A Food and Drug Administration advisory panel recently recommended the approval of a new blood test that can detect colon cancer. This comes at a time when more young people are getting diagnosed with colorectal cancer. Flavio Rocha is the physician-in-chief at OHSU’s Knight Cancer Institute. He joins us to share more on what this trend means and what new advances in technology can tell us.
This transcript was created by a computer and edited by a volunteer.
Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. We turn now to the huge increase in the early onset of cancer diagnoses. According to a recent study, new cancer cases among people under the age of 50 increased 79% over a recent 30-year period. Screening guidelines for some cancers have been lowered in response. The federal government now says mammograms should start at age 40 and colon cancer screenings at age 45. Flavio Rocha joins us to talk about what’s happening. He is a surgical oncologist who focuses on liver and pancreatic cancers. He’s also the physician-in-chief at OHSU’s Knight Cancer Institute. It’s good to have you on the show.
Flavio Rocha: Thanks for having me, Dave.
Miller: The New York Times reported recently that millennials born around 1990 are at almost twice the risk of colon cancer right now, compared to people born in the 1950′s, and have a risk of rectal cancer that’s four times as high. What other cancer risks are increasing for young people?
Rocha: Yeah, that’s a great question. We’ve seen this phenomenon of early-onset cancer, cancers in adults over 18 but younger than 50. And although the focus has been on GI cancers, including colon cancer, there are some other sites within the GI space. So things like appendiceal cancer, even pancreas cancer and liver cancer. Outside of the GI sphere, breast cancer also seems to be increasing. Hence, you saw the recommendation coming back to 40 years old for mammograms.
Miller: Is this something that you’ve seen just in the course of your own clinical life? I mean, do you see a higher percentage of younger patients now since you started practicing 20 years ago?
Rocha: That’s indeed the case. Both myself and colleagues around the country are seeing this and we’re trying to understand why this is happening. There are several factors that are known to increase cancer, like family history, of course, but certainly environmental factors – things like tobacco use, alcohol use, sedentary lifestyle, obesity, and whether we’re seeing those more in a younger population. There are some other suspected ones, like looking at your microbiome, or even antibiotic use, or environmental exposure such as microplastics, other things. They haven’t quite been proven yet, but we think may be contributing to this increase.
Miller: You’ve just mentioned a lot of things. Some of them are about behaviors that people can change, some of them … microplastics … I’m sure everyone listening now has heard study after study saying that they’re in all of us, they are everywhere. I don’t even know how you would do a study to find out the effects of them in some cases because we are all the test cases on some level.
But what are the studies that you find most persuasive, that have shown the possible reasons for these increases? Because you mentioned so many different potential factors. Which ones do you think have the best evidence to say that this is probably a real piece of the puzzle?
Rocha: I would say for cancer in general, cessation of smoking, tobacco use, has really been a dramatic change. And we’ve seen that with the decrease in lung cancers that we’ve been able to catch early with the combination of screening and tobacco cessation, and that applies across cancers. People think of tobacco use for lung cancer, but it’s actually a leading cause of risk for pancreas cancer as well. So those are things that we know we can modify.
Certainly, obesity and inactivity have always been linked through epidemiological studies to cancer use. And then dietary factors, as you hinted at, are also more difficult to trace directly. Things like red meat and other dietary changes – these are things that people are interested in knowing about. I think the most important thing to think about, especially in this young population, because the screening may not capture all the cancers in all the age groups, just be sure to keep your health up, see your physician, see your provider. And make sure that if you’re having symptoms that may predispose you to a diagnosis of cancer: unexplained weight loss, blood in your stools, etc. Get those checked out.
Miller: A recent study found that for younger people with colon cancer, there can be a longer time between the onset of symptoms – for example, blood in the stool that you just mentioned – and a diagnosis. A longer time between the onset of symptoms and diagnosis than for older people or older patients. What does that mean for the treatment of cancer?
Rocha: That’s a great question. I think for the most part, the earlier we can catch cancer, the better options we have to treat it and potentially for cure. I think, while I don’t want to create any kind of panic in the population, I do want to make sure that symptoms are not ignored. Most people don’t think of cancer in younger folks because they think it might be something more reasonable, more explainable. And because the screening guidelines don’t catch everyone, as you just mentioned, colon cancer has only been lowered from 50 to 45. And I’ve seen colon cancer in patients as young as 18. So again, there is a way to try to find that fine balance of making sure you keep your health screenings and don’t ignore your symptoms.
Miller: What you’re talking about there – seeing a symptom and assuming, no, this is something else, this is not cancer. From the articles that I read, that assumption could be both in the individual – the patient – and in healthcare professionals as well. How do you change that social awareness?
Rocha: That’s a good point. It is on both sides. Nobody wants to diagnose anybody, especially when they’re young, with cancer. But I think the important thing to remember is to keep the screening guidelines. Make sure you follow those. For things like colon, breast, lung, cervical cancer, those are things we screen for, but not to be totally dismissive of any symptoms.
I think what’s brought this on more in the public sphere, as well, has been some of the more public figures that have developed early-onset cancer, like Chadwick Boseman or even the Princess of Wales, who’s had cancer now at age 42.
Miller: Do you think that’s leading to people who have symptoms, to be more likely to ask questions of their doctors?
Rocha: I certainly hope so.
Miller: Although that does make me wonder how much of this is up to patients themselves to self-advocate, as opposed to healthcare professionals saying, “I’m up on the research. I know about epidemiology. Ten years ago, I wouldn’t have recommended a screening but now I’m going to.” Shouldn’t that be up to doctors?
Rocha: No, I completely agree with this. This is part of, not just us, but a whole body of researchers that also function in the epidemiological space in population health studies. And of course, screening is always a challenging thing because it’s something you have to recommend for an entire population, so there are some feasibility issues with that as well. You have to be able to figure out who are going to be the high-yield populations. And I tell you a population that’s particularly at risk, for example, are underrepresented minorities, that sometimes can have significant disparities in not only cancer screening but also treatment.
Miller: The recommendations for starting these screenings, whether it’s a colonoscopy or a fecal test, or I guess, now there’s a newly recommended and approved blood test for colon cancer, or mammograms – when the onset dates change, how much does that lead to people getting those tests at earlier ages? I’m just wondering if, when it goes from 50 to 45, if that means that more 46-year-olds are gonna get the test, or if research finds that that’s actually not the case.
Rocha: I think what you’re getting at, Dave, is implementation science. And so, yes, the colon cancer recommendations were only changed in 2021, when it dropped to 45. The US Preventive Health Task Force just reaffirmed their recommendation for mammograms at age 40 about a month or two ago. And so we’re gonna have to wait and see if that dissemination of information, the outreach that we do, as you said, in the medical community will have an impact.
As you know, we’re also still catching up from COVID-19 screenings that were delayed, given the capacity issues. So we are a little bit behind the eight ball but hoping to catch up
Miller: Still, we talked about early on in 2020, maybe 2021. But you’re saying that you’re still seeing people who didn’t, say, get a recommended colonoscopy at the beginning of the pandemic, who still haven’t.
Rocha: Well, no, what we’re seeing now are the cancers that have resulted from perhaps delaying the screening.
Miller: So they should have gotten the screening in 2020, 2021. They didn’t. And now you’re treating those cancers that could have been caught earlier.
Rocha: Correct.
Miller: How big a difference does that make? If someone’s listening right now and is thinking, “I’ve heard about the colonoscopy prep,” for example, “and the liquids you have to drink” … sorry … “and the liquids that come out [and] I don’t want to go through that.” What would you tell them, in terms of the difference between catching colon cancer now, as opposed to a year from now?
Rocha: I think that’s a great disease site to actually delve into a little bit, because you mentioned the stool-based test. Those actually have become more prevalent. And as far as we can educate people to use those, they can serve as a screening mechanism for those that truly need the colonoscopy. And if your stool-based test is negative, we know that you can hold off on your colonoscopy. Whereas, if it’s positive, we can focus that limited resource, the colonoscopy part, to those individuals.
And as a surgeon, for most solid tumors, if you can remove it surgically, that’s typically the best outcome. Because what happens is, as cancer grows and spreads, it first grows locally and regionally, to things like lymph nodes, before eventually spreading to distant sites where it’s much harder to treat when it gets to that stage.
Miller: In general, what are the differences when it comes to treating somebody for cancer who is 20 or 30 or 40, as opposed to 70 or 80?
Rocha: I think one big thing about having the advantage of youth is the ability to be able to take more treatments, perhaps more aggressive treatments; whereas, if you have more comorbidities, if you’re older in age, it may be harder for you to actually be exposed to some of the other agents that we have. I do think that sometimes the genetics also may be different. Genetic tumors in younger folks can sometimes be more aggressive. But again, their youth is in their advantage because we’re able to actually do more aggressive treatment for them.
Miller: But it seems like it goes in two directions – that they may have been diagnosed a little bit later, so the disease may have progressed more, or they may have more serious or fast-moving kinds of cancer. But you can also be more aggressive in the treatment.
Rocha: Correct.
Miller: One of the big stories that I’ve heard in terms of oncology over the last half-century is one of incredible successes. Diagnoses that had often been essentially death sentences in the past, now have miracle treatments of various kinds. Medications have gotten more sophisticated. We all hope that they’ll get even better. There are more targeted medications, early detection has made a big difference for a lot of people, but this increase in cancer rates for young people, it seems to be taking you in the opposite direction that oncologists are used to. What has this been like for you as a doctor, as an oncologist?
Rocha: Well, again, lots to unpack there, Dave. But I think two things are clear: One, since 1991, cancer mortality has actually decreased by 33%. A lot of that due to all the work that’s been done in the research space and the clinical space. And so overall, I think we are making progress against cancer.
I think what we’re seeing in the younger folks, we’re trying to figure out why that’s the case. One of the reasons is maybe that we are increasing screening in the appropriate population that’s older, and we just don’t have the screening recommendations for younger people.
Miller: Just to be clear, what we’re looking at here is not an increase in cases because of more screening. This is an absolute increase in cases. It’s not just that you’re better at looking, so you’re better at finding. There are more cases.
Rocha: There are more cases. Now, the question is, if we were to screen, would we find even more? We actually don’t know that. What is exciting on the therapeutic front that you mentioned is, we do have more treatments now, besides, let’s say, chemotherapy. Immunotherapy has significantly evolved. And so those are treatments that we can do to harness the body’s own immune system that does not involve chemotherapy.
Miller: As opposed to just this kind of blanket poison that kills fast growing cells, including cancer, and is devastating for a human body.
Rocha: Correct. Using your own cells, turning off the brakes in your immune system to fight the cancer that’s got your DNA in it.
Miller: What other research has gotten you most excited, specifically in the realm of early-onset cancers right now?
Rocha: Well, I think the most exciting thing will be, you hinted at a blood-based marker. Now, we don’t have that. It’s not quite ready for prime time, but there are several studies that are actually looking into, can you get a blood test to diagnose, not only if you have cancer, but what specific type of cancer that you have. And again, the goal is, can we pick that up earlier, in order to have a better chance to treat it for cure?
Miller: You say not ready for prime time, but a majority of this panel did say “yes, we’ll approve this,” even if it misses some percentage of cancers, a higher percentage of colon cancers than folks would like. They still said overall, it’s worth saying yes to it. But you’re saying you’re not so convinced.
Rocha: I think we still have to do more research. And I think what you’re hinting at is we are doing several studies now on what we call cell-free DNA or circulating tumor DNA in several cancers. And it seems to be promising, but we’re not yet at the point where we can make treatment decisions based solely on that particular test.
Miller: Flavio Rocha, thank you very much.
Rocha: Thank you.
Miller: Flavio Rocha is the physician-in-chief at OHSU’s Knight Cancer Institute. He is a surgical oncologist who joined us to talk about the really huge increase in early-onset cancer diagnoses in young people, meaning people ages 18 to 50.
Contact “Think Out Loud®”
If you’d like to comment on any of the topics in this show or suggest a topic of your own, please get in touch with us on Facebook, send an email to thinkoutloud@opb.org, or you can leave a voicemail for us at 503-293-1983. The call-in phone number during the noon hour is 888-665-5865.