Treatment - Chemotherapy


  • History of Chemotherapy
    • Mustard gas, a poison, was used in World War I (1914).  The soldiers who had cancer and were exposed to the gas showed improvement in their cancers.  These healing effects of mustard gas were discovered by accident and called “chemotherapy”  
    • Many changes have occurred in chemo
      • The types of drugs used
      • How the drugs are given to the patient
        • Intravenous [IV, injected in a vein]
        • Orally [pills, by mouth]
        • Catheter [through a tube sewn into the body when the veins cannot handle the drugs or when the amount of drugs is very large] 
      • The strength of the drugs [dosage]
      • The combinations of drugs
      • How often chemo is given [frequency]
      • How long the series of chemo treatments last (6 weeks, then a break for a few months) [duration]
    • Prior to the 1950s, treatment for the majority of cancers was limited to either surgery or the use of radiation

Chemotherapy today

  • There are more than 100 different chemotherapy drugs
  • The discovery of the use of methotrexate in curing a rare cancer marked the first time a cancer had been cured
  • This led to the development of many of today’s common cancer treatments
    • The drugs are used in different proportions or amounts
    • The drugs are combined with other chemo drugs (chemo cocktail)
  • The amount and type of chemo you receive is based on the
    • The type of cancer cells (histology)
    • The size of your tumor
    • Whether or not your cancer has spread (metastasized) 
How chemo works
  • Cancer cells grow and duplicate quickly.
  • Chemo uses drugs that kill cells or slow down their duplication.
  • In general, chemotherapy drugs affect the DNA of the cells by interfering with cell duplication.
  • Chemo drugs are poisons that breaks up the DNA so that it cannot make new cells
Why both cancer and healthy body cells are affected by chemo
  • Chemo drugs affect the DNA of both the cancerous and healthy cells
  • The healthy cells that are particularly susceptible to chemo are by cells that multiply quickly:
    • The skin (including body, facial, and head hair)
    • The digestive system (gastrointestinal tract)
    • The bone marrow (that makes red and white blood cells)
Goals of chemotherapy
  • Cure
  • Control - extend length and quality of life when hope of cure is not realistic
  • Palliation – ease symptoms/ improve comfort

Purpose(s) for Chemotherapy

  • Shrink the size of a tumor before surgery or radiation
  • Kill or poison cancer cells when surgery is not an option (to destroy or slow the growth of cancer cells)
  • Kill or poison any remaining cancer cells that were not removed during surgery (to stop cancer from spreading)
  • Relieve cancer pain or other symptoms

Why you may receive a different combination and dosage of chemo drugs than the patient sitting next to you

  • The most common reason is because your cancer is different from the patient sitting next to you (you have a different type of breast cancer)
  • Another reason is that you may have had severe side effects and they are using a different combination of drugs (cocktail) to see if you react better to the treatment
  • Another reason is that one of you may be on a clinical trial that is using a drug combination that may or may not be better than standard treatment for your type of cancer.
Chemotherapy is the treatment of choice for:
  • Leukemias, lymphomas (blood forming cells)
  • Solid tumors that have metastasized
  • Cancers with high potential of spread/ recurrence
How does it work?
  • Attack cells when they are dividing (cancer cells divide much more often than do normal, healthy cells)
  • Damage genetic material inside the cell that allows the cell to divide and reproduce
  • Block chemicals that the cell needs to enable it to divide and reproduce

Types of chemotherapy

  • Standard therapies used alone or in combination with newer therapies and other treatments
    • Alkylating agents
    • Interferes with DNA replication (cross link DNA strands) and inhibits cancer cell growth
    • Most agents are cell cycle nonspecific
    • Such as:  Busulfan (Myleran), Cyclophosphamide, Temozolamide (Temodar)
  • Antimetabolites
    • Drugs that interfere with one or more enzymes or their reactions that are necessary for DNA synthesis.
    • They affect DNA synthesis by acting as a substitute to the actual metabolites that would be used in the normal metabolism
    • Inhibit protein synthesis, substitute metabolites, or structural analogues during DNA synthesis and inhibit DNA synthesis
    • For example, antifolates interfere with the use of folic acid
  • Most are cell cycle/phase specific
    • Such as: 5-fluorouracil (5-FU), 6-mercaptopurine (6-MP), Capecitabine (Xeloda), Gemcitabine)
  • Anti-tumor antibiotics
    • A type of anticancer drug that blocks cell growth by interfering with DNA, the genetic material in cells
    • Interferes with nucleic acid synthesis and function. Inhibit RNA synthesis
    • Also called anticancer antibiotic and antineoplastic antibiotic
    • Most agents are cell cycle nonspecific
    • Such as:  Dactinomycin (Cosmegen), Bleomycin, Daunorubicin (Cerubidine, Rubidomycin) and Doxorubicin (Adriamycin PFS, Adriamycin RDF)
  • Topoisomerase inhibitors
    • Enzymes that participate in the overwinding or underwinding of DNA. ... In order to prevent and correct these types of topological problems caused by the double helix
    • Chemical compounds that block the action of topoisomerases (topoisomerase I and II), which are enzymes that control the changes in DNA structure by catalyzing the breaking and rejoining of the phosphodiester backbone of DNA strands during the normal cell cycle
    • Such as:  Etoposide, Irinotecan (Camptosar), Topotecan (Hycamtin)
  • Mitotic inhibitors
    • A type of drug that blocks cell growth by stopping mitosis (cell division); also called antimitotic agent
    • Bind with microtubular proteins, crystallize the mitotic spindle, and result in metaphase arrest
    • Phase cycle specific
    • Such as:  Docetaxel (Taxotere), Eribulin (Halaven), Ixabepilone (Ixempra), Paclitaxel (Taxol), Vinblastine

Methods of Administration

  • Oral
  • Intravenous (IV)
  • Catheter, port, pump
  • You sit in a room alone or with other patients who are also getting chemo
    • Your family or friends can come sit with you while you receive the treatments
    • You may want to bring a blanket because if your treatment lasts for a few hours, you may get cold (the liquid in the IV is cold)
    • You may want to have a glass with some ice chips to suck on
    • You may want to drink a mild tea, like ginger tea to help reduce the upset stomach
    • If you are diabetic, you need to bring a healthy snack or drink so that your blood sugar doesn’t get too low while you are in treatment
  • Injection
  • Intrathecal
  • Intraperitoneal (IP)
  • Intra-arterial (IA)
  • Topical

Classifications of Chemotherapy

  • Cell cycle specific agents (phase specific)
    • Major effects exerted only when cells in a specific part of the cell cycle
  • Cell cycle nonspecific agents
    • Effects are exerted on cells at any phase

The Cell Cycle and Phase-Specific Chemo

  • Many chemotherapy drugs are designed to attack the cells during a specific phase of cell reproduction, such as:
    • One drug may target the cell ONLY during the G1 phase
    • Another drug may target the cell ONLY during the S phase


  • Cell Phase:
    • G1 phase (pre DNA) 8-48 hrs
      • RNA and protein synthesis actively preparing for DNA synthesis
    • S phase (DNA synthesis) 10-30 hrs
      • DNA doubles in preparation for mitosis
    • G2 phase (pre-mitotic phase) 1-12 hrs
      • DNA synthesis discontinues and prepares for cell division
    • M phase (mitosis) 1 hr
      • Spindle formation, separation of chromosomes and cell division
    • G0 phase (resting phase)
      • Cell is no longer dividing and highly resistant to chemotherapy during this phase