital


Gastroenterology Lancaster, PA

Advanced Endoscopic Interventional

Partner Regional Gastroenterology, Inc

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  • Dr. Mark Johnston is a gastroenterologist in Lancaster, PA and is affiliated with multiple hospitals in the area, including Penn Medicine Lancaster General Hospital and Lancaster Regional Medical Centers. He received his medical degree from Drexel University College of Medicine and has been in practice 32 years. He specializes in advanced endoscopic interventional and is experienced in gastroesophageal reflux, interventional gastroenterology, esophageal cancer, and barrett's esophagus.

Education & Training

  • National Capital Consortium
    National Capital ConsortiumFellowship, Gastroenterology, 1993 - 1995
  • National Capital Consortium
    National Capital ConsortiumFellowship, 1992 - 1993
  • Naval Medical Center (Portsmouth)
    Naval Medical Center (Portsmouth)Residency, Internal Medicine, 1985 - 1990
  • Drexel University College of Medicine/Hahnemann University
    Drexel University College of Medicine/Hahnemann UniversityClass of 1985
  • Penn State University
    Penn State UniversityB.S., 1976 - 1980

Certifications & Licensure

  • PA State Medical License
    PA State Medical License 2004 - 2022
  • VA State Medical License
    VA State Medical License 1987 - 2022
  • American Board of Internal Medicine Gastroenterology

Awards, Honors, & Recognition

  • Doctor Honoris Causa Medical University Tirana, Albania, 2016
  • CMS Meaningful Use Stage 1 Certification EpicCare Ambulatory EMR, Epic Systems Corporation, 2012
  • Fellow (AGAF) American Gastroenterological Association, 2008
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Publications & Presentations


Journal Articles

  • Safety and efficacy of endoscopic spray cryotherapy for Barrett’s esophagus with high-grade dysplasia  
    Shaheen NJ, Greenwald BD, Peery AF, Dumot JA, Gastrointest Endosc, 1/1/2010
  • Cryospray ablation (CSA) in the palliative treatment of squamous cell carcinoma of the esophagus  
    Cash BD, Johnston LR, World Journal of Surgical Oncology, 1/1/2007
  • Dysplasia and Cancer in a Large Multicenter Cohort of Patients with Barrett’s Esophagus  
    Sharma P, Falk GW, Weston AP, Reker D, Sampliner RF, Clinical Gastroenterology and Hepatology, 1/1/2006
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Books/Book Chapters


  • Low Pressure Cryospray Ablation of High Grade Dysplasia in Barrett's Esophagus: 2 Year Follow-up
    Johnston, MH, Gastrointest Endosc, 1/1/2013
  • Endoscopic Spray Cryotherapy for Esophageal Cancer: Safety and Efficacy
    Greenwald BD, Dumot JA, Lightdale CJ, Abrams JA, Mallat DB, , David DS, Nishioka NS, Burdick SJ, Shaheen NJ, WolfsenHC, Gastrointest Endosc, Digestive Diseases Week, Chicago, 1/1/2009
  • Safety and Efficacy of Endoscopic Spray Cryotherapy for Barrett's Esophagus with High-Grade Dysplasia
    Shaheen NJ, Greenwald BD, Dumot JA, Wolfsen HC, Abrams JA, Burdick SJ, Barthel JS, Wang KK, Nishioka NS, Mallat DB, Zfass AM, Smith JO, Lightdale CJ, Gastrointest Endosc, 1/1/2009
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  • Cryotherarpy 
    Philadelphia, PA - 1/22/2006
  • GERD, Barrett’s Esophagus, Esophageal Cancer and Cryoablation 
    Tirana, Albania - 1/1/2003
  • Update in Gastroenterology: GERD, IBD and Virtual Colonoscopy 
    Tirana, Albania - 1/1/2002
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Professional Memberships

Hospital Affiliations