What is Chemotherapy, and How Does It Work?
What is chemotherapy?
Cancer chemotherapy is a treatment regimen that uses drugs to kill cancer cells, or inhibit their ability to grow. Unlike radiation and surgery, however, the medication is systemic, which means it travels throughout the body to find and attack the cancer cells that may have spread, or metastasized, to other areas. Because cancer cells typically grow and divide faster than healthy cells, cancer cells are more susceptible to chemotherapy but damage to healthy cells is often unavoidable and accounts for the side effects that can be seen with it. Most chemotherapy is given in combination with another drug to target cells in different ways to optimize the results and it also decreases drug resistance. Additionally, in cases where a cure or control are not an option, chemotherapy, usually given as a single agent, can be given to relieve symptoms (palliative therapy) caused by cancer.
Chemotherapy can be administered at a doctor's office, outpatient clinic, hospital or at home, dependent on the type of chemotherapy prescribed. Some chemotherapy is given regularly during a specific period of time, while others are given for as long as they are effective against the cancer. However, chemotherapy is usually given intermittently, with periods of treatment followed by periods of recovery (where no chemotherapy is administered).
Types of Chemotherapy
Chemotherapy can be used as an adjuvant therapy, given after surgery to kill any cancer cells that may remain, or to kill cells that have metastasized. Neoadjuvant therapy is given to shrink the tumor before surgery. Chemotherapy can also be used as the primary therapy, typically for leukemia or lymphoma.
The type of chemotherapy and the specific agent to be used is determined by factors such as:
- Type of cancer
- Location of cancer
- Stage of the cancer
- Your general health
Types of Chemotherapy Administration
Chemotherapy can be administered via several routes dependent on your type of cancer:
- Intravenously - via needle, catheters, ports or pumps
- Orally - administered in pill, capsule or liquid form to be swallowed
- By injection - administered via a needle or syringe either intramuscularly (into the muscle), subcutaneously (under the skin and into the fat tissue) or intralesionally (directly into the cancerous area of the skin) or into the affected body cavity
- Topically - applied to the surface of the skin
Prior to your chemotherapy, your doctor may have you take certain medications such as steroids, allergy medications, anti-nausea medications, sedatives or antibiotics. After your chemotherapy, you should rest, eat a healthy diet, drink plenty of fluids and exercise to help reduce fatigue. Because chemotherapy can affect your immune system, avoid people who are sick and hand hygiene is the best way to deflect infections.