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Barbara A. Parker, MD

Professor of Clinical Medicine
Medical Director, Oncology Services
Rebecca and John Moores Cancer Center
University of California
San Diego, California

Current Research

  • Seeking new therapies for the treatment of drug resistant and metastatic breast cancer.
  • Laboratory studies are ongoing to advance a promising drug to clinical trials that could improve response to chemotherapies in patients with advanced disease.
  • These preclinical studies are poised to move to clinical trials and could impact patients soon.
Early stage breast cancer is treatable with standard therapies, but even after ostensibly curative therapy, the breast cancer can come back many years later. Recurrent breast cancers are often resistant to the drugs used to treat the original tumor. Cancer stem cells are thought to be responsible for drug resistance and breast cancer recurrence. Drs. Parker and Kipps have identified a marker on cancer stem cells that makes them targets for anti-cancer therapy. They are conducting laboratory studies to test strategies to target this marker and kill cancer stem cells.

Full Research Summary

Although initially responsive to hormone therapy and chemotherapy, most metastatic breast cancers will develop resistance to these therapies. Some breast cancers express ROR1, which is a surface protein ordinarily found on cells in embryos, but not on normal adult breast cells. Patients with breast cancers that express ROR1 typically have more aggressive disease.
Drs. Parker and Kipps discovered that breast cancer cells in which ROR1 is present have characteristics of cancer stem cells, which are cells that can regenerate the tumor and may be responsible for metastasis and recurrence, even after apparently successful therapy. The team found that the residual cancer cells remaining after paclitaxel therapy had enriched proportions of cells expressing ROR1 and other cancer stem cell-associated markers.  
They have found that a targeted anti-ROR1 drug called cirmtuzumab significantly increased the anti-tumor effect of paclitaxel chemotherapy in breast cancer cells with high ROR1 levels. Cirmtuzumab is a humanized monoclonal antibody targeting ROR1 and is currently in Phase I studies.
This year, the team will continue these efforts in studies from patient samples to determine the relative expression of ROR1 in patient samples and the effect of chemotherapy on increasing cancer stem cells with high levels of ROR1. They will also test a cirmtuzumab drug formulation in breast cancer laboratory models with low or high proportions of ROR1+ tumor cells.


Dr. Barbara Parker is involved in the studies of novel personalized therapies for the treatment of breast cancer, the impact of diet and lifestyle on breast cancer outcomes, and the quality of life of breast cancer survivors. She is the principal investigator for the Cancer and Leukemia Group B/Alliance clinical trials at UCSD. Dr. Parker is the Medical Director for the Women's Healthy Eating and Living Study of over 3,000 breast cancer survivors. She is also the principal investigator for ATHENA Breast Health Network at UCSD where she leads efforts in establishing personalized screening and risk assessment for women at the time of mammography. She is a co-investigator on the ISPY2 clinical trial in high risk early stage breast cancer and serves on the ISPY2 New Agent Selection Committee.

Grid Researcher Headshot - Parker B

BCRF Investigator Since


Donor Recognition

The Macy's Award

Area(s) of Focus