Over the course of his career, medical oncologist and internist Dr. Mark Fesen has provided patient care and patient education across central Kansas and beyond. Since 2012 he has served as a medical oncologist at Central Care Cancer Center, a recipient of the 2016 Champion of Farmworker Health Award from the Kansas Statewide Farmworker Health Program. Dr. Mark Fesen is also a founding member of the Southwest Oncology Group, an affiliate of the University of Kansas at Hutchinson Clinic.

From 1993 through early 2012, Dr. Mark Fesen served patients as a senior member of the medical oncology department at Hutchinson Clinic in Hutchinson, Kansas, joining the practice following service as a lieutenant commander in the US Public Health Service. He has also served the public as a community educator and as medical director of Hospice of Reno County.

Dedicated to advancing the field of oncology, Dr. Mark Fesen hosted the 2016 Komen Impact panel discussion on breast cancer research. He attended the meeting of the National Physicians Council for Healthcare Policy in the same year and remains a vice chair of this legislative body. Also the author of Surviving the Cancer System: An Empowering Guide to Taking Control of Your Care, he has earned widespread recognition and media coverage for his work as a patient advocate.