Q&A: Dr Siwan Thomas-Gibson

Interview: Viel Richardson
Portrait: Christopher L Proctor

April is Bowel Cancer Awareness Month. What are the signs that people should be aware of?
The bowel can produce a lot of different symptoms; luckily many of them are not suggestive of serious illness. However, there are some that we call ‘alarm symptoms’, and any person suffering from these should visit their doctor as a matter of urgency. These are: bleeding from the bottom, either fresh red bleeding or blood mixed in with the stool; a significant change in bowel movements that persists for more than a couple of weeks; a mass or lump in the stomach area that does not go away; or unexplained weight loss over a period of a few months. Bowel cancer can also cause anaemia, leading to the patient getting breathless or constantly feeling weak or tired.

What is the best way to combat bowel cancer?
Screening is key. With bowel cancer, we are not only looking for the disease, but also its precursors. What I find very exciting is that an effective screening programme can prevent a great many people from developing this cancer at all, as well as helping us to catch it early in others. While we call it ‘bowel cancer screening’, we are also looking for non-cancerous abnormalities that might develop into cancer.

What are those abnormalities?
Bowel cancer usually develops from a growth called a polyp, and these will often go through several stages, from benign through precancerous to cancerous. Polyps can be anything from 2-3mm to 3-4cm in size. One of the most important things about bowel cancer screening, and an important part of endoscopy, is this ability to pick up growths and remove them before they become cancerous.

What tests do you use in the screening?
The screening programme in the United Kingdom makes use of three different tests. There are ‘stool tests’, where the patient provides a stool sample and we check for traces of blood or cancer markers. Another test uses a CT scanner to give the patient what we call a virtual colonoscopy. If that is done well, you can identify even very small polyps. The third method is an endoscopic examination of the bowel, which is my field. This is where we pass a flexible endoscopic telescope through the bowel, visually inspecting it for any anomalies. This can either be a full colonoscopy, where the camera is passing all the way around the bowel, or what we call a ‘sigmoidoscopy’, where you examine the highest risk part of the bowel.  

Are there any side effects or other issues with these tests?
They are all very safe, but as with any medical procedure there will be some drawbacks for different people. Some feel extremely uncomfortable about being asked to provide stool samples, even though we have developed very quick and easy ways of doing so. Also, while they are the least intrusive, stool samples are not 100 per cent accurate and tend to only pick up polyps or tumours that are already bleeding.

Undergoing a CT scan is a bit more invasive, as it involves exposure to radiation and requires a strong laxative to be taken to clear out the bowels. However, it doesn’t involve any sedation and will find even very small polyps. One real advantage is that if the scan comes back and the results are completely clear, you can rule out the possibility of bowel cancer. The disadvantage of this scan is that if a polyp is found, then you will need to return for an endoscopic examination to examine the polyp. An endoscopic colonoscopy is the most intrusive option and also requires a strong laxative. In most cases, it also requires the patient to have some sedation in order to relax enough for the procedure. However, it is extremely accurate and gives us the ability to remove growths we find during that initial examination, so only one procedure is required.

How does a cancerous growth present inside the body?
The bowel wall should be quite smooth, with a uniform colour and some folds along it. An anomaly would usually appear like a raspberry or strawberry protruding from the surface. Often a cancerous growth will be found among a number of non-cancerous polyps.

What do you do with those other polyps?
That will be quite a complex decision, made on a case by case basis. We will always aim to remove all the polyps, but the decision on when and how to proceed will be dictated by the medical priorities. If, for example, there is a very large tumour that is blocking the bowel, the priority will be to remove that and we can return at a later date to remove any non-cancerous polyps.

Is there a demographic that is most at risk?
Bowel cancer is slightly more common in men, but is one of the most common cancers in both men and women. After the age of 50, everyone should consider having some form of screening. While the most common age for developing bowel cancer is in the seventies or eighties, we know that there is an increasing instance of this form of cancer developing in younger people in their thirties and forties. If you’re young and exhibit any of the alarm symptoms, you need to go and see your doctor urgently, as being young is no longer the protection it once appeared to be.

One group of people who are at higher risk, irrespective of their age or lifestyle, are those who have a strong family history of bowel cancer, particularly if it has occurred in more than one first-degree relative, or if a sibling or parents has developed bowel cancer under the age of 50. For these people, screening at a much earlier age than usual, even if they are asymptomatic, is a good idea.

You chair the Joint Advisory Group on Gastrointestinal Endoscopy (JAG). What is the role of the group?
JAG is a multidisciplinary group that was set up to improve the quality of endoscopy throughout the UK. The aim is to improve the quality of training for endoscopists and the quality of experience for patients. Through the group, we are responsible for ensuring high quality endoscopy in every unit, both NHS and private.

How do you do this?
We do it through developing a series of standards covering the quality of endoscopy training, operational competence and endoscopic units. We look at things like, what is the complication rate for individual endoscopists? Too high a rate suggests that they may need extra training to raise their standards. Are the nurses in the units given enough training? Are the endoscopes de-contaminated properly between uses? Is the information that patients are given accessible, accurate and relevant? Every year, JAG-accredited units have to submit data relating to their performance in each area. I am extremely proud of the fact that the group is recognised as a global leader in this field.

What about units that do not have accreditation?
Actually, that wouldn’t happen in the NHS, because bowel cancer screening units and endoscopists have to be accredited. Things are a bit different within the private sector, where JAG has only very recently started the accreditation process. In addition, bowel cancer screening can be performed by any endoscopist in the private sector. The vision is that all private units will gain JAG accreditation, as endoscopy should only be performed in units where the necessary expertise and experience are available. If you are a patient, you want your procedure to be done by an endoscopist in a unit that carries out the procedure on a regular basis. Private medicine does not automatically equal superb quality, but JAG is working hard to raise standards. The endoscopy unit here at The London Clinic is a real exemplar of the best the private system can offer. It is one of the oldest and most established, having been set up by Dr Christopher Williams, a doyen of British colonoscopy, and it has first class staff, using the latest technology.

Looking from your role as chair, are there any areas that need particular attention?
Both in the NHS and private sector, the workforce is a big issue—we are struggling to fill all posts available. That is something that we at JAG are focusing on, especially in relation to employment conditions. If we look after our workforce with great training, good places to work and decent rates of pay, we will retain them, because endoscopy is a wonderful specialism to work in.

What is the direction of travel for innovation in colonoscopy?
The real innovation we are working on is structural as opposed to technical. It is about taking what is an already very effective screening programme and making it better, because there is always room for improvement. We need to be better at getting the message out to at-risk groups, because the wider the system, the more effective it is. And we need to ensure that everything is in place for the examination to go well the first time around—that the patient understands the necessary preparation, so when they arrive, they are well prepared; that they understand the role of chaperones and that we can help to arrange one if necessary; that we have addressed the feelings of embarrassment that sometimes keep people from being screened at all. Technical innovations will always play a part, but real innovation in screening programmes is about efficient and effective communication between the medical world and the patient and between the clinicians themselves.

What do you like most about working in the world of endoscopy?
I was attracted by the fact that colonoscopy is a very difficult technique—mastering the dexterity needed to operate the telescope and negotiate the anatomy of the bowel are challenges I really enjoy. It is also different every time—in fact, even for the same patient, two examinations can be very different. In the vast majority of cases, I can talk to my patients, which is a really pleasing aspect of the procedure. I always say that colonoscopy is a true team effort, with the patient being part of the team.

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