Anal Cancer Overview

+ -Text Size

Treating Anal Cancer TOPICS

Chemotherapy for anal cancer

Chemotherapy (chemo) is the use of drugs to treat cancer. Some drugs can be swallowed in pill form, while others need to be put into a vein or muscle. Once the drugs enter the bloodstream, they spread throughout the body to reach and destroy the cancer cells.

Often 2 or more drugs are used together because one drug can boost the power of the other. In anal cancer, chemo combined with radiation treatment often cures the cancer without the need for surgery. Doctors sometimes also give chemo after the cancer has been removed by surgery. The chemo is meant to kill any cancer cells that were left behind because they were too small to be seen. Chemo may also be used to treat anal cancer that has spread to distant sites such as the lungs or liver.

While chemo drugs kill cancer cells, they also damage some normal cells, causing side effects. These side effects will depend on the type of drug, how much you get, and how long you take it. Common side effects may include:

  • Nausea and vomiting
  • Loss of appetite
  • Hair loss
  • Diarrhea
  • Mouth sores
  • Easy bruising (from a shortage of blood platelets)
  • Feeling very tired (fatigue) or short of breath (from a shortage of red blood cells)
  • Increased chance of infection (from a shortage of white blood cells).

Most of the side effects go away when treatment is over. Talk with your doctor or nurse about side effects, as there are often ways to help. To learn more, see our document Understanding Chemotherapy: A Guide for Patients and Families.


The main treatment for anal cancer that has not spread is chemo combined with radiation treatment (called chemoradiation or chemoradiotherapy). When given together, these 2 treatments often cure the cancer without the need for surgery. Often, chemo is used by itself either before or after chemoradiation to help shrink the cancer further.

Patients with HIV

Most of the time people with HIV infection can be given the same treatment as others with anal cancer, and they can have a good outcome. Patients who have advanced HIV disease and weakened immune systems may need to have less strong chemo.

Last Medical Review: 01/14/2013
Last Revised: 04/18/2014