What is the treatment for bowel cancer?

Summary

There are different treatments for bowel cancer (colorectal cancer). Which one is right depends on:

• Which part of the bowel is affected.

• How big the cancer is.

• Whether the cancer has spread.

• General health - for example, whether the person has other medical conditions, or if they have frailty.

• The genetic makeup inside the cancer cells.

Bowel cancer treatments include:

• Surgery, to remove the cancer.

• Chemotherapy, to try to stop cancer coming back after surgery, or if the cancer has spread.

• Radiotherapy - for rectal cancer, and sometimes colon cancer that has spread.

• Targeted therapy and immunotherapy - newer medicines that can treat advanced bowel cancer that has spread.

• Other palliative treatments to control symptoms.

If you think you may have bowel cancer, find out what to do here.

In this series of articles centred around bowel cancer you can read about bowel cancer symptoms, bowel cancer causes, and bowel cancer treatment - all written by one of our expert GPs.

The rest of this feature will take an in-depth look at treatments for bowel cancer, as at Patient, we know our readers sometimes want to have a deep dive into certain topics.

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Cancer

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Cancer

Bowel cancer

Colon cancer and rectal cancer (also called colorectal cancer) are common in the UK. The colon and rectum are parts of your bowel. Most cases occur in people aged over 50. If bowel cancer is diagnosed at an early stage, there is a good chance of a cure. In general, the more advanced the cancer (the more it has grown and spread), the less chance that treatment will be curative. However, treatment can often slow the progress of the cancer.

by Dr Doug McKechnie, MRCGP

Bowel cancer treatment

There are several different treatments for bowel cancer. Treatment decisions can be complicated, and the options are usually decided by a team of different specialists, including colorectal surgeons, oncologists, gastroenterologists, and palliative care specialists.

Bowel cancer care includes:

Surgery

If bowel cancer is caught early enough - before the cancer spreads - an operation can be done to remove the cancer.

For localised bowel cancer that hasn't spread, surgery to remove it can be curative - although it's not guaranteed.

Very small, early stage cancers can sometimes be removed from inside the bowel during a colonoscopy or sigmoidoscopy - called a local resection.

For larger cancers, an operation to remove part of the colon might be offered. There are various different procedures depending on where the cancer is located. Generally, they involve cutting out the part of the bowel that contains the cancer, along with nearby lymph nodes - because cancer can spread to those lymph nodes. The two cut ends of the bowel are usually joined back together.

Some operations require the creation of a stoma, which can be temporary or permanent. A stoma is a connection between the bowel and the surface of the tummy (abdominal) wall. Poo comes out of the stoma and collects into a disposable bag that's worn over the top of it.

Occasionally, when the cancer has spread to the liver or the lungs, an operation might be offered to remove the affected part of those organs. This is only suitable for a few people. Usually, cancer that's spread can't be fully removed by an operation.

Side-effects

Surgeries for bowel cancer are major operations. They usually require at least a few days recovery in hospital, and a longer period of recovery at home.

Side-effects and risks of surgery include:

• Not being able to remove the cancer completely.

• Cancer returning despite the operation.

• Developing a leak where the two cut ends of bowel were joined together - an anastomotic leak.

• The bowel being slow to start working again - an ileus.

• Infections.

• Developing a blood clot.

• Bleeding.

• Nerve damage that might affect sexual function or the bladder, when performing operations on the rectum.

Chemotherapy

Chemotherapy for bowel cancer can be used:

• After surgery, to reduce the chance of the cancer returning. This is usually offered when the cancer has grown into the outer wall of the bowel, or if the cancer has spread to nearby lymph nodes. This is called adjuvant chemotherapy.

• Before surgery, to shrink the tumour. This is called neoadjuvant chemotherapy.

• As the main treatment for cancer that has spread to other organs - metastatic or advanced bowel cancer.

Chemotherapy given before or after surgery can help to stop the cancer from coming back after it's been removed.

Once bowel cancer has spread to another part of the body, it's usually not possible to remove it completely. Instead, chemotherapy for advanced cancer aims to treat symptoms from the cancer and allow people with cancer to live longer.

There are various different chemotherapy drugs and combinations. Most of them are given through a drip (intravenously).

Side-effects

Side-effects vary from drug to drug. In general, chemotherapy side-effects include:

• Feeling sick (nausea) and vomiting.

• Feeling tired.

• Hair loss.

• Diarrhoea.

• A sore and painful mouth.

• Being vulnerable to infections.

Radiotherapy

Radiotherapy uses controlled radiation to kill cancer cells.

Radiotherapy can be used to treat rectal cancer. It's generally not used for cancer in other parts of the bowel, although it's sometimes used to treat symptoms of advanced bowel cancer that has spread to other organs.

Radiotherapy can be used:

• Before surgery, to shink the tumour (neo-adjuvant radiotherapy).

• After surgery, to reduce the risk of the cancer coming back (adjuvant radiotherapy).

• To treat symptoms (palliative radiotherapy).

Side-effects

Side-effects of radiotherapy include:

• Feeling tired.

• Diarrhoea.

• Sore, painful skin around the anus.

• Symptoms of bladder irritation, like discomfort in the bladder, pain when weeing, and having to wee more often.

• Long-term effects of inflammation in the rectum, such as:

  • Bleeding from the bottom.

  • Feeling like the bowels haven't completely emptied when pooing.

  • Diarrhoea or mucus discharge from the bottom.

Targeted therapy and immunotherapy

Targeted therapies are drugs that affect the ways cancer cells grow. Immunotherapy uses specially-produced antibodies that trigger your immune system to attack and destroy cancer cells.

Targeted therapies and immunotherapy can be used to treat advanced colon or rectal cancer: bowel cancer that has spread to other parts of the body.

Most targeted therapies and immunotherapies are only suitable if the cancer has specific genetic changes. These can be tested for in the original biopsies from when the cancer was first diagnosed.

Examples of targeted therapies include cetuximab (Erbitu) and panitumumab (Vectibix). Pembrolizumab (Keytruda) is an example of an immunotherapy drug that has recently been approved for use in the NHS.

Side-effects

Side-effects differ from drug to drug. In general, they can include:

• Skin rashes.

• Diarrhoea.

• Allergic reactions to the drug.

• Joint pain.

• Abdominal pain.

Palliative treatments

Palliative treatment means treatment that aims to reduce, or control, symptoms.

Palliative treatment can be given alongside treatment that is aiming to cure the cancer. It can also be used if curative treatment is not possible.

Palliative treatment might include:

• Chemotherapy.

• Radiotherapy.

• Targeted treatment or immunotherapies.

• Some types of surgery, such as:

  • Forming a stoma to bypass a large cancer that is blocking the bowel.

  • Placing a stent to open up a section of bowel that is blocked by a large tumour.

• Other medications to control symptoms, such as pain relief medication and anti-sickness drugs.

• Complimentary treatment, such as relaxation therapy, massage, music, yoga, and acupuncture.

• Support groups for people who are living with cancer.

Palliative treatment can be given at any stage of treatment. Palliative care is not only for people who are at the end of their life. It can benefit people at other stages, too.

Complications of bowel cancer

Bowel cancer can cause various different complications as it grows. They include:

• Bleeding, which can lead to anaemia.

• A complete blockage of the bowel (bowel obstruction). This is an emergency which needs urgent hospital treatment.

• Spread to other organs (metastasis).

Bowel cancer prognosis

The prognosis for someone with bowel cancer can vary a lot. It depends on where the tumour is, how advanced the cancer is, what treatments have been tried already, and their general health. If you have bowel cancer, your specialist care team can give you the most accurate details about your prognosis, because they have the most information.

The prognosis for early bowel cancer is generally good. Bowel cancer that is only in the bowel, or has spread to the lymph nodes, but not other organs, can potentially be cured with an operation. Once bowel cancer has spread to other organs, it usually can't be cured completely, but treatments can help to slow how fast it grows.

Doctors and researchers often use a statistic called '5 year survival' to estimate prognosis in cancer. This looks at large groups of people and describes how many of them will still be alive at five years after diagnosis. This gives an idea of the prognosis for a group of people, but can't tell exactly what will happen to an individual.

In England and Wales, between 2013 and 2017, the 5 year survival rates for bowel cancer, according to Cancer Research UK, were:

• For stage 1 bowel cancer (cancer that has only grown into the inner part of the bowel wall), around 90 out of every 100 people are alive five years after diagnosis.

• For stage 2 bowel cancer (cancer that has grown into the inner and outer part of the bowel wall), more than 80 out of every 100 people are alive five years after diagnosis.

• For stage 3 bowel cancer (cancer that has spread to the lymph nodes), around 70 out of every 100 people are alive five years after diagnosis.

• For stage 4 bowel cancer (cancer that has spread to other organs), around 10 out of every 100 people are alive five years after diagnosis.