Colorectal Cancer Treatments - Radiation Therapy

Radiation therapy uses high-energy radiation from X-rays or particles to kill cancer cells.

It is a major part of the treatment for rectal cancers. It’s also sometimes used as a treatment for colon cancers. There are several reasons your health care provider may recommend this therapy:

  • To try to shrink a tumor before surgery (for rectal cancer). This may make it easier to remove and will reduce the damage surgery might cause. When it’s used before surgery, it’s called a neoadjuvant therapy.

  • To try to kill any cancer cells left after surgery. When radiation is used after surgery, it’s called an adjuvant therapyFor colon cancer, this may be used if your health care provider has removed a cancer that was attached to an organ or to the lining of your abdomen, and the health care provider is not sure all the cancer cells were removed. 

  • To ease symptoms caused by tumors that can't be treated with surgery or that have spread to other organs.

Radiation therapy is not a substitute for surgery. Surgery is generally the main treatment for colorectal cancer, except in cases of advanced cancers that cannot be removed with surgery, in people who are not healthy enough for an operation, or to ease the symptoms of blockage, bleeding, and pain in those with advanced cancer.  

To plan your entire treatment strategy, consult with a team of cancer specialists. This might include a surgeon, radiation oncologist, and medical oncologist.

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