Cancer Was Not Going to Defeat My Life Rectal cancer patient Don Leighton discusses his diagnosis and cancer treatment cancer. During his chemotherapy and radiation treatments, he made sure to not let it interfere with his life. Visit to learn more about Don's journey with colorectal cancer. Oncology Associates provides a full range of personalized cancer care at two Omaha clinics as well as at cancer treatment clinics throughout Nebraska. The physicians of Oncology Associates include: * Stephen J. Lemon, MD * Irina E. Popa, MD * Susan Constantino, MD To learn more about OA's approach to personalized cancer treatment as well as about the oncologists and staff, please visit These cancer survivors and patients videos are produced by Dr. Stephen J. Lemon of Oncology Associates to help provide useful cancer information to cancer patients and survivors..