Chemotherapy is a type of treatment for cancer that uses drugs or medications to destroy cancer cells. Cancer cells are rapidly dividing. Chemotherapy acts by killing these rapidly diving cancer cells.
Objectives of Chemotherapy
- To destroy all malignant cancer cells without excessive destruction of normal cells.
- To control the growth of the tumor if cure is no longer possible.
Mechanism of Action
Cancer cells grow and divide quickly. Chemotherapy works by stopping or slowing the growth of these cancer cells. Chemotherapeutic agents work by impairing the mitosis or cell division of fast-dividing cells, thus they are termed cytotoxic as they cause damage to these cells. However, it can also damage healthy normal cells that are quickly dividing, such as the cells that line the mouth and intestines and those that cause the hair to grow. Damage to these normal cells poses side effects of the chemotherapy use. These side effects usually get better or go away after chemotherapy is over.
What does chemotherapy do?
- Chemotherapy CURES cancer. Chemotherapy destroys cancer cells to the point that your doctor can no longer detect them in your body and they will not grow back.
- Chemotherapy CONTROLS cancer. Chemotherapy keeps cancer from spreading, slows its growth, or destroys cancer cells that have spread to other parts of your body.
- Chemotherapy helps EASE cancer symptoms.
Contraindications of Chemotherapy
- Infection. Chemotherapeutic drugs can cause immunosuppression. Cells in the bone marrow are rapidly dividing in normal circumstances. Thus, this results to decreased production of red and white blood cells (myelosuppression). As myelosuppression occurs, hence, immunosuppression also occurs.
- Impaired renal or hepatic function. Drugs used in chemotherapy are nephrotoxic and hepatotoxic.
- Pregnancy. Chemotherapeutic drugs are known to cause congenital defects to the unborn child.
- Bone marrow depression. Administering chemotherapeutic drugs may aggravate the condition.
Chemotherapy Treatment Schemes
- Combined modality chemotherapy. In this type of treatment scheme, chemotherapeutic agents are used in combination with other cancer treatments such as radiation therapy or surgery. In present times, most cancers are treated in this way. It helps radiation therapy and biological therapy work better.
- Neoadjuvant chemotherapy (preoperative chemotherapy). In this type of treatment scheme, initial chemotherapy is designed to shrink the primary tumor. It makes a tumor smaller before surgery or radiation therapy.
- Adjuvant chemotherapy (postoperative treatment). This treatment is used to destroy cancer cells that may remain after surgery or radiation therapy.
- Palliative chemotherapy. This treatment is given without curative intent but simple to decrease the tumor load and increase life expectancy.
image courtesy of http://www-cancer.us