1. inhibiting the maturation and proliferation of malignant cells. 2. an agent having such properties.
a. therapy — a regimen of treatment aimed at destruction of malignant cells and utilizing a variety of chemical agents that directly affect cellular growth and development.
— The chemicals and drugs used in the treatment of cancer may be divided into three groups. The first group, the alkylating agents, are capable of damaging the DNA of cells, thereby interfering with the process of replication. Among these drugs are chlorambucil, cyclophosphamide, mustine hydrochloride and triethylene thiophosphamide (thiotepa). The antibiotic actinomycin D (dactinomycin) is also included in this group. — The second type of drugs used in cancer chemotherapy are the antimetabolites. As the name suggests, these drugs interfere with the cancer cell's metabolism. Some replace essential metabolites without performing their function, while others compete with essential components by mimicking their functions and thereby inhibiting the manufacture of protein in the cell. Included in this group are cytosine arabinoside, floxuridine (FUDR), 5-fluorouracil (5-FU), mercaptopurine (6-MP), methotrexate and thioguanine. — The third group of chemicals employed in the treatment of cancer are ‘natural products’ that directly affect the mechanism of cell division. The plant alkaloids, e.g. vincristine and vinblastine, stop cell division at metaphase (a subphase in cell mitosis). The enzymes, e.g. L-asparaginase, starve tumor cells by catabolizing substances (e.g. asparagine) which they need for survival. Hormones change cell metabolism by making the cellular environment unfavorable for growth of certain tumors.