Dr. Robin L. Obenchain

Dr. DeRoock joined Ironwood Cancer & Research Centers in 2009 after completing residency in Internal Medicine followed by fellowship in Hematology and Oncology at the University of California at Davis. He is a first-generation Panamanian-American fluent in both English and Spanish. He previously earned his medical degree at the University of Arizona. Dr. DeRoock is board certified in Internal Medicine, Hematology and Medical Oncology. He has been active in developing clinical trials for pancreatic cancer and lymphoma, and has presented his research findings at the American Society of Hematology Annual Meeting as well as the Annual Pan-Pacific Lymphoma Conference. He specializes in all adult cancers and hematologic disorders.Supportive Cancer Care You Can TrustYou can find that team at Ironwood Cancer & Research Centers. With community-based centers strategically located throughout the Metro Phoenix area, Ironwood offers advanced therapies and a multi-disciplinary approach usually associated with large academic centers – but with a personalized touch recognizing the individual needs of the patient.Studies have shown the importance of a multi-disciplinary approach in effectively treating cancer. We spare you time and worry simply by having all the doctors, therapists, and resources you need in one convenient location, eliminating the delays and miscommunication. These collaborative efforts ensure the highest standards of care. Because Ironwood is actively involved in cutting-edge research, you can also benefit from promising new treatments through participation in clinical trials. Dr. Deroock is rated as a Distinguished provider by MediFind in the treatment of Iron Deficiency Anemia. His top areas of expertise are Pulmonary Embolism, Nodular Lymphocyte-Predominant Hodgkin Lymphoma (NLPHL), Childhood Iron Deficiency Anemia, and Iron Deficiency Anemia.

Joining Ironwood Cancer & Research Centers in 2004, Dr. Shtivelband received his medical degree and PhD in Experimental Hematology in Russia. After Internal Medicine Residency, Dr. Shtivelband received fellowship training in Hematology and Medical Oncology at MD Anderson Cancer Center in Houston, where he stayed for an additional year to participate in experimental research. Treating patients with all kinds of malignancies and benign hematological problems, Dr. Shtivelband has particular interest in developing research programs to bring the newest advances in the field of Oncology and Hematology to our community. Dr. Shtivelband also heads the Ironwood Cancer & Research Center's research program. He is Board Certified in Internal Medicine, Hematology and Medical Oncology. Dr. Shtivelband is rated as a Distinguished provider by MediFind in the treatment of Iron Deficiency Anemia. His top areas of expertise are Hemochromatosis, Non-Small Cell Lung Cancer (NSCLC), Plasmacytoma, and Lung Cancer.

Dr. Anita Koszyk-Szewczyk joined Ironwood Cancer & Research Centers in July 2009, after completing her Hematology and Oncology training at Penn State University Hershey Medical Center. Dr.Szewczyk has earned her medical degree at Jagiellonian University Collegium Medicum in Krakow, Poland and Honours Biology at McMaster University Hamilton, Canada. She served as Chief Fellow at Penn State University and her special interests include all forms of adult cancers and hematological disorders with special interest in Breast Cancer. She is originally from Poland and Canada. She is board certified in Internal Medicine, Hematology and Oncology. Dr. Koszyk is rated as a Distinguished provider by MediFind in the treatment of Iron Deficiency Anemia. Her top areas of expertise are Breast Cancer, Paget Disease of the Breast, Childhood Iron Deficiency Anemia, Iron Deficiency Anemia, and Bone Marrow Aspiration.