Episode Transcript
[00:00:09] Speaker A: Hello listeners, My name is Dr. Jabed Ahmed. I am a gastro trainee from North West London and a member of the BSG Education Committee.
Welcome to the BSG Podcast From Top to Bottom.
This is a new podcast series from the BSG where we will be speaking to authors involved in various BSG guidelines which are available to our BSG members.
We hope these episodes will provide a new way to stay up to date with the latest guidance coming out.
Almost all colorectal cancers arise from polyps, but only a small proportion of polyps progress to colorectal cancer progression usually follows a timeline of at least a decade and the endoscopist cannot predict which polyp will progress. So the usual practice is to remove all that is detected.
In healthy patients, the risk from over treatment is small, hence the balance favors polypectomy.
In people whose life expectancy is less than 10 years, the likelihood of over treatment increases.
Today I'll be speaking to Dr. Ravi Rajan who is a Consultant Gastroenterologist at the University Hospital of North Tees and a Research Fellow at Newcastle University.
He is one of the authors of the joint BSG and ACP GBI guidelines on management of colorectal polyps in patients with limited life expectancy.
The guidelines provide evidence based and pragmatic recommendations on how to approach this group of patients.
We will cover how the guidance was produced, the recommendations and other important factors that we need to be aware to implement this guidance effectively.
Dr. Ranjan, thank you for coming onto the podcast.
[00:01:46] Speaker B: Thank you very much for inviting Right.
[00:01:48] Speaker A: So we will dive right in. So first question, why do you think this guidance was needed to be created?
[00:01:56] Speaker B: So this guidance is for people who have got limited life expectancy or life expectancy of less than 10 years. The need for this guidance was because we have got a more aging population and more and more people with more comorbidities get more investigations done because of availability of investigations and increasing safety of investigations.
At the same time, the risk of complications from invasive investigations or invasive procedure goes up in such people who have got multiple comorbidities.
But for the clinicians, the endoscopists who do colonoscopy and polypectomy, it becomes a little bit difficult to plan management for these patients. So for example, if a frail patient has a colonoscopy for whatever reason and is found to have a polyp, you, the endoscopists need to make that decision about removing the polyp.
In absence of any guidance, it's very difficult for an endoscopist to make an informed decision along with the patient about the risks and benefits of removing the polyp as well as the risks of not removing the polyp due to increasing aging population. Due to increased availability of investigation, more and more such polyps are being found in these patients.
And due to no national or international guidance that management is not standardized across the country.
It does need to be individualized anyway. But due to absence of a clear cut guidance, people do it based on either their own experiences or their own perceptions of risk. This guidance aimed to provide an objective evidence of where the risks and benefits stand and to provide a standardization to help make that decision and to have that discussion with the patient.
[00:03:52] Speaker A: And could you tell us a bit more about how these joint guidelines were created and what is the importance of a multidisciplinary guidance development group?
[00:04:01] Speaker B: So this guidance was created with the help of a guidance development group or a Delphi panel which included specialists from different subspecialties such as gastroenterologists who do most of the endoscopies, colorectal surgeons who also do endoscopies and deal with the complications after if a complication happens in a polypectomy.
We had elderly care physicians who have got a better understanding of comorbidities and life expectancy. There were epidemiologists who could help us make some decisions about the prevalence of cancer and the risks.
We had general practice practitioners who look after people more holistically. We had clinical endoscopists, also called as nurse endoscopists, who also do lots of such colonoscopies.
And we had some anaesthetists who are also very good at judging risks from a major surgery if it's required.
[00:04:58] Speaker C: There were patient representatives as well.
[00:05:02] Speaker B: There was a team of 26 such specialists and we all had three rounds of discussions of our Delphi panel.
We started by proposing some statements based on some research I had done as a part of my MD and some research we had done as a group, such as judging the dwell time of the polyps or sojourn time of cancer once it has developed in a polyp.
Some research about how we calculate life expectancy and what life expectancy score would be practically possible to do on this group of patients and the risk of complication from polypectomy, etc.
We did a qualitative study where we discussed with the endoscopists on what are the difficulties they find in management of polyps in patients with limited life expectancy. And based on all these research and information we got from these, we created Some draft statements.
These were discussed in our Delphi panel meeting and there were three rounds of discussion and three rounds of voting which led to formation of these 33 statements.
[00:06:10] Speaker A: And what are the factors that change the risk benefit ratio for polypectomy for elderly patients?
[00:06:16] Speaker B: So there are a few things to consider there.
One, we need to consider what's the risk of a polyp turning into cancer in that patient's lifetime, especially if their lifetime is short or reduced. And here we are talking about people whose lifetime is less than 10 years.
We need to consider what are the risks of doing a polypectomy, or what are the complications which can happen during a polypectomy. And also equally very important, what would be the consequence of a complication of a polypectomy. When I say complication, I'm talking about risk of perforation, risk of bleeding, or risk which is posed by the bowel prep or the procedure itself.
Just for an example, if a relatively fit and young PACE patient, say for example, a 60 year old person, gets a perforation due to a large polypectomy, their chances of recovering from it are much higher than an 80 year old if they get a perforation.
So even though we may quote a perforation rate of 1 in 2500, the consequence of that perforation would be very different for a patient with multiple comorbidities or frailty.
So when we developed this guidance, we took into account the risk of complication as well as the consequences of the complication as well.
And putting that together with the risk of a polyp causing a cancer in that patient's lifetime, we are trying to generate a balance of where the risk of complication or consequence of complication of a polypectomy is higher than the risk of the polyp actually causing any problem in that patient's lifetime.
[00:07:58] Speaker A: Thank you.
The guidance emphasizes the tailoring the decision making to the individual.
Are there any patient groups this guidance will not apply to?
[00:08:08] Speaker B: So yes, there are certain groups where this guidance is not really applicable. For example, for the patients who have already developed the colorectal cancer, this guidance is not made keeping them in mind. So this guidance shouldn't be used for those patients. Similarly, for patients who have got any accelerating factors for polyp growth, this guidance doesn't apply to them. Example of accelerating factors would be presence of inflammatory bowel disease or any genetic syndromes which make them predisposed to forming or increasing polyp or even recurrence of polyp at a previous polypectomy site.
[00:08:44] Speaker A: And in what instances in these patients should you consider non invasive investigations and potentially no therapy?
[00:08:52] Speaker B: So that is a very good question because a part of this guidance also talks about appropriateness of investigation.
If we do an investigation like any other investigation, we should have a clear outcome planned as well.
For example, if we do a CT colonogram, which would be the non invasive investigation for polyp detection, we should think about what will we do with the results if a patient is not fit for a colonoscopy or if the colonoscopy is deemed to be too high risk for a patient.
If a CT colonogram shows us that there is a, for example, 10 millimeter polyp, what will we do about it? Would we offer the patient a surgery because we thought colonoscopy was high risk? The surgery would be high risk as well.
So if we are planning an investigation, we should think about what will we do with the results and will it actually benefit the patient. It may sometimes be appropriate to do an investigation for prognostic purposes. For example, if we want to know whether there is a cancer or not.
But the threshold of the therapy at the outcome of investigation needs to be discussed with the patient beforehand. For example, we can talk to the patient and say, look, we are going to do a scan to look for colorectal cancer. We may find incidental polyps, but we would not need to do anything about it.
And sometimes there may be chance even doing a fit test.
We need to talk to the patient that if this fit test is positive, we, we would go on looking for cancers.
Do we need to do that investigation? Especially if a patient is not fit enough to undergo an intervention, we can have that discussion beforehand to say, look, even if we find something, we won't be able to do anything about it.
So doing this investigation would only be for prognostic purposes. It won't do you any good. And you may have a group of patients who may not want any investigation at all. So these discussions should be held at quite an early stage, preferably in the primary care, which is something we have recommended in our guidance.
[00:10:55] Speaker A: You have mentioned quantification of life expectancy of an individual is challenging. How did you go about this in the guidance?
[00:11:03] Speaker B: So indeed, life expectancy calculation can never be accurate.
It would be imprecise.
And there are several different calculators.
There are some frailty indexes and then frailty doesn't always equate to life expectancy, but it gives us a fair idea of which patients are at higher risk of having a short life expectancy.
So we have recommended that frailty indexes and usually there is a clinical frailty score or E Frailty Index. These can be used to identify the patients at the very beginning when they're being referred for an investigation with a colonoscopy.
The patients with risk of short life expectancy can be identified there. And if the referring clinician or for example a GP feels that some patient, a patient has got high frailty index, they should calculate their life expectancy. And we have recommended using Charles and Comorbidity Index for doing this. The reason we picked this Charles and Comorbidity index is because it's easy to apply. The questions it asks can be easily answered by looking into patient's record or if you have got the patient in front of you, the patient can easily answer those questions.
This is also available online and it doesn't take more than two minutes to calculate that index. So it's quite easy to use, quite easy to apply and it has been validated in a UK based endoscopy user population.
Now, Charleston Comorbidity Index gives a possible 10 year life expectancy in percentage.
There's also another life expectancy calculator called Gagne's Life Index which gives one year mortality and this is also based on Charleston Comorbidity Index. We used annual life expectancy based on the calculator of the Charleston Comorbidity Index and we use that in our modeling work to know the risk of a cancer progressing, a polyp progressing to cancer in that patient's lifetime.
Now, we have stressed a few times that you would get a number from the Charleston Comorbidity Index. It's never absolute.
There are many factors which the indexes don't count, but what it does is it gives us a objective value to start a discussion with the patient about their life expectancy and mortality.
We always have to remember polyps are not cancers in themselves, unless we have proved it that way and we remove polyp to remove the risk of cancer in future.
And that's where it becomes important is how long the future we are looking into and for people with short life expectancy, we are only looking into as long as their life is remaining. So if it's less than 10 years, if the polyp is unlikely to cause any problems in 10 years doing a polypectomy, we will be exposing those patients to the risks of polypectomy without offering them any benefit.
So life Expectancy index must be used with a bit of caution.
It gives us objective value, it gives us a starting point for discussion, but it's not absolute.
[00:14:19] Speaker A: And how did you calculate the average annual cancer transition rate for various polyp sizes?
[00:14:27] Speaker B: So we used the published evidence up till now. I did a systematic review of all the published literature about polyp growth time.
It is a bit difficult to calculate such estimate because we do not watch the natural progression of polyps. If we see a polyp, it's just removed.
There are some older studies when endoscopy was not as advanced.
So in 70s there is a study by Steiker where the polyps were monitored radiologically till they reached a certain size. And when they reached a certain size they were removed mostly by surgery.
Those studies give us an idea of how quickly or how slowly the polyps grow.
In recent times there are some modeling studies which is based on statistics and assumptions and then modeling it, which gives us a fair idea and probably that's the best possible evidence we can get, which calculate the dwell time of the polyp, which is the time from polyp inception to progression of cancer in the polyp.
And then also once there is a cancer in the polyp, the time that takes to manifest clinically, which we have called sojourn time of cancer. That can also be calculated in more recent times. There is a study by Brenner which looks into 3 to 4 million German population undergoing colonoscopy. And they have used some modeling work as well to give us an annual transition rate of cancer. And because of such a large number of patient, it is pretty reliable.
There was also this Nordic trial where they looked into incidence of cancer in the colonoscopy population.
And from that we can calculate that on an average, from the time there is a cancer developed in a polyp to the time it actually shows clinically is about three years, even going up to six years.
So based on the polyp dwell time, which is the time from polyps beginning to polyp turning into or polyp growing malignancy within the polyp and cancer sojourn time, which is cancer developing in polyp to cancer actually clinically manifesting.
This allowed us to calculate the annual transition rate for the polyps or polyp to symptomatic malignancy.
[00:16:47] Speaker A: The guidance mentions using SMSA scoring. Is there a role for NICE and JNET classifications in understanding the risk in this cohort?
[00:16:57] Speaker B: So NICE and genetic classification would help us to know presence of dysplasia or malignancy in the polyp itself. And we do recommend in the guidance that the polyps, especially the ones which are diagnosed endoscopically, should Be carefully assessed for surface characteristics of cancer. For example, if it's JNATE3, then you know that you're dealing with the cancer where this guidance doesn't apply at all.
So there's definitely a role for nice, Genet or even Kudo if it's being used to assess the surface of the polyp. Because before applying this guidance, we need to be certain that there is no cancer in the polyp. Already having said that, as I was just saying that even if there is a cancer in the polyp, it still takes a certain length of time before it would clinically manifest. But having that discussion with the patient about removing such a polyp, it would be useful to have that discussion with this background that even if there is a cancer in the polyp, it would still take three years or up to six years before it manifests. So certainly NIAC and Genet are important in assessing that surface pattern. The smsa, on the other hand, also assesses difficulty of the colonoscopy and difficulty of the polypectomy, because the risks of polypectomy increase with difficulty of the polypectomy. So larger size means larger risk of perforation or bleeding. Difficult access just means that risk of incomplete excision, etc.
[00:18:25] Speaker A: And how did you calculate the risk of polyp complications?
[00:18:30] Speaker B: So risk of polyp complications didn't really need to be calculated. It was just picked from the English Bowel Cancer Screening Program. Complication rates.
All units tend to keep a record of their own complication rate with national Bowel Cancer Screening Program involving a large number of patients. And the data from there is fairly reliable.
[00:18:52] Speaker A: So, coming onto your new guidance, could you go through the conservative and polypectomy models that you use to help create your decision aid in the form of the table of recommendations?
[00:19:03] Speaker B: So yes, we did a modelling work and in the modeling work there were three aspects. One is life expectancy of the patient.
Other was risk of progression to cancer in the polyp, which the patient has.
And the third is risk of complication from the polypectomy itself.
Now, for the life expectancy we just use the Charleston Comorbidity index for conservative management model and the risk of cancer developing in the polyp.
Each model started with a clinical scenario of a cohort of 1,000 patients with a particular size polyps and a particular Charleston comorbidity index score.
For example, a polyp sized 10 to 19 millimeter with a Charleston comorbidity score of 5.
The model then used the health states to represent all possible outcomes and events that can occur to the simulated individual.
For example, again, the health states were a baseline polyp which has not got any malignancy, a polyp with a cancer in it, which fell into three categories. So one is preclinical cancer year one, which means that there's cancer in polyp, but it hasn't spread. And that's the first year.
What I was talking earlier, we had the assumption, based on the evidence that cancer in the polyp takes three years before it clinically manifests or spreads. So the preclinical cancer year one other health state was preclinical clinical cancer year two, and the third was preclinical cancer year three.
And the next health state was clinical cancer and the final health state was patient died.
An annual cycle was then applied, at the end of which the simulated individual either remained in the polyp stage or pre clinical cancer year one could progress to either death or preclinical cancer year two, and preclinical cancer year two could progress to preclinical cancer year three or to death.
So the whole model ran about the risk of cancer in that cohort of 1,000 patients.
And then we applied the risk of polypectomy to these patients for each year. So if we did a polypectomy based on the data from bowel cancer screening, just to give you an example, for a polyp between 10 to 19 millimeter, the risk of significant complication requiring hospitalization is 25 out of 1000.
If the patient is on antithrombotic medication, the risk goes up to 75, so multiplies threefold.
And then we combine these models to develop a table which you can see in the guidance document, which tells us what's the risk of progression of malignancy in that patient's lifetime and what's the risk of complication of doing a polypectomy for a polyp of certain size.
[00:22:05] Speaker A: Thank you.
You also have a helpful table explaining the role specific recommendations. Could you kindly summarise this for the listeners?
[00:22:13] Speaker C: So the role specific recommendation has got two sections. One is at the time of diagnostic referral where we have recommended that the referer should consider comorbidity and frailty when discussing referral with the patient. And if the referral is appropriate, frailty score and Charles and comorbidity index should be included. If possible, the endoscopy booking team or admin team should collaborate with the clinical team to create a process for identifying the patients with frailty or significant comorbidities who need to be escalated to the clinical team for review. The pre assessment team can then identify these patients, calculate their frailty score and Charles and comorbidity index and refer the appropriate patients for further assessment and discussion of options.
These patients should then be assessed in a clinic, their scores calculated and discuss the possible options with them considering conservative management when it's suitable, or to decide which test is appropriate and plan a management ceiling with them. The second part of the table talks about post diagnostic procedure polyp management decisions. For example, for the polyps which have been diagnosed but not removed, which is often the case for complex polyps which are diagnosed on routine colonoscopy. We have recommended that these patients being referred to polyp MDT should have a Charles and comorbidity index calculated and utilize the guidance document to decide what's the most appropriate management strategy and then to have this discussion with the patient in a clinic and to agree on some shared decisions here. I would also like to talk about how to use this rag table which is presented in the guidance.
[00:24:02] Speaker B: This table probably summarizes the whole guidance.
It has got lots of information on it, but all that information is quite helpful in having a discussion with the patient.
And there are two tables. One table is for the patient who are patients who are on anticoagulation and one table is for the patients who are not on anticoagulation.
On the top axis or the x axis of the table we have got different polyp sizes and on the vertical axis we have got patients with different chance and comorbidity indexes. It's a rag table. So some boxes are in red, some are in green and some are in amber.
The red boxes are the ones for the patients where the risk of polypectomy are much higher than the risk of progression to cancer.
Green is where risk of polypectomy is lower than the risk of progression to cancer and therefore polypectomy is recommended.
Amber is where both these risks are almost similar. So either option would have equal risks. So there's basically no risk free option. There's always some risk. It's all about balancing which risk is higher and which risk is acceptable.
For an example, if a patient with Charleston comorbidity index of 5 if they have got a bigger than 20 millimeter polyp and they are on anticoagulation. If you look at the table, the adverse Event risk is 135 out of 1000, but the risk of them having a malignancy in their lifetime, which should be roughly closer to 6 years, is 161 out of 1000 so here we are comparing 161 out of 1000 risk of cancer to 135 risk of adverse event.
Now, considering adverse event would happen then and there at the time of polypectomy or closer or just after the time of polypectomy, the risk of cancer is in their lifetime, which is over next five to six years.
The numbers are quite close to each other. So we have said this either option has got similar risks. And that's where the discussion with patient becomes important on what is important to the patient, what risk are they willing to take?
This guidance doesn't tell us what to do, it doesn't dictate us what to do. This guidance is just to facilitate a discussion with the patient in order to reach an informed decision where all the risks accepted by the patient or the clinicians and they have got some evidence to support it.
[00:26:44] Speaker A: Thank you.
And what does the guidance say about follow up and surveillance for these patients?
[00:26:50] Speaker B: So that is a very important aspect of this because we are talking about patients with limited life expectancy and any investigation would have some consequences, even if it's psychological or anxiety.
We need to think about what benefit are we offering by doing any follow up.
We have recommended that if the decision is to do a conservative management for a polyp based on this guidance, these patients do not really usually require follow up because with passage of time, the reason for doing conservative management would be even stronger.
And similarly, if a patient has had a polypectomy, the surveillance would not really offer any benefit because the benefit surveillance offers is over a period of up to 10 years of time. And we are talking about people whose life expectancy is already less than 10 years. So by doing more invasive surveillance, we'll just expose them to more risk without offering them any benefit. But again, as I said, this guidance doesn't dictate us on what to do. This is a discussion to be had with the patient. Because if the patient is very anxious and if doing surveillance helped elevate their anxiety, a non invasive investigation can be considered. For example, a conservatively managed polyp in a very selected patient, mainly for their psychological well being, if required, can be surveyed. But in general it's unlikely to offer any benefit.
[00:28:22] Speaker A: And I think you've emphasized already the importance. But could you please summarise the key messages regarding patient communication for these decisions?
[00:28:31] Speaker B: Absolutely. As we have been talking throughout this interview, that this is all about shared decision making, informed shared decision making with the patient. The guidance presents the risks and benefits, but we have to remember this is all based on a statistical model and people can be on the wrong side of statistics. So you cannot say with certainty to anyone that you would not have a complication of procedure or you would not have a cancer if you don't remove a polyp. This just tells us what are the risks or what are the chances of people having a cancer in their lifetime or people having a complication in their lifetime. So this discussion needs to be quite frank and clear with the patient and it needs to be individualized. So you may have a patient who is more anxious about risk of stroke by stopping anticoagulation because they have had a stroke in past and they do not want to accept that risk of stopping anticoagulation even though the guidance suggests that they should have a polypectomy. We need to respect that patient's own fears and patient's own perception of risk.
Other way around, this guidance may suggest doing conservative management, but the patient may have had a bad experience due to a family member having a colorectal cancer and they are not willing to accept that risk of cancer. So this table just helps in that discussion, but it doesn't tell us or dictate us on this is what you should do. It just gives a recommendation. The decision ultimately needs to be individualized to the patient and should be between the patient and the clinician.
[00:30:02] Speaker A: Thank you. And final question. What are your take home messages for our listeners you'd like to give for these guidelines?
[00:30:10] Speaker B: So I think one big take home message, especially for the polyps, is that sometimes doing nothing is wise.
Just because we are trained to remove polyps doesn't always mean that we should remove polyps. During these discussions we had with our Delphi team and the qualitative study, someone said that if you have got a hammer in the hand, everything looks like nail to you.
Similar thing can be said for the colonoscopist. You've got a scope in your hand. Every polyp you want to just remove. But we should sometimes in patients with comorbidities and short life expectancy, need to pause and think. Do we necessarily need to remove this polyp? And are we going to offer these people any benefit or are we just exposing them to risk?
[00:30:57] Speaker A: Thank you so much Dr. Ranjan for speaking to me today on the BSG podcast From Top to Bottom. I'm sure I speak for our listeners when I say this guidance will definite be helpful in our day to day practice. And thank you again.
[00:31:09] Speaker B: Thank you very much for giving me this time and opportunity and thank you to our listeners.
[00:31:13] Speaker A: Please check out the other episodes available and keep a lookout for upcoming new episodes very soon.
