Understanding Cancer

Bowel & Colon Cancer

New Zealand has one of the highest rates of bowel cancer in the world.

What to expect before, during, and after radiotherapy treatment:

Explore The Patient Pathway

Most bowel cancers start as benign growths on the wall of the bowel or small intestine. These are called polyps and look like small spots or cherries on stalks. Most are not cancerous, however, one type of polyp, an adenoma can become malignant and can form a tumour in the bowel glands.

Once cancer cells are in the wall, they can travel into the bloodstream or lymph nodes; from here the cancer cells can travel to other parts of the body. The most common places for bowel cancer cells to spread to are the liver and the lungs.

There are a few very rare bowel cancers. Some are very slow growing, and most need a different treatment to more common bowel cancer.

In more detail

By far the most common bowel cancer, adenocarcinomas originate in the glands that line the bowel wall. These glands produce the mucus that allows digested matter to pass easily through the large intestine and out of the body. Adenocarcinomas make up about 95% of all bowel cancers. There are some rare variations to this type, mucinous tumours and signet ring tumours, but the treatment is the same as for standard adenocarcinomas.

Other varieties of cancer that attack the bowel and colon include squamous cell carcinomas, which start in the skin-like lining of the bowel. There are also sarcomas which are cancers of the smooth muscle that supports the bowel, and carcinoid tumours, slow growing cancers of hormone-producing tissue.

Lymphomas are the most rare - they account for about 1% of all bowel cancers. They usually attack the lymph nodes. Each of these cancers has a unique behaviour pattern and growth rate and require treatment that is quite different to the more common adenocarcinomas.

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The Patient Pathway

First Specialist Appointment

At the first specialist appointment you will meet with your specialist radiation oncologist (RO) to discuss the proposed radiotherapy treatment approach and answer any questions and concerns you may have.


At the treatment planning appointment a patient care specialist (nurse or radiation therapist) will explain the procedures in more detail and answer any concerns that you might have about ARO or your treatment.


During the days following your orientation and treatment planning appointment our team of experts (physicists, radiation therapist planners and your radiation oncologist) work together to develop the ideal treatment plan for you. This involves a highly sophisticated planning software system and review process to guarantee safe and effective delivery of treatment. Depending on the site and complexity of the treatment, this stage can take up to two weeks.

First Day of Treatment

You’ll need to arrive 10-15 minutes before your allocated treatment time so that we can greet you and to give you time to get changed for your treatment.

If you are driving, we recommend you enter Gate 3, 98 Mountain Road and drive up the ramp to the mid level car park. Please walk across the link bridge to Auckland Radiation Oncology (ARO). Please report to the ARO reception desk. See location and parking for more information.

During Treatment

Weekly reviews with your radiation oncologist or one of our patient care team will be conducted to monitor any side effects and provide on-going support and advice as required.

Last Week of Treatment

An appointment will be scheduled for you to meet with a member of our patient care team to ensure appropriate care is organised after your last treatment visit. This may include regular monitoring of blood results, appointments for dressings and management of side effects.

Following Treatment