Patient and Nurse

Cancer Care

Why would I choose Greater Regional for my cancer care?

When you choose Greater Regional Oncology and Infusion Center for your cancer care you will receive a team of physicians and staff who are dedicating themselves to excellence in the management of your health. 

Patients faced with the diagnosis of cancer and the uncertainty that it brings are often confronted with confusion and fear. Greater Regional Oncology and Infusion Center will work closely with you, your family and physicians to coordinate evaluations, treatment planning, therapy, and follow-up and counseling. 

Our Providers

Philip Collitier,  MD
Bradley Hiatt, DO
John Martens, MD
Christian Schultheis, MD, FACP
George Voynov, MD
Adam Gliniewicz, MD

We are here to help and will provide you with a clear understanding of your cancer and the appropriate treatment options available. We take the time to make sure you are thoroughly informed and will answer all your questions. 

Contact Us

Oncology and Infusion Center

Medical Center

1700 W. Townline St

Creston, IA 50801



8 a.m.- 5 p.m.

What is Cancer?

"Cancer" is a general term used to describe more than 200 diseases characterized by abnormal uncontrolled growth of cells that invade and destroy healthy tissue. Cancer can begin in any part of the body and may remain localized to one organ in the body or spread to other parts of the body. 

How is Cancer Treated?

The treatment of cancer is constantly undergoing change as we learn more about the disease and its treatment. Today, many patients with cancer can be cured of their disease.

There are three main types of cancer treatment which include surgery, radiation therapy, and chemotherapy. These treatments can be used alone or in any combination, depending on the type of cancer and its stage.


Surgery is used to remove tumors from the body. When cancer cells are localized to one small area of the body and there is a little risk that cancer cells will spread to other parts of the body, surgery may be used as the only form of treatment. In other situations, surgery may be used as a means to obtain tissue to diagnose the cancer or used in  combination with one of the other forms of treatment. 

Radiation Therapy

Radiation therapy is also an effective way to treating cancer. It may be used by itself or in conjunction with surgery or chemotherapy. Radiation therapy is often used in situations where the complete surgical removal of the tumor is not possible or would cause serious deformity. Radiation therapy is often used in addition to surgery when there is evidence of localized spread of cancer cells beyond the area of surgical resection. Radiation can be used to try to reduce the tumor size prior to surgery. 


Chemotherapy is medication given to kill cancer cells and is administered under the direction of a medical oncologist. There are many different chemotherapy medications which can be used to treat cancer. Chemotherapy is usually used in situations where there is a significant risk of cancer cells have already spread. Chemotherapy is sometimes used simultaneously with radiation in order to enhance the effectiveness of both therapies. 

Learn More About Our Cancer Care

John Martens.jpg

Dr. John Martens, MD

Certified in Radiation Oncology by the American Board of Radiology.