A hematologist-oncologist is a physician who specializes in the diagnosis, treatment and/or prevention of blood diseases and cancers such as iron-deficiency anemia, hemophilia, sickle-cell disease, leukemia and lymphoma. This physician is trained in hematology — the study of blood — and oncology — the study of cancer. Hematologist-oncologists do not usually treat operable cancers such as prostate cancer, but specialize in treating blood cancers, such as Hodgkins and non-Hodgkins lymphomas, leukemias and multiple myelomas. A hematologist-oncologist may also specialize in the management of solid tumors.