Gregory E. Idos, M.D., M.S.

(877) 460-4673
Gregory E. Idos, M.D., M.S.
Gastroenterologist
Clinical Expertise
  • Gastroenterology
Research Area
  • Cancer Genetics and Genetic Testing
  • Endoscopy and Colonoscopy
  • Cancer Screening and Prevention
  • General Gastroenterology
Academic Appointments
  • Associate Professor, Department of Medicine, Division of Gastroenterology
  • Associate Professor, Center for Precision Medicine
  • Monsignor Clement Connolly Professor in Medical Oncology
Clinical Teams
Gastroenterology
Gastrointestinal Cancers
Genetic Counseling

So compassionate ... I've never met a doctor who cared as much as he did for my father. — Patient's Child

A rare combination of gifted scientist and clinician, Gregory Idos, M.D., M.S., earns raves for his bedside manner, while he blazes new research trails.

Dr. Idos is a board-certified gastroenterologist and trained cancer geneticist, who specializes in the care of patients with Lynch syndrome, FAP (familial adenomatous polyposis) and other inherited syndromes. The goal of his research is to find new ways to prevent cancer and to improve treatment and care for cancer patients.

A UCLA graduate, Dr. Idos has a master’s degree from Keck School of Medicine of USC. He received his medical degree at University of Vermont, continued his residency training at USC and completed his gastroenterology fellowship at Brigham and Women’s Hospital at Harvard. Dr. Idos is an associate professor in Division of Gastroenterology and leads one of the largest multicenter studies examining the benefits and harms of “multiplex” gene panel testing. His research also focuses on the evaluation of novel technologies with the goal of providing new tools for hereditary cancer risk assessment and the development of novel cellular models to elucidate the fundamental mechanisms of microsatellite instability and Lynch syndrome.

The recipient of numerous honors and awards, Dr. Idos is part of City of Hope’s growing effort to employ precision medicine to better diagnose, treat, cure and prevent cancer.

Location

Education & Experience

Board Certifications

  • 2013, Diplomate, American Board of Gastroenterology
  • 2011, Diplomate, American Board of Internal Medicine

Degrees

  • 2014–2018, Masters in Clinical, Biomedical, and Translational, Investigation, Department of Preventive Medicine, Keck School of Medicine of USC, Los Angeles, CA
  • 2006, M.D., University of Vermont College of Medicine, Burlington, VT
  • 1999, B.S., Molecular, Cellular, and Developmental Biology, University of California Los Angeles, Los Angeles, CA

Fellowship

  • 2009–2012, Clinical and Research Fellow in Gastroenterology, Hepatology, and Endoscopy, Harvard Medical School, Brigham and Women’s Hospital

Residency

  • 2007–2009, Internal Medicine, Los Angeles County Hospital, University of Southern California, Los Angeles, CA

Internship

  • 2006–2007, Internal Medicine, Los Angeles County Hospital, University of Southern California, Los Angeles, CA

Professional Experience

  • 2020–present, Associate Professor, Center for Precision Medicine
  • 2019–present, Associate Professor, Division of Gastroenterology, Department of Medicine, City of Hope, Duarte, CA
  • 2014–2019, Assistant Professor of Clinical Medicine, Keck School of Medicine of USC, Los Angeles, CA
  • 2012–2014, Instructor of Clinical Medicine, Keck School of Medicine of USC, Los Angeles, CA

Awards & Memberships

Awards

  • 2009–2010, Fellowship Teaching Award, Brigham and Women’s Hospital, Department of Internal Medicine, Harvard Medical School
  • 2008–2009, Senior Resident of the Year, Los Angeles County General Hospital, Department of Internal Medicine, University of Southern California
  • 2006–2007, Intern of the Year, Los Angeles County, Department of Internal Medicine, General Hospital, University of Southern California
  • 1998, Deutsch Forschung Gemeinshaft Research Fellow Award, University of Muenster Division of Hematology Oncology
  • 1998–1999, Howard Hughes Undergraduate Research Fellow, Cedars Sinai Hospital, University of California Los Angeles
  • 1997–1998, Minority Scientist Developmental Research Fellow, CARE Scholar Program, University of California Los Angeles

Memberships

  • 2018–present, The International Society for Gastrointestinal Hereditary Tumours
  • 2013–present, American Society of Clinical Oncology
  • 2012–present, Collaborative Group of the Americas on Inherited Colorectal Cancer
  • 2012–2015, American Association for Cancer Research
  • 2009–2012, European Association for the Study of the Liver
  • 2009–2012, American Association for the Study of Liver Diseases
  • 2009–present, American College of Gastroenterology
  • 2009–present, American Gastroenterological Association
  • 2006–2010, American College of Physicians
  • 2002–2010, American Medical Association

Publications

  • Idos GE, Kurian AW, Ricker C, Sturgeon D, Culver J, Kingham KE, Koff RB, Chun NM, Rowe-Teeter C, Lebensohn A, Levonian P, Lowstuter K, Partynski K, Hong C, Mills MA, Petrovchich IM, Ma C, Hartman A-R, Allen B, Wenstrup RJ, Lancaster JM, Brown K, Kidd J, Evans B, Mukherjee B, McDonnell K, Ladabaum U, Ford JM, Gruber SB. A Multi-Center Prospective Cohort Study of the Diagnostic Yield and Patient Experience of Multiplex Gene Panel Testing For Hereditary Cancer Risk. JCO Precision Oncology. In Press.
  • Huyghe JR, Bien SA, Harrison TA, Kang HM, Chen S, Schmit SL, Conti DV, Qu C, Jeon J, Edlund CK, Greenside P… Idos GE…Gruber SB, Peters U. Discovery of common and rare genetic risk variants for colorectal cancer. Nature genetics. 2019 Jan;51(1):76.
  • Schmit SL, Edlund CK, Schumacher FR, Gong J, Harrison TA, Huyghe JR, Qu C, Melas M, Van Den Berg DJ, Wang H, Tring S… Idos GE…Gruber SB. Novel Common Genetic Susceptibility Loci for Colorectal Cancer. JNCI: Journal of the National Cancer Institute. 2018 Jun 16.
  • O’Day EM, Idos GE, Hill C, Chen JW, Wagner G. cytidine monophosphate N-acetylneuraminic acid synthetase enhances invasion of human triple-negative breast cancer cells. OncoTargets and therapy. 2018; 11:6827.
  • Idos GE, Gupta S. When should patients undergo genetic testing for hereditary colon cancer syndromes. Clinical Gastroenterology and Hepatology. 2018 Feb 11 1;16(2):181-3.
  • Jiang X, Finucane H, Schumacher F, Schmit S, Tyrer J, Han Y, Michailidou K, Lesseur C, Kuchenbaecker K, Dennis J, Conti D... Idos GE… Lindstroem S. Shared heritability and functional enrichment across six solid cancers. bioRxiv. 2018 Jan 1:453480.
  • Ricker CN, Koff RB, Qu C, Culver J, Sturgeon D, Kingham KE, Lowstuter K, Chun NM, Rowe-Teeter C, Lebensohn A, Levonian P… Idos GE. Patient communication of cancer genetic test results in a diverse population. Translational behavioral medicine. 2018 Jan 29;8(1):85-94.
  • Ricker CN, Hanna DL, Peng C, Nguyen NT, Stern MC, Schmit SL, Idos GE, Patel R, Tsai S, Ramirez V, Lin S. DNA mismatch repair deficiency and hereditary syndromes in Latino patients with colorectal cancer. Cancer. 2017 Oct 1;123(19):3732-43.
  • Siantz E, Wu B, Shiroishi M, Vora H, Idos GE. Mental Illness Is Not Associated with Adherence to Colorectal Cancer Screening: Results from the California Health Interview Survey. Digestive Diseases and Sciences. 2017 Jan 1;62(1):224-34.
  • Ricker C, Culver JO, Lowstuter K, Sturgeon D, Sturgeon JD, Chanock CR, Gauderman WJ, McDonnell KJ, Idos GE, Gruber SB. Increased yield of actionable mutations using multi-gene panels to assess hereditary cancer susceptibility in an ethnically diverse clinical cohort. Cancer Genetics. 2016 Apr 30;209(4):130-7.
  • McDonnell KJ, Gallanis GT, Heller KA, Melas M, Idos GE, Culver JO, Martin SE, Peng DH, Gruber SB. A novel BAP1 mutation is associated with melanocytic neoplasms and thyroid cancer. Cancer Genetics. 2016 Mar 31;209(3):75-81.
  • Schumacher FR, Schmit SL, Jiao S, Edlund CK, Wang H, Zhang B, Hsu L, Huang SC, Fischer CP, Harju JF, Idos GE, Lejbkowicz F, Manion FJ, McDonnell K, McNeil CE, Melas M, Rennert HS, Shi W, Thomas DC, Van Den Berg DJ, Hutter CM, Aragaki AK, Butterbach K, Caan BJ, Carlson CS, Chanock SJ, Curtis KR, Fuchs CS, Gala M, Giocannucci EL, Gogarten SM, Hayes RB, Henderson B, Hunter DJ, Jackson RD, Kolonel LN, Kooperberg C, Kury S, LaCroix A, Laurie CC, Laurie CA, Lemire M, Levine D, Ma J, Makar KW, Qu C, Taverna D, Ulrich CM, Wu K, Kono S, West DW, Berndt SI, Bezieau S, Brenner H, Campbell PT, Chan AT, Chang-Claude J, Coetzee GA, Conti DV, Duggan D, Figueiredo JC, Fortini BK, Gallinger SJ, Gauderman WJ, Giles G, Green R, Haile R, Harrison TA, Hoffmeister M, Hopper JL, Hudson TJ, Jacobs E, Iwasaki M, Jee SH, Jenkins M, Jia WH, Joshi A, Li L, Lindor NM, Matsuo K, Moreno V, Mukherjee B, Newcomb PA, Potter JD, Raskin L, Rennert G, Rosse S, Severi G, Schoen RE, Seminara D, Shu XO, Slattery ML, Tsugane S, White E, Xiang YB, Zanke BW, Zheng W, Le Marchand L, Casey G, Gruber SB, Peters U. Genome-wide association study of colorectal cancer identifies six new susceptibility loci. Nat Commun. 2015 Jul 7; 6:7138.
  • Nissim, S, Idos GE, Wu BU. Genetic Markers of Malignant Transformation in IPMN of the Pancreas: A Meta-analysis. Pancreas. 2012 Nov;41(8):1195-205
  • Chih DY, Park DJ, Gross M, Idos G, Vuong PT, Hirama T, Chumakov AM, Said J, Koeffler HP. Protein partners of C/EBPepsilon. Exp Hematol. 2004 Dec;32(12):1173-81.
  • Jones LC, Tefferi A, Idos GE, Kumagai T, Hofmann WK, Koeffler HP. RARbeta2 is a candidate tumor suppressor gene in myelofibrosis with myeloid metaplasia. Oncogene. 2004 Oct 14; 23(47): 7846-53.
  • Diederichs S, Baumer N, Ji P, Metzelder SK, Idos GE, Cauvet T, Wang W, Moller M, Pierschalski S, Gromoll J, Schrader MG, Koeffler HP, Berdel WE, Serve H, Muller-Tidow C. Identification of interaction partners and substrates of the cyclin A1-CDK2 complex. J Biol Chem. 2004 Aug 6; 279(32): 33727-41. Epub 2004 May 24.
  • Muller-Tidow C, Readhead C, Cohen AH, Asotra K, Idos G, Diederichs S, Cauvet T, Yang R, Berdel WE, Serve H, Koeffler HP. Successive increases in human cyclin A1 promoter activity during spermatogenesis in transgenic mice. Int J Mol Med. 2003 Mar; 11(3): 311-5.
  • Muller-Tidow C, Wang W, Idos GE, Diederichs S, Yang R, Readhead C, Berdel WE, Serve H, Saville M, Watson R, Koeffler HP. Cyclin A1 directly interacts with B-myb and cyclin A1/cdk2 phosphorylate B-myb at functionally important serine and threonine residues: tissue-specific regulation of B-myb function. Blood. 2001 Apr 1; 97(7): 2091-7.
  • Muller-Tidow C, Metzger R, Kugler K, Diederichs S, Idos G, Thomas M, Dockhorn-Dworniczak B, Schneider PM, Koeffler HP, Berdel WE, Serve H. Cyclin E is the only cyclin-dependent kinase 2-associated cyclin that predicts metastasis and survival in early stage non-small cell lung cancer. Cancer Res. 2001 Jan 15; 61(2): 647-53.
  • Muller C, Readhead C, Diederichs S, Idos G, Yang R, Tidow N, Serve H, Berdel WE, Koeffler HP. Methylation of the cyclin A1 promoter correlates with gene silencing in somatic cell lines, while tissue-specific expression of cyclin A1 is methylation independent. Mol Cell Biol. 2000 May 20(9): 3316-29.
  • Muller C, Yang R, Idos G, Tidow N, Diederichs S, Koch OM, Verbeek W, Bender TP, Koeffler HP. c-myb transactivates the human cyclin A1 promoter and induces cyclin A1 gene expression. Blood. 1999 Dec 15; 94(12): 4255-62.
  • Muller C, Yang R, Beck-von-Peccoz L, Idos G, Verbeek W, Koeffler HP. Cloning of the cyclin A1 genomic structure and characterization of the promoter region. GC boxes are essential for cell cycle-regulated transcription of the cyclin A1 gene.
  • J Biol Chem. 1999 Apr 16; 274(16): 11220-8.
  • Idos G, Muller C, Koeffler HP. Cyclin A1 promoter regulation. UCLA Undergraduate Science Journal. 999 Aug (1); 34-36.

Ratings & Reviews

Ratings and reviews below are gathered from the Press Ganey Clinician and Group Consumer Assessment of Healthcare Providers and Systems (CG CAHPS) survey. CG CAHPS is a standardized survey that is used to measure a patient's experience in the physician office setting. Ratings are an average of all responses to questions about a provider's care, with five stars being the highest.
5.0
Recommend this provider office
5.0
Provider explain in way you understand
5.0
Provider listen carefully to you
5.0
Show respect for what you say
5.0
Spend enough time with you
4.9
Know important info medical history
4.9
Rate provider 0-10
03/27/26
I will always recommend it.. - Verified patient
03/27/26
Yes, I would recommend them forever. - Verified patient
03/17/26
Very good - Verified patient
03/17/26
I have had a very good experience - Verified patient
02/16/26
Dr. Idos is very smart and professional. You can tell he cares about his patients and enjoys his work. - Verified patient