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
2013-2014 BCRF Project:
(The Pink Agenda Award)
In contrast to Dr. Zellars’s partial breast irradiation (PBI) and concurrent chemotherapy studies, other PBI trials had higher rates of local recurrence in women with triple negative and estrogen receptor (ER) negative breast tumors. Consequently to determine benefit of PBI and concurrent chemotherapy with respect to local control in this population, Dr. Zellars designed a randomized trial of PBI with concurrent vs. sequential chemotherapy in women with ER- breast cancer. Also his team wishes to continue enrolling patients in their trial of pre-operative PARP inhibitor and radiation in women with residual disease after neoadjuvant chemotherapy. The combination of radiation (which causes DNA breaks) and PARP inhibitor (which prevents repair of the DNA breaks) should result in great cancer cell kill than either agent alone.
Abstracts showing very low rates of toxicity with partial breast irradiation (PBI) and concurrent chemotherapy (PBICC) were presented at ASCO 2012 and ASTRO 2011. Additionally, in contrast to other PBI studies, the PBICC trials had lower rates of local recurrence in women with triple negative and ER negative tumors than reported in some studies by others. Consequently to determine benefit PBICC in this population, the Zellars team designed and opened a randomized trial of PBI with concurrent vs. sequential chemotherapy in women with ER- breast cancer.
The results of the SPECT study suggest that cardiac tissue may be far more sensitive to radiation than previously believed. Dr. Zellars’s team confirmed the original results of the trial when their recently completed second method of analysis reported similar findings. A manuscript, detailing the results, was accepted for publication and a second manuscript is nearing completion.
Based on the results of their latest study, the researchers were able to further develop ultrasound elasticity imaging. The resulting newly designed elasticity algorithm will be used to evaluate tumor response to concurrent PARPi and irradiation (POPI) in women who had an incomplete response to neoadjuvant chemotherapy. The goal is to define imaging characteristics that will be predictive of tumor response.
Approximately 75 patients have been enrolled in a study of cytokine expression changes during radiation for breast rancer, and complete accrual is expected by December 2014. Thus far the researchers have found changes in expression of certain cytokines and proteins that occur during the course of whole breast radiation and submitted an abstract detailing these results at the San Antonio 2013 conference.
Dr. Zellars is a graduate of the Johns Hopkins School of Medicine. He completed his residency at the University of Michigan in the Department of Radiation Oncology, where he was Chief Resident from 1995-96. He next accepted an appointment as an Assistant Professor of Radiation Oncology at the University of Texas Health Science Center in San Antonio. During his tenure there, Dr. Zellars also served as Clinic Director and Vice Chair. Before returning to Johns Hopkins and the Sidney Kimmel Comprehensive Cancer Center, he was at Georgetown University Department of Radiation Medicine. Currently, Dr. Zellars is Associate Professor in the Department of Radiation Oncology and Molecular Radiation Sciences at Hopkins. In January 2013, Dr. Zellars was appointed Assistant Director for Clinical Trials Accrual at the Sidney Kimmel Comprehensive Cancer Center, where he will focus on the recruitment of minority patients to clinical trials.
Dr. Zellars's primary research interests are the evaluation of putative prognostic factors for local failure and the development of new radiation therapy techniques, all with respect to breast cancer.