Colon Cancer: Should Young People Worry?

Introduction

0:00Hi, I'm Michelle Dang, and I'm filling in for Wendy Zuckerman this week.

0:05And to start off today's episode, I want you to meet Becca Lynch. Becca lives in Colorado with her dog. She's 30 years old now, but throughout her 20s, she was leading a pretty hectic life. Kind of have always been pretty, like full steam ahead. I've never been like comfortable not being busy. She was getting her master's, growing her career, and being super active. I go like climbing, I go to the gym, I was running a lot. I did a half marathon in 2024.

0:38Playing live music. Yeah, I have a little duo with a friend of mine that we play around town sometimes.

Becca's Story

0:45But a couple of years ago, when Becca was 28, she noticed a change in her body. Specifically in one area, the poo department. She noticed she was going number two more often, like five to six times a day. And it wasn't just that. There were a couple of weird things she saw in these frequent poos. And fair warning, we're about to get a bit detailed here. So for one thing, there was blood. It was like a dark, almost mucusy, kind of thicker, bloody substance that was everywhere.

1:19Like when I was going to the bathroom. And it was every single time. And the other thing she noticed is that her poo started to take on a different shape than usual. Like thinner size-wise, like pencil thin. I did the thing that everybody does. Like I googled it. Obviously, I googled all my symptoms. The results spit out quite a list of things it could be. Ulcerative colitis, IBS, Crohn's disease. Becca thought she should get it checked out, but didn't go in right away. And then one day, she was scrolling on social media.

1:50Someone's video came across my feed. I think it was on Instagram of someone talking about the exact same symptoms. She had said, like, for years she thought she just had hemorrhoids, right? But this woman didn't have hemorrhoids. She had something a lot scarier, colon cancer. It was really advanced, stage four. And she was making these videos to tell people what to watch out for.

Diagnosis

2:13And this was the push that Becca needed. I think it definitely solidified, like, okay, I should go to the doctor. Her doctor ordered a colonoscopy. So Becca eventually went through the prep where you have to drink this gross liquid and poo a whole lot. And then she went in. I went there first thing in the morning. They just took me back and I met the doctor who was going to be doing it. You know, he was very, like, chipper and just like, yeah, we're going to figure out what's going on. He's like, could be a bunch of things. Like, it might just be hemorrhoids.

2:44Like, don't worry about it. You're going to be in and out of here in half an hour. Like, I'll see you in there. And then they rolled me back and that was it. I took a lovely nap. When Becca woke up, there was a nurse there. And immediately, Becca could tell something wasn't good. The nurse told her she was going to go out to the waiting room to get Becca's friend who had come to pick her up. And she was just like, we're bringing your friend back because the doctor has to tell you something. And I was like, something bad?

3:16And she was like, yeah. And then she left. I waited there for 10 minutes. She left me with a bag of goldfish and a Sprite. I sat there and waited. And eventually, my friend came back. And I was trying to keep it light. But at that point, I think I kind of knew. Like, I knew it wasn't going to be good, obviously. The doctor came back in. And I just remember, like, it was more so his body language and, like, facial expressions that were more upsetting than, like, what he was saying.

3:47Because he had been this very, like, chipper, bubbly person before, like, the last time I had seen him. When he came back in, he was very sad. And he, like, sat at the foot of my bed. And he just was like, we found a mass. It's five centimeters, about the size of a lemon.

Colorectal Cancer

4:03For Becca to officially get a diagnosis, the doctor told her she would need more scans and surgery. And he kind of ended it with being, like, if it is cancer, which I'm certain that it is, you'll be the youngest person that I've ever seen with it.

4:19Becca was eventually diagnosed with stage 3 colon cancer at age 29. And this was really weird. She didn't have any of the usual risk factors. They ran genetic tests and didn't find any explanation. It all felt very strange. I knew that it was happening, but it really felt like I was, like, watching it happen to someone else. But from that moment on, like, time kind of split. And I just went into this kind of numb headspace of, all right, well, we have to deal with this. So, you know, we're going to deal with it and we'll figure it out.

Increasing Cases

4:53And Becca isn't the only person having to deal with this and figure it out. Around the world, more and more young adults are getting diagnosed with colorectal cancer. In the U.S., 1 in 5 people diagnosed with it are now younger than 55. That's a big increase from just a few decades ago, when only 1 in 10 colorectal cancers were being diagnosed in younger people. And that's not the only concerning thing. We're hearing that young adults are more likely to get diagnosed with a cancer that has already progressed pretty far, despite being otherwise healthy.

5:26So, today on the show, we're going to talk about what exactly is going on here. Why are so many young people suddenly turning up with this type of cancer? And we'll hear more about what this has looked like for Becca. All that is coming up. This episode of Science Versus is presented by Amazon Health AI. Guys, we've got to talk about your secret late-night internet searches.

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Discussion

6:53Welcome back. I'm producer Michelle Dang. Today on the show, we're looking at colorectal cancer. And with me is senior producer Rose Rimler. Hey, Rose. Hi, Michelle. You know, Rose, I wanted to make this episode because I kept seeing scary headlines about this, about colorectal cancer increasing in young people. Have you been seeing these headlines too? Yes, I have. I've been seeing headlines about people getting colorectal cancer really young.

7:25And there's been some really high-profile people that have gotten it and unfortunately actually died from it. So I'm thinking of the guy from Black Panther. That was a little while ago. Yeah, Chadwick Boseman. Yes. Yeah, he died from it in 2020 and he was only 43. Oh, that's awful. Yeah. And then just last month, the actor James Van Der Beek, he also died from colorectal cancer and he was 48. Right. Yeah.

7:56And by the way, this term colorectal cancer, it includes both colon cancer and rectal cancer and sometimes also called bowel cancer. Okay, got it. And for years, doctors have thought of these cancers as cancers that older people get. In fact, Becca ran into this too. The hospital that I went to, they put me in this support group. It was like a Zoom support group for other people with GI cancers. And I joined it once and it was like me and then four women all in their like 70s and 80s.

8:27And they were all so kind and so lovely and they were very sweet to me. And like, I think one of them told me she was pissed off at God on my behalf, which I thought was very sweet. And the thing is, like, these cancers are still more common in older people. If you are under 50, the risk of getting this cancer is actually very low, way less than 1%. But this increase is real and it's freaking doctors out. So it's not, because sometimes you hear about a disease going up

8:57and it turns out what's really happening is that doctors are getting better at catching it or diagnosing it or something. But in this case, it sounds like what you're saying, Michelle, is that no, it's actually going up in young people. It's simply going up. Okay. There's more cases and there's more deaths. Okay. And doctors really caught onto this in the 90s. But the risk keeps increasing with each generation. Like, take a 40-year-old who's part of the millennial generation. My generation. Oh, your generation.

9:27Yep. And compare it to a 40-year-old who's part of the boomer generation. My generation, spiritually. No, just kidding.

9:36Yeah, so the 40-year-old millennial, compare it to a 40-year-old boomer. The millennial has a two to three times greater risk of developing colorectal cancer. So if you're 40 now, basically, your risk of colon cancer or colorectal cancer is higher than someone who was 40, you know, in the 80s or 90s. Yes, exactly. Jeez. Wow. That's real. Yeah. Yeah. And in the U.S., colorectal cancer was just declared the leading cause of cancer death in people under 50. It's led to nearly 4,000 deaths a year.

10:09Wow. So the thing I want to talk about next is the fact that when young people are diagnosed with this cancer, a lot of the time it's really serious. You hear about people turning up with stage 3 or stage 4 cancer upon diagnosis. And studies have found that more than half of cases in early onset colorectal cancer are caught at these later stages. That sucks. Yeah, this makes this cancer sound really scary because stage 4, for example, is when the cancer has already started to spread to different organs and other parts of the body.

10:43And if this is the case, it can be incredibly hard to cure. Your chance of dying within five years with colorectal cancer at stage 4 is about 80%. Wow. Okay. So I wanted to find out, like, why is this?

Symptoms

10:58Yeah, what's going on here? So I called up Dr. Michael Foote. He's a gastrointestinal oncologist from Memorial Sloan Kettering Cancer Center. And he's been watching what's going on here. We've been worried about this for a while, you know, over 10, 15 years. But it has reached a critical point in the last few years. And I wanted to know, is there something weird or creepy about the colorectal cancer that young people are getting? Like, is it moving faster or is it more aggressive?

11:28And Michael told me, no. Based on the studies we have, it looks like... Once they're diagnosed, the tumor behaves pretty similarly to a dozen adults. It responds to treatments in the same way. It can be just as aggressive. So why are young people showing up sicker? Michael says that young people's symptoms tend to be worse and the cancer spread further, not because of this, you know, idea that cancer is more aggressive, but because it's often getting caught a lot later than it is in older people. Not their fault.

11:59But they've had a longer amount of time before they were diagnosed to catch this. Well, that makes sense to me, Michelle, because they're not routinely getting screened. Because they're too young to start getting screened with colonoscopies. So if there was a really young cancer, a really new cancer that wasn't causing any symptoms, there would be no way for them to know. But an older person who is getting screened, that would get picked up. Yeah, exactly. Like, the main reason that we find this cancer is with a colonoscopy. And we're just not usually giving those to young people unless something is wrong.

12:33And what is interesting is that in older people in the U.S., rates of this kind of cancer have actually been decreasing. Like, fewer people are getting it, fewer people are dying from it. And we think that's partly because we've gotten, like, pretty good at getting older people to go get colonoscopies regularly, where they can catch polyps in your gut that might turn into cancer. So the rates in older people are going down, but the rates in younger people are going up? Mm-hmm. Yeah. It's a dichotomy or discrepancy of, like, why is it going down for most of the people who are getting this?

13:07Right. But going up particularly for young people. And because of that, several years ago, doctors did decide to lower the recommended age for your first colonoscopy, for most people, from 50 to 45. There's actually people who say it should be even lower. Okay. Another piece of all of this is that for a lot of these young people, the symptoms can be easily confused for other things. Here's Michael again. I have a young person right now who's in their 30s, in their mid-30s, who has an extremely aggressive cancer type

13:42that is very, very sick with metastases all over his bones. So this patient of Michael's has stage four colon cancer. And what's weird is that Michael told me that their main symptom was back pain. Wow. Okay. I mean, that could be anything. Like, who doesn't have back pain? I could imagine you wouldn't go and get seen for that, you know, certainly not by an oncologist. Who would think you'd have cancer just because your back hurts?

14:13Yeah, exactly. Here's Michael. Why are you having so much back pain? Why is this going on? No one would ever think about colon cancer. And then we found it. You know, we found it on a colonoscopy, and he's been ongoing with treatment. How did that patient react when they heard the news? They were absolutely terrified. Yeah, and the real reason this patient had the back pain was because the cancer had spread to his spine. Are they still with us? They are, yeah. And, you know, it's not great. They're treating the cancer, but it's aggressive.

14:45So basically, Michael and his team are just trying to make him feel better and give him as much time as they can. Less pain, at least. Mm-hmm. Yeah. Now, Michael says that that back pain as the only symptom is extremely rare. Yeah, we're really freaking everyone out, Michelle, with that one, that story.

15:04I'm sorry, yeah. But, you know, changes in your stool are much more common. Okay. Like blood in your stool and even abdominal pain. But even those symptoms are something that you could mistake for something else. Mm-hmm. Okay, actually, Michelle, I have a question for you. I have seen, like, a lot of chatter about this online and people talking about, like, symptoms to watch out for. But mostly they just say, like, look for any change in your bowel movements. It's like, get that checked out. And I find that really broad, like, not very helpful.

15:36I've seen those kinds of videos, too. And I'm curious, too, like, what exactly should you look for in your poop? Yeah. And so I asked Michael for you. Thank you. He told us that you shouldn't panic over a few weird poo days. Hmm. But it's more like if you see changes or feel pain that lasts for weeks, then get it checked out. This includes things like diarrhea, constipation, and dark, tarry stools or blood, like what Becca saw. And Michael has some more particular advice here, too. What we typically say with the stool is the stools become thinner, meaning, you know, if there's a tumor there, it starts to press on the colon and, like a little cylinder, squeezes the stool into a thinner shape, right?

16:20Because if there's less space in the tunnel, you have a smaller diameter there for the stool to go through. So it starts to get thinner. And while Becca, she had a lemon-sized tumor in her colon. Right. And she was talking about the skinny stools as well. Mm-hmm. Like, the mass was putting a lot of pressure on my colon, which was obviously making me having to go to the bathroom a lot more often. And the mass was also what was bleeding. So that's where the blood was coming from. That makes sense. But Becca's experience with her cancer speaks to another huge problem that doctors are seeing. Because some of this stuff, like some of these poo symptoms, they often don't show up until the cancer is already pretty far along.

16:57When the tumor is already there and has had a chance to grow and cause problems. Which is still so crazy to me because when I think about, like, how long I was having symptoms, really, it was like noticeable symptoms were only a few months. And it was still stage three. Yikes. And that plus the fact that some of the symptoms can be vague means that sometimes young people get misdiagnosed by doctors or even told they're too young to have colorectal cancer. So, you know, they don't get the tests that they need. Like, in a big survey, four in ten young people with colorectal cancer were initially told that they were too young to have it.

17:33Oh, wow. Okay. Overall, it can take, like, a really long time for young people to get diagnosed. And one study found that compared to older people, young people waited 40% longer to get a diagnosis from an oncologist. So, by the time they get to us, it's further along in their disease course. So, bottom line, it's not the disease itself that's doing something weird. It seems to be more like it's sneaking up on people and their doctors too. And getting found after it's had a lot of time to get dangerous.

18:06So, I guess that answers the question of why is it more likely to be caught at a later stage in younger people? But it doesn't answer the question of why are younger people getting it at all in such increasing numbers. Yes, that is the big question. And actually, we'll be looking at that next.

Causes

18:24Why is this all happening? Because I'm very impatient. I want to know now. Yes, so after the break, we'll take a look and talk to the scientist who's trying to find out. Okay, I can wait until after the break.

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21:48or any GLP-1 receptor agonist medicines. It is not known if ZepBound is safe and effective for use in children. Don't share needles or pens or reuse needles. Don't take if allergic to it. Or if you or someone in your family had medullary thyroid cancer. Or if you've had multiple endocrine neoplasia syndrome type 2. Tell your doctor if you get a lump or swelling in your neck. Stop ZepBound and call your doctor if you have severe stomach pain or a serious allergic reaction. Severe side effects may include inflamed pancreas or gallbladder problems. Tell your doctor if you experience vision changes before scheduled procedures with anesthesia,

22:23if you're nursing, pregnant, plan-to-be, or taking birth control pills. Taking ZepBound with a sulfonylurea or insulin may cause low blood sugar. Side effects include nausea, diarrhea, and vomiting, which can cause dehydration and worsen kidney problems. Talk to your doctor. Call 1-800-545-5979 or visit zepbounds.lily.com.

22:48Welcome back. I'm Michelle Dang. We just learned that colorectal cancer is on the rise in young people. And the question now is why? So we're on the trail trying to figure it out.

Investigation

22:59Like, what the hell is going on here? And I'm here with senior producer Rose Wermuller. Hello. Hey, Rose. So, yeah. One thing that comes up a lot is diet. People are eating a lot more ultra-processed food than they were before. Mm-hmm. And a big study just came out on this. It looked at this big data set of almost 30,000 nurses and their health. I don't know if you're familiar, like, the nurses. The nurses' health study? Yeah. Yeah. It's a group of nurses that have been followed for a long time and used in a bunch of studies.

23:32Mm-hmm. And what they found in this study is that people who ate the most ultra-processed food had a 45% higher chance of having polyps in their gut, which polyps can be harmless, but sometimes they do lead to cancer. Okay. So people who ate more ultra-processed food had more polyps. Very suspicious. It's not super surprising because, as we know from the ultra-processed foods episode, they tend to be associated with a lot of bad health outcomes. Mm-hmm. Um, as we know from the fiber episode, if you're not eating a lot of vegetables,

24:06you need the fiber and vegetables. Um, so that all makes sense that that would be bad for your gut and probably create an environment that could be helpful for growing cancer. Yeah. It's like we always come to that conclusion in Science vs. Episodes. We do. It's like, eat vegetables. Oh, okay. Mm-hmm. Over and over and over and over. Yeah. And that is because we do think there's some stuff that could be causing problems in ultra-processed foods, like preservatives. And then we also know that eating a lot of red meat, especially charred meat and processed meats,

24:41are linked to some cancers, too. Yeah. Actually, working on the ultra-processed food episode, I stopped buying, like, lunch meat. Oh, really? Like, sometimes I'd have, like, turkey, sliced turkey meat. Yeah, I don't eat that anymore. Sliced turkey meat? Yes, because it has nitrates and nitrites in it, and that has been associated with cancer. What about cheese boards? Cheese boards? Does that count? Oh, sorry. I meant, like, prosciutto and salami. Oh, like, charcuterie boards. Yeah, yeah, yeah. Charcuterie boards. Once in a blue moon.

25:11I don't set out my spread of, you know, peeled grapes and charcuterie boards every night anymore. Yeah. But, um, overall, it's probably a good idea to eat less of this stuff. And there are a few other risk factors that might be at play here, too. Things like obesity, lack of exercise, smoking, and alcohol. Mm-hmm. But I kept thinking, like, there's got to be something else going on here because I keep seeing and hearing stories of people with very healthy lives that eat great, exercise a bunch, yet still getting colorectal cancer at a very young age.

25:49So here's Dr. Michael Foote, who we heard from earlier. Most of the people that we see are actually pretty healthy. I have a patient who was a vegan, you know, who came in, and she was, like, astounded. She had an early-stage colon cancer, so we were able to remove it with surgery and then treat her, and she's doing well. But, you know, she didn't really drink very much. She didn't smoke at all. So, you know, that's kind of the scary thing, I think, for all of us. Yeah. I'm thinking about Becca, who we met earlier. She seemed very healthy.

26:19Mm-hmm. I don't know what she was eating, but it didn't sound like she was sitting down at McDonald's for every meal. Yeah. Similarly, Becca told me she wasn't big on processed foods or alcohol. I don't know. Like I said, I was 28. I was healthy. Like, I had just run a half marathon. I really wasn't thinking I might have cancer. My energy levels were fine. I was still go, go, go. So, what could be going on here? Lots of scientists are wondering if there's something else weird in the environment that people were exposed to that's maybe contributing to this or perhaps changed up the gut microbiome.

26:54They're on the hunt for explanations, and so I want to talk about one of these ideas. Okay, great. One scientist we talked to is looking for clues inside the cancers themselves, like the actual DNA of these tumors. And his name is Professor Ludmille Alexandrov, and he's a cancer biologist at the University of California, San Diego. I actually specialize in cancer genetics and cancer genomics, and my focus is on understanding the processes that cause cancer. Several years ago, Ludmille and several colleagues started this big study looking at the genetics of colorectal cancer tumors.

27:28So, what they did is they collected a bunch of tumors from people who had this kind of cancer. And they ended up with almost 1,000 tumors from across 11 different countries. Then they brought these samples back to the lab to test their genetic profiles. So, Ludmille says inside a tumor, you can see these molecular fingerprints. These are made up of unique patterns of genetic mutations that can actually tell you a lot about that person's life. Molecular fingerprints, which we call mutational signatures, are what cause the tumor.

28:02So, for example, if you smoke tobacco cigarettes, you're going to mutate in a very specific way many cells of your body, for example, the lung. And we can say, whoa, this person smoked cigarettes. If you drink alcohol, you can see exactly the same thing. Wow, I didn't know scientists could do that. That's kind of cool. Yeah, I didn't either. I don't know what my cells could tell about me. I know, I was just thinking that. And a good chunk of these samples were tumors that came from younger people. About 15% of all the samples we collected were early onset cases, which is a very large number.

28:38You wouldn't expect that number. When we were designing the study, we would expect it less than 5%. Oh, so you weren't looking for that at the time. No, not at all. Now that he had this data with all these younger people in it, he could compare the tumors to see if there were genetic differences between the tumors and the younger and older people. To try and see, like, was there anything different that might help explain why the cancer is showing up more and more in young people? And he found that, yes, there was something different between these two groups.

29:08There was actually this particular set of fingerprints that stood out. And essentially, the difference was striking. If you look at individuals who are younger than 40, more than 50% of them had these very specific patterns of mutations. And when they looked into this specific pattern, it turned out that this type of mutation is often caused by certain bacteria that find their way into the gut. Okay. And what can happen is that bacteria that get into our gut can release a toxin called caulibactin.

29:39Rose, what do you know about caulibactin? Caulibactin? I don't know anything about it. Does it have something to do with cauliflower? Caulibactin? Yeah. No, it does not have anything to do with cauliflower. Okay. Well, that was my best guess. But it's something that gets made by some bacteria. Like, for example, some types of E. coli make it. Oh. That's caulibactin. Yeah. It's more like a caulibactin than a caulibactin. Caulibactin. Caulibactin. Yeah. Yeah.

30:10And one thing that caulibactin does is it can damage our DNA because of how it works as a toxin. I think of it as a weapon system, a weapon system that certain bacteria have, and they use it to protect themselves from other bacteria. So this is like a weapon that the bacteria create for themselves? Yes. Exactly. So this is bacteria scooting around in our guts, pooting out this toxic substance. Yeah. I like that phrase, pooting.

30:41Yeah. If a bunch of these, like, bacteria get into your gut that make caulibactin, when the bacteria encounter other bacteria, they'll start pooting or shooting this stuff out in all directions. It's like a little bacteria war. Chemical warfare. Yeah, exactly. That's the theory. And some of that caulibactin could be slamming into cells in the wall of your gut, and that's where it can mess with your DNA. Oh, so that caulibactin chemical warfare stuff damages the cells of the gut, and somehow that damages your DNA as well?

31:18Mm-hmm. Yeah. To break it down a bit more, what happens is caulibactin can hit a cell and then cause damage to the DNA in that cell. The cell will try to repair that damage, but sometimes it doesn't work. So you get mutations, and when that cell replicates, of course, those mutations replicate too. Mm-hmm. And so sometimes mutations do nothing. Same thing with these caulibactin mutations, but other times they might be the first step toward a cancerous tumor. Right.

31:49But what's really interesting here is that Ludmille and his team were actually able to track down when these fingerprints were left behind because they could put together this genetic tree and track mutations over time. At a basic level, how it works is the trunk of the tree shows you the DNA's original state, and then it hits a mutation, grows a new branch. Then another mutation, another branch. This sort of thing allowed Ludmille's team to put together an estimate of how old the person was when this mutation happened.

32:19Wow. Yeah. This detective work is fascinating. Here's Ludmille again. We always saw that molecular fingerprint in the trunk of the tree. And what that means is that it happens very early. So studies have estimated that these caulibactin mutations happened when people were kids, before they were 10 years old. Ah, before they even had the chance to start drinking or smoking or… Yeah, yeah. Wow. So the seed is planted very early. Which is, you know, super surprising.

32:51And even more surprising, Ludmille says more recent work that's unpublished points to an even narrower window that it might have happened. The more proper estimate is probably within the first two years of life. Oh, wow. So we think it's happening something in very, very early life. What we think happens is that when you have a young child, a year old, two years old, their microbiome and their immune system are getting formed, the microbiome in the colon. And if they get disinfection, they get many, many mutations.

33:28And if you get many, many mutations at an early age, including some of the driving mutations that cause cancer, then if you get it at age two, well, now you're on the fast track for cancer. You get cancer in 20 or 30 years when you're a young adult.

33:45Two? Yeah, two. Oh, my God. This little baby. That's interesting. He says infection. Does he mean this bacteria that poots out the, what was it, colibactin? Is that the infection he's talking about? Yeah, when Ludmille says infection, he's talking about this idea that some kind of bacteria ended up in these people's guts as little kids. Okay. Maybe E. coli, which is pretty common in our guts. Maybe something else. And they pooted out a bunch of this colibactin.

34:17And maybe that contributed to colorectal cancer developing years and years later. Wow. Yeah. Now, we do have to mention here that it's correlation, not causation. We can't test this by putting this bacteria into a bunch of babies, you know. Yeah. But we do have studies in some mice showing that when you put colibactin-making bacteria in their guts, they do get more tumors. So, that's some more evidence of a potential link here. But let's assume that this is a real link. Do we have any idea, like, where this infection came from in the first place?

34:52So, we don't exactly know, but Ludmille was, like, the things that babies are exposed to that can affect the microbiome does change a lot from one generation to another. Like, younger people might have been exposed to more or different antibiotics. Maybe it's related to C-section rates or breastfeeding versus formula. Or maybe it's as simple as, like, a lot of us. Like, everybody got exposed to a particular bacteria, and it caused an infection, and it just happened to do more damage if it happened to you as a baby.

35:22And I suspect that these microbes, some microbes that may be very harmless for us when we're adults, are not that harmless for a one-year-old that's forming its immune system. Huh. Yeah. Like, it could have been a pandemic, a very quiet pandemic that some people are feeling the repercussions of now. Wow, that's fascinating. Yeah. And now, this is just one possible contributor. Uh-huh. Scientists are going full steam ahead to try to solve this mystery.

35:54Other suspects include other types of bacteria, maybe viruses, also chemicals in the environment, or medications, like the antibiotics. That makes sense. So, overall, we're getting a bunch of hints here, but no clear smoking gun. And this means that people like Becca don't have answers about where their cancer might have come from. But the good news is that Becca's doctors got her into treatment fast after she was diagnosed. So, Becca had surgery. They took out the tumor, some lymph nodes, and more than a foot of her colon.

36:28Oh, man. And they got rid of all the cancer that they could find, but doctors also had her do chemotherapy last year. And after her last treatment, she celebrated with friends. Like, they had a picnic in the park. I asked her what they had. Oh, gosh. I think we just had a lot of cheese. It was really funny. I met with a dietician early on during chemo, and they actually told me to, like, eat a lot of cheese. That's a nice blessing. Yeah, say less. Like, I'll have no problem eating a lot of cheese. But she's not totally out of the woods.

36:59I finished, in quotes, end of August. And so now people will ask, like, so you're done now, right? And it's like, yes and no. So, Becca has to go back every three months for scans and blood work. And this part will last two years. There's a 25% chance of her cancer coming back during this time. Hmm. Um, so every three months, I get to be, like, a ball of anxiety and not know what's going to happen.

37:30But other than that, I'm just trying to, I don't know, focus on being here and feeling good right now. What do you wish you had known? I wish I had a good answer for this. I don't know. I, I think the biggest hurdle for me was, like, getting over this fear of being, like, thought of a certain way, right? Like, my life was kind of always going 100 miles an hour. And I feel like I had built a big part of my personality around, like, being this very independent person.

38:01And nothing will humble you faster than this experience. And so, I think it was, it was actually that first support group I went to with all of the, like, 70-year-old women. And one of them just told me, like, you have to learn how to let the love in. Like, you have to. Like, you can't do this by yourself. And so, I think, I think I would tell myself, like, it's going to be okay. Um, and, you know, your friends are going to show up in ways that you would never have expected. And, like, that's what's, that's what's really going to get you through it is the people in your life.

38:36That's Science Versus. All right. Thanks, Michelle. Thanks, Rose.

38:46Before we get to the citations, we've got a special sponsored segment for you with a very fun fact from the team. You're going to hear from Science Versus producer Aketty Foster Keys. Here it is.

38:59This segment is brought to you by the all-new Audi Q3. Here's an impressive fact. The Q3 features a roomy, comfortable, refreshed interior with a 12.8-inch touchscreen. Now, let's get to Dinner Party Genius.

39:20I'm Aketty Foster Keys, and this is our segment, Dinner Party Genius, sponsored by Audi. I'm here with senior producer Meryl Horne. Hi, Meryl. Hey, Aketty. We're here to give you a fun science fact that will help you charm the crowd at your next party. Okay, Meryl. So, the fact that I want to talk to you about comes from research that I've been doing about running. Huh. For an episode coming out soon. And it's about really long-distance running, like ultramarathons. Hmm.

39:50Science is still figuring out what happens to our body when we run for super long periods of time. And it turns out there might be something strange going on in our brains when we do this. Huh. So, there was a small study that looked at runners who competed in a really long race. Like, they went all the way from Italy to Norway. Whoa. How long is that? It's close to 2,800 miles and more than 4,000 kilometers.

40:22Oh, my God. Okay. So, this is like Forrest Gump level running. Yeah, exactly. Jeez. And, of course, they got their brain scan along the way. Oh, so they popped into a brain scan during the run. Got it. Right. And so, when scientists looked at the scans, they found something that they weren't expecting to see. They saw that during the race, these runners, their brains shrank a little. Ooh, that sounds bad. Yeah, it does sound pretty bad, right?

40:52Yeah, their brains shrank. Okay. Yeah. They lost, on average, about 6% of their gray matter. But, the good news is, it wasn't permanent. Oh, okay. Well, that's good. The scientists also scanned people's brains after the race, about eight months afterwards. And their brains had gone back to normal, like nothing had ever happened. So, if you ever run over 2,000 miles, your brain might shrink a little bit, but don't worry. It'll all bounce back when it's over.

41:24That's the fun fact. Yeah. It might shrink, but it might come back, too. It will come back. Okay. Do you feel prepared for your next dinner party? Oh, yes, yes. I am so prepared with this fun fact. Yeah, I am ready for the party. Okay. Thanks, Meryl. Thanks, Akere.

41:48That segment was brought to you by the all-new Audi Q3. Here are a few more fun facts. The all-new Audi Q3 features more power and more space than ever before. Plus, Quattro all-wheel drive gets you there with confidence. It's built to impress. Kind of like you at your next dinner party. Say yes to the all-new Audi Q3. Made for the yes life. Learn more at AudiUSA.com. Okay, Rose, we're back.

42:19Time for citations. Can I tell you how many we have in this week's episode? You sure can. There are 72 citations. And where can people find them, Rose? You can find them in the transcript of the episode. And you can find that by clicking a link in the show notes. Cool. Thanks, Rose. Thanks, Michelle. Thanks, Michelle. This episode was produced by me, Michelle Dang, with help from Rose Rimler, Meryl Horn, and Aketi Foster Keys.

42:50Wendy Zuckerman is our executive producer. We're edited by Blythe Terrell. Fact-checking by Erica Akiko Howard. Mix and sound design by Bobby Lord and Bumi Hidaka. Music written by Bobby Lord, Bumi Hidaka, So Wiley, Emma Munger, and Peter Leonard. And thank you to Professor Caitlin Murphy. Science Versus is a Spotify Studios original. Listen for free on Spotify or wherever you get your podcasts. Follow us and tap the bell for episode notifications. We'll factor soon. We'll be right back.