Radiation Therapy
Radiation therapy (also called radiotherapy) is local therapy. It uses high-energy rays to kill cancer cells. It affects cancer cells only in the treated area.
Doctors use two types of radiation therapy to treat cancer. Sometimes people receive both types:
- External radiation: The radiation comes from a machine. Most patients go to the hospital or clinic for their treatment, generally 5 days a week for several weeks. In some cases, external radiation is given during surgery.
- Internal radiation (implant radiation): The radiation comes from radioactive material placed in thin tubes put directly into or near the tumor. The patient stays in the hospital, and the implants generally remain in place for several days. Usually they are removed before the patient goes home.
People may want to ask the doctor these questions before having radiation therapy:
- Why do I need this treatment?
- What are the risks and side effects of this treatment?
- Are there any long-term effects?
- When will the treatments begin? When will they end?
- How will I feel during therapy?
- What can I do to take care of myself during therapy?
- Can I continue my normal activities?
Treatment for Colon Cancer
Most patients with colon cancer are treated with surgery. Some have both surgery and chemotherapy. A colostomy is seldom needed for people with colon cancer.
Although radiation therapy is not commonly used to treat colon cancer, sometimes it is used to relieve pain and other symptoms.
Treatment for Rectal Cancer
For all stages of rectal cancer, surgery is the most common treatment. Some patients receive surgery, radiation therapy, and chemotherapy. About 1 out of 8 people with rectal cancer needs a permanent colostomy.
Radiation therapy may be used before and after surgery. Some people have radiation therapy before surgery to shrink the tumor, and some have it after surgery to kill cancer cells that may remain in the area. At some hospitals, patients may have radiation therapy during surgery. This is called ORT. People also may have radiation therapy to relieve pain and other problems caused by the cancer.
Side Effects of Cancer Treatment
Because treatment often damages healthy cells and tissues, unwanted side effects are common. Side effects depend mainly on the type and extent of the treatment. Side effects may not be the same for each person, and they may change from one treatment session to the next. Before treatment starts, the health care team will explain possible side effects and suggest ways to help the patient manage them.
The NCI provides helpful booklets about cancer treatments and coping with side effects. Booklets such as Radiation Therapy and You, Chemotherapy and You, and Eating Hints for Cancer Patients may be viewed, downloaded, and ordered from https://cissecure.nci.nih.gov/ncipubs. These materials also may be ordered by calling the Cancer Information Service at 1-800-4-CANCER.
Surgery
It takes time to heal after surgery, and the time needed to recover is different for each person. Patients are often uncomfortable during the first few days. However, medicine can usually control their pain. Before surgery, patients should discuss the plan for pain relief with the doctor or nurse. After surgery, the doctor can adjust the plan if more pain relief is needed.
It is common to feel tired or weak for a while. Also, surgery sometimes causes constipation or diarrhea. The health care team monitors the patient for signs of bleeding, infection, or other problems requiring immediate treatment.
People who have a colostomy may have irritation of the skin around the stoma. The doctor, nurse, or enterostomal therapist can teach patients how to clean the area and prevent irritation and infection. The section called "Rehabilitation" has more information about how patients learn to care for the stoma.
Chemotherapy
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.
