How Chemotherapy Medications Work

What is Chemotherapy?

Chemotherapy or “chemo” treats cancer using different chemicals (medications), which are also known as:

  • Anti-cancer drugs
  • Anti-neoplastic agents
  • Chemo drugs
  • Biotherapy
  • Hormones

Usually given in combination, these drugs target cancer cells that are growing or dividing. They can also affect normal, healthy cells.

Since cancer is a word to describe many different diseases, there is no one type of treatment that is used universally. Chemotherapy is used for a variety of purposes:

  • To cure a specific cancer.
  • To control tumor growth when cure is not possible.
  • To shrink tumors before surgery or radiation therapy.
  • To relieve symptoms (such as pain).
  • To destroy microscopic cancer cells that may be present after the known tumor is removed by surgery (called adjuvant therapy). Adjuvant therapy is given to prevent a possible reoccurrence.


How Chemotherapy Medications Work

Chemo drugs work actively against rapidly dividing cells in the body, such as:

  • Bone marrow, which produces red and white blood cells and platelets
  • Hair follicles
  • The lining of the mouth, throat, stomach, intestines and rectum

Chemotherapy drugs are not selective. They cannot tell the difference between cancer cells and healthy cells, and they may destroy both. Fortunately, normal cells recover and cancer cells die. While the normal cells are recovering, you may experience some side effects. Most of these side effects can be prevented or lessened with drugs and other treatments. Your oncology nurse will discuss these with you.


How They Are Given

Chemotherapy drugs are given intravenously (through a vein) or orally (by mouth) and travel throughout the body. They may be given before (neoadjuvant therapy) or after (adjuvant therapy) surgery to treat primary cancer.

Chemo is given in cycles, which includes alternating treatment periods and rest periods. This gives normal cells a chance to recover, but does not give cancer cells enough time to multiply. Each treatment may take a few hours, depending on the type of drugs used and the length of time it takes to administer each drug. Treatments may be repeated every one to four weeks, three to six months, or longer depending on your treatment plan.


Side Effects

Chemotherapy side effects can range from minor to life-threatening conditions depending on the chemo drug used, the dosage and a person’s overall health. Medical professionals will inform you about all the potential side effects of any treatment they prescribe before you give your consent. These side effects are discussed in detail in the “Chemotherapy and You” book you will receive.

Different people have different reactions to the same chemotherapy. If you undergo chemotherapy, you will not know how you will react or what side effects you will experience until a few days after your first chemotherapy session.

Listen to your body, pay attention to what you are feeling and always report symptoms to your doctor or nurse. Your initial experience will help you prepare for and cope with future chemotherapy sessions.