Time Stamps

  • 01:24 Screening Options Besides Colonoscopy
  • 11:22 How FIT, FIT-DNA, and CT colonography differ and when each makes sense
  • 12:52 Colonoscopy and Frequency
  • 19:29 How adenoma number, size, and histology guide surveillance intervals

Show Notes

Pearl 2: The best test is the one that gets done

  • Colorectal cancer screening, regardless of form, reduces risk of developing colorectal cancer!
    •  And also reduces mortality and system cost
      • Example: A study by Kaiser Permanente 
        • D dedicated outreach efforts (e.g., sending screening reminders, at-home fecal immunochemical testing kits) 
          • Reduced CRC deaths among Black patients 
            • 52 per 100,000 in 2009 to 23.5 in 2019 
          • Deaths per 100,000 for Hispanic, white, and Asian patients decreased to 20 during the same time period.
    • Other studies:
      •  Risk of developing colorectal cancer was lower in patients invited to undergo colonoscopy vs those that were not.
  • Population health goal = get screening to 80%
    • currently are at 60%.3
  • In normal-risk individuals, there are a host of potential “non-invasive” tests that can be utilized 
    • Fecal Immunochemical Test (FIT):  Stool card test that is sent back to lab and can be sent to patients directly
      • Methodology: Tests for human hemoglobin;
        • Test positivity depends on what µg/g cutoff is used to indicate a positive result (e.g., 10 µg/g vs 20 µg/g)
      • Frequency: Needs to be done yearly 
        • Pros: Done at home
        • Cons: Recall can be an issue
      • Accuracy: Sensitivity and specificity are dependent on the screening cut-off for the test
        • In one meta-analysis from 2019, pooled sensitivity ranged from 71 – 91%, and specificity ranges from 90 – 95%.
      • No specific complications
    • Cologuard (i.e., FIT-DNA): Stool based test
      • Methodology: Combines stool DNA for advanced polyp (1cm or bigger) + a FIT test
      • Frequency: Done every 3 years
        • Pros: Done at home, covered by ALL insurance
      • Accuracy: Specificity 87-90%, Sensitivity 92-94%5
    • CT Colonography: An imaging test that is less commonly used for screening due to its relatively invasive methods without offering intervention
      • Methodology: Effectively the same as colonoscopy in that you require a bowel prep and colonic insufflation for evaluation
      • Frequency: Every 5 years
      • Accuracy: Sensitivity 73-99%, specificity 80-93% for polyps >6mm
    • Blood based tests: Newer tests for detection of colorectal cancer with less ability to identify advanced polyps.
      • Blood based tests are still NOT recommended 
        • Low sensitivity 
        • Lack of longitudinal and comparative data on test performance
      • Advancements in tests continue! 
        • Certain tests demonstrating ability to detect and monitor ongoing presence of early-onset CRC.7
          • Specificity of 87.5% (95% CI, 79.4%–92.7%)
          • Sensitivity for screening-relevant EOCRC stages I–III was 97.3% (95% CI, 90.6%–99.3%) and the sensitivity for premalignant lesions with high-grade dysplasia was 61.5% (95% CI, 35.5%–82.3%). 
          • Observed a reduction in the liquid biopsy values after surgery, reaching negativity after 4 days.
      • Tip:  blood tests can be a part of the armorarium for screening for patients that otherwise do not undergo other types of screening
  • Non-invasive tests are two-step tests! 
    • Positive non-invasive tests require colonoscopy as follow-up!
      • Set this expectation up-front!
        • If patients are unwilling to undergo colonoscopy then they should not get colon cancer screening as the outcome will be the same regardless
      • Patients who undergo colonoscopy with adequate prep AND with an endoscopist with adequate adenoma detection rate and have negative findings… 
        • Could be considered for a return to non-invasive testing
      • Patients who undergo colonoscopy and are found to have adenomas will typically require ongoing surveillance with colonoscopy! 
        • At this time, there is no role for returning to non-invasive methods. 
          • However, there are studies that are exploring this.
    • TIP:  Patients with known causes of rectal bleeding (e.g., hemorrhoids)
      •  Could interfere with FIT or Cologuard and may be poor candidates for screening with these methods!

Pearl 3: Colonoscopy is the gold standard for colorectal cancer screening, as it is currently the only test with the potential to identify and intervene upon precancerous polyps

  • ACG guidelines are concrete regarding the different thresholds for time between screening colonoscopy! 
    • Depends on:
      • Number
      • Size
      • Types of polyps removed
    • Intuitively, lower risk findings get longer intervals between screening while higher risk findings require shorter intervals 
      • Example 1-2 tubular adenomas <10mm in size 7-10 years vs 5-10 tubular adenomas, 1 adenoma >10mm 
        • Or containing villous histology or high grade dysplasia results in 3 year window
    • The windows between colonoscopy screening are largely driven by the underlying mechanisms behind which CRC develops!
      • The majority of CRC develops through the well-described adenoma-to-carcinoma sequence
        • Of sporadic CRC, approximately 70% develop from adenomatous polyps and the remaining 30% from sessile serrated lesions (SSLs) through the SSL-to-carcinoma sequence.
      •  In both pathways, the relatively slow development of the majority of CRC from precursor lesions (over the course of 10-15 years) 
        • Presents a valuable opportunity to prevent CRC and identify patients in early disease stages.
  • Patients with normal screening colonoscopies who can wait 10 years for their next surveillance! 
    • Have the full range of screening options available to them, including noninvasive options (e.g., Cologuard).
      • This is in contrast to diagnostic colonoscopies (i.e., after a positive FIT or cologuard) 
        • If a patient has a positive non-invasive test but negative colonoscopy, there is currently NO evidence to support returning to non-invasive screening methods
    • Even if a patient has a normal colonoscopy, it remains critical to continue to screen for red flag symptoms!
      •  CRC can sometimes develop rapidly and aggressively, or an adenoma can be missed.
  • For patients that are high-risk (e.g., familial polyposis syndromes, inflammatory bowel disease, family history of early-onset CRC), colonoscopy remains the only recommended screening approach for colorectal cancer

Transcript

Dr. Xavier Llor: I think it’s still true that the best approach when it comes to colon cancer screening is the one that gets done, meaning we need to get people screened one way or another.

Dr. Shreya Trivedi: Welcome to the Core IM  Five Pearls podcast, bringing you high-yield evidence-based pearls. I’m Dr. Shreya Trivedi.

Dr. Stephen Le Breton: And I’m Stephen Le Breton, an internal medicine resident at Beth Israel Deaconess Medical Center.

Dr. Shreya Trivedi: And today we’re going to compare the four non-invasive and perhaps more accurately two-stage screening options, and we’ll go through exactly what each of the tests are detecting and how to better counsel our patients when they do get a positive result that requires a colonoscopy. And then we’ll cover surveillance intervals after colonoscopy and really try to synthesize it in a way that makes sense because of course, it’s not only clinically relevant, but also very relevant for boards. And you’ll hear from four GI experts.

Dr. Xavier Llor: My name is Xavier Llor. I’m a gastroenterologist, and 11 years ago I moved to Yale to head the GI cancer prevention program.

Dr. Rachel Issaka: My name is Dr. Rachel Issaka. I’m a gastroenterologist and a health services researcher at the Fred Hutchinson Cancer Center and the University of Washington in Seattle.

Dr. Joseph Feuerstein: My name is Dr. Joseph Feuerstein. I’m the clinical chief with gastroenterology at Beth Israel.

Dr. Samir Gupta: I’m Samir Gupta. I’m a gastroenterologist and a professor of medicine at UC San Diego.

Dr. Shreya Trivedi: All right, let’s dive in.

Screening Options Besides Colonoscopy

Dr. Shreya Trivedi: Okay, so let’s say we’re thinking about screening colonoscopies. We have a patient who’s 48 years old for a well visit talking through the different options we have for screening. Remember, this is not diagnostic, this patient’s asymptomatic. How do we think about the best options for colorectal cancer screening?

Dr. Stephen Le Breton: I do think there’s this implicit idea that colonoscopy is the gold standard and that everything else is somehow second best. But I think the hot take for screening options for colorectal cancer is that there really is not a one-size-fits-all for patients, especially those that are not at increased risk. So practically speaking, I feel like my head canon has always been to separate these tests into screening as invasive or non-invasive tests.

Dr. Shreya Trivedi: Yeah, I love that because I can imagine there’s probably a group of patients who would not want to do a stool test, and then there’s another probably group of patients who’d want to avoid a colonoscopy at all costs.

Dr. Stephen Le Breton: I’m so glad you brought that up because even before we get into the non-invasive tests, it’s so important to tell our patients that if this non-invasive test is positive, then you need a diagnostic colonoscopy.

Dr. Rachel Issaka: If there’s anything I want listeners to walk away with, it’s really understanding that all of those non-invasive tests are what we consider to be a two-stage screening strategy, meaning that if somebody has an abnormal result for whether it be FIT, a capsule colonoscopy, or a virtual colonoscopy, that they in fact need a full colonoscopy examination of their colon to correlate with those abnormal results. And a lot of patients sometimes forget that or don’t get that message when they initially complete those tests. They often think that these are one and done tests and they’re simply not.

Dr. Shreya Trivedi: Yeah. So it sounds like we shouldn’t be calling these tests non-invasive, but really just relabeling them as two-stage screening tests.

Dr. Stephen Le Breton: I love that. And this is really why we should ask before ordering a stool card or a CT colo if a person is even willing to undergo a colonoscopy. And then the second important thing is to set that expectation for what a positive test for these two-step tests might mean.

Dr. Joseph Feuerstein: A positive test by no means indicates cancer. A positive test, for example, on a multi-stool DNA just indicates there may be an advanced polyp. And again, this is the concept of colon cancer prevention so that when we do a colonoscopy, we can still remove that polyp and prevent cancer.

Dr. Shreya Trivedi: Yeah, I really appreciate the framing also that this is cancer prevention, right? We’re in the business right now trying to find and prevent polyps from escalating into cancer. So let’s start with our first two-stage screening cancer prevention test, which is stool testing. I think this is the one that most of us have heard about, and the first step would be a FIT, which is a type of FOBT, a Fecal Occult Blood Test.

Dr. Stephen Le Breton: So FIT is the classic stool card that we think of. It detects a globin part of the hemoglobin, which makes it more specific than the older Guaiac FOBT tests. That being said, it still doesn’t have great sensitivity because it relies on both the size of the adenoma and it needs for these early-stage cancers or advanced adenomas to bleed. Adenomas that are less than six millimeters are essentially invisible to the FIT, and it really doesn’t do much better up to nine millimeters.

Dr. Shreya Trivedi: Yeah, I think that helps set the rationale for getting a FIT yearly. So the rationale for the annual FIT is that repeating the testing over time compensates for a low single-test sensitivity, right? The lesion might not bleed on one occasion, but might bleed on another. So we’re going to yield a cumulative sensitive fatigue that’s going to be higher than just the one time sensitivity.

Dr. Stephen Le Breton: Awesome. Let’s move on to the FIT DNA, or I think as a lot of us know it, as the Cologuard. So this is a test that is sent directly to home and is covered by all insurances. It combines both the FIT test that we just talked about as well as stool DNA for advanced polyps, which are defined as polyps that are one centimeter or bigger.

Dr. Joseph Feuerstein: The FIT test is purely looking at blood in the stool. It’s an immunohistochemical test that’s being run. The stool DNA test, in order to increase its yield above FIT testing, they combined a two-part test. So it’s looking for both stool DNA and blood in the stool.

Dr. Stephen Le Breton: So that combination in the Cologuard improves sensitivity, but at the expense of more false positives.

Dr. Joseph Feuerstein: So when we talked about a false positive of the Cologuard test, I don’t know, is it a false positive because the stool DNA was positive, or was the FIT test positive because there was a drop of blood in the stool, let’s say from a hemorrhoid or something else. And that’s why stool DNA has up to 7% false-positive rate that goes up as one gets older as well.

Dr. Shreya Trivedi: Yeah, I think it’s so tricky when people have hemorrhoids, and we push our discussions like, what would they do for these patients? And they did say try to avoid a FIT or Cologuard in someone who has known hemorrhoids, or say a FIT comes back positive and the patient tells you later, “Oh, maybe it’s from their hemorrhoids.” Then the GI physician said, “No, they would still want this person to go be seen by GI for a colonoscopy.”

Dr. Stephen Le Breton: Hemorrhoids are so common, especially in the day and age where all of us are scrolling on our phones on the toilet every single day.

Dr. Shreya Trivedi: So real.

Dr. Stephen Le Breton: And the other reason for this higher false positive with the Cologuard is because there’s so many different types of pathology in the GI tract beyond adenoma that could drive the false positive results, particularly with either the blood or the stool DNA.

Dr. Rachel Issaka: With FIT DNA, we tend to see more false positives, but that’s in large part because the changes in DNA that the test is looking for are not specific to colorectal cancer and can be associated with other cancers of the gastrointestinal tract. In fact, we’ve seen data show that when patients have an abnormal fit DNA and get a normal colonoscopy, that endoscopists, one spend more time looking throughout the colon because they’re worried that they’re missing something, and that they also order more tests, for example, recommending an upper endoscopy or recommending a CT scan because they’re worried and they want to make sure that those changes from DNA are not indicative of cancer elsewhere in the gastrointestinal tract.

Dr. Shreya Trivedi: Yeah, I think that makes sense with the added benefit of catching DNA from the GI tract with the trade-off of wondering, oh, are we missing something in the colonoscopy? All right, next up and third, let’s briefly talk about blood-based tests, which are newer, and I have to say something I had not heard about before.

Dr. Joseph Feuerstein: Now there’s also actual cancer tests as well, which are new. Those are the blood tests. So that I would say is a little bit of a change because really what we’re talking about in GI in general is colon cancer prevention. We call it colon cancer screening, but that’s a misnomer. We’re really trying to prevent colon cancer. We’re trying to find a polyp, remove the polyp before it ever becomes a cancer. A blood test for cancer identification is actually a cancer screening test, and that is a different type of modality.

Dr. Stephen Le Breton: So the nuance for these blood-based tests are that they’re actually screening for colorectal cancer specifically, and they have less of an ability to identify those advanced polyps in the way that the other two-stage screening tests do.

Dr. Shreya Trivedi: Okay. So from what I understand, these blood-based tests are not recommended yet, so why are we talking about them?

Dr. Stephen Le Breton: So I think it’s because we have this goal of reaching an 80% colorectal cancer screening rate in the US, and so this could potentially be a part of the armorarium of tests that we could use.

Dr. Rachel Issaka: That 80% goal that we’re trying to reach in this country, that number is hovered around 60 to 65% for a really long time, and everybody’s grappling with how do we get to that 80% goal? And for some people, the belief is that blood-based tests is the thing that will get us there.

Dr. Shreya Trivedi: Okay, so it sounds like these blood tests may be helpful in the future for people who we can’t capture through our usual screening mechanisms, but the big caveat is that these blood tests are not good at detecting precancerous lesions and more just for the actual colorectal cancer.

Dr. Rachel Issaka: The fourth one I’ll mention is the CT colonography, what’s sometimes called a virtual colonoscopy. And this is a CT scan in which we’re, again, taking pictures of an individual’s colon and then looking for polyps in that way. The CT colonography and the capsule endoscopy are most likely going to pick up polyps that are a little bit larger, so six millimeters or larger in size; they aren’t necessarily going to see those smaller polyps that well.

Dr. Stephen Le Breton: So a CT colonography is effectively very similar as a colonoscopy in that you still have to do a bowel prep, need to undergo colonic insufflation for evaluation. And since it detects polyps based on morphology rather than biology, it ends up being kind of similar to FIT in that there’s a size threshold to actually detect these polyps, and that reflects the spatial resolution of the imaging rather than testing for a biological property of the lesion.

Dr. Shreya Trivedi: Yeah, so it’s similar in terms of that six millimeter threshold of catching adenomas the way we would see with the stool-based testing and sounds similar in terms of the CT colonography. One thing that I find is interesting that we’ve bucketed this under the non-invasive two-stage screening, because I don’t know about you, Steve, but doing prep seems pretty invasive to me, but it is what it is. I guess it still counts as someone not doing a colonoscopy. But I think it is fair to say with all of these, we still have to remember even with CT colonography, if there is something even slightest detected, you still have to go through the colonoscopy and get the actual removal of the polyp or mass that might be found.

Dr. Stephen Le Breton: Exactly. So to summarize, my own takeaway from this pearl is that these tests are not just different in convenience, but they’re actually looking for fundamentally different things. The FIT is asking, “Is it bleeding today?” Whereas the FIT DNA or Cologuard is asking, “Is it bleeding or shedding abnormal DNA?” And then the CT colo asks, “Can we physically see a polyp that is large enough to detect on imaging and is intervenable?”

Dr. Shreya Trivedi: Yeah, and then I think once I started thinking about it this way, then the strengths and limitations of each test made a bit more sense to me. And I think another way to think about it is from a sizing perspective: tiny adenomas under six millimeters, they’re basically invisible to stool testing. They’re not shedding enough material yet. The FIT DNA adds a bit more sensitivity, but you still struggle with smaller lesions. But as lesions do get larger, particularly greater than 10 millimeters, they become more biologically active, bleeding more or structurally louder that you might catch it on CT colonography, and those detection rates get higher.

Dr. Stephen Le Breton: Exactly. And it also helped me understand why the annual FIT matters so much, because FIT is not a one-time snapshot. It’s more like repeated surveillance for intermittent biologic activity. And so a polyp that isn’t bleeding this year may bleed next year as it continues to grow.

Dr. Shreya Trivedi: Yeah. And ultimately, I think the underlying message is not to think, okay, what’s the best test? But one, what’s the best test that is most likely going to get done? And then from there, understanding the limits and the reasoning behind the frequency and the follow-up. 

 Colonoscopy and Frequency

Dr. Shreya Trivedi: So now that we walk through the two-stage screening tests, a.k.a. the non-invasive screening test, let’s talk about what most people consider the gold standard: colonoscopy.

Dr. Stephen Le Breton: Right. The stool and imaging tests can only flag that something might beep. Colonoscopy is amazing because it’s both diagnostic and therapeutic. It finds those precancerous polyps and then removes them in the same procedure before they can grow into those cancers.

Dr. Shreya Trivedi: Yeah. And just to emphasize something Dr. Feuerstein said in our last section, this test, the colonoscopy, or if you’re getting a sigmoidoscopy, similar idea- we’re thinking about cancer prevention because a colonoscopy or the flex sig is going to find and remove the polyp before it can progress to cancer.

Dr. Stephen Le Breton: Exactly. But the practical next step to discuss is what comes up when frontline conditions are counseling patients when to re-screen after colonoscopy. And the surveillance interval depends on the number, size, and histology of the polyps found.

Dr. Samir Gupta: Our guidelines recommend that for people who have conventional adenomas or ulcerated lesions, that they have some kind of colonoscopic surveillance based on the numbers, size, and type of polyps that could be one year, it could be three, it could be five or seven, it could be ten years, depends on the lesions. For people who have simple hyperplastic polyps in the distal colon, that’s treated as a normal finding. Almost all those patients can go 10 years.

Dr. Shreya Trivedi: Yeah, so the ACG guidelines are pretty concrete with what are the different thresholds for one-year follow-up versus three, five, seven, and 10-year follow-up. And I think importantly, all these recommendations are assuming that you’ve had a high-quality colonoscopy with adequate prep and complete polyp removal, and that’s also wording you want to look out for on board questions and things too. And honestly, before this episode, I’d probably just memorize this before board prep and then immediately forget about them.

Dr. Stephen Le Breton: Exactly. And they’re so hard to remember that I always feel like I have to look them up when I’m in clinic and advising patients on this. But the pattern actually becomes pretty intuitive if you just think: how worried are we that this colon is growing a dangerous polyp, and how much of a polyp farm is this patient?

Dr. Shreya Trivedi: I never heard that term before this episode, but I guess it makes sense. So let’s start with the low-risk findings. You get longer intervals with that. So if someone has a normal colonoscopy 10 years, if they find one to two small tubular adenomas and the threshold that you want to remember is under 10 millimeters, that’s pretty reassuring, and you can get away with seven to 10 years.

Dr. Stephen Le Breton: Exactly. But as either the number of adenomas increases or the biology looks more aggressive, the interval shortens. So when a patient has three to four small adenomas, we’re looking at about three to five years. 5 to 10 adenomas, we’re looking at three years. And any advanced adenoma, meaning one that’s 10 millimeters or larger, has villous histology, or a high-grade dysplasia, also gets a three-year or shorter follow-up.

Dr. Shreya Trivedi: Yeah. I think the memory trick for me was thinking similarly the size and number threshold, and I think it’s the number member is 10. So if there’s more than 10 adenomas, you worry. Or if it’s more than 10 millimeters or AKA one centimeter, if you need to do that conversion in your head, you also worry. So that histology also is there, but then the number greater than 10 or the size greater than 10 millimeters or one centimeter.

Dr. Stephen Le Breton: And I think one thing to think about too is that if someone has more than 10 adenomas on a single exam, and really kind of  is a polyp farm, as we like to say, you start thinking more beyond routine surveillance, and you might start to consider a polyposis syndrome.

Dr. Shreya Trivedi: Yeah. And we should also say there’s a whole separate conversation about serrated polyps, which behave a lot more aggressively and progress a lot faster than the classic adenoma carcinoma pathway that we expect to move along after the classic adenoma carcinoma pathway that usually kind of takes 10-ish years.

Dr. Stephen Le Breton: Right. And we won’t get all into the serrated surveillance intervals here, but I think the simple rule of thumb is really that large serrated lesions or serrated lesions with dysplasia should make you think that a patient is higher risk and usually warrant closer surveillance.

Dr. Shreya Trivedi: And then a point about normal colonoscopies, I think it’s important to remember that just because someone has a normal colonoscopy doesn’t mean they’re completely in the clear for the next 10 years.

Dr. Stephen Le Breton: And so going back to one of our earlier points, it’s really important to keep screening for symptoms even after a patient had a “normal colonoscopy.” It’s important to remember, endoscopists are humans too, and things can be missed, or things can just grow really, really fast. One of the reviewers actually mentioned a patient who literally had a colonoscopy six months prior to their colorectal cancer diagnosis, and then the repeat colonoscopy ended up showing a new colorectal cancer.

Dr. Shreya Trivedi: Humbling is the word for this episode. Okay, so let’s round out this what happens after a normal colonoscopy discussion. Let’s say someone initially had an abnormal stool test, a FIT, in the past. Can they ever go back to one of those non-invasive options that we talked about in the last section?

Dr. Samir Gupta: Well, if someone has, for example, an abnormal FIT and a normal colonoscopy, and it was done by a colonoscopist with an adequate adenoma detection rate, the bowel prep was excellent, that patient’s at low risk for colon cancer, and they can wait 10 years before repeating colon cancer screening. After 10 years have gone by, they can consider all options. So they could consider doing a non-invasive test at that point or doing a colonoscopy. Most of those patients end up being recommended at doing colonoscopy, but the option is there.

Dr. Shreya Trivedi: So a positive FIT test does not permanently lock someone into colonoscopy surveillance. If the follow-up colonoscopy was truly normal, with the caveat being one: did the patient have adequate prep? And two, did the endoscopist have an adequate adenoma detection rate? Which I think is, I just want to point out- it’s ironic to say because it’s something that’s described a lot in the literature, but in practical real life, it’s not like you’re going to be able to look up a GI doctor and look up what their adenoma detection rate is.

Dr. Stephen Le Breton: Exactly. And just to say it out loud, if the colonoscopy does find adenomas, then there’s no returning back to those non-invasive tests. Of course, there is ongoing research that’s exploring this idea and actually looking into whether some of these patients could get away with just annual FIT testing versus continuing on colonoscopy-based surveillance.

Dr. Shreya Trivedi: Okay. So what I’m taking away is that with colonoscopy surveillance, we should be really thinking about how worried are we that this colon is going to keep making dangerous polyps? And so if we find one to two tubular adenomas that are small, what does small mean? If they’re less than 10 millimeters or less than one centimeters, we’re okay with following up seven to 10 years after removing one to two tubular adenomas that are small. Say you have three to four small tubular adenomas; come back in three to five years, a bit more gray, but being more cautious. And then where do you want people to come back in three years? So if it’s five to 10, small tubular adenomas less than 10 millimeters, or if the sizing or the histology worries you. So if the size of any adenomas is more than 10 millimeters or one centimeter, that bothers you coming back in three years, or if the path report of any-sized adenoma is high grade dysplasia, come back in three years. And if the number is greater than 10 adenomas, then come back in one year, and let’s evaluate for polyposis syndrome.

Dr. Shreya Trivedi: And that is a wrap for today’s episode. If you got anything out of this podcast, if it inspired you, or ask us to please send it to one other colleague who might also learn something from this episode too.

Dr. Stephen Le Breton: And a big, big thank you to our discussants, Dr. Samir Gupta, Dr. Rachel Issaka, Dr. Xavier Llor, and Dr. Joseph Feuerstein, as well as our peer reviewer, Dr. Elizabeth Housman.

Dr. Shreya Trivedi: And thank you to Dr. Dexter Nwachukwu for the graphic, as well as all the other people who made this episode possible. As always, we love hearing feedback. Please email us at hello@coreiampodcast.com. Opinions expressed are our own and do not represent the opinions of any affiliate institutions. Thank you and take care.

References