What is bowel cancer?
Bowel cancer, also known as large bowel cancer or colorectal cancer, affects the colon and rectum, which make up the large bowel. Most cases of bowel cancer affect the large bowel, although approximately 1,700 people are diagnosed with small bowel cancer every year in the UK. When discussing bowel cancer or colorectal cancer, we refer to large bowel cancer or cancer that specifically affects the colon or rectum (or both).
Approximately 42,900 people are diagnosed with bowel cancer every year in the UK, making it the fourth most common type of cancer. It is primarily diagnosed in people aged 50 and over.
Bowel cancer starts in either the rectum or colon and occurs when cells begin to multiply in an abnormal and uncontrolled way. Bowel cancer can spread beyond the large bowel through the lymphatic system and the bloodstream. If the cancer spreads, one of the first places it can spread to is the lymph nodes in the stomach. The large bowel and the liver are connected via the bloodstream, so it’s common for bowel cancer to spread to the liver.
Bowel cancer symptoms
Due to the placement of bowel cancer and the role the large bowel plays in digestion, many symptoms may present themselves, including, but not limited to:
- Rectal bleeding
- Blood in your stool
- Changing bowel habits, e.g. pooing more/less often, or looser stool/constipation
- Weight loss
- Abdominal or rectal pain
- Feeling like you need to empty your bowels, even after you’ve just been to the toilet
- A lump in the abdomen or rectum (mainly on the right side)
If you notice any symptoms, you should speak with your GP as soon as possible. These symptoms may be a sign of other conditions, most of which are not serious and aren’t cancer, but your doctor must be able to rule out bowel cancer if you present with any of these symptoms.
Occasionally, bowel cancer can cause a bowel obstruction which can be very serious. If you notice any of the following symptoms or think you may have a bowel obstruction, you should seek immediate medical attention:
- Abdominal cramps and pain
- Excessive bloating
- Unable to pass wind
- Being sick
Bowel cancer risk factors
Many factors may increase your risk of developing bowel cancer, including genetic disorders and lifestyle choices. Some of the risk factors associated with bowel cancer include:
- Age – approximately 40% of bowel cancer cancers occur in people over the age of 75
- Lack of fibre – around 30% of bowel cancers are linked to a diet lacking in fibre.
- Meat consumption – it’s estimated that 13% of all bowel cancer cancers are linked to eating too much red and processed meat.
- Weight – 11% of bowel cancers are caused by being overweight or obese.
- Smoking – it’s thought that 7% of bowel cancer cases are linked to smoking.
- Alcohol – approximately 6% of bowel cancer diagnoses can be linked to alcohol consumption.
- Genetic predisposition – if you have a first relative with bowel cancer, you are more likely to develop the disease.
- Chronic bowel diseases – if you have a bowel condition such as Chron’s or ulcerative colitis, you may be more likely to develop bowel cancer.
If you fit into the categories above, this does not mean that you will develop bowel cancer – these are just common risk factors that may play a part in cancer development. Eating a healthy diet, reducing alcohol consumption, stopping smoking, and exercising may prevent your risk of developing bowel cancer.
Bowel cancer staging
Bowel cancer is mostly staged using the TNM (tumour, node, and metastasis) system. An oncologist or specialist will look at the size of the tumour, called the T stage, which include:
- Tis – the cancer is in its earliest form in the mucosa
- T1 – the cancer is in the bowel’s inner layer only
- T2 – the cancer has grown into the bowel wall’s muscle layer
- T3 – the cancer has spread into the bowel wall’s outer lining
- T4a – the tumour can be found in the bowel wall’s outer lining and has spread to the abdominal organ tissue layer
- T4b – the cancer has grown into organs surrounding the bowel
The next step is to assess whether the cancer has spread to lymph nodes. This includes:
- N0 – the cancer has not spread to nearby lymph nodes
- N1a – cancer can be detected in one lymph node.
- N1b – cancer can be detected in two or three lymph nodes
- N1c – cancer can’t be detected in nearby lymph nodes, but it can be found in surrounding tissue.
- N2a – cancer can be detected in four to six lymph nodes.
- N2b – cancer can be detected in seven or more lymph nodes
- M0 – the cancer has not spread
- M1a – the cancer has been detected in one other part of the body or organ, such as the liver, but it hasn’t been detected in the tissue that lines your stomach.
- M1b – the cancer has been detected in two or more other parts of the body or organs, but it hasn’t been detected in the stomach lining tissue
- M1c – the cancer has been detected in other parts of the body or organs and has been detected in the tissue lining your stomach.
The final part of staging is related to metastasis which looks at whether the cancer has spread to other body areas outside the bowels. Your doctor may also grade bowel cancer using the number staging system or the Duke’s system.
Bowel cancer treatment
There are a few different treatment options for bowel cancer. At Rutherford Cancer Centres, we provide chemotherapy, proton therapy and radiotherapy for bowel cancer treatment. In some cases, surgery may be offered, and different treatments may be combined, such as chemotherapy and radiotherapy.
Not everyone can have the same treatment because it depends on where your cancer is, how advanced it is and your current state of health. Sometimes, treatment aims to cure the cancer, whilst in more advanced cases, it may be used to relieve symptoms and make the patient more comfortable. Your consultant oncologist will talk you through your options to find the best solution.
Bowel cancer survival rate
One of the biggest questions people diagnosed with bowel cancer have is the survival rate. Generally speaking, 80% of people live for one year post-diagnosis, 60% live for five years post-diagnosis, and 55% survive for ten years. As with most cancers, the earlier they are detected, the better your chance of survival is. However, some cancer can be more aggressive or harder to treat, meaning the chance of survival can be reduced.
Bowel cancer treatment at Rutherford Cancer Centres
The more you know about bowel cancer, the quicker you may be able to spot the signs. This Bowel Cancer Awareness Month, we’re inviting people who think they have symptoms of bowel cancer to speak to one of our expert consultants and enquire about our diagnostic imaging services. Similarly, if you have been diagnosed with bowel cancer and want to explore your treatment options, we are here for you. For additional cancer support, please visit Macmillan Cancer Support.