American Cancer Society (Cancer Glossary)
Medical oncology is a subspecialty of internal medicine. Medical oncologists provide chemotherapy and other nonradiation and nonsurgical procedures.
Answers.com
Medical Oncology is the branch of medicine that deals with tumors, including study of their development, diagnosis, treatment, and prevention. [Greek onkos, mass, tumor + –LOGY.]
Arizona Cancer Center (Glossary)
Medical Oncology is the study and treatment of cancers with chemicals, biological products, or immunotherapy.
Mondofacto dictionary
Medical Oncology is a subspecialty of internal medicine concerned with the study of neoplasms.
Wikipedia (Definition)
Medical Oncology is the branch of medicine that studies oncology (cancer, tumors) and seeks to understand their development, diagnosis, treatment, and prevention.