Daphne Stewart

Dr. Daphne Stewart is a Clinical Professor of Medicine in the division of Medical Oncology at the USC Norris Comprehensive Cancer Center and Keck School of Medicine. Dr. Stewart is certified by the American Board of Internal Medicine in Medical Oncology and Hematology. Her specialty is breast cancer care.

Dr. Stewart was born and raised in California, a 5th generation California resident, and lover of the west coast. She speaks Spanish fluently. She graduated from the University of California, Berkeley after earning a bachelor’s degree in English literature with a particular interest in F. Scott and Zelda Fitzgerald’s work. She attended Columbia University, Vagelos College of Physicians and Surgeons, in New York City, and earned a Medical Doctorate Degree. She returned to Southern California and completed her Internal Medicine residency and Hematology and Medical Oncology fellowship at the University of California, Los Angeles, David Geffen School of Medicine. Prior to joining USC Keck School of Medicine, she was a clinician and researcher specializing in women’s cancers at City of Hope National Medical Center.

Her clinical specialty is Breast Cancer, including treatment of patients at high risk for a diagnosis of breast cancer, early-stage breast cancer, breast cancer survivorship, and metastatic breast cancer. She also has extensive experience in managing gynecologic malignancies and blood clotting disorders associated with cancer. Her research is focused on developing novel therapies to manage breast cancer, with the goal to deliver new interventions to her clinical practice in order to improve patients’ outcomes. She is a committed investigator in numerous clinical trials aiming to assess benefit and tolerability of new therapeutics and drug combinations.

Throughout her career she has focused on patient care, dedicating herself to providing the highest quality oncology care to patients in order to ensure the most meaningful benefits. She supports her patients by understanding their expressed goals while relentlessly fighting cancer. She highly values and is deeply inspired by the personal relationship she establishes with each of her patients.

• Columbia University, New York, NY: Alpha Omega Alpha Society, 1998
• David Geffen Scool of Medicine at UCLA, Los Angeles, CA: Specialty Training and Advanced Research Fellowship Recipient (STAR), 2003
• City of Hope, Duarte, CA: Arti Hurria Mentoring and Clinical Teaching Award, Education and Mentoring (Teaching), 2020

• University of California, Berkeley, Berkeley, CA — BA — 1993 — English, Honors
• Columbia University, New York, NY — MD — 1998 — Medicine
• University of California, Los Angeles, Los Angeles, CA — Internship — 2000 — Internal Medicine
• University of California, Los Angeles, Los Angeles, CA — Residency — 2002 — Internal Medicine
• University of California, Los Angeles, Los Angeles, CA — Fellowship — 2005 — Hematology/Oncology
• University of California, Los Angeles, Los Angeles, CA — MS — 2008 — Biomathematics: Clinical Research

• MammaTrace – a tumor naïve cell-free DNA methylation test for minimal residual disease in breast cancer. NPJ Precis Oncol. 2026 Jul 23; 10(1).. View in PubMed
• HER2-Low and HER2-Ultralow Metastatic Breast Cancer and Trastuzumab Deruxtecan: Common Clinical Questions and Answers. Cancers (Basel). 2025 Dec 17; 17(24).. View in PubMed
• PARP Inhibitors in Ovarian Cancer: Resistance Mechanisms, Clinical Evidence, and Evolving Strategies. Biomedicines. 2025 May 06; 13(5).. View in PubMed
• Impact of Structural Racism and Social Determinants of Health on Disparities in Breast Cancer Mortality. Cancer Res. 2024 12 02; 84(23):3924-3935.. View in PubMed
• Immunologic Signatures of Peripheral Blood T Cells Reveal the Outcome of p53MVA Vaccine and Pembrolizumab Treatment in Patients with Advanced Ovarian Cancer. Cancer Res Commun. 2023 12 20; 3(12):2585-2595.. View in PubMed

• Matsuo, Koji
• Oh, Hans
• Wu-Williams, Anna
• Roman, Lynda
• Haiman, Christopher
• Blosnich, John