Colorectal Cancer: Why You Shouldn’t Put Off Getting Screened (podcast)

Early detection can often prevent colon and rectal cancers

Walter Coyle, MD, colorectal cancer specialist at Scripps Clinic (podcast)

Dr. Walter Coyle, Gastroenterology, Scripps Clinic

Early detection can often prevent colon and rectal cancers

Colorectal screenings aren’t something we typically want to talk about, but skipping out on these important procedures could put your life at risk. According to the American Cancer Society, excluding skin cancers, colorectal cancer is the third most commonly diagnosed cancer in the United States, and is the third leading cause of cancer deaths. Roughly 50,000 people are expected to die from colorectal cancer this year alone. But getting past the “eww” factor and talking to your doctor about colonoscopies and other screening methods could help you avoid this often preventable disease.


In this episode of San Diego Health, host Susan Taylor and guest Walter Coyle, MD, who leads the Division of Gastroenterology at Scripps Clinic, discuss the symptoms of colorectal cancer, or lack thereof, who’s at risk and what to expect before and during a colorectal cancer screening. 


There’s been some debate on what age people should start getting screenings for colorectal cancer. Traditionally, screenings began at age 50, but the American Cancer Society recently recommended that be lowered to age 45. There has been a spike in the rate of colorectal cancer in younger people, although it’s not exactly clear why. Colon cancer deaths in people under 50 have increased 11 percent in the past decade. Dr. Coyle recommends a less invasive type of test starting at age 45, then moving on to more traditional methods such as colonoscopies at age 50 in the absence of any irregularities.

Listen to the episode on the importance of colorectal cancer screening

Listen to the episode on the importance of colorectal cancer screening

Podcast highlights

Podcast highlights

How many people are affected by colorectal cancer? (1:16)

Dr. Coyle: About 140,000 new cases will be reported this year between colon and rectal cancer. About 50,000 will die this year.

What are the symptoms? (1:28)

Dr. Coyle: The most common symptoms are, none. We actually find it by screening now. But if you're having symptoms, it'll be bleeding, usually from the rectum, [and would] be bright blood. There can be bloating. There can be a change in bowel habits. Pain is common, and not just for a day or two. It's usually something that's been going on for several weeks. That's when you should seek out attention from your doctor.

Who's at risk? (3:00)

Dr. Coyle: The death rate is actually about equal for men and women, but women are protected while they're still having their periods from estrogen. So, women get it about 10 years later than men, but they catch up. So at the end, men and women have the equal death rate from colon cancer.


Susan Taylor: What are the risk factors?


Dr. Coyle: There's environmental and there's genetics. Smoking is a huge factor. Being obese, not eating lots of fresh fruit and vegetables, a diet that's higher in red meat, particularly processed red meat.


Susan Taylor: What about family history?


Dr. Coyle: About 5 percent have strong family histories. If your mom, dad or aunt or an uncle have had polyps or cancer, it can double, triple, even quadruple your risk to get colon cancer. So, it's important to talk to mom and dad and brothers and sisters and ask: "Hey, what'd your colonoscopy show?" The worst thing is not to share that information. If they have a family history of colon cancer or they have colon cancer, you now have a family history and might be able to be screened sooner.


Susan Taylor: What about different ethnic groups?


Dr. Coyle: We know African-Americans have a higher rate. In fact, several societies have now said we should start screening African-Americans starting at age 45.

How do you screen for colorectal cancer? (4:56)

Dr. Coyle: Well, the big thing about screening is just getting a screening test done. I follow the guidelines that came out last year.


There's three separate tiers of screening. Tier one, which they consider the best, is colonoscopy and a test called FIT testing, which is a stool test that looks for blood.


Tier two [includes] a CT colography, the stool DNA test, and the flexible sigmoidoscopy.


Tier three is the capsule, and right now it's only FDA approved if you've failed a colonoscopy, and that's why it's tier three.


The capsule has a camera in it. It takes about 40,000 images as it travels through your gut. But the problem is the prep has to be even tougher than the prep for a colonoscopy. There can't be any stool in your colon at all. So it's a two-day vigorous prep, and it can still miss things, but it's better than nothing. But I actually rarely order it, except for the person who can't physically have a colonoscopy.


Susan Taylor: Why couldn't someone physically have a colonoscopy?


Dr. Coyle: These would be people who are just too ill. They have a certain anatomy that makes it not conducive or they are just scared of having a colonoscopy. So for those people, I usually use a DNA test or the stool FIT test. I prefer the FIT test because it's almost as good as the stool DNA test, but it's much cheaper. It's about $25.

What is a FIT test? (6:26)

Dr. Coyle: It's called the fecal immunochemical test. It's really a cool test. Before, they would actually check for blood in your stool, and if you ate a lot of red meat, or stuff like that, it could make it false positive.


[FIT] actually checks for human hemoglobin. Hemoglobin is heme plus globin. This specifically checks for globin. It's very specific to humans. It doesn't matter how much red meat you have. It's a one-time test. You can do it and you can mail it back to your doctor's office. It's just a little smear. Costs about $25. It's very good at detecting colon cancer. It's not quite as good at detecting polyps. It can miss about 15 percent of colon cancers, where colonoscopy hardly misses any colon cancers.

What is a colonoscopy? (7:22)

Dr. Coyle: For a colonoscopy, you come in and we sedate you. So you're very relaxed. We give a combination of a Valium-like drug and a weak narcotic, and that combination makes you very relaxed. Most people don't even know they've had the test, and they wake up, "Oh, it's over."


Some places are using a medication called propofol, in which you're completely out, which essentially is general anesthesia. The scope's about the size of my little finger and we go around all the way to the end of your colon, which is over on the right side of your body, and on the way out we look very carefully for polyps.

What is a polyp? (7:54)

Dr. Coyle: Think of me as a dermatologist of your colon. I find lumps, and bumps, and moles and things like that. If I see anything that doesn't look natural, I take it off, and we call it a polyp. But some polyps are precancerous and some aren't. The whole test takes maybe 12 to 15 minutes if there's no polyps. Every polyp takes me about a minute to take off. So sometimes it takes 20 minutes to do it all.


We send [the polyp] to the lab in formalin usually. They look at it and tell us what kind of polyp it was, what the risk was. Occasionally it'll have cancer in it. That's very unusual though.


Susan Taylor: If you take a polyp out, does that mean it's precancerous?


Dr. Coyle: Half the polyps that we take out are called hyperplastic, and it's like the little skin tags people have on their neck and armpits. They would have never ever gone to cancer. But the other ones are adenomas. Those are precancerous, and if we had left it in there, it could have become cancer. We're not that good yet to say, "Oh this adenoma would never go to cancer."


So we take out all the adenomas and all the polyps, and we think most of them over time would have become cancer if you live long enough, or the polyp lasted long enough. But some polyps probably would never turn into cancer, but we can't tell. It's like the dermatologist who takes off a lot of things off your skin that would have never become melanoma to prevent that one melanoma.


Susan Taylor: But if a polyp is found and it's taken out, does this still put you at increased risk down the road for getting colorectal cancer?


Dr. Coyle: If it's a hyperplastic polyp, there is no risk at all. We keep normal screening, which is every 10 years for colonoscopy. If it's an adenoma, yes, it does increase your risk, and we shorten down the interval for screening to three years or five years because you grow new ones. I call it picking the weeds. I go in there and each five years there's more polyps, so I just take them out.

What's the difference between colonoscopy and sigmoidoscopy? (11:02)

Dr. Coyle: The flexible sigmoidoscopy covers only a portion of the colon, whereas the colonoscopy does the whole colon.


A sigmoidoscopy is a good test. It saves lives, decreases colon cancer. Canada is relying heavily on flexible sigmoidoscopy and FIT testing. However, I sort of view it like a mammogram. You're doing a mammogram on one breast and you're assuming that with that one mammogram it tells you what's going on in the other side, and that's not necessarily true. So gastroenterologists as a society, and the American Cancer Society think colonoscopy is the better test.


With the flex sigmoidoscopy, there is no sedation. It's safer that way, but it can be inconvenient too, and you still have to prep for a flexible sigmoidoscopy.

How do you prepare for a colonoscopy? (11:45)

Dr. Coyle: Well, it's gotten a lot better. Let's put it that way. It used to be the gallon stuff. You'd have people sitting there trying to drink this gallon of stuff. It's deflating. It's now split prepping. So even if it is the gallon, it's a half gallon and then a half gallon. [The drink] is a liquid that tastes like saltwater that lavages you out. It's not a true cathartic where you get cramps. It's a laxative to get you going. So it doesn't cause a lot of cramps.


But a gallon by anyone is hard to drink. So now they developed low volume preps, and there's several on the market. You drink about eight to nine ounces, and then you do another eight to nine ounces four or five hours later. But their effect is the same. You're still going to poop 10 to 15 times, but just less cramps, tastes better and you can drink whatever you want, Gatorade, tea, ginger ale and stuff like that. So, it actually is much more palatable, and people are finding it's not so bad.

What happens if you have colorectal cancer? (15:09)

Dr. Coyle: Usually it's surgery. If we find a polyp that I can't take out, we're going to cut out that section of the bowel, and we'll take the lymph nodes that are around the bowel and based on that we decide if you need further therapy.


If it's very superficial and no lymph nodes are found, we won't do anything else. If there's any lymph node involvement or it's spread, then we will usually add chemotherapy to that.


The exception of that is rectal cancer. Because the rectum is fixed at the bottom, we actually can give radiation. So, we can give chemotherapy radiation beforehand, shrink it down. Sometimes the cancer is gone but we still operate. So the cure rates are higher for rectal cancer for the same stage as regular colon cancer. So that's very exciting. We've really made a huge headway in the last decade or so.

What's the survival rate for colorectal cancer? (16:12)

Dr. Coyle: If you find it early, which is through various screenings, it's a 90 percent five-year survival. So we cure 90 percent. If you wait and present when it's already spread, it's a 13 percent five-year survival. So it's huge. That's why screening is so important. Even if you have cancer, we can still save your life.

At what age should you get screened? (16:43)

Susan Taylor: Traditionally the guidelines have been to start checking for colorectal cancer at age 50. But now the American Cancer Society came out not so long ago and said, "No, actually we think we should begin screening at age 45 because younger people seem to be getting colorectal cancer. There's a spike in that." Why the spike for younger people, and when should you start getting screened?


Dr. Coyle: Well, we did a study at Scripps and looked at our last 2,000 or so patients with colon cancer, and we looked at the ages. Ten percent were less than 50, and that sort of matches the national average. We tried to look at why. Were they heavier? Were they smokers? Did they have family histories? Nothing came out that separated them out. So, it's very frustrating. We think something in the environment has made them more prone to get this, but we can't figure out what it is right now.


Having said that, the American Cancer Society did a modeling exercise saying, if we move screening down, could we save lives in those 10 percent? What's concerning is that mortality has gone up in people under 50 for colon cancer 11 percent in the last 10 years, and that's what they're trying to stop. But it's a problem because you do a lot of extra colonoscopies in people that wouldn't need it. We've tried to decide what to do. They didn't put any restrictions on what kind of screening. They said, "Just consider screening [at age] 45." It's a qualified recommendation, not mandatory.


What I recommend now is that patients age 45 get the stool test, the FIT test. You can mail it in. If that's negative, you can feel good. Get that every year, and then I think the regular guidelines would say FIT test or colonoscopy at age 50 would happen. Of course, if you have any symptoms, you immediately should get a colonoscopy if you're 45 or older.


Susan Taylor: Is the spike in younger folks getting colorectal cancer because they're not going to the doctor to be checked for it?


Dr. Coyle: We've looked at that and asked: Is it the doctors not thinking about it, or is the patient staying at home and not going in because they were too busy. We're not sure.


It's fine to go to your primary care doctor. They're very good at sorting out, "Oh, I think this is just a hemorrhoid. Oh, I think we should definitely do a flexible sigmoidoscopy or a colonoscopy."


Susan Taylor: So I guess the bottom line is the colonoscopy can save your life, right? But you're saying only about 60 percent of the people who should be screened for colorectal cancer actually have the test. Is that correct?


Dr. Coyle: There was a big push by all the societies to get 80 percent of people eligible screened by this year. But the problem is people still avoid it.


I get the idea, "I don't have time to do a colonoscopy, I don't have that." In that case, just give me a stool sample. If that's negative, we're good to go. But the other side of that coin is if it's positive, you really need a colonoscopy, because that means you could have colon cancer.