Michael P. O'Leary
Biography
Michael P. O'Leary, M.D., F.A.C.S., F.S.S.O., is Health Sciences Assistant Clinical Professor of Surgery in the Division of Surgical Oncology at the University of California, Irvine, and Division Chief of Surgical Oncology at the Long Beach Veterans Affairs Medical Center. O'Leary received his M.D. from the University of California, Irvine School of Medicine in 2012, completed general surgery residency at Harbor-UCLA Medical Center in 2019, and completed a Complex General Surgical Oncology fellowship at City of Hope Comprehensive Cancer Center in 2021. He is board certified in both General Surgery and Complex General Surgical Oncology.
O'Leary's research focuses on peritoneal surface malignancies, regional cancer therapies including hyperthermic intraperitoneal chemotherapy (HIPEC) and pressurized intraperitoneal aerosolized chemotherapy (PIPAC), and oncolytic virotherapy. He has authored over 50 peer-reviewed publications in journals including Annals of Surgery, Annals of Surgical Oncology, JAMA Surgery, Molecular Therapy Oncolytics, and Journal of Translational Medicine. His work spans clinical outcomes research in cytoreductive surgery and HIPEC, health disparities in cancer care, and preclinical studies of novel oncolytic viruses for pancreatic, colorectal, and breast cancers.
O'Leary serves as Associate Program Director for the Complex General Surgical Oncology Fellowship at UC Irvine and is a member of the Society of Surgical Oncology Peritoneal Surface Malignancy Disease Site Working Group Committee. He has received multiple teaching awards including the Excellence in Teaching with Humanism Award from UCLA School of Medicine in 2015 and 2019, and was named Fellow of the Year at City of Hope Comprehensive Cancer Center in 2020. O'Leary is an elected Fellow of the American College of Surgeons and the Society of Surgical Oncology.
Return to topEducation
- B.S. in Microbiology, University of California, Davis, 2008
- M.D., University of California, Irvine, School of Medicine, 2012
Distinctions
- Fellow, American College of Surgeons, 2014
- Fellow, Society of Surgical Oncology, 2019
- Inductee, Gold Humanism Honor Society, University of California, Irvine, School of Medicine, 2011
- Nominee, Outstanding Resident Teacher Award, The Association for Surgical Education, 2019
- First Place, Commission on Cancer, Best Cancer Related Manuscript, Southern California Chapter, American College of Surgeons, 2024
- Third Place, Commission on Cancer, Best Cancer Related Manuscript, Southern California Chapter, American College of Surgeons, 2025
- ACGME Fellow of the Quarter, Graduate Medical Education, City of Hope Comprehensive Cancer Center, 2020
- Intern of the Year, Harbor-UCLA Medical Center, Surgery Internship, 2013
- Fellow of the Year, City of Hope Comprehensive Cancer Center, 2020
Areas of Expertise
- Surgical Oncology
- Oncolytic Virotherapy
- Hyperthermic Intraperitoneal Chemotherapy
- Colorectal Cancer Treatment
- Peritoneal Surface Malignancy
- Immunotherapy for Microsatellite Instability
- Hepatic Artery Infusion Therapy
Recent Publications
- Ramalingam K, Liang J, O'Leary MP, Lum SS, Caba-Molina D, “Medicaid Expansion and Overall Survival of Lower Gastrointestinal Cancer Patients after Cytoreductive Surgery and Heated Intraperitoneal Chemotherapy” (opens in new tab), Annals of Surgical Oncology, vol. 32, pp. 687-694, 2025.
- Wong P, O'Leary MP, Mahuron K, Schoellhammer H, Faynsod M, Paz B, Melstrom LG, “Practice Patterns of Surveillance in Sentinel Lymph Node-Positive Malignant Melanoma: An International Survey”, American Journal of Clinical Oncology Cancer Clinical Trials, vol. 48, pp. 410-414, 2025.
- Ali A, Wang Fai L, O'Leary MP, Whealon M, “Great Debates: Surgery or Watch and Wait after Total Neoadjuvant Therapy for Rectal Cancer”, The American Surgeon, 2024.
- Lee D, Roman M, Newman GL, Lopez Y, Ashman ZW, O'Leary MP, “Large Intestinal Obstruction and Perforation from Metastatic Merkel Cell Carcinoma: A Case Report”, Cureus, 2023.
- Odeluga N, Banapour P, Choong K, O'Leary MP, Lau C, “Safety and Feasibility of Robotic-Assisted Partial Nephrectomy and Partial Hepatectomy for Soft Tissue Sarcoma”, Advances in Laparoscopy, 2022.
- Nguyen AH, O'Leary MP, De Andrade J, Ituarte P, Kessler J, Li D, Singh G, Chang S, “A Natural History of Renal Neuroendocrine Neoplasms: a NET by any other name?” (opens in new tab), Frontiers in Endocrinology, vol. 11, pp. 624251, 2021.
- Woo Y, Chaurasiya C, O'Leary M, Han E, Fong Y, “Fluorescent Imaging for Cancer Therapy and Cancer Gene Therapy” (opens in new tab), Molecular Therapy Oncolytics, 2021.
- Nguyen AH, O'Leary MP, De Andrade JP, Ituarte P, Warner S, Melstrom L, Kessler J, Fong Y, Li D, Singh G, “Presentation and Survival of Gastro-entero-pancreatic Neuroendocrine Tumors in Young Adults versus Older Patients” (opens in new tab), The American Journal of Surgery, 2021.
- Choong KC, O'Leary MP, Ituarte P, Warner SG, Melstrom L, Fong Y, Singh G, “Distal Pancreatectomy, Pancreatoduodenectomy, and Total Pancreatectomy for Pancreatic Neuroendocrine Tumors – Same Organ, Different Outcomes”, Clinics of Surgery, vol. 5, no. 12, pp. 1-8, 2021.
- Ituarte PHG, Nelson RA, O'Leary MP, Raoof M, Singh G, “Age-Adjusted Incidence of Synchronous Colorectal Liver Metastases by Sex, Race, and Age Group”, HPB, 2021.
- O'Leary MP, Wang C, Sandhu J, Malhotra G, Thornblade L, Lau SC, Melstrom L, Fong Y, Singh G, Fakih M, “Salvage Regional Therapy using Hepatic Artery Infusion Pump in Unresectable Chemotherapy Resistant Colorectal Liver Metastases” (opens in new tab), American Journal of Surgery, 2021.
Most Cited Publications
- Choi AH, O'Leary MP, Merchant SJ, Sun V, Chao J, Raz DJ, Kim JY, Kim J, “Complications of Feeding Jejunostomy Tubes in Patients with Gastroesophageal Cancer” (opens in new tab), Journal of Gastrointestinal Surgery, vol. 21, no. 2, pp. 259-265, 2016.
- Dumitra S, O'Leary MP, Raoof M, Wakabayashi M, Dellinger TH, Han ES, Lee SJ, Lee B, “The Comprehensive Complication Index: A New Measure of the Burden of Complications after Hyperthermic Intraperitoneal Chemotherapy” (opens in new tab), Annals of Surgical Oncology, vol. 25, no. 3, pp. 688-93, 2018.
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Last updated on 6/2/2026.