The hematologic malignancies. Leukemia, lymphoma, and myeloma

Many of the conceptual advances in the treatment of advanced cancer have resulted from studies of the hematologic malignancies: The signal importance of complete remission, the complete disappearance of evident disease, as the major contributor to significant palliation; the first studies of adjuvant therapy, that is chemotherapy given to patients free of disease, which demonstrated prolongation of disease-free periods; the first studies of intensification, including early, intermittent, and late; combination chemotherapy; and finally, the important observation that advanced metastatic malignancies can be cured were made in studies of these important diseases. Because of treatment advances that have occurred over the last 10 to 20 years, the majority of patients with adult hematologic malignancies that were once considered universally fatal can be either cured or have substantial palliation. Treatment for adult acute leukemia has advanced such that 15% to 20% of patients have prolonged disease and treatment-free survivorship; in Hodgkin's disease, over 70% of patients can be cured; and for the lymphomas, the majority or 50% to 60% of patients can be cured with available treatments. Major treatment advances in supportive treatment such as allogeneic transfusion and allogeneic and autologous bone marrow transplantation improve the perspective for control of the hematologic malignancies. In addition, the potential for biologic response modifiers or the biologic products of normal cells that are normally involved in the regulation of both proliferation and differentiation show enormous potential for the treatment of advanced disease. Studies of interferon have shown promising early results in chronic granulocytic leukemia and in hairy cell leukemia. A new class of drugs, the acridine analogs, of which AMSA (4'-[9-acridinylamino]methanesulfon-M-anisidide) is a member, has been introduced and has established activity against acute leukemia. VP-16 (etoposide) has just become commercially available and is an important drug both in leukemia and lymphoma. Finally, the discovery of new knowledge about the biochemical pharmacology of drugs such as arabinosyl cytosine has offered a major advance in salvage treatment and the potential for substantial further improvement in the frontline management of these diseases. The rapid advances in both palliative and curative treatment for the hematologic malignancies have generally found broad application to the management of advanced cancer arising from other organ systems.