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BCRF Grantee Since


Donor Recognition

The Pink Agenda Award

Area(s) of Focus

Richard C. Zellars , MD

Assistant Director for Clinical Trials Accrual
Associate Professor, Department of Radiation Oncology and
Molecular Radiation Sciences
Sidney Kimmel Comprehensive Cancer Center
Johns Hopkins University
Baltimore, Maryland

Current Research


In spite of significant advances in breast cancer treatment, many challenges remain in achieving a cure for all women. Responses to treatment vary widely and there is an urgent need to find ways to improve outcomes.  Dr. Zellars’s BCRF research grant provides support for two clinical trials aimed at optimizing the use of radiation therapy in both the pre-surgery (neoadjuvant) and post-surgery (adjuvant) scenario to address these needs.

For many women, neoadjuvant chemotherapy (NAC) can result in complete response, meaning the tumor is no longer clinically detectable after therapy. However, breast cancer patients with residual cancer after neoadjuvant therapy have worse outcomes than women with no residual disease.  While pre-operative radiation has been used with NAC, it has not been shown to significantly improve outcome. One of Dr. Zellar’s studies is testing whether PARP inhibitors (PARPi), a new class of targeted anti-cancer drugs, may be used to sensitize cancer cells to pre-operative radiation. Based on laboratory studies, Dr. Zellars believes that combining a PARP inhibitor with preoperative radiation should further shrink any cancer left after NAC. 

Over the last 30 years, breast conserving surgery plus radiation has become the standard recommendation for early stage breast cancer based on results from clinical trials that show it provides equal benefit as more extensive surgery. Researchers are now considering whether decreasing radiation exposure with new techniques such as partial breast irradiation (PBI) may have similar benefits.  Clinical trials thus far, however have yielded mixed results, with breast cancers that do not have the estrogen receptor (ER-) faring worse with PBI. Dr. Zellars will compare two combination approaches to see which achieves the best results in this high risk population: 1) Radiation prior to chemotherapy; 2) Radiation with chemotherapy. Results from this study may provide women with an alternative treatment choice to reduce the risk of recurrence.

Johns Hopkins'"Progress and Promises" profiles Dr. Richard Zellars and his achievements in radiation treatment therapy. 


Dr. Zellars’s research aims to improve the facility, safety and efficacy of radiation for breast cancer. He has designed and completed two phase 1 trials evaluating partial breast irradiation and concurrent chemotherapy, a phase III trial evaluating cardiac perfusion changes in women receiving radiation with or without active breathing control and a trial to assess the use of PET/CT to identify the lumpectomy bed for radiation treatment. He has a phase I trial evaluating a PARP inhibitor and concurrent pre-operative breast irradiation and a phase III trial of PBI with sequential versus concurrent chemotherapy in women with ER negative breast cancer. He is investigating the role cytokines may play in the development of radiation-induced toxicity and tumor-associated outcomes.

In 2012 Dr. Zellars was appointed Assistant Director Clinical Trial Accrual for the Sidney Kimmel Comprehensive Cancer Center and elected as Co-Chair of the NCI Breast Oncology – Local Disease (BOLD) Task Force.