Treatment decisions for rectal cancer

Bowel cancer can start in the large bowel (colon cancer) or the back passage (rectal cancer). Your treatment depends on whether you have colon or rectal cancer, as well as the stage and type of your cancer.

This page is about how your doctor decides which treatment you need for rectal cancer that hasn’t spread to another part of your body.

When colon and rectal cancer spread to another part of the body it is called advanced bowel cancer.

Treatment overview

The main treatments for rectal cancer that hasn’t spread are:

• surgery
• radiotherapy
• chemotherapy 
• combined chemotherapy and radiotherapy (chemoradiotherapy)

You have one or more of these treatments, depending on your situation.

Surgery

Most people with rectal cancer have surgery. The 2 main types of surgery for rectal cancer are trans anal endoscopic microsurgery (TEM) and total mesorectal excision (TME).

Trans anal endoscopic microsurgery (TEM) is a small operation. The surgeon removes the cancer along with a border (margin) of healthy tissue. You might have TEM surgery if you have a very early stage cancer and a low risk of your cancer coming back after surgery.

Total mesorectal excision (TME) is the most common type of surgery for rectal cancer. The surgeon removes the part of the rectum that contains cancer, as well as a border (margin) of healthy tissue around it. They also remove the fatty tissue (mesorectum) around the rectum. 

Depending on your situation, your doctor might suggest you also have radiotherapy or chemoradiotherapy before the surgery, or chemotherapy after surgery. This is to lower the chance of your cancer coming back.

Radiotherapy

Radiotherapy uses high energy rays to destroy cancer cells. If your doctor thinks you need radiotherapy, you usually have it before surgery.

Some people only need a short course of radiotherapy. Doctors call this short course preoperative radiotherapy or SCPRT.

You have daily radiotherapy for 5 days and then have:

• surgery straight away (within 10 days from starting the radiotherapy)
• delayed surgery (at least 4 weeks after radiotherapy)

You don't usually have radiotherapy after surgery. But your doctor might suggest this if you were diagnosed with rectal cancer as an emergency and had an emergency operation. Or if your rectal cancer comes back soon after your surgery.

Chemotherapy

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. The drugs circulate throughout the body in your bloodstream.

You might have chemotherapy combined with radiotherapy (chemoradiotherapy) before or after surgery. Or you might have chemotherapy on its own after surgery, to lower the risk of the cancer coming back. This is called adjuvant chemotherapy.

Chemotherapy and radiotherapy together (chemoradiotherapy)

Chemotherapy combined with radiotherapy is called chemoradiotherapy or chemoradiation. You usually have chemoradiotherapy before surgery. Doctors also call this long course chemoradiotherapy.

You might have chemoradiotherapy before surgery if:

• your rectal cancer has spread to nearby structures and tissues
• it might be difficult for your surgeon to remove the rectal cancer with a clear border of tissue (margin)

 You usually have:

• radiotherapy every week day for around 5 weeks
• a chemotherapy drug called fluorouracil (5FU)
• surgery 6 to 10 weeks after completing chemoradiotherapy

Deciding which treatment you need

A team of doctors and other professionals discuss the best treatment and care for you. They are called a multidisciplinary team (MDT).

Doctors choose your treatment after considering your risk of the cancer coming back after treatment. They consider many factors including:

• whether the cancer is in the low, middle or high part of your rectum
• how far it has grown or spread (the stage) - for rectal cancers, doctors use the TNM staging system
• how abnormal the cells look under a microscope (the grade)
• whether your cancer has spread into blood vessels
• whether your cancer has spread into the sheet of tissue surrounding the rectum (mesorectal fascia)

They also consider your general health and fitness level. And they talk to you about your treatment, its benefits and the possible side effects.

Doctors sometimes group people with rectal cancer into groups, according to their risk of the cancer coming back after treatment. This helps them decide about treatment. There are 3 groups described below:

• low risk
• moderate risk
• high risk

Treatment by stage

The doctor uses your MRI scan results to decide your risk group. But this might change after surgery. After your operation, a specialist doctor (pathologist) looks at your cancer in the laboratory. You might need further treatment if the pathologist’s report shows your risk of the cancer coming back is higher than the surgeon previously thought.