Blood test for multiple cancers studied in 10,000 women, and is our Sun boring?
welcome to the podcast for me. I Two thousand twenty. I'm Sarah Crespi. This is going to be our first corona virus free episode in a while. I up this week. I talked with staff writer. Jocelyn Kaiser about a study involving ten thousand women who all received a blood test for multiple types of cancer are blood beast. Biopsies coming to a clinic near you. Then we have researchers team reinhold. He's here to talk about his paper. On how the sun is a lot less variable it's magnetic activity compared with similar stars. What does it mean that our son is a little bit boring? Now we have staff writer Jocelyn Kaiser. She wrote a story this week about a large trial of blood based test for different kinds of cancer. Hi Jocelyn Hi. Who's producing this test? And WHO's testing it? So the test has been developed by a group of researchers at Johns Hopkins University and they Have been working on the test. For years they call cancer seek and last year the company picked up. The test is called What kinds of cancer can be detected with a test like this in principle many different kinds of cancer and in this test the cancer is included Liver Cancer Ovarian Breast Cancer Lung Cancer? Thyroid Lymphoma and some other types. What were they detecting in the blood that could catch all these different things so they were detecting was DNA? That is shed by cancer cells when they die into the blood they're tiny amounts of it but it is a signature of the cancer because certain genes are often mutated in cancer. That's what drives the cancer's growth and so by looking for sixteen different genes mutations in these genes in DNA in the blood the researchers could detect various types of cancer. But they didn't necessarily know what kind of cancer it was by looking at the result of the blood test they didn't necessarily node type of cancer. Or where it was in the body. Let's go to the study here so you talk about the group that are spaded in the study. Sure but just to tell you. What's different about this? Until now people developing these tests have been developing them by getting a big group of people some of them with cancer. The ino that who have cancer and the other group of people don't have cancer and they've looked at whether their tests can tell who has cancer and who doesn't what's different here is that they took another big group of people women in this case and what they wanted to know is we don't know if any of these women have cancer or not rethink. They don't have cancer but we know that some of them probably do and that is the more real world situation where you'd be using tests like this. So that's what's so important and they recruited about ten thousand women who all get healthcare in Pennsylvania through the geissinger healthcare system. And that's the group that took the blood test. How long did this study gone for? I think it's been going on for at least a couple of years. But each woman when she enrolled in the study and got her blood test she was then followed for a year. What happened if a woman in this study had a positive result on her blood test so if she had a positive result on the first blood test she was asked to come back later for a second blood test. That look a few more things in the blood to make sure that it wasn't a false positive although it didn't rule out of false positive and if that test was also positive than she would be invited to come in for an imaging test and imaging would confirm the diagnosis yes. The imaging would tell her doctor if she did actually have some lump somewhere that might be cancer but even then you may have to do more while usually Joe Biopsy to make sure it actually is cancer because you can have lumps. That aren't cancer overall. Were they able to catch many cancers in this group of what ten thousand women? The blood test was able to detect twenty six cancers in this group of ten thousand women which doesn't sound like a lot but it's actually not that many cancers that are going to pop a group to size they found other cancers in other ways but the total was only about one hundred cancers knew what were they looking for with other methods. And how did they compare? The other methods are what's called standard screening tests like mammography conus coppee. And if you're smoker you might get along scandal look for lung cancer. Those are tests that are part of routine medical care and part of the studies design was to keep encouraging women to do that testing. Because this isn't supposed to substitute for those tests. Found another twenty four lung breast or colon cancers we have the blood tests finding some cancers and the typical screenings finding some cancers and overall. How many cancers did you say there were another batch cancers that were found through symptoms or other things that brought them to the attention of the doctor so the total was ninety six cancers so is this a lot of cancer the answer to that comes from epidemiology studies that look at how many cancers will occur in a group of women this age which is sixty five to seventy five in one year and according to that data you only expect about one hundred cancers in one year in this group of women at doesn't mean that this test found or the study found all cancers it may not have found all of them but it is in the neighborhood of what you'd expect one concern that a lot of people have about tests like the screens like this is false? Positives will something get flagged and it's incorrect but then the patient has to undergo invasive procedures did happen a lot in the study in about a hundred women. There was a positive blood test in the woman underwent imaging and she did not end up cancer in in some cases twenty two cases the way that doctors confirmed that she didn't have cancer involve an invasive test like a colonoscopy or three cases they actually did surgery so there were women who had sort of a scare and had to undergo some kind of unpleasant testing and in the end they did not have cancer. What about false negatives people who had cancer but it wasn't detected by the split test whilst negatives would be the woman who's cancer was found with conventional screening or symptoms and not by the blood test? And so the idea. There is that while this will pick up more than the conventional approaches. That's right the researchers say. They're not saying this should substitute for these other approaches. It should be additive to conventional screening. And that's something they tracked among the women in study yet. One question they had is if women were getting this blood test. Would they think this blood test will find any cancer? I might have. I don't need to go get my mammogram. But they encouraged women to keep getting those mammograms and they went back later and they looked at their medical records and found out that they continue to get mammograms which is exactly what they hope to see because they did not want to discourage them from getting those tests one thing I found really encouraging from this study was You mentioned in one draft of your story that I saw that a women with ovarian cancer that it was detected very early in her and that is something that has proven really difficult to find before this is a really good example of what the tests ultimate goal is a woman who agreed to be on on video made by Geissinger system in her name's Rosemary and she talked about what happened to her which she signed up for. The study. Didn't think they were gonNA find anything. And then they told her she had a positive test so she came in for the imaging found out she had a stage one ovarian cancer which is very small the very earliest stages of cancer. She had surgery and she says in the video that she hasn't had any side effects and she looks really healthy and she's getting ready to go for a walk with her husband and that is really ultimately what this test is hoping to do because if it's caught early and you have taken out through surgery chances are you're gonNA cancer is gone for good. I mean not always but what's next for this type of testing more studies to kind of roll it out. Yes so that's a little unclear because if you want to do things right and you WanNa go out and give this test to everybody and the researchers who developed this test can see it being given us a test once a year when you get your annual exam while to get to that point you have to do a lot more research you have to look at whether it actually helps the people who take it live longer as a group than if they didn't take this test because for example it could be catching early. Tumors that would have been found before long anyway. So you know it's not worth the cost could be finding tumors that were never going to grow. And so that's not worth the cost either and it may involve removing tumor. Didn't really need to be removed. The way you answer that question how it affects the overall survival of the people taking it is you do have very long study over many years loss of people where you have to get tested one group that doesn't and you look at the end of the ten years or whatever it is to see if more people are still alive from the group that took the test makes. It seem like this isn't going to be ruled out any time soon to clinic near you. Well that could still happen. Because for example there's another company developing this kind of testing grail and they are to starting a big prospective study like the one that was done by Hopkins and Pennsylvania. And they're talking about possibly commercializing their tests in a year so so even though it hasn't been through that sort of very rigorous long-term study it shows whether it increases survival. They couldn't end up selling it and it might not be covered by your healthcare. You have to pay for it yourself. But people could be asking their doctors to get it and one person. I talked to said the issue. There is her patients come in with tests. They'd had done in that way. That haven't really been validated. And they want her to do something about it and the question is will doctors know what to do with this will be meaningful for patients care. Art Thank you so much Jocelyn through welcome Sarah. Good to talk with you. Jocelyn Kaiser is a staff writer at science. You can find a link to her story and the related research paper at science MAG DOT org slash. Podcast STAY TUNED FOR AN INTERVIEW WITH TIM O. Reinhold about comparing the sun's activity to other similar star search. This week's episode is brought to you by Q. Eko KIMIKO CREED SUPER COOL hands on projects designed to expose kids to concepts in steam. That's stem plus art and design all from the comfort of home. Ky-ko's mission is to help kids build confidence creativity and critical thinking skills and have a blast doing it. 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The Sun is a lot less variable than similar stars. T MOS here to talk about how they figured this out and what it might mean team. Oh there are these records of the sun's activity going back a long time hundreds of years. And even there's one case where we have a nine thousand year data set on changes in activity of the Sun. Where do these values come from the hundred years that you mentioned so this is from sixteen hundred something of fifty something so this is when the telescopes and vendors and Galileo really used for example already to draw sunspots so derek exists drawings like several hundred years old from sunspots on the sun and this is one evidence for magnetic activity and then people started to take records of the sunspots and Yeltsin since eighteen hundred eighteen? Also we have really good coverage of these. So this is the magnetic activity basic need the number of spots on some other timescale scale that you referred to the nine thousand years this is from cosmic isotopes. So does this from ice cores and tree rings exactly. Why are you looking into this? What this question up. We are studying the sun and other sun like stars particular and one way to compare the sun to to figure something out about the to compared to Sun with other Saas which are like the sun symbol. Amass OUR TEMPERATURE. Arabia's something like this therefore we studied Kepler's laws which are similar in all the parameters that could constrain for example the effective temperature especially also the rotation period of the Star we measured the variability of these stars and founded there exists stocks which are much more variable than the sun although the star saw similar and all the other parameters right and this has been something people had thought was going on for a while. Yes exactly the basic question is as our son quieter than other stars or is it similar to us and is one question that we wanted to address to answer how people looked at this. Before in other stars on the one hand you can measure for the metric variability so this is just observing the style for quite a long time when be measured is the rotational variability of the sun so on rotational time scouts like a month or so so the sun spins around once a month? Your roughly twenty seven days. Yes and then. If you observed the sun for long enough then you can measure the variability of dislike pref light so the brightness of various because we have dark spots on the sun and the sun rotates towards us than become starker and if it rotates spots rotate away from us so then becomes brighter again. So you can more or less. Think of sine wave if you want to so changes in activity are visible because dark spots. Show up sometimes. How does this darkening relate to activity your origin of these exploits magnetic field which emerges to the surface? The Sun has eleven year cycle so every eleven years very active and becomes inactive comes active against that is like a very clear signal there but we were studying the rotational variability on shorter timescales. And Calm Time. There'd be less difference as it rotated from one side to the other but in active side. There'd be a lot more differences. You'd see a lot more variability. In how bright the Sun was when the rotational times gosta destroyed. Yeah how did you collect information on other sun like stars we took data from the nauseam mission which looked for for planets around other stars. The good thing about cells copacetic also monitored the brightness of hundred thousand stars among these there are many solar like stars. We studied the very ability of almost three thousand dollars. Final sample which are sold alike than we determine the rotational variability on for your time base when Kepler is looking for EXO planets. It's looking for changes in brightness in stars so how is what you're doing different from that of the planet orbits a star and then move in your line of sight so this is just a very short signal in time. It's just like a the sudden drop in the brightness whereas the rotational variability of signal is a very different signal at transit of blended much more periodic than the rotational variability for example Clearly distinguish signals were the stars that you looked at for this study all rotating for about ten percent of sample we have rotation periods measured for the stars. These are the stars which are interesting because we found that most of the star sweat rotation period could be determined. He styles are much more active than the sun so whereas the other ninety percent where we don't know the rotation period because the signal is not Berwick enough or they just don't have spots the very much more like the son you found that when you are able to determine the period how fast. They're rotating that they had a lot more variability in the four year that you looked at them yes exactly. So we know the rotation period. They're a lot more variables so there are five times more variable than those when we couldn't measure their addition period but there also exists stars which are up to ten times if our son has a big spot on it. How long does it take to appear and then disappear is there? Is it like a year? Is it like a month? I mean how. How quick is this activity? This is the problem with the sun because the sunspots have sometimes shorter lifetimes than one rotation period so if a spot appears than it rotates away from you and if it doesn't come a gun because the meantime yeah that's the problem. Yeah I got it. So what how does those data sets the humans drawings of the sun over a couple of hundred years and this nine thousand year data from Ice Cores and tree rings? How do those compare with what you found in your study? Do they match up these recordings basically show you the eleven year? Solar cycle and the solar cycle can be dated back nine thousand years or six hundred over four hundred years and we showed in our study that this is also consistent if you take current data measure the variability so this nicely alliance with a magnetic activity so you can really take the the brightness variability as a proxy for magnetic activity could our son be in a lull could it actually you know have a period of extreme variability coming up sometime. This is one possible explanation of our results. We showed that there is a nice distribution of these very abilities. The stars where we could measure the rotation period these basically populate too high variability edge so it is possible that the son wants becomes much more active because we cannot distinguish the sun from all these other stars so this is just one possible explanation but timescale is hard to say. I mean ninety. Nine thousand years to son was more or less normal as it is no but my thousand years is nothing for for star like a second for human. Yeah thank you so much team. Oh yes are you. T more reinold is a post doctoral researcher at the Max Planck Institute for Solar System Research you can find a link to his paper at science mag dot org slash podcast and that concludes this edition of the Science. Podcast if you have any comments or suggestions for the show right to us that's is podcast at a s dot. Org You can listen to the show. I'm the science website at science mag dot org slash podcast. Dariel find links to the researcher news discussed in the episode. And of course you can subscribe on overcast. Stitcher spotify Pandora Apple podcasts. And many other places. The show was edited and produced by Sarah Crespi with production help from prodigy. Meghan Cantwell and Joel Goldberg. Jeffrey Cook Compose Music on behalf of Science magazine publisher triple. As thanks for joining us.