Essay: Current recommendations for large bowel screening to diagnose bowel cancer

In this essay I will be discussing the current recommendations for large bowel screening, to diagnose bowel cancer, including those categorised as high risk. I will also be discussing the role of imaging in the initial diagnosis and the subsequent follow up.
The NHS have found that bowel cancer is one of the most common cancers in the UK, with around 40,000 new cases being diagnosed every single year. This means that approximately 1 in every 20 people will develop bowel cancer at some point within their lifetime. However, the earlier it is detected, the higher the rate of successful treatment and survival. This is why bowel screening is so important. It has been found that around 90% of those who suffer from bowel cancer are over the age of 60, so therefore it is important to ensure bowel screening is mainly aimed at those of this age range, as they are at a higher risk.
There are two types of bowel screening methods currently used within the UK. These are the faecal occult blood test and bowel scope screening. The FOB test is available to everyone between the ages of 60 and 74. This test is sent out every two years by post and it works by checking if there is any indication of blood in the patient’s stool sample. This is useful as blood in faecal matter can an early symptom of bowel cancer.
The second method of bowel screening is called bowel scope screening. This is a test that only needs to be done once, and is gradually being implemented into use across the UK. It is often used after an abnormal result has been found during an FOB test. According to the NHS, “As of March 2015, about two-thirds of screening centres were beginning to offer the test to 55-year-olds.” This includes both males and females. Bowel scope screening basically involves the patient undergoing colonoscopy procedure to look inside the lower bowel of the patient for polyps, which are small lesions. The doctor or nurse then removes these polyps during a biopsy as they can become cancerous, and result in cancer of the bowel.
It is important to assess and discuss whether or not screening of the bowel is actually viable and a necessity for the NHS to provide, particularly because budget and staff resources are so limited. According to NICE, 2014, the bowel screening programme provided by the NHS, as described above, does meet the UK National Screening Committee’s criteria for an effective and purposeful screening programme. This is a result of evidence provided from 3 RCTs which showed that these screening methods actually reduced the mortality rate of bowel cancer by an estimate of 16%. (Mandel et al, 1993; Hardcastle et al, 1996; Kronborg et al, 1996; Hewitson et al, 2007).
The disadvantages and “possible harms” of the bowel cancer screening programme according to the NHS Bowel Cancer Screening Programme, 2006 include: anxiety, colonoscopy complications i.e. bleeding, bowel perforation and even death, people may also have too much trust in a normal screening result and don’t understand the limitations of screening and that they may still be at risk and as a result ignore potential symptoms. The NHS does try and avoid this though by providing as much information to the patient as possible. Also, as stated before it has been proven that screening methods can reduce the mortality rate by approximately 16%, so any downsides to this screening are outweighed to certain extent, as long as all the measures are taken to prevent any colonoscopy complications and anxieties that are common with this diagnostic investigation.
The complications of colonoscopy which are mentioned above were found during a study by Rabeneck et al, 2008, of 100,000 people between the ages of 50 and 75 years old. This is appropriate as this is the usual age range involved in bowel screening. If there are major contraindications to a colonoscopy, CT colonography may be used. Anxieties related to screening and false hope/ignorance due to a normal result have not been formally investigated as of right now, but it is considered a risk by many experts as mentioned by Rhodes, J.M. (2000) in a “Joint Position Statement” by the British Society of Gastroenterology, the Royal College of Physicians, and the Association of Coloproctology of Great Britain and Ireland.
Imaging is used not just to screen for bowel cancer, e.g. colonoscopy. It is also used during the treatment and follow up if it is found that metastatic growths are present within the patient. During the staging of bowel cancer treatment contrast-enhanced CT of the chest, abdomen and pelvis is often used unless there are major contraindications, in which case MRI is routinely used. These are used to check the spread of metastatic disease throughout the body and diagnose what stage the cancer is at.
After treatment of the cancer patients usually undergo regular surveillance to monitor any recurrence of the cancer. According to NICE guidelines (2011), this is usually at least two CTs within the next three of the chest, abdomen and pelvis, along with other tests such as regular serum carcinoembryonic antigen tests.