Titles and Affiliations

Associate Professor in the Department of Internal Medicine
Komen Distinguished Chair in Clinical Breast Cancer Research
Clinical Director, Breast Cancer Program, Harold C. Simmons Comprehensive Cancer Center
UT Southwestern Medical Center
Dallas, Texas

Conquer Cancer, the ASCO Foundation

Research area

Testing combination immunotherapy strategies to prevent recurrence for triple- negative breast cancer. 


While recent treatment advances significantly improved outcomes for those diagnosed with operable early-stage breast cancer, more than 40 percent of patients with residual hormone receptor-negative, HER2-negative (“triple-negative”, TNBC) breast cancer will experience a life-threatening recurrence within three years after therapy. The clinical challenge is further complicated by growing evidence that TNBC is a diverse disease where responses to therapy can vary widely between patients. Dr. McArthur and her team believe that an immune-based therapeutic strategy may render tumor diversity within TNBC less critical and increase therapeutic success.

Progress Thus Far

Preclinical studies led by collaborator and Nobel Laureate Dr. James Allison demonstrated that destruction of tumor tissue by cryoablation (freezing) induces activation and maturation of critical immune cells and subsequent activation of tumor-specific immune cells. Moreover, concurrent stimulation of the immune system with an immunotherapy enhanced the magnitude and potency of the immune response. Based on this data, Dr. McArthur and her team conducted a pilot study of preoperative cryoablation combined with a single dose of immune therapy in patients with early-stage breast cancer. Based on the success of these pilot studies they launched a phase II study of immune stimulation with cryoablation plus dual immunotherapies (with ipilimumab and nivolumab) in patients with TNBC and residual disease after conventional chemotherapy. The impact of this intervention on three-year recurrence rates will be determined, and 11 patients are currently enrolled.

What’s next

The study will continue enrolling up to 80 patients at Cedars Sinai Medical Center 
and the Providence Cancer Institute with several additional sites to be added.


Heather McArthur, MD, MPH joined UT Southwestern Medical Center in 2021 as the Komen Distinguished Chair in Clinical Breast Cancer Research. She is a medical oncologist with a clinical practice dedicated to the care of patients with breast cancer. Her research activities are focused on innovations in the diagnosis and treatment of breast cancer, with a particular interest in novel immune therapy strategies. Dr. McArthur completed formal medical oncology training at the University of British Columbia. There, she was awarded the highly competitive Canadian Association of Medical Oncology/Canadian Institute for Health Research R&D Fellowship which funded an advanced clinical research fellowship at MSKCC. Thereafter, she joined MSKCC as faculty and in that role developed the institutional breast cancer immunotherapy program before joining Cedars-Sinai in 2016. She has a Master’s in Public Health with a focus on clinical trial design from Harvard University and has mentored many medical students, residents, fellows, and junior faculty in the conduct and reporting of several studies - two of which directly informed national (NCCN) treatment guidelines.
Dr. McArthur has designed, conducted, and reported on many studies in breast cancer and has held several leadership positions in the field including US Co-Chair of a Breast International Group Immunotherapy Taskforce, member of an NCI Breast Cancer Immuno-Oncology (IO) Working Group, member of a NCI Breast Cancer IO Task Force, and member of the Alliance for Clinical Trials in Oncology Immunotherapy/Immune Monitoring Working Group. She has served on the ASCO Conquer Cancer Foundation YIA/CDA Grant Selection Committee, the ASCO Breast Cancer Symposium Program Committee, and as a faculty member for the ASCO Annual Meeting Grant Writing Workshop. She is currently on the ASCO Annual Meeting IO Scientific Committee and participates in the ASCO Leadership Development Program. She has served as a reviewer for numerous journals including Science, the New England Journal of Medicine, and Cancer, and has authored more than 70 articles, review articles, invited commentaries, and book chapters on breast cancer.