Jonathan Bruce Greer, M.D.

Headshot of Jonathan Bruce Greer
  • Director, Peritoneal Surface Malignancy Program
  • Assistant Professor of Surgery


Adrenal Cancer, Colorectal Cancer, Cytoreductive Surgery, Gastric Cancer, Gastroesophageal Cancer, Gastrointestinal Cancers, Gastrointestinal Stromal Tumors (GIST), General Surgery, Hyperthermic Intraperitoneal Chemotherapy (HIPEC), Neuroendocrine Tumors, Paraganglioma, Retroperitoneal Sarcomas, Sarcoma, Small Bowel Cancer, Stomach Cancer, Surgical Oncology more

Research Interests

heated intraperitoneal peritoneal chemotherapy (hipec); peritoneal surface malignancy; peritoneal metastasis; molecular profiling of intraperitoneal tumors; immunotherapy in solid tumors; clinical trials more

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The Johns Hopkins Hospital

Appointment Phone: 443-997-1508
600 N. Wolfe Street
Baltimore, MD 21287
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Jonathan B. Greer, M.D. is an assistant professor of surgery, within the Johns Hopkins Department of Surgery, and oncology, within the gastrointestinal cancer program at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University School of Medicine. He is the director of the peritoneal surface malignancy program and the program director for the complex general surgical oncology fellowship. He is also a member of the gastric cancer center, the sarcoma program, and the neuroendocrine multidisciplinary clinic.

Dr. Greer’s areas of clinical expertise fall mainly within complex general surgical oncology. Within gastrointestinal surgical oncology, Dr. Greer frequently operates on metastatic colorectal and appendix cancer, gastric and gastroesophageal cancer, and neuroendocrine tumors. A particular clinical interest is in cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal mesothelioma, pseudomyxoma peritonei and tumors of the appendix (both low grade appendiceal mucinous neoplasm or LAMN and high-grade adenocarcinomas or cancers, including goblet cell tumors), colorectal cancer, and gastric cancer. A member of the sarcoma program, Greer operates on retroperitoneal sarcomas and gastrointestinal stromal tumors (GIST). He also has expertise in complex operations for adrenocortical carcinoma and paragangliomas.

Dr. Greer received his undergraduate and medical degrees from Brown University in Providence, Rhode Island. He completed a residency in general surgery at the Massachusetts General Hospital/Harvard Medical School in Boston. He performed a research fellowship in immunology at Memorial Sloan Kettering Cancer Center, in New York, and a clinical fellowship in complex general surgical oncology at the University of Pittsburgh Medical Center.

He is a member of the Association of Academic Surgeons, the American College of Surgeons, the Society for Surgery of the Alimentary Tract, the Trans-Atlantic Retroperitoneal Sarcoma Working Group, the Connective Tissue Oncology Society, and a fellow of the Society of Surgical Oncology (FSSO). more


  • Director, Peritoneal Surface Malignancy Program
  • Program Director, Complex General Surgical Oncology Fellowship
  • Assistant Professor of Surgery
  • Assistant Professor of Oncology

Departments / Divisions

Centers & Institutes



  • MD; Warren Alpert Medical School of Brown University (2008)


  • Surgery; Massachusetts General Hospital (2011)
  • General Surgery; Massachusetts General Hospital (2016)


  • Surgical Oncology; University of Pittsburgh Medical Center (2018)

Board Certifications

  • American Board of Surgery (General Surgery) (2017)
  • American Board of Surgery (Surgical Oncology) (2019)

Research & Publications

Research Summary

Research interests include the molecular drivers of peritoneal metastasis, the role of immunotherapy in peritoneal malignancy, clinical outcomes research to enhance patient selection in cytoreductive surgery with and without hyperthermic intraperitoneal chemotherapy (HIPEC), and clinical trials for gastric cancer, sarcoma, neuroendocrine tumors, and peritoneal surface malignancy.

Selected Publications

Nizam W, Fackche N, Pessoa B, Kubi B, Cloyd JM, Grotz T, Fournier K, Dineen S, Veerapong J, Baumgartner JM, Clarke C, Patel SH, Wilson GC, Lambert L, Abbott DE, Vande Walle KA, Lee B, Raoof M, Maithel SK, Russell MC, Zaidi MY, Johnston FM, Greer JB. Prognostic Significance of Preoperative Tumor Markers in Pseudomyxoma Peritonei from Low-Grade Appendiceal Mucinous Neoplasm: a Study from the US HIPEC Collaborative. J Gastrointest Surg. 2021 Sep 10; ePub ahead of print.

Fackche N, Schmocker RK, Kubi B, Cloyd JM, Ahmed A, Grotz T, Leiting J, Fournier K, Lee AJ, Powers B, Dineen S, Veerapong J, Baumgartner JM, Clarke C, Gamblin TC, Patel SH, Dhar V, Hendrix RJ, Lambert L, Abbott DE, Pokrzywa C, Lafaro K, Lee B, Zaidi MY, Maithel SK, Johnston FM, Greer JB. The Utility of Preoperative Tumor Markers in Peritoneal Carcinomatosis from Primary Appendiceal Adenocarcinoma: an Analysis from the US HIPEC Collaborative. J Gastrointest Surg. 2021 Feb 25; ePub ahead of print.

Kubi B, Nudotor R, Fackche N, Nizam W, Cloyd JM, Grotz TE, Fournier KF, Dineen SP, Powers BD, Veerapong J, Baumgartner JM, Clarke CN, Patel SH, Lambert LA, Abbott DE, Vande Walle KA, Raoof M, Lee B, Maithel SK, Staley CA, Johnston FM, Greer JB. Impact of Perioperative Blood Transfusions on Outcomes After Hyperthermic Intraperitoneal Chemotherapy: A Propensity-Matched Analysis. Ann Surg Oncol. 2021 Aug;28(8):4499-4507.

Chen L, Oke T, Siegel N, Cojocaru G, Tam AJ, Blosser RL, Swailes J, Ligon JA, Lebid A, Morris C, Levin A, Rhee DS, Johnston FM, Greer JB, Meyer CF, Ladle BH, Thompson ED, Montgomery EA, Choi W, McConkey DJ, Anders RA, Pardoll DM, Llosa NJ. The Immunosuppressive Niche of Soft Tissue Sarcomas Is Sustained by Tumor Associated Macrophages and Characterized by Intratumoral Tertiary Lymphoid Structures. Clin Cancer Res. 2020 Aug 1;26(15):4018-4030

Kim TS, Cavnar MJ, Cohen NA, Sorenson EC, Greer JB, Seifert AM, Crawley MH, Green BL, Popow R, Pillarsetty N, Veach DR, Ku AT, Rossi F, Besmer P, Antonescu CR, Zeng S, DeMatteo RP. Increased KIT inhibition enhances therapeutic efficacy in gastrointestinal stromal tumor. Clin Can Res. 2014 May 1; 20(9):2350-62.

Activities & Honors


  • NIH Summer Internship in Biomedical Research, 2002
  • Summer Research Assistantship, Brown University, 2008
  • Alpha Omega Alpha, Brown Medical School, 2008
  • Henry Thomas Randall Prize, Brown Medical School, 2008
  • Teaching Citation, Tufts University School of Medicine, 2012
  • John L. Cameron, M.D., Distinguished Clinical Service Award, Department of Surgery, Johns Hopkins University School of Medicine, 2022


  • American College of Surgeons, 2008


  • Society for Surgical Oncology, 2016


  • Association for Academic Surgeons, 2018


  • Connective Tissue Oncology Society, 2019

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