Bowel Cancer

Diagnosing Bowel Cancer

Patients diagnosed with bowel cancer in its earliest stage have a good prognosis and the vast majority of patients can be cured, usually with surgical treatment.

There are several tests that may be conducted if Bowel Cancer is suspected. Usually, when people are worried, they speak to their GP, who will organise tests:

• FIT (Faecal Immunochemical Test) is usually the first test. FIT is a screening tool used to detect hidden blood in stool samples, which can be an early sign of bowel cancer. The test is simple and can be done at home by collecting a small sample of your stool and the GP sends it to a lab for analysis.
• Blood tests may also be organised to look for blood loss (measuring iron deficiency or anaemia) or elevated tumour markers (CEA)
• The GP may also perform a rectal exam, here they will insert a gloved finger and feel for any lumps that might suggest polyps or even a tumour. Unfortunately, this test would only reach the first part of the bowel (the rectum)

Not everyone with a positive FIT test has bowel cancer, but not everyone with a negative FIT test is cancer free. Sometimes the GP will not refer onto further screening, but a patient feels strongly they would like further investigations. Dr Andy Gaya recommends two approaches:

• Bupa and other companies offer excellent generalised health screening Private cancer screening tests | Bupa UK
• Trucheck is an advanced Multi Cancer Early Detection Blood test which can detect a variety of cancers at an early stage from a blood test Trucheck™ cancer test from blood in healthy people | Trucheck™.

It is important to note that there is no 100% accurate screening test, and whilst negative screening tests are reassuring there can sometimes be “false negatives” which is why screening tests are repeated every few years.

If any of these tests suggest that bowel cancer might be present, then the patient is referred to a hospital gastroenterology unit for more in depth examinations of the bowel. These involve inserting equipment into the back passage to take a look at the bowel and even take biopsies to check for cancer. The two main checks are:

• Flexible sigmoidoscopy – Examines the last part of the bowel (patient needs an enema before the procedure starts)
• Colonoscopy – Examines the entire colon with a camera – this needs full bowel preparation beforehand to empty the bowel of all poo

Once bowel cancer is diagnosed the patient is usually scanned so their doctors can see if the cancer has spread to other parts of the body. The most common scans are:

• CT Scan – This scans the abdomen and pelvis to determine the stage of the bowel cancer, and look for any signs of lymph node involvement or if cancer has spread to other places
• MRI Scan – Done for rectal cancer to give the surgeon and oncologist a better idea of what type of surgery is required, and whether radiotherapy is needed. It helps to determine whether a temporary or permanent stoma is needed. Sometimes liver MRI is done too if there is a concern about spread to the liver
• PET scan – If there is concern about cancer spread, this scan is often performed to look for involved lymph nodes or spread to other organs.

The common type of bowel cancer (from the glandular cells) is known as adenocarcinoma. There are other, much rarer types too, such as neuroendocrine tumours, squamous carcinomas, gastrointestinal stromal tumours (GIST) and melanoma and lymphoma.

Bowel cancers behave slightly differently depending on where in the colon they are situated, which greatly affects which treatments will be most successful.

Put simply, the bowel is divided into ‘left colon’, ‘right colon’ and the rectum. The right colon is where the bowel starts and from here waste passes up and along (ascending and transverse colon). The left colon is the last part of the bowel where waste travels down towards the rectum (descending colon). The rectum is the last part of the bowel where waste is stored until the person gets to the toilet.

Cancer doctors have made the following observations about bowel cancers (although everyone is different and this is why personalised medicine based on your exact cancer type is vital):

• Left Colon Cancer: less likely to be genetic than right sided and sometimes aggressive
• Right Colon Cancer: more likely to be genetic, respond differently to chemotherapy than left sided.
• Rectal Cancer: less likely to be genetic

Doctors also stage or grade cancer to guide the best treatment plan for a patient. In Bowel Cancer its ‘stage’ is categorised as follows:

• Stage 1 – Tumour is confined to the inner surface of the bowel or muscle only with no invasion into the deeper layers of the bowel
• Stage 2 – Tumour grows through the muscular layer into the fatty tissue around it, or sometimes the complete thickness of the bowel wall. All lymph nodes clear
• Stage 3 – Tumour involving the bowel wall but also local lymph nodes
• Stage 4 – Tumour has spread to other organs or distant sites