Chehalis 360-345-1381
Olympia 360-754-5168
Fax (all clinics) 360-345-1382

Our Providers

As active and involved members of Lewis and Thurston county, Dr. Osborn and his dedicated staff are committed to providing compassionate, prompt, and state-of-the-art cancer care in our community. Read about our clinics here.

Dustan C. OsbornMD, PhD

Dr. Osborn earned his PhD in biophysics at Michigan State University, his MD at Dalhousie University, and his Oncology training as a fellow at the Dana Faber Cancer Center at Harvard University. He completed a fellowship in medicine at Harvard Medical School. He is board certified in Medical Oncology and Internal Medicine. He has served as Chief of Staff at Capital Medical Center in Olympia, Washington, and was on the Board of Trustees for over 10 years. He has chaired Tumor Board at Capital Medical Center and Providence Hospital Centralia. He has also participated in clinical research and facilitated many patients getting into national clinical trials.

In his spare time, Dr. Osborn has an extreme passion for photography which is featured on this site as well as in both clinics. He also enjoys hiking, literature, and history.

Marles GeistMSN, ARNP

Marles attended Washington State University for her pre-nursing courses, Boston University for her Bachelor of Science in Nursing, and Portland University for her Masters of Science in Nursing specializing in the care of adults. She has worked abroad, served on Providence Hospital Ethics Committee, and was the unit manager of the Intensive Care Unit at Providence Hospital Centralia. She has instructed in the nursing program at Centralia College, St. Martin's University, Lower Columbia Community College, as well as in a privately-owned continuing education business which provided nursing education across the United States.

Marles enjoys gardening, hiking, and cooking; she has also mastered the art of taekwondo in which she has achieved a black belt.

Oncology/Hematology Specialist serving Olympia & Chehalis, Washington.