RT Book, Section A1 Cairns, Rob A. A1 Tannock, Ian F. A1 Wouters, Bradly A2 Tannock, Ian F. A2 Hill, Richard P. A2 Bristow, Robert G. A2 Harrington, Lea SR Print(0) ID 1127472594 T1 Tumor Growth, Microenvironment, and Metabolism T2 The Basic Science of Oncology, 5e YR 2016 FD 2016 PB McGraw-Hill Education Medical PP New York, NY SN 9780071745208 LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1127472594 RD 2024/10/04 AB Tumors grow because the homeostatic mechanisms that maintain the appropriate number of cells in normal tissues are defective, leading to an imbalance between cell proliferation and cell death and to expansion of the cell population. The use of autoradiography with tritiated thymidine in the 1950s and 1960s, and the subsequent application of flow cytometry, have allowed a detailed analysis of tumor growth in terms of the kinetics of proliferation of the constituent cells. The proliferative rate of tumor cells varies widely between tumors; slowly proliferating or nonproliferating cells are common, and there is often a high rate of cell death. Several normal tissues, including bone marrow and intestine, contain cells with high rates of proliferation, and damage to these cells is often dose-limiting for chemotherapy. The rate of cell proliferation in tumors may be an important factor in determining prognosis and response to therapy.