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Margaret Mary Showel, M.D.

Headshot of Margaret Mary Showel
  • Assistant Professor of Oncology


Acute Lymphoblastic Leukemia (ALL), Acute Myeloid Leukemia (AML), Hematologic Malignancies, Leukemia, Medical Oncology, Myelodysplastic Syndromes (MDS) more

Research Interests

Leukemia, ALL

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Sibley Memorial Hospital

Appointment Phone: 202-660-6500
5255 Loughboro Road NW
Johns Hopkins Kimmel Cancer Center
Washington, DC 20016 map
Phone: 202-660-6500 | Fax: 202-660-6501

Johns Hopkins Sidney Kimmel Comprehensive Cancer Center

Appointment Phone: 410-955-8964
401 N. Broadway
Baltimore, MD 21231 map
Phone: 410-955-8893 | Fax: 410-614-3809

The Bunting Blaustein Cancer Research Building

Appointment Phone: 410-955-8964
1650 Orleans St.
Suite 288
Baltimore, MD 21287 map
Phone: 410-955-8781 | Fax: 410-614-3809


Margaret M. Showel, M.D., is an assistant professor of oncology at Johns Hopkins University School of Medicine, as well as a hematologist in the Johns Hopkins Kimmel Cancer Center at Sibley Memorial Hospital. Dr. Showel is board certified in medical oncology by the American Board of Internal Medicine. She also practices out of The Bunting Blaustein Cancer Research Building in Baltimore, Maryland.

Dr. Showel has expertise in acute lymphoblastic leukemia, acute myeloid leukemia, hematologic malignancies, leukemia, medical oncology and myelodysplastic syndromes. 

Dr. Showel earned her medical degree from Rush Medical College. She completed a residency in internal medicine at Rush Presbyterian/St. Luke's Medical Center and a fellowship in oncology at Johns Hopkins University School of Medicine. more


  • Assistant Professor of Oncology

Departments / Divisions

Centers & Institutes



  • MD; Rush Medical College (2002)


  • Internal Medicine; Rush-Presbyterian-St Lukes Medical Center (2006)


  • Oncology; Johns Hopkins University School of Medicine (2009)

Research & Publications

Selected Publications

View all on PubMed

McCurdy, S.R., Kasamon, Y.L., Kanakry, C.G., Bolaños-Meade, J., Tsai, H.L., Showel, M.M., Kanakry, J.A., Symons, H.J., Gojo, I., Smith, B.D., Bettinotti, M.P., Matsui, W.H., Dezern, A.E., Huff, C.A., Borrello, I., Pratz, K.W., Gladstone, D.E., Swinnen, L.J., Brodsky, R.A., Levis, M.J., Ambinder, R.F., Fuchs, E.J., Rosner, G.L., Jones, R.J., Luznik, L. "Comparable composite endpoints after HLA-matched and HLA-haploidentical transplantation with post-transplantation cyclophosphamide." Haematologica. 2017 Feb;102(2):391-400. doi: 10.3324/haematol.2016.144139. Epub 2016 Oct 20.

Pratz, K.W., Rudek, M.A., Gojo, I., Litzow, M.R., McDevitt, M.A., Ji, J., Karnitz, L.M., Herman, J.G., Kinders, R.J., Smith, B.D., Gore, S.D., Carraway, H.E., Showel, M.M., Gladstone, D.E., Levis, M.J., Tsai, H.L., Rosner, G., Chen, A., Kaufmann, S.H., Karp, J.E. "A Phase I Study of Topotecan, Carboplatin and the PARP Inhibitor Veliparib in Acute Leukemias, Aggressive Myeloproliferative Neoplasms, and Chronic Myelomonocytic Leukemia." Clin Cancer Res. 2017 Feb 15;23(4):899-907. doi: 10.1158/1078-0432.CCR-16-1274. Epub 2016 Aug 22.

Gojo, I., Beumer, J.H., Pratz, K.W., McDevitt, M.A., Baer, M.R., Blackford, A.L., Smith, B.D., Gore, S.D., Carraway, H.E., Showel, M.M., Levis, M.J., Dezern, A.E., Gladstone, D.E., Ji, J.J., Wang, L., Kinders, R.J., Pouquet, M., Ali-Walbi, I., Rudek, M.A., Poh, W., Herman, J.G., Karnitz, L.M., Kaufmann, S.H., Chen, A., Karp, J.E. "A Phase 1 Study of the PARP Inhibitor Veliparib in Combination with Temozolomide in Acute Myeloid Leukemia." Clin Cancer Res. 2017 Feb 1;23(3):697-706. doi: 10.1158/1078-0432.CCR-16-0984. Epub 2016 Aug 8.

Kasamon, Y.L., Bolaños-Meade, J., Prince, G.T., Tsai, H.L., McCurdy, S.R., Kanakry, J.A., Rosner, G.L., Brodsky, R.A., Perica, K., Smith, B.D., Gladstone, D.E., Swinnen, L.J., Showel, M.M., Matsui, W.H., Huff, C.A., Borrello, I., Pratz, K.W., McDevitt, M.A., Gojo, I., Dezern, A.E., Shanbhag, S., Levis, M.J., Luznik, L., Ambinder, R.F., Fuchs, E.J., Jones, R.J. "Outcomes of Nonmyeloablative HLA-Haploidentical Blood or Marrow Transplantation With High-Dose Post-Transplantation Cyclophosphamide in Older Adults." J Clin Oncol. 2015 Oct 1;33(28):3152-61. doi: 10.1200/JCO.2014.60.4777. Epub 2015 Aug 10.

Agrawal, V., Christenson, E.S., Showel, M.M. "Tyrosine kinase inhibitor induced isolated pericardial effusion." Case Rep Oncol. 2015 Feb 13;8(1):88-93. doi: 10.1159/000375484. eCollection 2015 Jan-Apr.

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The Patient Rating score is an average of all responses to physician related questions on the national CG-CAHPS Medical Practice patient experience survey through Press Ganey. Responses are measured on a scale of 1 to 5, with 5 being the best score. Comments are also gathered from our CG-CAHPS Medical Practice Survey through Press Ganey and displayed in their entirety. Patients are de-identified for confidentiality and patient privacy.

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