TY - CHAP M1 - Book, Section TI - Chapter 31. Cancer Chemotherapy A1 - Panus, Peter C. A1 - Jobst, Erin E. A1 - Masters, Susan B. A1 - Katzung, Bertram A1 - Tinsley, Suzanne L. A1 - Trevor, Anthony J. PY - 2009 T2 - Pharmacology for the Physical Therapist AB - Cancer is a disease of cells characterized by a shift in the control mechanisms that govern cell proliferation and differentiation. Cells that have undergone neoplastic transformation often express normal fetal cell surface antigens or display other signs of apparent immaturity. Cancer cells may also exhibit qualitative or quantitative chromosomal abnormalities, including translocations and amplified gene sequences. Cancer cells proliferate excessively and form local tumors that can compress or invade adjacent normal structures. Within local tumors, a small subpopulation of cells can be described as tumor stem cells. These cells retain the ability to undergo repeated cycles of proliferation and can migrate to distant sites in the body to colonize various organs in the process called metastasis. Thus, tumor stem cells can express clonogenic (colony-forming) capabilities. Chromosomal abnormalities in tumor stem cells reflect their genetic instability, which leads to progressive selection of subclones that can survive more readily in the host’s multicellular environment. Abnormalities in various metabolic pathways and cellular components (e.g., expression of cell-surface drug transporters) accompany neoplastic progression. The invasive and metastatic processes, as well as metabolic abnormalities resulting from the cancer, cause illness and eventual death unless the neoplasm can be eradicated with treatment. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/19 UR - accessphysiotherapy.mhmedical.com/content.aspx?aid=6095262 ER -