Progress in the treatment of cancer over the past two decades has been rapid with many new and novel therapeutic modalities arriving at an unprecedented pace. Overall cancer mortality rates have actually begun to fall in parallel with progress in the diagnosis and treatment of malignant disease. Despite our advances in the understanding of the biology and molecular genetics of cancer, as well as the availability of an increasing array of effective therapies, cancer treatment today and for the foreseeable future will include the traditional modalities of surgery, radiation therapy and chemotherapy. Myelosuppressive agents with their potential hematopoietic toxicities remain the mainstay of systemic treatment for both metastatic and early stage cancer. The complications of cancer chemotherapy have serious impact on a patients well being and overall quality of life. Fortunately, advances in cancer treatment have been accompanied by equally impressive progress in the availability of a wide array of supportive care modalities which have greatly enhanced the ability of oncologists to minimize the impact of cancer and its treatment on patient quality of life as well improve delivery of potentially curative cancer treatment. Despite the increasing complexity of modern cancer treatment, it is the obligation of the oncologist as well as the entire cancer care team to be certain that cancer patients receive the optimal supportive care available for their disease and its treatment. Among the most serious and potentially life threatening toxicities of cancer treatment are the hematologic toxicities accompanying myelosuppression including anemia and associated asthenia and fatigue, neutropenia and fever associated with infection in the immunocompromised patient and thrombocytopenia and accompanying risk of bleeding. Special supportive care needs arise in the very elderly care patient that may tax the ability of even the most skilled clinician. Despite theconsiderable progress that has been made with more effective and safer treatment strategies, myelosuppressive chemotherapy will remain the mainstay of systemic treatment for cancer for the foreseeable future. While considerable progress has occurred, better methods and broader application of supportive care measures are needed to reduce the symptomatic effects of cancer and the associated toxicities associated with cancer treatment. No area of cancer supportive care better illustrates the progress that has resulted from advances in our understanding of cellular and molecular biology, genetic engineering and the development of more effective yet often more toxic cancer treatments than that of the hematopoietic growth factors. This volume will review and integrate the major advances in our understanding of the underlying molecular biology and pharmacology of these agents along with the results of well designed and executed randomized controlled trials of the erythroid stimulating agents, the myeloid growth factors and the new thrombopoietic agents each addressing a major threat associated with bone marrow suppression accompanying cancer treatment. The current clinical utilization of these agents is based on numerous randomized controlled trials and meta-analyses along with evidence-based clinical practice guidelines developed by professional societies guiding their appropriate and cost-effective use in clinical care.