WAHO 2021-2022 Board of Directors


Benjamin Parsons_WAHO
Benjamin M. Parsons, DO
Medical Oncologist/Hematologist
Gundersen Health Care System, La Crosse Clinic

Benjamin Parsons, DO, supports and has actively participated in multi-institutional clinical trials, working to advance research in the La Crosse area. He has published works on lung cancer, prostate cancer, elderly patients with cancer, and lymphoma. His clinical interests include lymphoma, multiple myeloma, leukemia, breast cancer, and prostate cancer. 

Dr. Parsons strives to be a physician who respects the wishes of his patients, while working hard to control their disease. Throughout his professional career he has worked to restore patients’ health and improve their quality of life through a holistic philosophy, while embracing the values of compassion, equality, and excellence.


Ron Kirschling_WAHO
Ron J. Kirschling, MD
Medical Director
Aspirus UW Cancer Center, Wisconsin Rapids

Ron Kirschling, MD, has been a practicing clinician for over 30 years. He is currently a hematologist and medical oncologist in Wisconsin and is board certified in internal medicine, medical oncology, hematology, and palliative medicine. Dr. Kirschling has practiced in many different clinical settings, including emergency room medicine, primary care, and as a flight surgeon with 29 years of service in the Air Force.


William Matthaeus_WAHO
William G. Matthaeus, MD
Aurora Advanced Healthcare


Thomas Giever_WAHO 2
Thomas Giever, DO, MBA
Assistant Professor, Medicine
Froedtert & the Medical College of Wisconsin

Immediate Past President

Ruth M. O’Regan, MD
Chair and Charles A. Dewey Professor, Department of Medicine
Associate Director for Education and Mentoring
Wilmot Cancer Institute, University of Rochester
Rochester, NY

Ruth M. O’Regan, MD, focuses on identifying mechanisms of resistance to breast-cancer therapies and the development of new therapies with a specific focus on triple negative breast cancer. She has led several trials focused on new therapeutic approaches for breast cancers resistant to standard therapies.

Dr. O'Regan earned her medical degree from University College Dublin. She completed her internal medicine residency at the Medical College of Wisconsin and her hematology/oncology fellowship at Northwestern University.

Past President

Kurt Oettel_WAHO
Kurt R. Oettel, MD
Medical Oncologist
Gundersen Health Care System, La Crosse Clinic


Dean Gruber, RPh
Vice President of Industry Relations
altScripts Specialty Pharmacy
Sailaja Kamaraju, MD
Froedtert & the Medical College of Wisconsin
Adedayo Onitilo_WAHO
Adedayo A. Onitilo, MD, PhD, MSCR, FACP
Director, Cancer Care and Research
Marshfield Clinic Health System, Weston Center

Adedayo Onitilo, MD, PhD, MSCR, FACP, is principal investigator of WinCORP, providing access to NCI-sponsored clinical trials to more than 680,000 people in Wisconsin, and parts of Michigan, Iowa, and Minnesota. He is editor-in-chief for Clinical Medicine and Research, and holds a clinical faculty position at the University of Wisconsin.

Dr. Onitilo is board certified in internal medicine, hematology, medical oncology, and hospice and palliative medicine. He earned his medical degree at Ogun State University in Nigeria. He completed his residency at Columbia University, College of Physicians and Surgeons - Harlem Hospital in New York, and fellowship in oncology/ hematology at the Medical University of South Carolina, where he earned a master of science degree in clinical research. Dr. Onitilo earned his doctorate degree in epidemiology from the University of Queensland, Australia.

He is a member of the Wisconsin chapter of the American Cancer Society and Wisconsin Cancer Council Steering Committee.

Dhimant R. Patel, MD
System Medical Director
Aurora Cancer Care
Peter J. Polewski, MD, MA
Aurora Cancer Care
Nataliya Uboha_WAHO
Nataliya Uboha, MD, PhD
Assistant Professor, Department of Medicine
University of Wisconsin

1801 Research Boulevard Suite 400
Rockville, MD 20850
Tel: 301.984.9496 | Fax: 301.770.1949
Email Us