2015 Antineoplastics

Critical Facts IconCRITICAL FACTS I: General concepts
(if med school is a Minnesota forest with millions of trees,
these are the red pines)

  1. The GOAL is to eradicate the cancer cells without affecting normal tissues (the concept of DIFFERENTIAL SENSITIVITY).  The REALITY is that all cytotoxic drugs affect normal tissues as well as malignancies aim for a favourable therapeutic index.

  2. Cancer drugs can be divided into two general classes:  CELL CYCLE SPECIFIC DRUGS (CCS; esp. plant alkaloids and antimetabolites), and CELL CYCLE NON-SPECIFIC DRUGS (CCNS; esp. alkylating agents and some natural products).  Antineoplastic agents can also be organized according to their chemical class, mechanism of action, therapeutic use or their toxicities.

  3. The CELL KILL HYPOTHESIS proposes that actions of CCS drugs follow first order kinetics:  a given dose kills a constant PROPORTION of a tumor cell population (rather than a constant NUMBER of cells).

  4. Resistance to cancer chemotherapeutic drugs is a major limitation to treatment.  PRIMARY RESISTANCE occurs when some inherent characteristic of the cancer cells prevents the drugs from working;  ACQUIRED RESISTANCE occurs when cancer cells become resistant during treatment.  MULTIDRUG RESISTANCE is particularly problematic; this occurs when tumour cells become cross-resistant to a wide range of chemically dissimilar agents after exposure to a SINGLE (typically natural product) drug.

  5. Based on mechanism of action, there are 8 major categories of antineoplistic drugs:  1)  drugs that prevent DNA synthesis, 2)  drugs that disrupt DNA and/or RNA synthesis, 3)  antimitotics, 4)  immune system modifiers, 5)  drugs that interfere with protein function, 6)  angiogenesis inhibitors, 7)  differentiating agents, and 8)  drugs that interfere with hormone function.  Supporting agents must also be considered when discussing antineoplastics
Email: Dr. Janet Fitzakerley | ©2015 University of Minnesota Medical School Duluth | Last modified: 5-may-15 2:18 PM