Approximately 80 per cent of bowel cancer cases develop in people aged 60 years and above. Two thirds of bowel cancers develop in the colon, with the remaining third developing in the rectum. Many patients visit the doctor for the first time when their cancer is already at a very advanced stage and has spread to the liver and other organs. Unfortunately, such patients die within a year, despite the best possible treatment.
Risk Factors For Bowel Cancer
- Eating a high-fat diet
- Bowel conditions like Crohn’s disease and ulcerative colitis
- A family history of bowel cancer
- Alcohol misuse
- Excess smoking
- Blood in stools and/or bleeding from rectum.
- A change in normal bowel habits that persist for more than six weeks, such as diarrhoea, constipation, or passing stools more frequently than usual.
- Persistent abdominal pain.
- Unexplained weight loss.
- In some cases, it can also cause an obstruction in the bowel.
Origin And Spread
- Most cases of bowel cancer first develop as clumps of cells on the inner lining of the bowel. These clumps are known as polyps. (But development of polyps does not necessarily mean that you will get bowel cancer.)
- Bowel cancer can spread through the walls of the bowel into nearby lymph nodes.
A doctor will carry out a physical examination known as digital rectal examination. It involves the doctor gently placing his finger into the anus, and then up into the rectum, trying to feel any lump. In further examination, the tests that are used to confirm diagnosis of bowel cancer are:
- Colonoscopy – the examination of the entire large bowel.
- Barium enema - a type of X-ray to study the bowel in more detail.
Further testing will be done if the diagnosis of bowel cancer is confirmed. It is usually carried out for two reasons: To check if the cancer has spread from the bowel to other parts of the body and to help decide what will be the most effective treatment. The tests may include:
- CT scan and MRI scan - to provide a detailed image of the colon.
- Ultrasound scans - to look inside other organs, such as liver, to see if the cancer has spread there.
- Chest X-rays - to assess the state of the heart and lungs.
- Blood tests - the cancerous cells release a special protein, known as tumour marker, which can be detected through a blood test.
Staging And Grading After Diagnosis
At the completion of these examinations and tests, it should be possible to determine what stage and grade the cancer is. Staging refers to how far the cancer has advanced, and grading relates to how aggressive the cancer is and how likely is it to spread.
Bowel Cancer Treatment And Management
A multi-disciplinary team comprising a number of specialists is necessary to treat bowel cancer. They include gastroenterologist-physician cum surgeon (a specialist in bowel surgery), clinical oncologist and specialist in the non-surgical treatment of cancer.
The recommended treatment plan will depend on the stage and location of the bowel cancer.
Radiotherapy In Two Ways
- If the cancer is confined to the rectum, radiotherapy will 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 it is a very early stage bowel cancer, it should be possible to surgically remove the cancer with no requirement for any further treatment. But this is uncommon because most patients are diagnosed very late.
Radiotherapy given before surgery for rectal cancer can be performed in two ways:
- It is given before surgery, in cases ofrectal cancer.
- It is used to control symptoms andslow the spread of cancer, in casesof advanced bowel cancer (whereit is also referred to as palliativeradiotherapy).
- External radiotherapy - a machine is used to beam high energy waves at the rectum in order to kill cancerous cells.
- Internal (known as brachytherapy) - a radioactive tube is inserted into the anus and placed next to the tumour to shrink it.
CT scan and MRI scan will provide a detailed image of the colon
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 begun to spread into the muscles surrounding the colon, it will usually be necessary to remove an entire section of the colon. Removing some of the colon is known as a hemi-colectomy. Depending on the location of the cancer, possible surgical procedures are undertaken.
- Open colectomy - where the surgeon makes a large incision in your abdomen and removes a section of your colon.
- Laparoscopic colectomy - a type of ‘keyhole’ surgery to remove a section of the colon.
It is done in 3 ways. It can last up to 6 months.
Chemotherapy comes with all its known side effects. To mention are fatigue, nausea, vomiting, diarrhoea, mouth ulcers, hair loss, redness and soreness on the palms of hands and soles of feet, sensation of numbness, tingling and/or burning in hands, feet, and neck. These side effects should gradually pass when treatment is finished. It usually takes between three and six months for your hair to grow back.
- Before surgery for rectal cancer in combination with radiotherapy,
- After surgery to prevent the return of cancer.
- To slow the spread of advanced bowel cancer and to help control the symptoms.
Follow Up Treatment
Almost all survivors of colon cancer require some kind of follow up treatment through the rest of their lives. It is because of the definite possibility of recurrence. Repeated colonoscopy is the single best investigation to detect the recurrence of colon cancer. A recurrent colon cancer too can be treated successfully, if detected early.
"Survivors of colon cancer require some kind of follow up treatment for life"