Colorectal Cancer Prevention and Screening: An Update

Transcript:John L. Marshall, MD: Tony, should we lower the bar? Should we start screening high school seniors for colon cancer?

Tanios Bekaii-Saab, MD: Even if we consider that as an option, the limitation is that you will get even less compliance in that group of patients than with the elderly. This remains a disease, predominantly, of those above age 50. Although the incidence is rising in the younger patients, and I would hate to see younger patients with colon cancer, it’s still not a disease.

John L. Marshall, MD: I wonder if that’s because you live in a retirement community. In my world, half of my clinic is under age 50 right now.

Paul R. Helft, MD: I have the same issue.

John L. Marshall, MD: I have 30-year-old women, with children, with colon cancer.

Tanios Bekaii-Saab, MD: We see a lot of the younger patients because they come to the Mayo Clinic from across the whole region. The point, though, is that it’s heartbreaking. We just don’t understand it. And we have to justify doing a colonoscopy for close to 200 million people a year now.

John L. Marshall, MD: Right. Compliance. Risk.

Paul R. Helft, MD: I wanted to add, to Tony’s really good point, that the screening question is really a different question. I think what we can do, with a rising population of younger patients, is raise awareness about symptoms that need to be followed up on quickly. The story that we hear from our young patients, year after year, is that they had symptoms that were ignored, blown off, or not followed up on in an aggressive manner. And because of this rise, I think that one of the maneuvers that we can do—in the absence of completely revising the United States Preventive Services Task Force recommendations—is to raise awareness among primary care physicians.

John L. Marshall, MD: Yes. I was thinking the same thing. For rectal bleeding or gastrointestinal bleeding in a 33-year-old with some hemorrhoids—scope them. Don’t just blame it on hemorrhoids and try to make that the diagnosis.

Tanios Bekaii-Saab, MD: A quicker trigger finger and, essentially, a workup. We want to be careful, too, because then we end up in a situation where everyone will end up, regardless of maybe a little bleeding, with a justifiable reason to have a symptom that has changed. We don’t want everyone to have to undergo an expensive colonoscopy. That’s a significant burden on the healthcare system that’s already relatively broke, as we know. I think we have to bring awareness to the primary care physicians and to the patients, without instilling paranoia, though.

Paul R. Helft, MD: Yes, I agree.

John L. Marshall, MD: I don’t know if you think I’m crazy, but I’ve been watching this scientific space of the microbiome—the bacteria that live in our colons. We know now that there are some good ones and some bad ones. There are protective, different ones on the right side and different ones on the left side. One emerging theory is that in this group of young people who are treated with antibiotics early, wash their hands all the time, and don’t go out and play in the backyard—as I say, don’t eat enough dirt—prevalence may be higher. Do you all see that emerging too? Is that coming out as a way to screen for these young folks?

Paul R. Helft, MD: Yes. I am not an expert in this area, but I follow the science peripherally. There’s some really interesting science going on about microbiome shifting that’s happening as a result of multiple factors—not just antibiotics that are given in a medical setting but also antibiotics that are in the food supplies, the shift from traditional anaerobes to facultative anaerobes in various parts of the colon, and the importance of the APC gene and how it fits into both colorectal cancer and the health of the epithelium of the colon. That whole area of science, I think, is really important, and we’ll be thinking about this very differently in a decade.

Fortunato Ciardiello, MD, PhD: This brings back the social problem of food—processed food versus more natural food or organic food. Maybe we are creating a lot of problems, and we are creating a lot of diseases, in this way?

John L. Marshall, MD: Yes, as we alter it. But we’re also living longer and we’ve got to feed each other, so that’s the push and pull of the issues there. I’ll throw this out for discussion: Does anybody have a liquid biopsy that we should be getting from our primary care doctors? We don’t think carcinoembryonic antigen is it, but is there a gene test or something that’s coming out to help detect disease?

Dirk Arnold, MD, PhD: That’s clearly what I meant by this stepwise approach in screening. We already said today that we’re not offering enough in many countries—just the fecal occult blood test. We’re already offering enzymatic tests, which, in the feces…

John L. Marshall, MD: For the blood and the feces.

Dirk Arnold, MD, PhD: Right. And it is super-promising to see DNA, shed DNA, in the blood of patients that could be correlated with a tumor. I think this can be used as prescreening, and then a colonoscopy will declare the future for the patient.

John L. Marshall, MD: We each give recommendations to our patients who have had colon cancer of how to prevent the cancer from coming back or how to prevent new cancers. So on the list for me—and I’ll love for you guys to fill in—is exercise; aspirin in certain patients, but I’m saying everybody at this point; vitamin D; and chasing those levels and supplementing as you can. But then, at this meeting, nuts. Have you all seen this abstract?

Dirk Arnold, MD, PhD: Yes.

John L. Marshall, MD: It’s not peanuts, right? It’s tree nuts, so everybody understands. I’ve already gotten 20 emails from patients. Is anybody in on the nuts?

Paul R. Helft, MD: These data around especially the Mediterranean diet have been around for a long time. In fact, in the CALGB adjuvant study, we had a very powerful analysis of the Mediterranean diet versus the traditional American diet. And I have wondered whether or not the data about nuts are actually a marker of a different style of eating. People who include tree nuts in their diet probably have a different approach to eating in general.

Fortunato Ciardiello, MD, PhD: Typically, in America there is, unfortunately, a difference where you are trying to make everything else a drug. Basically, you take this and you take vitamin D. Or maybe you are just following a normal lifestyle that includes exposure to sunlight, exercise, and a normal diet, where you balance everything—putting everything together. Otherwise, you kill some foods because you consider them enemies, but you can eat them. It’s just a matter of balance and a matter of eating everything. We eat everything—every species. We are not lions. We are not like buffaloes. We are somewhere in the middle.

John L. Marshall, MD: I tell my patients, in the vitamin D story, to have lunch outside without sunblock. That’s just about the right amount of vitamin D conversion. That’s great. Does anybody have any other additional comments or advice you would give to a patient for the prevention of colorectal cancer? Did we cover everything you know?

Tanios Bekaii-Saab, MD: I think that pretty much covers it, but let’s go back, a little bit, to the story of the nuts. The nuts have been looked at in other diseases—cardiovascular disease, cholesterol, etc. And actually, they do provide health benefits across the board. The same happens when you give aspirin—you’re preventing more than just colon cancer. To Fortunato’s point, a healthy lifestyle means a balanced lifestyle. We tend to be busy. We tend to just say, “I’m going to have my energy bar this morning, but I’ll take my multivitamins.” That is not a good supplement.

Transcript Edited for Clarity