WHAT IS COLORECTAL CANCER
Colorectal cancer is cancer that starts in either the colon or the rectum. Colon cancer and rectal cancer have many features in common and they are often discussed together here, except for the section about treatment, where they are discussed separately.
THE NORMAL DIGESTIVE SYSTEM
In order to understand colorectal cancer, it helps to know something about the structure of the digestive system and how it works.
After food is chewed and swallowed, it travels to the stomach. where, it is partly broken down and sent to the small intestine. (The small intestine is the longest part of the digestive system -- about 20 feet long, but not very wide when compared to the colon). The small intestine helps breaks down the food and absorbs most of the nutrients.
What remains goes into the colon (large intestine), a muscular tube about 5 feet long. The colon absorbs water and nutrients from the food and also serves as a storage place for waste matter (stool). Stool moves from the colon into the rectum, which is the last 6 inches of the digestive system. From there, stool passes out of the body through the opening called the anus.
SYMPTOMS OF BOWEL CANCER
The symptoms of bowel (colorectal) cancer can include:
Because bowel tumours can bleed, cancer of the bowel often causes a shortage of red blood cells. This is called anaemia and may cause tiredness and sometimes breathlessness.
Sometimes cancer can block the bowel - this is called a bowel obstruction.
Other diseases, apart from cancer, can cause all the symptoms mentioned above. Many of these other conditions are much less serious, such as piles (haemorrhoids), infections or inflammatory bowel disease.
ABNORMAL GROWTHS IN COLON OR RECTUM
Most colorectal cancers start as a polyp (a growth that starts in the inner lining of the colon or rectum and grows toward the centre). Most polyps are not cancer. Only certain types ofpolyps, called adenomas, can become cancer. Taking out a polyp early, when it is small, may keep it from becoming cancer.
Over 95% of colon and rectal cancers are adenocarcinomas. These are cancers that start in gland cells, like the cells that line the inside of the colon and rectum. There are some other, more rare, types of tumours of the colon and rectum.
WHAT ARE THE 'RISK FACTORS OF COLORECTAL CANCER
While it is not known the exact cause of most colorectal cancers, there are certain known ‘risk factors’. A ‘risk factor’ is something that affects a person's chance of getting a disease. Some ‘risk factors’, like smoking, can be controlled, whilst others, such as a person's age, cannot be changed. But, ‘risk factors’ don't tell us everything . Having a ‘risk factor’, or even several, does not mean that you will get the disease and some people who get colorectal cancer may not have any known ‘risk factors’. Even if a person with colorectal cancer has a ‘risk factor’, although it is often very hard to know what part that particular ‘risk factor’ may have played in the development of the disease.
Researchers have found some risk factors that may increase a person's chance of getting polyps or colorectal cancer.
Risk factors you cannot change:
TREATING BOWEL CANCER
People with bowel cancer should be cared for by a multidisciplinary team (MDT). This is a team of specialists who work together to provide the best treatment and care. The team often consists of a specialist cancer surgeon, an oncologist (a radiotherapy and chemotherapy specialist), a radiologist, pathologist, radiographer and a specialist nurse. Other members may include a physiotherapist, dietitian and occupational therapist, and you may have access to clinical psychology support.
When deciding what treatment is best for you, your doctors will consider:
There are several treatments for bowel cancer, including:
♦ Biological therapy
Surgery is usually the main treatment for bowel cancer, but in about one in five cases, the cancer is too advanced to be removed by surgery. If you have surgery, you may also need chemotherapy, radiotherapy or biological therapy, depending on your particular case.
YOUR TREATMENT PLAN
Your recommended treatment plan will depend on the stage and location of your bowel cancer.
If the cancer is confined to your rectum, radiotherapy will usually be used to shrink the tumour, and then surgery may be used to remove the tumour. Sometimes, radiotherapy is combined with chemotherapy, which is known as chemoradiation.
If you have Stage 1 bowel cancer, it should be possible to surgically remove the cancer and no further treatment will be required.
If you have Stage 2 or 3 bowel cancer, surgery may be used to remove the cancer and, in some cases, nearby lymph nodes. Surgery is usually followed by a course of chemotherapy to help prevent the cancer from returning.
It is not usually possible to cure stage 4 (advanced) cancer. However, symptoms can be controlled and the spread of the cancer can be slowed using a combination of surgery, chemotherapy, radiotherapy and biological therapy where appropriate.
SURGERY- COLON CANCER
If the cancer is at a very early stage, it may be possible to remove just a small piece of the lining of the colon wall - this is known as local excision.
If the cancer has spread into muscles surrounding the colon, it will usually be necessary to remove an entire section of your colon. Removing some of the colon is known as a colectomy.
Depending on the location of the cancer, possible surgical procedures include:
♦ Left-hemi colectomy – where the left half of your colon is removed.
♦ Transverse colectomy – where the middle section of your colon is removed.
♦ Right-hemi colectomy – where the right half of your colon is removed.
♦ Sigmoid colectomy – where the lower section of your colon is removed.
There are two ways a colectomy can be performed:
In an open colectomy, the surgeon makes a large incision in your abdomen and removes a section of your colon.
A laparoscopic colectomy is a type of ‘keyhole surgery’, where the surgeon makes a number of small incisions in your abdomen and uses special instruments, guided by a camera, to remove a section of colon.
Both techniques are thought equally effective in removing cancer and have similar risks of complications. However, laparoscopic colectomies have the advantage of a faster recovery time and less post-operative pain.
Laparoscopic colectomies should now be available in all hospitals carrying out bowel cancer surgery, although not all surgeons perform this type of surgery. If you are considering having your bowel cancer surgery done using keyhole surgery, discuss this with your surgeon.
During surgery, nearby lymph nodes may also be removed. It is usual to join the ends of the bowel together after bowel cancer surgery, but very occasionally this is not possible and a stoma is needed.
ENHANCED RECOVERY PROGRAMMES
Enhanced recovery surgical programmes should be used for most bowel cancer patients. These programmes differ from traditional surgery by:
Ensuring patients are in the best possible physical condition before surgery.
Minimizing the trauma that patients go through during surgery - for example, minimally invasive surgery where possible and better pain contro,l ensuring patients experience the best possible rehabilitation after surgery.
Two common surgical procedures can be used to treat rectal cancers:
♦ Low anterior resection
Low anterior resection is a procedure used to treat cases where the cancer is in the upper section of your rectum. The surgeon will make an incision in your abdomen and remove the upper section of your rectum, as well as some surrounding tissue, to make sure any lymph glands containing cancer cells are also removed. They will then attach your colon to the lowest part of your rectum or upper part of the anal canal. Sometimes, they turn the end of the colon into an internal pouch to replace the rectum. You will probably require a temporary stoma to give the join-up time to heal.
♦ Abdominoperineal resection
Abdominoperineal resection is used to treat cases where the cancer is in the lowest section of your rectum. In this case, it will be necessary to remove the whole of your rectum and surrounding muscles to reduce the risk of the cancer re-growing in the same area. This involves removing the anus and its sphincter muscles too, so there is no option except to have a permanent stoma after the operation. (Bowel cancer surgeons always do their best to avoid giving people permanent stomas wherever possible).
SIDE EFFECTS OF SURGERY
Bowel cancer operations carry the same risks as other major operations, including the risks of bleeding, infection, developing blood clots or heart or breathing problems.
One risk is that the join-up in the bowel may not heal properly and may leak inside your abdomen. This is usually only a risk in the first few days after the operation.
Another risk is for patients having rectal cancer surgery. The nerves controlling passing urine and sexual function are very close to the rectum, and sometimes an operation to remove a rectal cancer can damage these nerves.
After bowel cancer surgery, the bowel is shorter than it used to be. This results in some patients needing to go to the toilet to open their bowels more often than before. This usually settles down within three to six months of the operation.
Griping pains in the abdomen
♦ Age - your risk gets higher as you get older
♦ Having had colorectal cancer or certain kinds of polyps before
♦ Having a history of ulcerative colitis or Crohn’s disease
♦ Family history of colorectal cancer
♦ Race or ethnic background, such as being African American or Ashkenazi.Type 2 diabetes
♦ Certain family syndromes, like familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC, also called Lynch Syndrome)
♦ The type and size of the cancer
♦ Your general health
♦ Whether the cancer has spread to other parts of your body
♦ What grade it is