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BCRF Grantee Since


Area(s) of Focus

Richard C. Zellars, MD

Professor and Chairman
Department of Radiation Oncology
Sidney Kimmel Comprehensive Cancer Center
Indiana University School of Medicine
Indianapolis, Indiana

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) setting 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. Women with residual disease after NAC, however, have worse outcomes than those women who achieve a pathologic complete response. Pre-operative radiation has been used with NAC, and is well tolerated, but this combination has not clearly shown a significant improvement in the complete response rates compared to NAC alone.  With the advent of PARP inhibitors, it may be possible to sensitize tumors to pre-operative radiation.  The PARP protein is integral to the repair of single strand (ss)DNA breaks. The combination of radiation, which causes ssDNA breaks, with a PARP inhibitor, which prevents repair of ssDNA breaks, should result in greater tumor response than with either agent alone. One of Dr. Zellar’s studies is testing this hypothesis. After three years of development, the trial is now open to accrual at affiliated hospitals within the Johns Hopkins Clinical Research Network and will open soon at the Simon Cancer Center at Indiana University.

Over the last 30 years, breast conserving surgery plus radiation has become the standard recommendation for early stage breast cancer. Researchers are now considering whether decreasing radiation exposure with new techniques such as partial breast irradiation (PBI) may have similar benefits. With support from BCRF, Dr. Zellars’ team was the first to show that PBI may be a safe and expeditious treatment option for many women with breast cancer.  Unfortunately, there are women for whom PBI alone may not suffice.  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 is conducting a clinical trial to compare two combination approaches to see which achieves the best results in this high-risk population. The trial will compare response rates with radiation prior to chemotherapy to those with radiation with concurrent chemotherapy. Results from this study may provide women with an alternative treatment choice to reduce the risk of recurrence. The trial is open to accrual at affiliated hospitals within the Johns Hopkins Clinical Research Network and will open soon at the Simon Cancer Center at Indiana University.



Richard Zellars is Professor and Chairman of the Department of Radiation Oncology at Indiana University and the Director of the IUH Radiation Oncology Service line.  Before he joined the IU team in early 2015, he was  an Associate Professor in the Dept. of Radiation Oncology at the Johns Hopkins University School of Medicine, and Assistant Director of Clinical trial Accrual at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins.  He graduated from the Johns Hopkins School of Medicine and subsequently completed a residency in Radiation Oncology at University of Michigan where he was Chief Resident from 1995-1996.  Dr. Zellars was an Assistant Professor/Vice Chair and Clinic Director of the Dept. of Radiation Oncology at the University of Texas Health Science Center at San Antonio.  Prior to returning to Johns Hopkins in 2000, he was an Assistant Professor in the Dept. of Radiation Medicine at Georgetown University in Washington DC.  His research aims to improve the facility, safety and efficacy of radiation for breast cancer.  Dr. Zellars has designed and completed two phase 1 trials evaluating partial breast irradiation and concurrent chemotherapy, a phase III randomized control 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 better identify the lumpectomy bed for radiation treatment.  Presently he has a phase I trial evaluating a PARP inhibitor and concurrent pre-operative radiation in breast cancer and a randomized phase III trial of PBI with sequential vs. concurrent chemotherapy in women with ER negative breast cancer.  Dr. Zellars is also doing research with respect to healthcare disparities.  He is currently investigating the role cytokines may play in the development of radiation-induced toxicity and tumor-associated outcomes in African-American (AA) women with breast cancer who typically have worse radiation toxicity and breast cancer outcomes than their Caucasian counterparts.  His research has been funded by the Breast Cancer Research Foundation.

Dr. Zellars is a member of the American Society for Therapeutic Radiology and Oncology (ASTRO), and the American Society of Clinical Oncology (ASCO).  He also serves on the National Comprehensive Cancer Network (NCCN) Breast Cancer Panel and is Co-Chair of the NCI Breast Oncology – Local Disease (BOLD) Task Force.   Dr. Zellars has been listed as one of the top doctors for women in Redbook, Ladies Home Journal and Newsweek magazines.