Chemotherapy is a method of treating various cancers that involves a single drug or combination of drugs. It works by destroying cancer cells and keeping them from growing, dividing and spreading. Chemotherapy is often the first form of treatment of cancers prior to attempting radiation therapy, surgery, biological therapy or bone marrow transplants.  In many cases, chemotherapy is used in conjunction with these treatments.

All living tissue in the human body is made up of cells. Cells grow and reproduce in a regular cycle to replace worn out cells with new, healthy ones. This cycle occurs in a gradual, orderly process. Cancer occurs when abnormal cells multiply in an out-of-control manner. As they spread, they can create life-threatening damage throughout the body.

Chemotherapy is the use of anti-cancer drugs to destroy the cancer cells and prevent them from growing and multiplying. Chemotherapy is used for three purposes in treating cancer:

• Cure. In some cases, chemotherapy can eliminate a malignant tumor or cancer and keep it from returning.
  
  
• Control. When a cure is not possible, chemotherapy can help keep a tumor or cancer from growing or spreading through the bloodstream or lymphatic system to other areas of the body. Chemotherapy has the potential to extend patients’ lives and their quality of life.
  
  

  

• Palliation. When cancer is in an advanced and incurable stage, chemotherapy can sometimes be used to relieve symptoms and give patients a better quality of life.

Chemotherapy is often used as a first line of treatment in cancer patients and may be administered without any other form of treatment. It has the advantage of treating the entire body, whereas other forms of cancer treatment focus on a specific area of the body affected by the cancer. In this way, chemotherapy is more encompassing and aims to destroy cancer cells that may not have been killed during other treatments.

However in the majority of cancers, chemotherapy is just one form of treatment used in combination with other therapies such as surgery, radiation or biological therapy. Chemotherapy treatment methods include:

• Neo-adjuvant therapy. Medications are used to shrink a tumor prior to radiation or surgery.
  
  
• Adjuvant therapy. Medications are used to shrink or destroy any cancer cells that may not have been destroyed with surgery or radiation therapy.
  
  
• Combination therapy. Enhance the effectiveness of radiation or biological therapy.
  
  
• Treatment for recurrent disease. Destroy or slow down cancers that have returned after being eliminated, or that have spread to other areas of the body.

For some types of cancer, physicians are able to conduct test that indicate whether or not the cancer will respond to chemotherapy. Though chemotherapy is often effective in killing cancer cells, it also can damage normal healthy cells. A variety of side effects that can make patients feel extremely ill can occur when the healthy cells are damaged. These side effects almost always disappear when these normal cells heal after a patient’s cancer is treated and chemotherapy sessions are ended.