TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine in Baltimore, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week.
This week's topics include utility of polygenic risk score and coronary calcium scans in predicting heart disease risk, positron emission tomography (PET) scanning in assessing cognitive impairment, promoting "goals of care" discussions, and integrating data for colon cancer survival prediction.
Program notes:
0:40 Integrated atlas for colon cancer and survival
1:40 Specific immune responses
2:40 Data to integrate in clinical care
3:41 Goals of care discussions
4:41 Wide range of ethnicities included
5:42 Just clinician facing not as effective
6:43 Figure out from the patient's standpoint
7:01 Coronary artery calcium and polygenic score
8:01 Traditional risk factors plus
9:01 Either lower or higher number
9:35 Clinical utility of PET scan in patients with cognitive symptoms
10:35 7.5% saw changes in diagnosis
Transcript:
Elizabeth: How helpful is PET scanning in diagnosing Alzheimer's disease?
Rick: Predicting the risk of coronary heart disease with either coronary calcium or gene risk.
Elizabeth: How can we promote communication about goals of care for hospitalized patients with serious illness?
Rick: And integrating data to predict survival with colon cancer.
Elizabeth: That's what we're talking about this week on TTHealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I'm Elizabeth Tracey, a Baltimore-based medical journalist.
Rick: And I'm Rick Lange, president of Texas Tech University Health Sciences Center in El Paso, where I'm also dean of the Paul L. Foster School of Medicine.
Elizabeth: Rick, I'm going to ask you to start with this notion of this integrated tumor, immune and microbiome atlas of colon cancer. That's in Nature Medicine.
Rick: Elizabeth, we've talked before about what we call "omics." Things like metabolomics and genomics -- different data sets that we can obtain from looking at either tissue or fluid specimens to predict a number of things.
This particular article deals with using omics to actually predict outcome of survival with colon cancer, a comprehensive genomic analysis on fresh-frozen samples from 348 patients affected primarily by colon cancer, and then they match that to healthy colon tissue. They looked at whole-genome sequencing, microbiome, and they looked at the immune system, to say, "If we use a combination of all three of those things, how well do they do compared to what are called conventional prognostic molecular biomarkers?"
What they determined was that if they used all of these things they could identify gene sequences; they could identify specific immune responses -- that is, a type 1 helper T cell -- they could use gene expression and furthermore a particular microbiome signature, Ruminococcus bromii. All of these were associated with a favorable outcome. In fact, when they combined all of those things together they identified a group of individuals that had excellent survival probability -- much better than conventional prognostic molecular biomarkers.
Elizabeth: These things are, of course, really sexy and fun, aren't they? These integrated giant datasets and attraction of their predictive capabilities. My question is, OK, what's practical about this? Does this tell us, like, "You need chemotherapy and you don't" or "This other intervention is going to be better for you"?
Rick: Great questions. I'd say there are two things that contribute to this particular information and its success. One is the ability to do all of these analyses fairly quickly and to do extensive analysis. Now, we have the data to be able to integrate that and use computer systems that allow us to do that.
Although this is just one particular cancer, I think it will become more widely available very quickly. I agree with you. It will tell us who is likely to do well and not do well and more particular I think we could use this to actually gauge what type of therapy we should use. Should we use an immunotherapy? Should we use a chemotherapy? This is the kind of information I think that we need to help drive those decisions.
Elizabeth: I would also point out, of course, that these are snapshots in time and that there is probably going to be the need to sequentially look at how all of these parameters change in somebody as their cancer develops and see the practicality of that.
Rick: That's true, Elizabeth. One of the things, for example, is we talked about a particular microbiome that was associated with improved outcome. It appears that microbiome might actually somehow modulate the immune system to attack cancer. If we do that, we can enrich the microbiome with that particular bacteria by administering something orally that can actually enhance anti-tumor immunity. That looks pretty exciting.
Elizabeth: We're watching. Let's turn to JAMA. This is something that's, of course, near and dear to my heart in my chaplain role. This is a look at an intervention to promote communication about goals of care for hospitalized patients with serious illness. They are trying to employ technology to try to facilitate this whole process, and they want to look at what's the impact of this.
What they did was a pragmatic randomized clinical trial of a clinician-facing communications-priming intervention versus usual care at three U.S. hospitals including a university, county, and community hospital, which I think is extremely important.
It involved providing the physicians with a one-page, patient-specific intervention, so-called Jumpstart Guide, to prompt and guide goals-of-care discussions. Their outcome was, were there documented discussions that they were able to see in the electronic health record within 30 days? They had 2,512 patients who were enrolled. A wide range of ethnicities were represented.
I thought that the outcome was a little bit soft. Among those who had a goals-of-care discussion documented, that was 34.5% of the people in the intervention group, versus 30.4% in the usual care group.
They do talk a lot about how this differs from their previous research. Their previous research included what they called a "bidirectional intervention" that used patient surveys to populate a one-page guide, summarizing the patient-specific communication and care preferences, as well as communication prompts, including example language. In that study, they were able to really dramatically improve this, from 31% to 74%. What they tried to do in this study was really facilitate the whole thing by employing technology and clearly had a much more incremental benefit.
Rick: Elizabeth, I think you hit the nail on the head. If it's just clinician-facing, that communication isn't as nearly as effective as when there is communication to the patient to prompt them, to inform the physician of what they want, and to the physician as well.
When you look at the downstream benefits, if you just inform the physician only, there were no differences with regard to intensive care unit admissions, emerging department visits, and palliative care consultations. Kudos to the investigators for doing this study. I think what it shows is the important thing is, you got to talk to the patients and the physicians.
Elizabeth: Right, I absolutely agree. The editorialist points out that we need to advance this discussion globally among all stakeholders who have anything to do with these end-of-life and goals-of-care discussions. These could include public awareness campaigns, regulations that promote advanced care planning, and enhanced training to support clinicians that encourages the culture of acceptance around this serious illness communication. I think those are all really important.
Rick: Yeah. What we're trying to do is figure out from the patient standpoint what their expectations are and setting realistic expectations for people that need palliative care so that we can allow them to have the last part of their life a quality of life, and not do unnecessary procedures or have them visit the emergency department or hospital.
Elizabeth: Another one in JAMA that's yours, "Coronary Artery Calcium Score and Polygenic Risk Score for the Prediction of Coronary Heart Disease Events."
Rick: This is an attempt to take a population of individuals and predict who is likely to have coronary heart disease. We do that by using typical risk factors. We have other things as well. One happens to be a coronary artery calcium score, and the other is what's called a polygenic risk score.
The first is actually looking at the coronary arteries. Individuals that have more calcium in those arteries are more likely to experience a coronary event over the next several years. We know that there are certain genes that are associated with the risk of having heart disease as well. Each of them has separately been proposed as novel markers in addition to what we already have to identify coronary heart disease, but no study has directly compared these markers in the same cohort.
The investigators took two observational, population-based studies for individuals that were between the ages of 45 and 79. One called the MESA study has almost 2,000 participants, and another study from the Netherlands has over 1,200. They used traditional risk factors to calculate what the risk of coronary heart disease was, and then they looked at the benefit of either using a calcium score or polygenic information separately or together.
The coronary artery calcium score did add additional information to the traditional risk scores. However, the use of the genetic information really didn't add anything. It wasn't as good as the calcium score -- good data that shows that the coronary artery calcium score really better discriminates than the polygenic risk score for predicting coronary heart disease.
Elizabeth: Of course, I'm going to pin you down and say, really? How much does it add to the predictive value of the traditional set of risk scores that we already have?
Rick: If you look at what's called a hazard ratio, it was about 2.6, a little over twice as effective as just using a routine risk score. That doesn't mean everybody needs to go out and have a coronary artery calcium score. It's in that middle group where people have an intermediate risk that the coronary artery calcium score can kind of either put you in a lower number or a higher number.
Elizabeth: As you know, I did one just for fun when they first came out because I was just really interested in it, in the technology, and it takes a very short time of course to have this done. I'm wondering with regards to expense and you got one more thing that people have to do, would you say this ought to be a routine for those people? That's a large number of people who are in that intermediate group.
Rick: Right. It's not terribly expensive. It does involve some radiation. You don't need to do it annually, for example. People that are in the intermediate risk, if it drives them to a higher risk it's going to change their therapy. That's where it's most beneficial.
Elizabeth: Finally, let's turn to JAMA Neurology. This is a look at the clinical utility of adding tau PET scanning to the diagnostic workup of patients with cognitive symptoms. This is something I am seeing increasingly and this whole notion of can we really nail down a diagnosis of Alzheimer's disease without doing a brain biopsy basically? Which, of course isn't going to be very helpful to anybody, except for historically. PET scanning, of course, has been used for quite a while in these folks.
They had a prospective cohort study, the Swedish BioFINDER 2 study, that they have been looking at these people from May 2017 through September of 2021. They have a total of 878 participants. In addition to their clinical workup, they also added this tau PET scanning to their evaluation. It led to a change in diagnosis in 7.5% of the patients and a change in medication in 5.5% of the patients, so not a huge delta I think.
Should we add it if we really feel like this person is at risk? Maybe we should add it. A kind of wishy-washy conclusion as far as I'm concerned.
Rick: I found this study really very unsatisfying. Here is why. They ask physicians, "How confident are you of your diagnosis?" before they did the test. Then they did the test and then they asked the physicians the same question. Based upon whether the test was positive or negative, the physician said, "I'm much more confident" or "I'm less confident" or "I changed therapy." It didn't prove the patient actually had what they thought they had.
In their discussion, they mentioned that ruling out underlying Alzheimer's dementia based on the negative tau PET scan -- in the absence of clear, objective, cognitive impairment -- is actually quite questionable.
Elizabeth: I thought it really was just like, "Wait a sec. We're going to employ this ferociously expensive technology in these folks and we really are not going to get much bang for the buck when we do."
Rick: Again, the only reason to do something like this is if it's going to change patients' management in a beneficial way. Just because physicians feel more confident, it doesn't mean that confidence based upon a test is particularly reliable.
Elizabeth: On that note then, that's a look at this week's medical headline from Texas Tech. I'm Elizabeth Tracey.
Rick: And I'm Rick Lange. Y'all listen up and make healthy choices.