Updates in Colorectal Cancer Screening Methods

Podcast Transcript

Dr. Scott Steele: Butts and Guts, a Cleveland Clinic podcast, exploring your digestive and surgical health from end to end.

Hi again, everyone, and welcome to another episode of Butts and Guts. I'm your host, Dr. Scott Steele, the chair of colorectal surgery here at the Cleveland Clinic in beautiful Cleveland, Ohio. And today, I'm extremely pleased to have Dr. Carol Burke here who is a world-renowned Gastroenterologist in the Department of Gastroenterology, Hepatology, and Nutrition at the Cleveland Clinic and Section Head of the Sanford R. Weiss MD Center for Hereditary Colorectal Neoplasia. Carol, welcome to Butts and Guts.

Dr. Carol Burke: Thanks so much for having me, Scott. And this is really great because March is Colorectal Cancer Awareness Month, so perfect timing.

Dr. Scott Steele: Fantastic. So today, we're going to talk a little bit about some updates in colorectal cancer screening methods. And I know the listeners out there who are repeat offenders know the deal, but for you as a first time guest here, tell us a little bit about your background. Where were you born, where'd you train, and how did it come to the point that you're here at the Cleveland Clinic?

Dr. Carol Burke: Thank you. Actually, I'm local. I was born in Mayfield Village, Ohio. I was raised there. I left high school a little bit early because I wanted to be a ski instructor during the day and a cocktail waitress at night, so I only applied to the University of Colorado and was on their ski team. Lived in California for a bit, had many jobs, eventually ended up at Ohio State University for medical school, residency at Riverside Methodist Hospital in internal medicine, and GI Fellowship at the Cleveland Clinic where I've been ever since the last 32 years.

Dr. Scott Steele: Well, we are so lucky to have you here. And so today we're going to be talking a little bit about the importance of colorectal cancer screenings and how they can help detect and many times hopefully prevent colorectal cancer. So just overall, to start, can you touch on who exactly should be receiving colorectal cancer screenings?

Dr. Carol Burke: The people that should get colorectal cancer screenings are average risk asymptomatic people that are the ages of 45 to roughly 75. And why am I calling out average risk asymptomatic individuals? Because the important thing about prevention of colorectal cancer is that if we detect polyps and prevent them or we detect early colorectal cancer when it's not symptomatic, then potentially it's curable. So people can either not develop colorectal cancer and not die from it if it's detected in its early stages. And that's in contrast to individuals that actually have symptoms or a family history of colorectal cancer. I know we'll talk a little bit about colorectal cancer symptoms. But for individuals that are experiencing some type of symptom or have a family history of colon cancer, those individuals are not average risk individuals, and they may need some type of evaluation, mostly colonoscopy to look at their colon and determine their risk.

Dr. Scott Steele: So that dovetails nicely into my next question. First of all, when people hear the term screening, what does actually screening mean? And then you've mentioned it a little bit, but what are the signs of colorectal cancer that people should be paying attention to?

Dr. Carol Burke: Great. Two questions. Let me start with the latter one. So the symptoms of colorectal cancer importantly may not have any symptoms when early. So that's the importance of screening, is doing a test to look to see if there is something that is turning into cancer or is early cancer. But symptoms that should not be dismissed include unexplained abdominal pain, change in bowel habits, unknown causes for iron deficiency anemia, gastrointestinal bleeding, whether that's bright red blood and rarely dark tarry stools, unanticipated weight loss. So those are some of the signs of colorectal cancer. But again, I wanted to point out that it's better to actually have screening, the test to determine if there are polyps or cancer, before symptoms develop. And when cancer is detected at an early stage, is curable.

Dr. Scott Steele: So, Carol, we've seen a little bit about the rise in popularity around stool-based tests like Cologuard, for example. Can you tell us a little bit more about the difference between a fit test, blood test and the stools, colonoscopies, these Cologuard tests? How do they all fit in?

Dr. Carol Burke: Yeah, it's really important to think about and discuss with patients these options because only 68 to 70% of Americans that are eligible for colorectal cancer screening have undergone screening, which is really unfortunate because the disease is preventable.

And so there's a variety of things from tests that require potentially two steps to tests that require one step. So for years and years and years, the earliest study done in the 1980s was looking at a stool test for blood, and that was called a fecal occult blood test. And it has been shown that it decreases both the incidents, as well as death from colorectal cancer, been around a long time and basically has been supplanted by another stool-based test called fecal immunochemical testing. The beauty of this other stool test is that it is an antibody that's checking for human globin evidence of human bleeding only from the colon, whereas the fecal occult blood test was a three stool sample test which looked for indirect evidence of blood by an enzymatic reaction.

So the fit test is where we're at today for a fecal blood test, and that is basically a small spear on the test itself that you stab your stool with, and then send it to the lab. So either of those tests are done annually. The newer kit on the block is called a multi-target stool DNA test. And I'm not going to say any commercial names. You mentioned the commercial name of the dancing box, but in fact, that test and more are becoming available, looks not only for blood in the stool with a fecal immunochemical test, but is also looking for changes in DNA, which is genetic material that's shed into the stool that could be a sign of either polyps or cancer. And then things that have fallen out of favor include a sigmoidoscopy, which is just a short scope up maybe a third of the way around the colon. And I always liken that to a mammogram and only having one breast checked rather than having both breasts checked.

And the single test that as a gastroenterologist and colorectal surgeons that we oftentimes are advocating is colonoscopy. Now, that requires a bowel preparation. Patients can be sedated. Most of them are. Some patients don't want sedation. But that is where the scope looks all the way around the six feet of colon and can detect polyps and cancer. And if polyps are detected, can be removed to prevent cancer. And the difference between the stool-based tests and the colonoscopy is if a stool-based test is positive, which could imply that you have early colon cancer or late colon cancer, even a polyp, they're not very good at detecting polyps, you need to move on to a colonoscopy to figure out why that test was abnormal. And then pretty soon, we will be having FDA-approved blood tests. So there are some results from blood testing where we're looking for changes in the bloodstream that might suggest cancer or polyps, but those are not ready for primetime yet. But I suspect within the next year or two, those will be available so we can get all of the eligible individuals in the United States that should have screening screened.

Dr. Scott Steele: So, Carol, can you talk about any other screening options available? We know about maybe some radiology tests that are a little bit older, maybe some of the new CT-guided colonography. Tell our audience a little bit about those.

Dr. Carol Burke: Yeah, sure. There are two other imaging modalities. One is the CT colonography. There was a large trial many years ago that actually compared colonoscopy to CT colonography, and that's basically having a CAT scan. It's a very quick CAT scan on your belly and on your back. And they take images, and then they render these images to make the type of view that we would see with the colonoscope. So they're looking at a tube, doesn't really require a bowel prep. It doesn't require sedation. It does require air to be put into the colon. And that very old study was shown to be almost as effective as colonoscopy for detecting large polyps, not so good for detecting really small polyps. So CT colonography is used, not all insurance companies pay for it.

And I think the benefit of using CT colonography is that for individuals that can't undergo a colonoscopy for some reason or the colon scope doesn't go all the way around them, then this would be a viable option to look at the colon to figure out what's going on or for patients that maybe can't come off a blood thinner to have some other type of test. And then the other imaging test, again, not very commonly used is using a pill camera, capsule colonoscopy. It takes a lot of prep, including ingestion of laxatives, as well as agents to help propel that capsule through the colon. And again, in some studies, was shown to be able to detect large adenomas, which are the adenomas that would be most likely in a short period of time to turn into cancer. But again, those two modalities, oftentimes not covered by insurance, a little bit more difficult to get done, not done in all centers, but a feasible approach if needed.

Dr. Scott Steele: So, Carol, I know you said that if you had a positive test that you may have to go on to get a colonoscopy, you should go on and get a colonoscopy. So truth or myth, if a patient completes a fit test like Cologuard, then they will never have to get a colonoscopy?

Dr. Carol Burke: Oh, thanks for that question. So, the myth is you will need to have ongoing colorectal cancer screening. So, if people choose a non-invasive, a non-colonoscopy method. Those stool tests are done on a yearly basis. It's hard enough to get people to have one fit test or one fecal occult blood test, let alone having them every year. And the accuracy and the benefit of those stool tests really require that approach. That's where all the accuracy of this test comes in, by repeated testing. And that's why some people choose colonoscopy. Because if that is a normal exam, then you are good for 10 years unless there's some other factor that increases your risk or you develop some symptoms. So, colonoscopy is chosen by many people because it may be inconvenient to change your diet and come in and have the procedure, but if it's normal, it's a 10-year exam. The fit test, and even Cologuard is on a yearly basis.

The other point I want to make, Scott, is people are reassured, oh, my fit test was negative, or my Cologuard was negative. When you look at the accuracy of these tests, these noninvasive tests, they're not 100%. And in fact, you can have false positives and you can have false negatives. So that's the other important thing when discussing with your provider about colorectal cancer screening, which is so important, is what's the accuracy of the test to detect cancer, and what's the accuracy detect polyps? And none of the tests on the market other than colonoscopy are really good at detecting polyps.

Dr. Scott Steele: So, we've had some of our podcasts talk a little bit about this more recent trend of younger people being diagnosed with colorectal cancer, leading to a change in guidelines, as you said, 45 earlier than 50. Do we know why this is?

Dr. Carol Burke: It's all conjecture at this point, Scott, but what we've seen from the cohort of people that were born roughly in the 1990s, that there is this uptake. The cancer seemed to be on the left side. The population is getting more obese, we're having more diabetes, we're exposed to a lot of toxins, so it is thought that there's things that people are exposed to in utero or in the environment that's leading to this. And there's a lot of interest in plastics, right? They're finding plastics in colon cancers and colon tissue. So, we don't know what it is, but it's in part lifestyle with obesity, lack of activity, increase in diabetes. But there probably is something, and it may have been early onset antibiotic exposure that changes the microbiome. But at this point, it's still conjecture.

Dr. Scott Steele: So, let's go back to talking about colonoscopy. There's a certain amount of hesitancy out there to having a colonoscopy. So what would you share with someone who is apprehensive about scheduling a colonoscopy?

Dr. Carol Burke: I'd like to know what the apprehension is. So some people are afraid of what we're going to find, and that's easily discussed during a conversation, right? I'm fear that you're going to find cancer. Well, you know what? If we find cancer and it's early, sometimes it can be fully removed through the colonoscope. Sometimes it requires having part of your colon removed. And when people think about colon cancer, A, they think of death. And early colon cancer is curable more than 95% of the time. Other people think, oh, if you find something, that means I'm going to have a bag. And in fact, the majority of individuals that have colon cancer that is picked up at early stage and don't have other complications, the colon is just cut apart and hooked up back together. So I like to dismiss, it's going to be a bag, I'm definitely going to die, or I'm afraid what you're going to find.

Then the next thing is, well, what else are you afraid of? Oh, someone, my friend's friend's sister's cousin had a perforation when they had a colonoscopy. So some people are afraid of complications, and the complications that are very rare, but of the most common ones that are reported, and this is much less than 1% of people would be some bleeding at the time of colonoscopy, oftentimes can be carried of right at the time of colonoscopy of a little polyp bleeds. We have equipment that we can use through the colonoscope, putting a hole in the colon called a perforation. Again, very rare when we're just looking. And equally rare, but a little bit more common, but still less than 1% when we remove a polyp. Missing an adenoma, right? Missing small polyps. Very old studies show that up to 25% of the time, we can miss really tiny polyps. And I want to reassure patients that very tiny polyps are no immediate and probably no long-term threat to your health.

And then people are afraid of complications from anesthesia or death. And I've been practicing for 32 years, I haven't had one death from colonoscopy, and anesthesia is very safe. Oftentimes now, when patients are undergoing colonoscopy, it's with conscious sedation, so very light sedation where patients aren't feeling any discomfort and propofol sedation where it's a little bit heavier sedation, but monitored my anesthesiologist. So cardiovascular things are very rare. And then Scott, I think the last thing is this prep. People were very concerned. And for years, the only prep we had was a gallon of salty tasting solution where you were drinking the gallon, eight ounces every 10 or 15 minutes until you get it down. And patients had some nausea, the taste of the solution wasn't good, and then you do have to stay by a bathroom because eventually, what goes in will come out.

But now over the last decade or so, there's been quite a bit of movement in the bowel preparation field. So now we're down to two liters of bowel prep or two, 175 milliliter bottles of solution, which is a little bit less than a Coke can with the addition of fluid. So better tasting things, much lower volume. And we found that the colonoscopy cleansing is much better with these low-volume solutions if you take part of it the night before beginning at 6:00 PM, and then you take the next dose four hours before your procedure because overnight, the small intestine is still secreting all kinds of fluid, liters and liters and liters of this, of bile stained yellow stained fluid that can coat the right side of the colon. So not only is prep tastier, it's smaller volume, but also it's a split dose where individuals don't have to take as much volume of the prep all at one time.

Dr. Scott Steele: So, let's say that you or a patient had a colonoscopy, and they did find a polyp. Does that mean that that patient has cancer?

Dr. Carol Burke: Absolutely not. So, I liken the polyps to maybe moles or warts on the skin, right? They live on the surface lining of the colon. And I would say by far and away, 98% of colon polyps can be removed right at the time that you have your colonoscopy. There is much less than 10% of patients that would come in and would have a very large polyp that wouldn't be removed with the standard equipment for colonoscopy. But polyps are benign lesions. They are not cancer, but they are the precursor for cancer. And the two kids on the block that are the precursors for colon cancer are something called adenomatous polyps or adenomas and serrated or sawtooth looking under the microscope type of polyps called sessile serrated polyps. So, gastroenterologists and colorectal surgeons are very good at detecting these polyps. The sessile serrated polyps live on the right side of the colon, and they can be tricky to see. That's the importance of taking your second dose of bowel prep four hours before your procedure, so you get all that bile fluid outside of the right side of the colon.

But these are benign lesions, if left in, could in years turn into cancer. So that's the importance of removing them. And then cancer oftentimes looks a lot different than a polyp, but some polyps can be malignant or cancerous. They can be fully removed, some of them with their very early cancers through the scope without surgery. But the ones that are slightly more advanced would require a little bit of a deeper resection called endoscopic submucosal dissection for early-stage cancers. And we have experts at the Cleveland Clinic in colorectal surgery and in gastroenterology that can take care of those. And then if it's more advanced cancer, then it does require usually part of the colon removed.

Dr. Scott Steele: So, are there any advancements on the horizon when it comes to colorectal cancer screening?

Dr. Carol Burke: I think the advancements coming down the road include these blood-based colorectal cancer screening tests. So that's going to be very important. A lot of them have come onto the market in individuals that have had cancer, and you're looking for recurrent cancer. So in the past, we had some kind of rough tumor markers that were seen in the blood called CEA, but now we're looking at cell-free DNA and circulating tumor DNA. So, these types of blood tests in an individual that has had cancer are very sensitive to pick up some of the beginning recurrences of cancer. And those same manufacturers are looking for the signals within the blood that would be useful to pick up sessile serrated polyps, adenomas, and, of course, early cancer, but there's nothing that's FDA-approved and on the market. But those, as I said before, will be available within the next year or so.

And in addition, there's going to be other tests similar to Cologuard. So they're going to be multi-target stool DNA tests. They will be taking advantage of a fit test for fecal called blood, but they will also be looking at micro RNA. The Cologuard is looking at DNA and methylation markers, but some of these new tests that will also be stool-based will include the fit and some genetic markers. And then there is a company in Canada that actually is looking at a urine-based test, and the Cleveland Clinic is looking at a test, and we've done this in other disease states before, looking at exhaled breath. So we're looking at signatures within either breath or the gas above a urinalysis test to see if we can predict colon polyps and colon cancer. So those are coming down the pike as well.

Dr. Scott Steele: Very interesting. And so now it's time for our quick hitters when we get to know you a little bit better. So first of all, what's your favorite food?

Dr. Carol Burke: My favorite food is tabbouleh. It's a parsley salad from Lebanon. And my husband's Lebanese, so we generally make some very good Lebanese food at home.

Dr. Scott Steele: What is your favorite sport either to watch or to play?

Dr. Carol Burke: My favorite sport to participate in is hot yoga.

Dr. Scott Steele: You've traveled all over the world. What's one place that remains on your bucket list?

Dr. Carol Burke: One of my most favorite trips was joining my Weiss Center colleagues going to New Zealand and seeing Rotorua, doing some sea kayaking, climbing a mountain, looking at the Hobbitville, so that was lovely. And what remains on my list is going to India. I'd love to see the Taj Mahal.

Dr. Scott Steele: And you said you're a Cleveland girl, so tell our listeners something that you like about beautiful northeast Ohio.

Dr. Carol Burke: Northeastern Ohio is the unsung secret. So, I don't want to tell too many people because then too many people will come here. But we have a lovely lakefront. We have hundreds of miles of bike trails. And one particular gem is the Cuyahoga Valley Towpath Trail, which connects Lake Erie all the way down past Columbus. So, we have wonderful bike and hike trails here, and we also have some lovely ski trails, not for downhill skiing in particular. As I said, I lived in Colorado for a while, but we have great cross-country ski trails, Holden Arboretum. We have lovely natural resources available, mostly free to Northeastern Ohioans and other visitors.

Dr. Scott Steele: Absolutely. So, give us a final take-home message for our listeners about colorectal cancer screening.

Dr. Carol Burke: The first message is please get screened if you haven't been screened. The second thing is talk to your family. If there is a family history of colorectal polyps or colorectal cancer, particularly at a young age or multiple relatives, please know that history and talk to your physician about that because you may warrant earlier onset colorectal cancer screening much before the age of 45, and sometimes more frequently than every 10 years. And then the last thing is don't dismiss symptoms of colorectal cancer, especially young people, but people of any age. If you've had rectal bleeding that's not explained, don't let someone tell you that's hemorrhoids. I can't tell you how many young people have been put off for a year saying, "Oh, it's nothing. Oh, it's irritable bowel. It's hemorrhoids," because you need to have a colonoscopy and be assured it's not cancer. An ounce of prevention is worth a pound of cure.

Dr. Scott Steele: Well said. And so to learn more about colonoscopies or to schedule a screening at a Cleveland Clinic location, please visit clevelandclinic.org/colonoscopy. Again, that's clevelandclinic.org/colonoscopy. You can also call us at 216.541.1494. That's 216.541.1494. Dr. Burke, thanks so much for joining us on Butts & Guts.

Dr. Carol Burke: Thank you, Scott.

Dr. Scott Steele: That wraps things up here at Cleveland Clinic. Until next time, thanks for listening to Butts and Guts.