Staging and prognosis for bowel cancer

What is cancer staging?

A range of tests can help show whether you have bowel cancer and whether it has spread from the original site to other parts of the body. This is known as staging and it helps your health care team advise you on the best treatment options.

Bowel cancer staging systems

The most common staging system for bowel cancer is the TNM system, which stands for tumour–node–metastasis. The Australian Clinico-Pathological Staging (ACPS) system may also be used in some hospitals.

The TNM system gives numbers to:

• how deep the tumour has gone into the bowel (T1–4)
• whether or not lymph nodes are affected (N1–2)
• whether the cancer has spread or metastasised outside the bowel (M0–M1).

Based on the TNM numbers, the doctor then works out the cancer’s overall stage. Around half of all bowel cancers in Australia are diagnosed at stage 1 or 2.

The stage can be predicted before surgery based on the results of early tests, but may be revised after surgery, following tests on the cancer tissue and lymph nodes removed during surgery.

If you are finding it hard to understand staging, ask someone in your health care team to explain it in a way that makes sense to you. You can also call Cancer Connect on 13 11 20. 

Stages of bowel cancer

• Stage 1 – tumour is found only in the inner layers of the bowel wall
• Stage 2 – tumour has spread deeper into the layers of the bowel wall
• Stage 3 – tumour is in any layer of the bowel wall and has spread into nearby lymph nodes
• Stage 4 – tumour has spread beyond the bowel to other parts of the body, such as the liver or lungs, or to distant lymph nodes

Prognosis

Prognosis means the expected outcome of a disease. You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for anyone to predict the exact course of the disease.

Your doctor can give you an idea about the common issues that affect people with bowel cancer. Generally, the earlier that bowel cancer is diagnosed, the better the chances of successful treatment, but people with more advanced bowel cancer may still respond well to treatment.

Test results, the type of cancer, the rate and depth of tumour growth, the likelihood of response to treatment, and factors such as your age, level of fitness and medical history are important in assessing your prognosis.