Careers in Hematology:
Hematology-Oncology: Do Two Halves Make a Whole?

Reed E. Drews, M.D.

Dr. Drews is Associate Professor of Medicine at Harvard Medical School and Program Director of the Hematology-Oncology Fellowship at Beth Israel Deaconess Medical Center.

Several years ago, a colleague, trained solely in hematology and now working primarily in the laboratory exploring vascular biology, argued that training in hematology should link not to oncology, but instead - if joined with any other discipline at all - to endocrinology with its study of hormones akin to hematopoietic growth factors. Recalling academic hematology programs that seemingly withered in the face of burgeoning oncology programs, I fully understood my colleague's concerns regarding the historic linkage between hematology and oncology training. Indeed, despite dual training, many graduates of combined hematology-oncology fellowships focus exclusively on oncology, leaving most aspects of hematology practice behind. With time, such attending physicians become increasingly uncomfortable addressing hematologic concerns, and attending physicians who are willing and able to cover both arenas (e.g., on a combined hematology-oncology in-patient consult service) are vanishing. So why not train only in oncology without hematology?

Hematology training alone is defensible: for instance, hematologists need not know how to diagnose and treat colon cancer. However, I believe that oncology without hematology is incomplete. The two worlds intersect at so many levels that to practice oncology without a solid foundation in hematology is less than whole. Not only do the two disciplines meld in understanding the biology of renegade neoplastic cells in leukemias, lymphomas, and solid tumors, but also they converge in diagnosing and managing a host of "benign" hematologic conditions that can accompany or complicate these malignancies. Examples of such combined clinical scenarios include: microangiopathic hemolytic anemia accompanying gastric carcinoma or mitomycin-C therapy; underproduction anemia resulting from myelosuppressive chemotherapies; disseminated intravascular coagulation accompanying solid tumors, acute promyelocytic leukemia, or infectious complications of chemotherapy-induced neutropenia; acquired factor VIII inhibitors associated with lymphomas or solid tumors; and heparin-induced thrombocytopenia accompanying heparin therapy of Trousseau's syndrome.

Therefore, oncologists should develop skills in diagnosing and managing hematologic conditions that often coexist with or complicate solid tumor care. Thus, coupling oncology with hematology training makes sense: perhaps we should call it "oncology-hematology" rather than "hematology-oncology." Adding some training in transfusion medicine would further bolster clinical knowledge.

The challenge for combined hematology-oncology training programs today is to produce graduates who, with an admitted bias toward treating malignancies either hematologic or oncologic, are equally adept at handling the full range of "benign" red cell, white cell, platelet, and coagulation abnormalities in their patients. With a burgeoning base of knowledge in both disciplines, the question now is: can we accomplish the curricular needs of combined hematology-oncology clinical and research fellowship training in three years, or should this be expanded to four years? The answer to this question may depend on the specific design of the training program - perhaps something to discuss in a future issue of "Careers in Hematology."