Chemotherapy is a drug, or a combination of drugs, that attacks cancer cells wherever they are in the body. Chemotherapy is often given in combination with other treatments, including surgery or radiation therapy. At Memorial Sloan Kettering, we can customize chemotherapy treatment based on detailed diagnostic information, such as the genetic features of a rectal tumor. This information can help us personalize your care plan, tailoring it to your specific needs and minimizing side effects as much as possible.

When is chemotherapy used for rectal cancer?

Chemotherapy may be given at different times for the treatment of rectal cancer, depending on the extent of the cancer and its location.

• Neoadjuvant chemotherapy is given before surgery to shrink a tumor and make it easier to remove. It is sometimes combined with radiation therapy. Neoadjuvant therapy is often used when cancer has spread beyond the rectum.
• Your care team may suggest neoadjuvant therapy if you have a tumor near the anus. The goal is to shrink the tumor in order to preserve the anal sphincter muscle and your ability to use the bathroom normally.
• Adjuvant chemotherapy is done after surgery or other primary therapy. It can help wipe out microscopic cancer cells that may not be detectable and can travel to other parts of the body. This treatment helps lower the chance that the cancer will come back.
• Hepatic artery infusion (HAI) is a kind of chemotherapy that is given through an IV. If rectal cancer has spread to the liver, HAI delivers chemotherapy drugs to the liver through a tiny pump that is implanted under the skin in the lower abdomen. HAI delivers treatment directly where a tumor is located.

At MSK, people with rectal cancer that has spread to other parts of the body have their tumor tissue analyzed to look for specific genetic mutations. Knowing about any mutations can help your care team determine which chemotherapy will be the most effective and minimize side effects.