Chemotherapy (chemo) uses drugs to treat cancer. Some drugs can be swallowed in pill form, while others need to be injected into a vein or muscle. The drugs enter the bloodstream to reach and destroy the cancer cells throughout the body. This makes chemo a systemic or “whole body” treatment.
To treat anal cancer, chemo can be:
- Combined with radiation therapy (known as chemoradiation) as the first treatment for most anal cancers, which can often cure the cancer without the need for surgery. If the cancer doesn’t go away completely after chemoradiation, more chemo might be given.
- Given (along with radiation) after surgery to try to destroy any cancer cells that were left behind because they were too small to see. This is called adjuvant therapy. It is meant to lower the chance of the cancer coming back.
- Used if anal cancer has spread to distant parts of the body, such as the liver or lungs. This can help keep the cancer under control or relieve symptoms it is causing.
Chemotherapy often uses 2 or more drugs because one drug can boost the effect of the other. The main combination used to treat anal cancer is 5-fluorouracil (5-FU) and mitomycin. The combination of 5-FU and cisplatin is also used fairly often, especially for advanced anal cancer.
Side effects of chemotherapy
Chemo drugs attack cells that are dividing quickly, which is why they work against cancer cells. But other cells in the body, such as those in the bone marrow (where new blood cells are made), the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemo, which can lead to side effects. Side effects depend on the specific drugs, the amount taken, and the length of treatment. Common short-term side effects might include:
- Nausea and vomiting
- Loss of appetite
- Hair loss
- Mouth sores
Because chemo can damage the blood-producing cells of the bone marrow, patients may have low blood cell counts. This can result in:
- An increased chance of infection (due to a shortage of white blood cells)
- Bleeding or bruising after minor cuts or injuries (due to a shortage of blood platelets)
- Fatigue or shortness of breath (due to low red blood cell counts)
Along with the risks above, some chemo drugs can cause other, less common side effects. For example, cisplatin cause nerve damage (called peripheral neuropathy). This can lead to problems with numbness, tingling, or pain in the hands and feet.
Most side effects improve once treatment is stopped, but some can last a long time or even be permanent. If your doctor plans treatment with chemo, be sure to discuss the drugs that will be used and their possible side effects.
If you get chemo, tell your doctor or nurse about any side effects as soon as you notice them. Your cancer care team can help you deal with them. For example, anti-nausea drugs can help control nausea and vomiting. Sometimes changing the treatment dosage or how you take your medicines can reduce side effects. Most side effects will stop when your course of treatment ends.
For more information about chemotherapy, see A Guide to Chemotherapy.
Last Revised: 01/20/2016