Colonic cancer (bowel cancer)

Colonic cancer can occur anywhere in the colon. The cells that line the colon may become damaged such that they begin to divide in an uncontrolled way. This may lead to the formation of a polyp or eventually a cancer. It is the third most common cancer in men and the second most common cancer in women in the UK with 40,000 cases diagnosed each year.

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What are the symptoms?

Common symptoms include:

  • Bleeding from the back passage
  • A change in the frequency of bowel activity
  • Abdominal pain
  • Weight loss and poor appetite

However, these symptoms are very common and are usually NOT due to colonic cancer.


How is the diagnosis made?

To make a diagnosis of colonic cancer it is essential to examine the colon either with a flexible telescope (flexible sigmoidoscope or colonoscope) or a special test called CT colonography. During colonoscopy if a cancer is seen a tiny portion of tissue (biopsy) is taken from the cancer for laboratory examination and a tattoo is often placed. In addition, a CT scan will be arranged to examine the lungs and liver to check that the cancer has not spread.


How can it be treated?

The best chance of curing colonic cancer is with an operation which aims to remove the segment of colon with the cancer in it along with the blood supply and lymph nodes (glands) that supply it. The type of operation will depend on the location of the cancer.

  • Right hemicolectomy involves removing the appendix and colon on the right side of the body and joining the small bowel back up to the colon so that the bowel functions normally.
  • Left hemicolectomy or sigmoid colectomy involves removing the colon on the left side of the body and joining the bowel back up together so that the bowel functions normally.
  • Subtotal colectomy involves removing the whole colon and usually joining the small bowel to the rectum.

These are the commonest types of operations but there are others which may be discussed and can be fully explained by your surgeon.

These operations can be done with single large incision (open surgery) or multiple small incisions (‘key-hole’ or laparoscopic surgery). The way in which the operation is to be performed depends on a number of factors relating to you, the cancer and your surgeon.


Is a stoma necessary?

A colostomy or artificial opening of the colon on to the abdominal wall is NOT usually necessary in these operations. The possibility of requiring a stoma will be discussed with you and if it is required then you will get all the support that you need.


Are there any other forms of treatment?

  • Chemotherapy: Once you have recovered from your surgery and the cancer has been thoroughly examined by the pathologist it may be appropriate to recommend a course of chemotherapy. This will depend upon your general state of health and the stage of the cancer. The stage of cancer gives an indication as to whether the cancer has spread to other organs (usually the glands close to the bowel, the liver or lungs). The stage of cancer is assessed by a combination of the tests that you had before your operation (CT) and the pathologist’s opinion when the cancer is examined under the microscope. If chemotherapy is recommended then you will be able to discuss it further with a specialist in this field (oncologist).
  • Liver surgery: If the cancer has spread to the liver it may still be possible to attempt to cure the cancer by removing a segment of the liver at an operation. If this is recommended then you will be able to discuss it further with a specialist in this field (hepatobiliary surgeon).
  • Colostomy: Some cancers can cause a blockage to the bowel and it may be recommended that a colostomy is performed to prevent this. This is particularly the case if you are very frail or the cancer has spread to many other organs.

All treatment options will be discussed fully with you and, with your permission the people important to you, before any decisions are made.


What are the chances of a cure?

Appropriate surgery offers the best chance of cure possibly combined with chemotherapy. The earlier the cancer is detected and treated then the more likely the cure. In early cancers the cure rate is greater than 90%, in cancers at a more advanced stage then the chances of cure are less than 50%.


Will I need to be seen again?

You will be checked on a regular basis following your treatment. The frequency with which you will be seen will depend on the stage of cancer and will be tailored to your own particular circumstances. This will usually include visits to the clinic, CT scans and colonoscopy.


Further information