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 stroke after cervical artery dissection, reducing clot formation in those with advanced cancer, USPSTF on breastfeeding, and a polygenic risk score for prostate cancer.
Program notes:
0:40 Polygenic risk score for prostate cancer
1:40 90th percentile or higher
2:40 Genetic risk for cancer
3:41 Avoid false positives
4:00 Cervical artery dissection and subsequent stroke risk
5:00 High in older people, Black and Hispanic people
6:00 Nonspecific symptoms may predict
7:00 Preventing clotting in patients with cancer
8:00 Standard dose followed by half dose
8:44 USPSTF on supporting breastfeeding
9:45 Support systems not that good
10:55 What is the best strategy to support?
12:14 End
Transcript:
Elizabeth: Trends in cervical artery dissection and recurrent stroke in the United States.
Rick: Preventing venous thrombosis — or clotting — in people with cancer.
Elizabeth: USPSTF on breastfeeding.
Rick: And using a polygenic risk score to screen for prostate cancer.
Elizabeth: That’s what we’re talking about this week on TT HealthWatch, 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, let’s turn to NEJM and take a look at this issue of a polygenic risk score and prostate cancer.
Rick: So, Elizabeth, over the last two decades, we’ve reported on many studies related to prostate cancer and most of our listeners may not realize it’s the most common cancer after skin cancer in males, and it caused 375,000 deaths in 2020. We know that catching it early and treating it early can prevent long-term poor outcomes, but there’s no internationally accepted population-based screening program for the early detection.
PSA alone oftentimes gives false positives. We’ve tried to refine that by using MRI analysis to see whether there’s cancer in the prostate gland. That’s helpful as well. But in terms of overall screening, there’s nothing that’s been generally accepted worldwide.
There is a genetic predisposition to prostate cancer. There are many single-nucleotide polymorphisms, small gene defects, that predispose to cancer risk as well. In fact, there are 130 of those that have been identified in people of European ancestry.
Okay. Let’s try to identify individuals that are of the highest risk; they derived a polygenic risk score based upon those 130 variants. If individuals were in the 90th percentile or higher of having a risk of prostate cancer, then they subjected them to prostate cancer screening by doing PSA, doing an MRI, and a biopsy.
Here is what they found. Just based upon the polygenic risk score — of course, there are about 10% of individuals that have very high score in the 90th percentile — of those that underwent prostate biopsy, prostate cancer was detected in 40%. Of those 40%, over half of them had prostate cancer that was classified as intermediate or high-risk. Importantly, if we would have just used PSA, we would have missed about three-fourths of them. It looks like in this particular patient population, using a polygenic risk score, we can find a better percentage of those that have clinically significant disease.
Elizabeth: Clearly, we’re headed into this direction of people having genetic assessments for lots of things and especially for their cancer risk ultimately. I guess I’m curious about the applicability of this approach in ethnicities other than those of European ancestry.
Rick: Now, that’s the important point. This is a very homogeneous population. In fact, all the participants were of European ancestry. In those individuals, they identify these 130 different genetic variants that were predisposing risk to prostate cancer. So, this needs to be extended to individuals that are of non-European ancestry and we might pick higher-risk individuals in the U.S. For example, we know that Black Africans and Caribbean ancestry are associated with an increased risk. The risk among people in European ancestry is about 1 in 8. For those of African American or Caribbean ancestry in the United Kingdom, it’s quoted as high as 1 in 4. Nevertheless, if we’re able to do that, Elizabeth, it suggests that’s maybe a better screening device than just PSA or MRI.
Elizabeth: Well, and it would be a lot less, in some respects, resource-intensive and could potentially have applicability to other risk assessments.
Rick: Right. Because what you want to do is you want to be able to assess the risk. You don’t want to have a lot of false positives and that’s what a high PSA does, and that’s where the polygenic risk score may be most beneficial.
Elizabeth: Let’s turn from here to Neurology, and this is a study that’s taking a look at incident trends and risk of recurrent stroke of cervical artery dissections in the United States between 2005 and 2019. Cervical artery dissection is a common cause of acute ischemic stroke, especially in those patients who are younger than 55 years.
What these authors wanted to look at was, what’s your subsequent risk of acute ischemic stroke after you’ve had this cervical artery dissection? So, they took a look at a bunch of data from a bunch of different databases and they wanted to find out the annual average percent change of cervical artery dissection incidence and then readmission risk after that, without concurrent acute ischemic stroke, and assessing death as a competing risk.
They looked at the time period from 2005 to 2019 and identified over 125,000 patients who had spontaneous cervical artery dissection and showed that it increased from 10.7 cases per million in 2005 to 45.6 per million in 2019. It was particularly high in older people, Blacks, and Hispanic populations. It points to the need to have a high suspicion in these folks, also to look at these underlying factors that might be responsible for this really rather remarkable increase.
Rick: There was a 5-fold increase in detection of cervical artery dissection, but the incidence probably didn’t increase. In the past, people didn’t look for it and many of the individuals that were at risk of stroke or had stroke, they didn’t have access to MRI or CT scans as commonly as we do now. So, the detection has gone up. I’m not sure the incidence has gone up very much.
You do make a good point; once you’ve had a cervical artery dissection, it’s less likely to recur. But, oh, by the way, if you detect it incidentally … what do I mean, incidentally? There are people who haven’t had a stroke, but they could present with local symptoms like neck pain or head pain or a pulsatile ringing in the ear. When they have a scan, they detect cervical dissection. Over the next 90 days, there’s a significant risk that they will subsequently experience stroke. All this information about cervical artery dissection ends up being incredibly important.
Elizabeth: Well, they do also point out that with regard to the incidence data, there was a steeper rise in incidence among patients ages 65 and older. Previously, those folks were not thought to be a part of that population. As they cited at the beginning, this was a common cause in folks who are younger.
Rick: Right. A lot of times, they just didn’t look for it. So, whether the incidence is rising or the detection rising, unfortunately, this study can’t “dissect” the difference between those two.
Elizabeth: Okay. So we’re going to agree that there’s a couple things to pay attention to here, but it sounds like we ought to be paying attention to cervical artery dissection in people when they come in for anything that suggests that they might be having a problem.
Rick: I agree, and since we now know it occurs more frequently than we realize, what we need is data on how best to prevent stroke in those individuals that have it.
Elizabeth: Agreed. Let’s go back to NEJM.
Rick: Preventing venous thrombosis or clotting in individuals that have cancer.
It’s widely known that patients with cancer are at a higher risk of developing venous thrombosis than the general population, and those clots can remain in the vein, or they can be dislodged and go to the lung and cause a pulmonary embolism, and those things can be life-threatening. Because individuals that have cancer and have had venous thrombosis or pulmonary embolism, they are recommended to be on anticoagulation for at least 6 months and then longer, if possible, unless the patient has bleeding episodes. That’s the risk of putting someone on anticoagulation.
All right. If we want to keep people on it longer, we want to prevent bleeding, let’s use half the dose after 6 months and see a) if it’s just as effective and b) can it decrease the bleeding risk?
That’s exactly what these investigators did. They took almost 1,800 individuals that over the previous 8 months had been detected to have venous thrombosis or pulmonary embolism. They completed 6 months of therapy at standard dose apixaban — 5 mg twice daily — and they randomized them to either continue on that or to half the dose, and they followed them over the next year to see how they did.
In both groups, the risk of having recurrent venous thrombosis or pulmonary embolism was about the same. However, those that had the reduced dose had a lower risk of bleeding, major bleeding; that’s a 25% lower risk. They also had a slightly lower mortality.
Elizabeth: Yeah. This is really good news because this is, of course, a really big problem in people with advanced cancer.
Rick: It is, Elizabeth. This is a really well-done study and I think will change how we treat these patients.
Elizabeth: We like those kinds of studies.
Finally, let’s turn to JAMA, and this is the USPSTF’s recommendations relative to supporting breastfeeding. To me, that sounds an awful lot like baseball, apple pie, and motherhood. How could you possibly object to the support of breastfeeding?
The task force notes that breastfeeding rates in the U.S. are relatively modest and, in data from 2021, just shy of 60% of infants at age 6 months are breastfed; 27%+ of infants at that age are exclusively breastfed.
So, in reviewing the evidence of primary care behavioral counseling interventions to support breastfeeding, they conclude that these have a moderate net benefit. They recommend providing interventions or referrals during pregnancy and after birth to support breastfeeding with a B recommendation.
I had no idea that the interventions or the support for women who are pregnant and have just given birth were not that good, but that’s what it sounds like. By examining all of these studies, they were able to determine that, in fact, there are really pretty significant holes in our push to try to get people to consider breastfeeding anyway.
They say that what we really need are formalized programs, both before and after pregnancy, that are delivered in a variety of settings. So, those might be in person or video, telephone, or text. They ought to include the voices of many people, so including peer support and other ways to encourage women to give this a try anyway and to stick with it if they can.
Finally, they note a lot of the women who choose not to do this are women who have jobs that they have to go back to right away, and in those jobs, they don’t get supported and aren’t given breaks so that they might engage in breastfeeding. And so, there’s a lot of places where improvement is really clearly needed.
Rick: Are the interventions that we do successful in increasing breastfeeding? Here are the holes. There are a lot of different things that look like they’re beneficial, but what’s really the best? And that’s where we’re lacking a lot of the information. None of the studies provide that evidence. Nevertheless, we know it’s beneficial and so the next studies should talk about, okay, what’s the best implementation.
Elizabeth: The editorialist notes that, within this examination of the literature, they’ve only found 37 new studies that were not included in the previous 2016 recommendation, so there has been a relative paucity of research that’s being done on what are these most effective methods. They also note, the editorialists, that clinicians are too often part of the problem, providing inconsistent or non-evidence-based recommendations to those families who are interested in breastfeeding. And, of course, we know that beyond the primary care setting we need structural-level changes, increased advocacy, funding, and research so that we can try to eliminate the breastfeeding disparities and achieve national breastfeeding goals.
Rick: Yeah. Those goals are all providing clearer implementation guidance. I hope that’s what the next focus is, so that the next update provides additional information that will help us.
Elizabeth: Okay. On that note then, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.
Rick: And I’m Rick Lange. Y’all listen up and make healthy choices.
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