Symptoms of colon and rectal cancer
The symptoms of bowel cancer may include any of the following:
The tiredness can happen if the cancer has been bleeding so the number of red blood cells is reduced (anaemia). Anaemia may also make you feel breathless.
Sometimes the cancer can cause a blockage (obstruction) in the bowel. The symptoms of this are:
When to consult your doctor
Although these symptoms can be caused by conditions other than colon or rectal cancer, it‘s important that you always have them checked by your doctor. As bowel cancer usually occurs in people over the age of 50, these symptoms in younger people are often thought to be due to other bowel problems, such as haemorrhoids (piles), irritable bowel syndrome (IBS) or ulcerative colitis.
If you have symptoms that don‘t improve within a few weeks, or if your symptoms are getting worse, it‘s important that you‘re referred to a specialist for tests to find out what the problem is.
How colon and rectal cancers are diagnosed
Usually, you begin by seeing your GP (family doctor). He will examine you and may refer you to hospital for tests.
Seeing your GP
Your GP will feel your abdomen and examine your back passage (a rectal examination). To do this, the doctor places a gloved finger into your back passage to feel for any lumps or swellings. This may be slightly uncomfortable but it should not be painful. It will be less uncomfortable if you are able to relax while he is doing this.
You may have a blood test to check for anaemia (a low number of red blood cells), which is common in people with cancer of the colon or rectum. You may also have blood tests to check the health of your liver and kidneys.
If your GP is unsure what the problem is, or thinks that your symptoms could be caused by cancer, he will refer you to a hospital specialist.
How long should I expect to wait for a referral?
The Department of Health has given the following guidelines to GPs to help them know when to arrange an urgent referral.
They should arrange an urgent referral for:
At the hospital
At the hospital the specialist will ask you about your general health, any previous medical problems, and whether you have any family history of bowel cancer. The specialist will examine you, and will probably repeat the rectal examination (as above).
The following tests may be used to diagnose colon and rectal cancer:
Waiting for your test results
It will probably take several days for the results of your tests to be ready and this waiting period will obviously be an anxious time for you. It may help if you can talk things over with a relative or close friend.
How the tests are carried out
These tests are done in the hospital outpatient department or on the ward by a doctor or nurse colonoscopist.
You will be asked to lie curled on your left side while a tube is gently passed into your back passage. A small hand-pump is attached to the tube so that air can be pumped into the bowel. This makes you feel that you want to pass a bowel motion, but the feeling will gradually go away once the test is over.
A proctoscope is a short tube that goes just into the rectum.
A sigmoidoscope is a longer tube that can be passed further up into the large bowel. Any abnormal areas can be seen with the help of a tiny light and camera on the end of the tube.
If necessary, a small sample of the cells (a biopsy) can be taken for examination under a microscope. The biopsy is not painful.
A proctoscopy or a sigmoidoscopy can be uncomfortable but shouldn‘t usually be painful. You should be able to go home as soon as the test is over.
If your doctor wants to look inside the whole length of the large bowel, you may have a colonoscopy. This will usually be done in the hospital outpatient department and takes about an hour.
For a colonoscopy the bowel has to be completely empty. This means following a careful diet for a few days before your test. The preparation is similar to that for a barium enema (see below). You will be given instructions by your hospital.
Just before the test, you may be given a sedative tablet to help you feel more relaxed, and you may feel sleepy during the colonoscopy. Once you are lying comfortably on your side, the doctor or nurse will gently pass a flexible tube (a colonoscope) into your back passage. The tube is made up of flexible fibres. It can easily pass around curves, and most of the large bowel can be examined. A tiny light and camera on the end of the tube help to show any abnormal areas or swelling.
During the test, photographs and samples (biopsies) of the cells on the inside of the large bowel can be taken. A colonoscopy can be uncomfortable, but the sedative will help you feel more relaxed.
Most people are ready to go home a couple of hours after their test. It‘s a good idea to arrange for someone to collect you from the hospital, as you shouldn‘t drive for several hours after a sedative.
This test will be done in the hospital x-ray department.
It‘s important that the bowel is empty so that a clear picture can be seen.
Your doctor or nurse will give you an instruction sheet before the test. On the day before the test, you will be asked to drink plenty of fluids and to take medicine (a laxative) to empty your bowel. Usually, on the morning of your enema, you shouldn‘t have anything to eat or drink. This may vary slightly from hospital to hospital.
Just before the test, to make sure that the bowel is completely clear, you may be given a bowel wash-out. The nurse will ask you to lie on your left side while a tube is gently passed into your back passage. Water is then passed through the tube.
You will be asked to hold the liquid in the bowel for a few minutes before you go to the toilet.
For the barium enema, a mixture of barium (which shows up on x-ray) and air is passed into the back passage in the same way as the bowel wash-out. It‘s important to keep the mixture in the bowel until all the x-rays have been taken. The doctor can then watch the passage of the barium through the bowel on an x-ray screen. Any abnormal areas can be seen.
The test can be uncomfortable and tiring, so it‘s a good idea to arrange for someone to travel home with you if possible.
For a couple of days after your enema, you may notice that your stools are white. This is the barium being removed from the body and is nothing to worry about. The barium can also cause constipation, and you may need to take a mild laxative for a couple of days after your test.
This is a newer test that is also called a virtual colonoscopy. It isn‘t widely available, so if you need one you may have to travel to a specialist centre. Instead of having a colonoscope put into your bowel, a computer uses CT scanning images to examine your bowel. Sometimes a CT colonography is done instead of a barium enema. It is still being researched as a way of diagnosing bowel cancers. Your doctor or nurse can discuss it with you further.
The preparation is the same as if you were having a colonoscopy, so you will be asked to drink fluids and take a laxative. CT colonography is done in the hospital CT scanning department and can usually be done as an outpatient. Just before the CT scans are taken the doctor will pass a tube into your back passage (rectum) and pump in some air and gas (carbon dioxide). This expands the bowel and helps to give a clearer picture. You will have two CT scans – one while lying on your back and one on your front. The computer then matches up the two scans to create a =virtual‘ image of the inside of your bowel. You may still have a colonoscopy (see above) if biopsies are needed.
Tests after a diagnosis of colon or rectal cancer
If the initial tests show that there is a cancer in the colon or rectum, further tests will be done to find out the size and position of the cancer, and to see whether it has spread. This process is called staging , and may take some time. The results will help
you and your doctor decide on the best treatment for you. Sometimes these tests may be done again, during and after treatment, to check on your progress.
The following additional tests are used most often:
Waiting for your test results
It will probably take several days to a couple of weeks for the results of your tests to be ready. The results of the tests will show the grade and the stage of the cancer. This information will be used by a team of doctors and nurses, known as the multidisciplinary team or MDT, to decide on the most appropriate treatment.
Waiting for results can be a difficult time. It may help to talk things over with a friend or relative. You can also contact one of our cancer support specialists or one of the organisations listed in the further resources section.
What the tests involve
You will probably have blood tests to assess your general health, and also to check for a particular protein that is sometimes produced by bowel cancer cells. The protein is called carcinoembryonic antigen (CEA). Proteins produced by cancer cells are sometimes called tumour markers as they may give an indication about how treatment is working or whether a cancer is coming back.
Abdominal ultrasound scan
This uses sound waves to look at internal organs, such as the liver and the inside of the abdomen, to see whether the cancer has spread to other organs. You will usually be asked not to eat or drink for at least six hours before the test.
Once you are lying comfortably on your back, a gel is spread onto your abdomen. A small device that produces sound waves is passed over the area. The sound waves are then converted into a picture by a computer. The test only takes a few minutes.
In some situations you may have a probe (like a tube) inserted into the rectum to produce ultrasound scans. This is known as an endoscopic ultrasound (EUS).
CT (computerised tomography) scan
A CT scan can show the size of the cancer and whether it has spread beyond the bowel. The scan is painless but takes longer than an ordinary x-ray (10–30 minutes).
CT scans use a small amount of radiation, which is unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. If you are allergic to iodine, or have asthma, you could have a more serious reaction to the injection, so it‘s important to let your doctor know beforehand.
The CT scan is painless but takes 10–30 minutes.
Just before the scan, a similar liquid is also passed into your back passage through a small tube. Although this may be unpleasant at the time, it makes sure that the best possible picture is produced. Once you are in position, the scan will be taken.
You will probably be able to go home when the scan is over.
PET (positron emission tomography) scan
PET scans are a newer type of scan and you may have to travel to a specialist centre to have one. They are not always necessary but you can discuss with your doctor whether one would be useful in your case. PET scans can be used to accurately define the cancer and find out if it has spread to other parts of the body.
A PET scan uses low-dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body. A very small amount of the glucose is injected into a vein, usually in your arm. A scan is then taken a couple of hours later. Areas of cancer are usually more active than surrounding tissue and show up on the scan.
Usually a PET scan is combined with a CT scan. A small amount of a radioactive substance is injected in the same way as a standard PET scan, and then the CT scan takes a series of x-rays. The scanner combines the two different types of information and allows your doctor to measure any changes in the activity of cells and to know exactly where in the body the changes are.
A PET/CT scan can be used to show whether the cancer has spread and to give information that will help the doctors decide on the best treatment. It is not used to replace a CT scan, so you may need to have both types of scans.
MRI (magnetic resonance imaging) scan
If you have a rectal cancer, this test can help to show the stage of the cancer and can give the surgeon information to help them plan an operation or to decide whether radiotherapy should be given before surgery. People with a rectal cancer will often have an MRI scan before surgery.
MRI scans aren‘t always needed for people with a colon cancer and your doctor can discuss whether you need to have this type of scan.
Before the scan you may be asked to complete and sign a checklist. This is to make sure that it‘s safe for you to have an MRI scan, because the scanner is a powerful magnet. The checklist asks about any metal implants you may have, for example a pacemaker, surgical clips, bone pins etc. You should also tell your doctor if you have ever worked with metal or in the metal industry as very tiny fragments of metal can sometimes lodge in the body. If you do have any metal in your body it‘s likely that you won‘t be able to have an MRI scan. In this situation another type of scan can be used.
Before having the scan, you‘ll be asked to remove any metal belongings including jewellery. Some people are given an injection of dye into a vein in the arm, which doesn‘t usually cause discomfort. This is called a contrast medium and helps the images from the scan show up more clearly. During the test you‘ll be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It‘s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan. It‘s also noisy, but you‘ll be given earplugs or headphones. You‘ll be able to hear, and speak to, the person operating the scanner.
Staging and grading of colon and rectal cancer
The stage of a cancer describes its size and whether it has spread beyond its original area of the body. Knowing the extent of the cancer helps the doctors decide on the most appropriate treatment.
Grading refers to the appearance of the cancer cells under the microscope. The grade gives an idea how quickly they may develop.
The exact stage of a colon or rectal cancer can often only be determined after surgery, when the pathologists can examine the cancer and the piece of healthy colon or rectum that has been removed.
Generally, colon and rectal cancers are divided into four stages, ranging from small and localised to cancer that has spread to other parts of the body. If the cancer has spread, this is known as secondary or metastatic cancer. If the cancer comes back after initial treatment it‘s known as recurrent cancer.
There are two different staging systems used to stage colon and rectal cancer. The first system, called the Dukes staging system, is gradually being replaced by the TNM staging system, which gives more detailed information.
The Dukes staging system:
Dukes A: The cancer is contained within the bowel wall.
Dukes B: The cancer has spread through the muscle of the bowel wall, but the lymph nodes are not affected.
Dukes C: The cancer has spread to one or more of the lymph nodes close to the bowel. Lymph nodes are usually the first place the cancer spreads to.
Dukes D: The cancer has spread to another part of the body such as the liver or the lungs (secondary cancer).
TNM staging system:
TNM stands for T for Tumour, N for Node and M for Metastases.
There are four levels used to describe the tumour:
T1 The tumour is only in the inner layer of the colon or rectum.
T2 The tumour has begun to grow into the muscle layer of the colon or rectum, but not all the way through it.
T3 The tumour has grown through the muscle layer or into structures next to the bowel.
T4 The tumour has broken through the outer covering of the bowel, or spread to other parts of the bowel, or other organs or structures close to the bowel.
There are three levels describing whether the lymph nodes are affected:
N0 No lymph nodes are affected.
N1 Between one and three lymph nodes close to the colon or rectum (regional nodes) are affected.
N2 The cancer has been found in four or more regional nodes.
There are two different levels to describe whether the cancer has spread to other parts of the body (metastases):
M0 The cancer hasn‘t spread to other parts of the body.
M1 The cancer has spread to other parts of the body.
To make it easier to understand the TNM system, doctors often combine the information about the tumour, the lymph nodes and whether the cancer has spread into stage groups:
Stage 0 – The cancer is in the very earliest stage and is only in the inner lining of the colon or rectum. This stage is sometimes called carcinoma in situ.
Stage 1 – The cancer is affecting the inner lining of the colon or rectum, or has begun to grow into the muscle, but no further. No lymph nodes are affected (T1, N0, M0 or T2, N0, M0).
Stage 2A – The cancer has grown through the outer muscle layer of the colon or rectum, but has not spread to nearby structures or to any lymph nodes or other parts of the body (T3, N0, M0).
Stage 2B – The cancer has spread through the outer muscle layer of the colon or rectum and into nearby structures, but it‘s not affecting any lymph nodes or other parts of the body (T4, N0, M0).
Stage 3A – The cancer is affecting the inner lining of the colon or rectum, or has begun to grow into the muscle, and is affecting between one and three lymph nodes close to the colon. It has not spread to other parts of the body (T1, N1, M0 or T2, N1, M0).
Stage 3B – The cancer has grown through the outer layer of the colon or rectum, or into nearby structures, and is affecting between one and three lymph nodes (T3, N1, M0 or T4, N1, M0).
Stage 3C – The cancer may or may not have grown through the wall of the colon or rectum, but is affecting four or more nearby lymph nodes. It has not spread to other parts of the body (Any T, N2, M0).
Stage 4 – The cancer may or may not have grown through the wall of the colon or rectum, may or may not have spread to nearby lymph nodes, but has spread to other parts of the body, such as the liver or lungs (Any T, Any N, M1).
There are three grades: grade 1 (low-grade), grade 2 (moderate- or intermediate- grade) and grade 3 (high-grade).
Low-grade means that the cancer cells look very like the normal cells of the bowel (the cells are sometimes described as being well differentiated). They are usually slow-growing and are less likely to spread.
In high-grade cancers the cells look very abnormal (the cells are poorly differentiated). They are likely to grow more quickly and are more likely to spread.
Moderate-grade cancers fall between these two grades and have a level of activity somewhere in between. They are sometimes described as being moderately differentiated.