What is radiotherapy for colorectal cancer?
Radiation therapy is the third pillar, alongside chemotherapy and the surgical removal of a cancer, and thus represents an important therapeutic measure in the treatment of a wide variety of cancers. Colorectal cancer, also called “colorectal carcinoma”, can be located in the large intestine, the so-called “colon” or the rectum, the so-called “rectum”. A colorectal cancer in the colon is usually not irradiated.
Depending on the stage, therapy here consists of either surgery alone or surgery followed by chemotherapy. In palliative situations, chemotherapy alone can also be used. However, radiotherapy can play several roles in the treatment of rectal cancer.
Both before and after surgery, radiotherapy can be used to perform various tasks. The most important goals of radiotherapy are the reduction of tumors and the prevention of so-called local recurrence, the recurrence of small tumors in the intestine after surgery. In colon cancer radiation therapy, X-rays are directed specifically at the tumor, thus inhibiting the cell division of the cancer cells.
To spare the remaining tissue, the entire dose of radiation is distributed over several sessions so that healthy cells can recover. Nevertheless, serious side effects of radiation therapy can sometimes occur in the short and long term. There are 3 different forms of radiation therapy: Radiation therapy is performed either before surgery, after surgery or as the sole therapy.
In the treatment of rectal carcinoma (cancer of the rectum), radiotherapy can play a decisive role before the final operation. Together with chemotherapy, it can be performed as so-called “neoadjuvant radiochemotherapy”. Neoadjuvant describes a supportive therapy that is carried out before the operation.
It is performed when the colorectal cancer is difficult to operate, has grown particularly large or is already in stage 2 or 3. The aim of the radiation therapy is to shrink the tumor and reduce the tumor mass in order to facilitate surgery. In combination with chemotherapy, the tumor cells become more sensitive and more susceptible to X-rays.
Furthermore, radiotherapy of colorectal cancer prior to surgery means that even after surgery a recurrence of the tumor in the intestine is less likely. The recurrence rate in the intestine is reduced by up to 50%. Ask also about rectal cancerEven after surgery, radiation therapy is only used for rectal cancer of the rectum.
In most cases, this is also carried out together with chemotherapy. After the operation has already been performed, one speaks of “adjuvant radiochemotherapy”. Its aim is to kill microscopic metastases of the colorectal cancer as well as individual remaining cells in the body and the intestine and thus prevent later metastasis or recurrence in the intestine.
If radiation has already been administered, chemotherapy must be administered after the operation. Further irradiation must be made dependent on the radiation dose and the damage to surrounding tissues. If no neoadjuvant therapy has been administered before the operation, radiation of the rectum can be started a few weeks after the operation.
Radiation therapy alone without surgery is usually not performed with the intention of healing. In advanced stages, when the tumor is difficult to operate on or has grown very large, radiotherapy can be used to relieve pain and treat other symptoms of cancer. Radiation therapy can shrink the tumor and may prolong survival.
In rare cases, if the colorectal cancer responds well to radiation therapy, surgery with removal of the tumor can even be performed subsequently. Radiation therapy alone can relieve digestive problems in the bowel, stabilize bone metastases so that fractures do not occur, and improve numerous other disease-related symptoms. More information on “metastases” can be found here
