Bowel cancer

Introduction

Bowel cancer (colorectal cancer) is the third most common cancer in Scotland in both men and women. Approximately 3,900 new cases were diagnosed in 2012.

The number of people being diagnosed is increasing. However, statistics released by the Scottish Government in February 2013 reveal that bowel cancer patients in Scotland are almost 50% more likely to survive compared to 30 years ago.

The five year survival rate for bowel cancer increased from 38 out of every 100 people with bowel cancer (38%) between 1983 and 1987, to 55 out of every 100 (55%) between 2003 and 2007.  

Early diagnosis

The sooner bowel cancer is diagnosed, the easier it is to treat successfully.

However, currently only 9 out of every 100 patients (9%) in Scotland are diagnosed at the earliest stages of the disease whilst 30 out of every 100 patients (30%) have advanced stages of the disease when patients first seek medical help for their symptoms. . 

This is why taking part in the bowel screening programme is so important.

The large bowel

The large bowel is part of the digestive system and is a long tube measuring approximately 150cm long. It extends from the small bowel on the right hand side of the abdomen to the anus or back passage.

The main purpose of the large bowel is to:

  • receive fluid like stool from the small bowel and absorb salts and excess fluid
  • get rid of waste from the body (stool, faeces, poo).

The folloiwing diagram shows the position of the small bowel.

Diagram showing the position of the small bowel. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows the position of the small bowel.

The bowel walls are made up of several layers of body tissues. Bowel cancers start in the innermost layer, the lining of the bowel. It is thought that most bowel cancers take five to ten years to develop.

Most begin as a small growth on the bowel wall called a polyp or adenoma. If left untreated then they may become cancerous and grow into the muscle layers under the lining and then through the bowel wall.

The cancer can then spread into organs that are close to the bowel, such as the bladder, womb, or prostate gland.

How does cancer begin?

Cancer occurs when the cells in a certain area of your body divide and multiply too rapidly. This produces a lump of tissue known as a tumour.

Bowel cancer happens when the cells in the bowel grow more quickly than normal.

Bowel cancer is also known as cancer of the large bowel or colon and rectum depending on where the cancer starts. Two-thirds of cancers are in the colon whilst the other third are in the rectum.

Most bowel cancers develop from polyps which are pre-cancerous growths which if identified can be removed before they develop into cancer.

If bowel cancer spreads

Sometimes bowel cancer spreads to another part of the body through the lymphatic system. The lymphatic system is made up of lymph nodes, which are part of the body’s immune system.

One of the first places bowel cancer spreads is to the lymph nodes in the abdomen.

Bowel cancer can also spread to other parts of the body through the bloodstream. The liver is a common place for bowel cancer to spread because blood flows directly from the bowel to the liver.

The following diagram shows how the blood and lymph flow between the liver and bowel.

Diagram showing how the blood and lymph flows between the liver and bowel. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows how the blood and lymph flow between the liver and bowel.

Last updated: 28 October 2013

Symptoms of bowel cancer

Early bowel cancer may have no symptoms. That is why taking part in the bowel screening programme is so important

Symptoms of bowel cancer can include:

  • blood in your stools (faeces)
  • bleeding from your rectum
  • a change to your normal bowel habits that persists for more than six weeks, such as diarrhoea, constipation or passing stools more frequently than usual
  • abdominal pain
  • unexplained weight loss
  • a lump that your doctor can feel in your back passage or abdomen
  • a lower than normal level of red blood cells (anaemia) that may cause increased tiredness or breathlessness.

If you regularly experience any of these symptoms, which are not normal for you, it is important that you see your GP.

It is unlikely that your symptoms are caused by a serious problem but it is important to be checked out. It is most likely to be a benign (non-cancerous) condition that can easily be treated by seeing the GP.

The earlier a cancer is picked up, the easier it is to treat it and the more likely the treatment is to be successful.

Last updated: 31 July 2013

Causes and risks factors of bowel cancer

A cause is something that leads to a person developing cancer. A risk factor is something that makes a person more likely to develop cancer.

Although the exact cause of bowel cancer is unknown, there are certain factors that may increase your risk, including:

  • Gender and age - bowel cancer affects both men and women. In the UK, around 95% of cases occur in people over the age of 50.
  • Family history - people with a first degree relative (such as their mother, father, brother, sister or child) under 45 or with two or more first degree relatives with bowel cancer may be considered for further testing.
  • Diet and lifestyle - an inactive lifestyle and a poor diet that is low in fresh fruit and vegetables may increase the risk of bowel cancer. A high intake of red and processed meat, smoking and excess alcohol may also increase the risk.

Other conditions

People with the following conditions may be at an increased risk of developing bowel cancer:

Having one or more risk factors does not mean that you will definitely get bowel cancer. Many people with one or more risk factors never get it. And sometimes people with none of these risk factors develop bowel cancer. Risk factors are only a guide to what may increase the risk.

Last updated: 31 July 2013

Diagnosing bowel cancer

Everyone living in Scotland, aged between 50 and 74 is invited for bowel screening every two years. Screening is carried out by taking a small stool sample three consecutive times and sending it to a central laboratory in Dundee to test for the presence of blood.

Patients who have been notified of a positive bowel screening test will be contacted by their local hospital and offered a colonoscopy as their first diagnostic test.

You can find out more about the bowel screening programme in our Screening Scotland zone.

Patients with symptoms

When patients go to their GP for consultation regarding bowel cancer, the GP will begin the diagnosis by asking you about your symptoms and whether you have a family history of bowel cancer.

They will then carry out a physical examination of your abdomen and an examination of your lower rectum. This is often called a digital rectal examination (DRE) and involves your GP gently placing their finger into your anus, and then up into your rectum.

A DRE is a useful way of checking whether there is a noticeable lump inside your rectum. This is found in an estimated 40 to 80 patients out of every 100 (40% to 80%) cases of rectal cancer. A DRE is not painful, but some people may find it a little embarrassing.

Your GP may also do some blood tests.

If your symptoms suggest that you may have bowel cancer, or the diagnosis is uncertain, you will be referred to your local hospital for further examination.

Tests commonly performed

Four tests are commonly used to confirm a diagnosis of bowel cancer:

  • Sigmoidoscopy and proctoscopy
  • Barium enema
  • Colonoscopy
  • Virtual colonoscopy (CT colonography).

See questions to ask the specialist.

Sigmoidoscopy and proctoscopy

Are examinations of your rectum and the lower large bowel. These tests allow the doctor or a specialist nurse to look inside the rectum (proctoscopy) or the lower part of the large bowel (sigmoidoscopy).

There are two types of sigmoidoscopy. A rigid sigmoidoscopy and a flexible sigmoidoscopy. There isn't a great deal of difference in what actually happens when you have the test. The rigid sigmoidoscope has a tube that doesn't bend and is shorter.

The tube is passed gently into the back passage to enable the doctor / nurse to see the bowel. During the test some air may be passed down the tube to allow a clearer view of the bowel.

To have a sigmoidoscopy you must have an empty lower bowel so you usually need to have an enema or strong laxatives beforehand to clear your bowel out. Your doctor or nurse may arrange for you to do the enema or take the laxatives at home the day before you go into the department for the test.

Barium enema

This can be used in combination with sigmoidoscopy and proctoscopy tests.

This is an X-ray of the large bowel. Doctors sometimes use it instead of a virtual colonoscopy. For this test you have to have an empty bowel.

You will be given laxatives to take the day before, asked to drink lots of fluids and not eat solid food the day before the test and asked not to eat and drink anything on the morning of the test.

Read more about a barium enema

Colonoscopy

Is an examination that looks at the whole of the inside of the large bowel.

You have this test in the outpatient department and it takes about an hour. The bowel needs to be empty. You will be given a list of things to help prepare your bowel for the test. These are likely to include stopping iron tablets, not eating solid food for two days before the test, drinking plenty of clear fluids and taking laxatives.

The tube is passed gently into the back passage to enable the doctor or nurse to see the bowel. During the test some air may be passed down the tube to allow a clearer view of the bowel.

Diagram showing a colonoscopy. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows a colonoscopy.

Virtual colonoscopy (CT colonography)

Instead of having the colonoscope put inside your bowel, the doctor looks at pictures created by a computer.

Before the test you have laxatives and plenty of fluids to clear out your bowel. You will also be asked to follow a special diet for a couple of days beforehand. Your doctor or nurse will give you full details.

The test uses a CT scanner, so you have this test in the CT scanning department. You can have it as an outpatient.

Further tests

If initial tests show that there is a cancer or a suspicion of a cancer  in the large bowel, you may need further tests to find out more about the cancer and whether it has spread. This is called staging. Doctors use this information to decide on the best treatment for you.

You may have some of these tests again during and after your treatment, to see how well your treatment is working:

  • CT scan
  • MRI scan
  • CEA blood test

CT scan

A CT scan takes a series of X-ray pictures of the body from different angles. The X-ray images are fed into a computer and form a detailed picture of the inside of your body.

If you have cancer of the large bowel, you are likely to have a CT scan of your chest, tummy (abdomen) and the area between your hip bones (the pelvis). The scan gives a detailed image of the cancer to show how big it is.

Your doctor can also use the scan to check whether the cancer has spread to another part of the body, for example, to the liver.
Before the scan you may be asked to not to eat or drink for four hours, drink a special liquid a few hours before and to drink more of the liquid in the X-ray department.

Read more about CT scans.

MRI scan

An MRI scan uses powerful magnets to build up a picture of the body. It can sometimes give more detail than a CT scan and is commonly used for cancers in the back passage (rectum).

Read more about MRI scans.

CEA blood test

Some bowel cancers make a protein called carcinoembryonic antigen (CEA) that can be found in the blood. Doctors usually take a blood sample to get a baseline reading of CEA levels when you are first diagnosed. Your doctor can then compare it to levels during your treatment to see if the treatment is working.

Read more about CEA tests.

Questions to ask

You may want to ask the specialist some questions before your tests start, such as:

  • How will I know if I have cancer of the large bowel or back passage?
  • Am I more likely to get bowel cancer than anyone else?
  • Should I be having bowel cancer screening?
  • What are the screening tests for bowel cancer?
  • Will changing my diet help to prevent bowel cancer?
  • Is there anything else I can do to lower my risk of getting bowel cancer?
  • What tests are you going to do?
  • What are you looking for?
  • Will the tests show whether I have cancer?
  • How reliable are the tests?
  • Do I have to do anything to prepare for any of the tests?
  • Are the tests painful?
  • Do any of the tests have after effects?
  • Can I have all the tests as an outpatient?
  • Can I bring someone with me when I have the tests?
  • How long will it take to get the results of the tests?
  • Who will give me the test results?

Getting test results

When the results of the tests are all finally done and assessed you will be called to see your consultant for the results.

Having tests then ultimately receiving a diagnosis of cancer is a frightening and often shocking experience. Many people find they struggle to take in everything that is said at their appointment, so it can be helpful to take someone with you to important appointments.

Around this time a clinical nurse specialist may take over co-ordination of your case. He or she will oversee the continuity of treatments, appointments and your best interests. They can also interpret any jargon and explain what will happen in more detail.

If you have been diagnosed with cancer and haven't been assigned a clinical nurse specialist, ask if one is available.

Last updated: 25 October 2013

Treating bowel cancer

The main treatment for bowel cancer in the first instance is usually surgery. Sometimes other treatments such as chemotherapy and radiotherapy are used and, in some cases, are necessary as initial treatment. This is known as neo adjuvant treatment. 

Removing early stage tumours

If you have a very small, early stage, cancer of the large bowel or back passage then your surgeon may just remove the cancer from the bowel lining. This operation is called a local resection.

The surgeon will also remove a border of healthy tissue from around the cancer that contains no cancer cells. This is to try and make sure no cancer cells were left behind.

Diagram showing a local resection of an early stage bowel cancer. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows a local resection of an early stage bowel cancer.

Your surgeon sends the tissue they've removed to the laboratory. A pathologist looks at the cells under a microscope to see how abnormal they are. This tells your doctor the grade of the cancer.

If the cells look very abnormal (high grade) your surgeon may decide you need a second, larger operation. The second operation is to remove more tissue that could contain cancer cells and lower the chance of the cancer coming back.

Surgery for bowel cancer

The type of operation you have depends on where the tumour is in your large bowel (colon). The surgeon makes a cut in your abdomen to remove the part of the colon containing the tumour. This operation is called a colectomy.

How much your surgeon takes away depends on the exact position and size of the cancer. Your surgeon will remove the lymph glands  closest to the bowel, in case any cancer cells have spread there.

If the left side of the colon is removed, the operation is called a left hemi colectomy.

Diagram showing the part of the bowel removed with a left hemicolectomy. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows the part of the bowel removed with a left hemicolectomy.

If the middle part of the bowel is removed (the transverse colon) it is called a transverse colectomy.

Diagram showing the part of the bowel removed with a transverse colectomy. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows the part of the bowel removed with a transverse colectomy.

If the right side of the colon is removed, it is called a right hemi colectomy.

Diagram showing the part of the bowel mremoved with a right hemicolectomy. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows the part of the bowel memoved with a right hemicolectomy.

If the sigmoid colon is removed it is called a sigmoid colectomy.

Diagram showing the part of the bowel removed with a sigmoid colectomy. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows the part of the bowel removed with a sigmoid colectomy.

After your surgeon removes part of the bowel with the tumour, they join the ends of the colon back together. The join is called an anastomosis.

Sometimes, to give the area time to heal, the surgeon makes a temporary colostomy or ileostomy higher up the bowel. You have the temporary stoma removed in another operation a few months later, called a stoma reversal.

In the meantime, you wear a colostomy bag over the opening of the bowel, to collect your bowel motions.

What is a colostomy

The surgeon forms a colostomy by stitching the end of the large bowel (colon) to a hole cut in the skin of your abdomen. So you have an opening on the abdomen called a stoma. The stoma is round or oval and looks moist and red, like the inside of your mouth. It doesn't hurt because it has no nerve supply. So you must be careful not to injure it because you won't be able to feel if you have done any damage.

Diagram showing a colostomy with a bag. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows a colostomy with a bag.

The stoma will be swollen just after your operation but it will get smaller and flatter. Faeces (stools) pass out of the stoma. You wear a bag stuck to the skin over the stoma to collect the stools. The stoma also oozes a white mucus. This is normal and the mucus collects in the bag with the faeces.

Temporary colostomy

Some people with bowel cancer have a temporary colostomy. The colostomy allows the bowel to heal after the cancer has been removed. A few months later, you have another operation to rejoin the bowel and close the stoma. This is called reversing the stoma.

Permanent colostomy

If you have a large amount of colon removed, your surgeon may not be able to join the ends of bowel that are left.

You may need to have a permanent colostomy. Your surgeon will avoid this if at all possible.

You will be able to ask questions about why you need a colostomy before you sign the consent form. Sometimes surgeons can't tell whether you will need a permanent colostomy until during the operation. They may not know how big the tumour is, or how much of the bowel it affects. Your surgeon will explain this to you before the operation.

What is an ileostomy

A surgeon creates an ileostomy by stitching the end of the small intestine, or ileum, to a hole that they cut in the skin of your abdomen. The hole is called a stoma. The stoma is round or oval and looks moist and red, like the inside of your mouth.

Bowel motions (stools) pass out of the stoma. They will be a mixture of bowel liquid and semi solid motion with some wind. The stoma does not hurt because it has no nerve supply. So you must be careful not to injure it because you won't be able to feel if you have done any damage.

Diagram of an ileostomy with a bag. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows an ileostomy with a bag.

The stoma is swollen just after your operation but  will get smaller and flatter. You wear a bag stuck to the skin over the stoma to collect the stools. The stoma also oozes a white mucus. This is normal and the mucus collects in the bag with the faeces.

Temporary ileostomy

Some people with bowel cancer have a temporary ileostomy. The ileostomy allows the bowel to heal after the cancer has been removed. A few months later, you have another operation to rejoin the bowel  and close the stoma. This is called reversing the ileostomy.

Stoma care

If you have a stoma it is important to look after it properly. You can read more about stoma care in our ileostomy article.

Total colectomy

Surgery to remove the whole colon is called a total colectomy. The surgeon makes a cut in the abdomen to remove the colon. They bring the upper end of the bowel out onto the surface of the abdomen to make a colostomy or ileostomy.

After these operations, you usually have a wound from the bottom of your breast bone (sternum) down to the level of your hip bones (your pelvis). Some people may have keyhole surgery for colon cancer instead of the open surgery described here.

Keyhole bowel surgery

Surgeons may use keyhole surgery to remove early stage bowel tumours. This type of operation is also called a laparoscopic resection. The surgeon makes several cuts in your tummy (abdomen), each smaller than 1.5cm, instead of making one large cut as you'd have with open surgery.

The surgeon passes a long, narrow tube called a laparoscope, and other instruments, through the cuts. The laparoscope has a light on the end so the surgeon can look into your abdomen. They remove the tumour through as small a cut as possible.

This type of surgery usually takes about 40 minutes longer than a traditional open operation.

Surgery for rectal cancer

You may have radiotherapy or chemoradiotherapy to shrink the cancer before surgery and make it easier to remove. This also lowers the chance of the cancer coming back in the back passage after surgery.

If you have a very small, early stage rectal cancer, your surgeon may be able to remove it in an operation called a local resection (trans anal resection). The surgeon puts an endoscope (a flexible tube with a light) in through your back passage and removes the cancer from the wall of the rectum. Surgeons call this operation trans anal endoscopic microsurgery (TEM).

Diagram showing anal endoscopic microsurgery (TEM) for early stage rectal cancer. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows trans anal endoscopic microsurgery (TEM) for early stage rectal cancer.

Total mesenteric excision (TME) for rectal cancer

During most operations for rectal cancer, the surgeon removes the cancer with a border of rectal tissue around it that is free of cancer cells. They call this border of tissue a 'clear margin'. 

They also remove fatty tissue from around the bowel and a sheet of body tissue called the mesentery (pronounced meez-ent-air-ee). This sheet of tissue surrounds the intestine, bowel and rectum. It contains all the blood vessels that supply the rectum and the lymph nodes that carry tissue fluid away from it.

So any lymph nodes that contain cancer cells are likely to be in the mesentery. Small groups of cancer cells may also spread into the mesentery.

If the cancer is in the lower part of your rectum, your surgeon will not be able to leave enough of the rectum behind for it to work properly.
 
So, the surgeon removes your anus and rectum completely. This is called an abdominoperineal resection (AP resection for short). Then the surgeon makes a permanent colostomy opening on your abdomen.
 
After this type of surgery you have two wounds. A wound on your abdomen and a second wound where your anus has been closed.

Diagram showing and abdoperineal resection of the bowel. © CancerHelp UKThis diagram, taken from the patient information of Cancer Research UK, shows abdoperineal resection of the bowel.

If cancer blocks the bowel

Usually surgery for bowel cancer is planned in advance, after tests have found the cancer. However, sometimes the cancer completely blocks the bowel at the time it is found. This is called bowel obstruction. In this situation you need an operation straight away.

The surgeon may put a tube called a stent into the bowel during an colonoscopy. The stent holds the bowel open so that it can work normally again. Alternatively, you may have immediate surgery to remove the tumour from the bowel.

Beating Bowel Cancer have produced a leaflet called Colonic stenting (PDF 934KB) that explains more about this process.

Chemotherapy

Chemotherapy uses anti cancer (cytotoxic) drugs to destroy cancer cells. The drugs work by disrupting the growth of cancer cells. As they circulate in the blood, they can reach cancer cells almost anywhere in the body and kill them.

The chemotherapy drugs doctors commonly use to treat large bowel cancer include:

If chemotherapy is recommended, unless the chemotherapy  treatment is complex, it will be provided locally.

Radiotherapy

Radiotherapy treats cancer by using high-energy rays to destroy the cancer cells, while doing as little harm as possible to normal cells.

When radiotherapy is recommended, you will be referred to a clinical oncologist (doctor who specialises in the treatment of cancer) and after consultation with you a course of treatment will be recommended.

The treatment will take place in one of the five radiotherapy departments in Scotland (Aberdeen, Dundee, Edinburgh, Glasgow and Inverness).

The type of machine that is used will depend on the reason for your treatment and the condition that you are being treated for.

Availability of treatment

You should note that the availability of treatment can vary across the local hospitals in Scotland, but all treatments your doctors think are appropriate will be available to you (often at a hospital within your health board area).

Clinical trials

All the time, scientists (including doctors and other health professionals) are developing new treatments or tests for all types of cancers.

Clinical trials test potential treatments to see if they should be approved for wider use in the general population. Any new potential treatment must be extensively and objectively tested to check that it works, is safe and doesn't have unacceptable side effects.

You may be able to take part in a clinical trial aimed at finding better treatments for bowel cancer. You can use these resources to find current trials for bowel cancer treatments:

Your doctor or nurse will be able to tell you more about taking part in a trial.

After bowel cancer treatment

After treatment has finished all cancer patients have follow-up appointments to check their progress. If you've been through treatment the follow-up procedure will be explained to you.

During this time you may have questions you would like to ask, such as:

  • How long will it take me to get over my treatment?
  • When can I go back to work and take up my usual sports, hobbies and activities again?
  • Where can I get help to deal with my feelings and emotions?
  • Do I have to pay for counselling?
  • Who can help me look after my stoma?
  • How do I get the supplies I need for my stoma?  Are these available on prescription?
  • Is there anyone who can give advice or support about treatment affecting my sex life?
  • What should I do if I have problems with my diet?
  • Can I see a dietician at this hospital?
  • What practical support is available?
  • Can I get any help with money problems, including claiming benefits?

You can read more about living with cancer in the NHS inform Cancer zone.

For more information about living with bowel cancer please visit the following websites:

Last updated: 28 October 2013

Before bowel cancer treatment

Once all your investigations have been carried out a specialist multi-disciplinary team (MDT) will meet to discuss the results.

The MDT will consider several different factors when working out the best treatment for you. These include:

  • the type of bowel cancer
  • the stage of bowel cancer
  • where the cancer is located
  • the general health of the patient, including previous and current health conditions and fitness
  • what the patient’s wishes are for treatment.

If the case is new to the MDT, the patient will receive a call following the initial MDT discussion from the nurse specialist (or other appointed person) to inform them of the outcome of the meeting and explain the next steps.

At this stage an outpatient appointment is usually made so that a face-to-face discussion can take place. This is an opportunity to ask questions and receive results. Information can be given about future treatment plans, and often, the patient will be given some time to go away and consider all the options outlined.

Questions you may want to ask

If you have been told you have bowel cancer you are likely to have a lot of questions. Some questions you may want to ask your doctor could include:

  • What is the stage of my cancer and what does this mean?
  • What is the grade of my cancer and what does this mean?
  • What is the likely outcome (prognosis) of my cancer?
  • What sort of treatment do I need?
  • What is the aim of the treatment?
  • Is there any choice of treatments?
  • Should I have any other treatment as well as surgery?
  • Is it possible to get a second opinion?
  • What are the short and long term side effects of treatment?
  • What written information can you give me about my treatments?
  • Is there a specialist nurse I can see?
  • How often will you want to see me after my treatment is finished?
  • What will happen at my follow up appointments?
  • What should I do if I am worried between appointments?
  • Is there anything I should be looking out for?

Questions for your doctor when bowel cancer is advanced may include:

  • What treatment do you recommend now my cancer has come back?
  • What are the side effects of treatment likely to be?
  • Is it possible for me to have surgery to remove secondary cancer?
  • Which other treatments can help with cancer in the liver?
  • I have had chemotherapy so is there another type of chemotherapy or cancer drug I could have?
  • Are there any experimental treatments or trials you would recommend for me?
  • Is there a counsellor here I could talk things through with?
  • What if I decide not to have treatment?
  • How can you help to manage my symptoms?
  • Is there a specialist nurse I can see?
  • Can I get help with travel costs?
Last updated: 05 August 2013