Chemotherapy uses anticancer drugs to kill cancer cells. It is called systemic therapy because it enters the bloodstream and can affect cancer cells throughout the body.
The patient may have chemotherapy alone or combined with surgery, radiation therapy, or both. Chemotherapy given before surgery is called neoadjuvant therapy. Chemotherapy before surgery may shrink a large tumor.
Chemotherapy after surgery is called adjuvant therapy. Adjuvant therapy is used to destroy any remaining cancer cells and prevent the cancer from coming back in the colon or rectum, or elsewhere.
Chemotherapy is also used to treat people with advanced disease.
Anticancer drugs are usually given through a vein, but some also may be given by mouth. The patient may be treated in an outpatient part of the hospital, at the doctor's office, or at home. Rarely, a hospital stay may be needed.
The side effects of chemotherapy depend mainly on the specific drugs and the dose. In general, anticancer drugs affect cells that divide rapidly, especially:
- Blood cells: These cells fight infection, help the blood to clot, and carry oxygen to all parts of the body. When drugs affect blood cells, patients are more likely to get infections, bruise or bleed easily, or feel very weak and tired.
- Cells in hair roots: Chemotherapy can cause hair loss. The hair grows back, but sometimes the new hair is somewhat different in color and texture.
- Cells that line the digestive tract: Chemotherapy can cause poor appetite, nausea and vomiting, diarrhea, or mouth and lip sores. Many of these side effects can be controlled with drugs.
|