Meet Who Started Our Mission

A History Of Expert Care

In May of 1981, Doctors Thomas Buroker and Robert Shreck joined together in Des Moines, Iowa to provide patients with a local option for being treated with cancer. Within two years, Dr. Mark Westberg and Dr. Roscoe (“Rocky”) Morton joined with Drs. Buroker and Shreck to form Medical Oncology & Hematology Associates.  Every physician in the State of Iowa came to refer to this practice as MOHA and the term MOHA became synonymous in the community with the delivery of excellent care by a group of physicians dedicated to their patients, their practice, and their partners.

Physicians knew they could refer patients to MOHA and knew their patients would be seen immediately and would be cared for in the best of hands.  Over time, MOHA became a trusted partner to all and set the standard of not only being immediately available but for also forming foundational relationships with patient and physicians alike.  This culture still drives our every move — the delivery of compassionate care to those suffering from cancer or blood disorders with an urgency that matches their condition.  

These visionaries built the foundation of Mission Cancer + Blood with the goal of being affable, immediately available, and able to all of our patients and our healthcare system partners. 


Thomas R. Buroker

Dr. Buroker completed his undergraduate work at The University of Iowa where he graduated in 1964. He went on to graduate from the College of Osteopathy Medical and Surgery (now the Des Moines University) in 1968. Dr. Buroker completed a residency at the Grace Hospital in Detroit in 1970. He completed a fellowship in Medical Oncology in 1974 at Wayne State University Medical School in Detroit. Dr. Buroker became a faculty member in the Medical Oncology at Wayne State University in 1974. In 1978, he left academic medical practice and moved with his wife to her hometown: Des Moines, Iowa. Dr. Buroker and Dr. Shreck founded Medical Oncology and Hematology Associates in May of 1981.

Robert R. Shreck

Dr. Shreck is a native of West Des Moines who did his undergraduate work at the University of Iowa, followed by three years in the U.S. Army. Medical school was at the University of Iowa and all post-graduate work was at the University of Utah in Salt Lake City. He returned to his hometown in 1979 to open a solo oncology practice and in early 1981 he and Tom Buroker founded Mission as a two-person practice. Dr. Shreck entered emeritus status in 2017.

Roscoe F. Morton

Dr. Morton joined Drs. Buroker and Shreck in June 1981 in the newly formed group Medical Oncology and Hematology Associates. Dr. Morton’s undergraduate work was completed in 1972 at the Colorado College in Colorado Springs where he received a B.A. degree in Biology. His M.D. was awarded 1976 with honors by University of Kansas School of Medicine where he was also elected to the Alpha Omega Alpha Honor Medical Society. Dr. Morton completed a residency in Internal Medicine at the University of Kansas School of Medicine Wichita Campus in 1979 and a fellowship in Medical Oncology in 1981 at the Mayo Graduate School of Medicine in Rochester.

Mark W. Westberg

Dr. Westberg graduated from Iowa State University with a B.S. degree in Zoology in 1972 and a minor in Physics. He completed medical school at the College of Medicine at the University of Iowa in 1976. Dr. Westberg completed a residency in Internal Medicine at the University of Iowa Hospitals and Clinics in 1979. He then entered practice in general internal medicine in Houston, Texas.  After 2 years of practice he returned to University of Iowa Hospitals and Clinics to do a fellowship in Medical Oncology and Hematology in 1981 and 1982. He was a research fellow at the University of Iowa Hospitals and Clinics from 1982 to 1983. He was the fourth partner of Hematology and Oncology Associates, joining in 1983.