Screening for diseases like cancer may seem a simple solution to catch the disease before it becomes serious. But in this episode we find out how complicated screening for cancer is.
Show Notes
When is screening for cancer the right course of action?
LINK: https://www.euro.who.int/en/health-topics/noncommunicable-diseases/cancer/news/news/2022/2/when-is-screening-for-cancer-the-right-course-of-action
A short guide to cancer screening. Increase effectiveness, maximize benefits and minimize harm (2022)
LINK: https://www.euro.who.int/en/health-topics/noncommunicable-diseases/cancer/publications/2022/a-short-guide-to-cancer-screening.-increase-effectiveness,-maximize-benefits-and-minimize-harm-2022
WHO Candid Conversations - Aron Anderson and Sue Cohen
LINK: https://www.youtube.com/watch?v=XavsJ1tc4iY
Screening for diseases like cancer may seem a simple solution to catch the disease before it becomes serious. But in this episode we find out how complicated screening for cancer is.
Show Notes
When is screening for cancer the right course of action?
LINK: https://www.euro.who.int/en/health-topics/noncommunicable-diseases/cancer/news/news/2022/2/when-is-screening-for-cancer-the-right-course-of-action
A short guide to cancer screening. Increase effectiveness, maximize benefits and minimize harm (2022)
LINK: https://www.euro.who.int/en/health-topics/noncommunicable-diseases/cancer/publications/2022/a-short-guide-to-cancer-screening.-increase-effectiveness,-maximize-benefits-and-minimize-harm-2022
WHO Candid Conversations - Aron Anderson and Sue Cohen
LINK: https://www.youtube.com/watch?v=XavsJ1tc4iY
Hello, and welcome to health and Europe podcast. I'm your host, Greg Bian. We've launched this podcast to bring you the latest on w H O's work in the European region. Our region is born and diverse from the Mid-Atlantic stretching. As far as the Chinese border, we work fasting, eating, and driven individuals and groups. This podcast is about hearing their stories and how they might impact your day to day. Life Screening for diseases in bleeding. Cancer might seem like a no brainer with more and more technology entering the field of health wouldn't screening offer a quick, easy cost effective solution to catch any number of diseases. In reality, though, screening is far more complicated ahead of world cancer day. A new guide on screening for cancer explains that w H O recommends screening for a, a very small number of cancers, cervical breast, and colorectal. This because screening is generally used to pick up asymptomatic people. And in some cases leads to overdiagnosis. Once a cancer is diagnosed through screening treatment generally begins. However, taking such a broad approach means it's possible. Some cancers detected that may not develop into something serious eating's treatment that may be unnecessary. This isn't to say that screening should be abandoned for these cancers, but instead that prevention and early diagnosis should be prioritized ahead of screening prevention means reducing the risk factors for cancers, such as vaccination against HPV for cervical cancer engines in diet for colorectal cancer and reducing alcohol consumption for breast cancer. While early diagnosis can mean education around symptoms or a strong health system to treat cases as they emerge in short screening, isn't it replacement from prevention and early diagnosis. It's a complicated topic, but one that's important to get the grips with. In this episode, I speak of Mave, a communications consultant, working with w O Europe to find out more how many types of cancer does w H O recommend that we screen for, well,
Speaker 2:This might come as a surprise, Greg, but w H O recommends organized screening pro uh, programs for three types of cancer, only breast, cervical, and colorectal cancer.
Speaker 1:Uh you're right. That, that is quite surprising. It doesn't seem, doesn't seem that many, at least, at least to me. So, I mean, how were these identified and, and could this number increase at all?
Speaker 2:Okay, good question. So the new w H O guide on cancer screening, um, divides cancer types into three categories. So we have though cancers for which there is strong evidence for high quality organized screening programs. And they're the three mentioned breast, cervical, and colorectal cancer. Then they've identified those for which there is ongoing research, uh, in screening to establish if they are effective. And the third group then are the types of cancer for which there is. Um, they're just, they're not even under consideration because, uh, the benefits are not expected to outweigh the harms of screening. And you have to remember, um, what, when we're talking about screening programs, we're talking about using significant resources. So it's really important to know that the screening program will be effective and that it represents a good use of resources. And then as I mentioned, they're also health arms associated with screening. Uh, sometimes that, you know, I don't think there's huge understanding of those harms and they need to be better understood and weigh up against the benefits. And all of this requires evidence to establish if a screening program is the best course of action.
Speaker 1:I mean, you speak there a little bit about, about harms and, and, uh, you know, how that plays into this, but, um, but if we have the technology to screen for cancer, wouldn't it make to just screen, just to be on the safe side? I mean, what are the real downsides?
Speaker 2:Oh, it's, it's such a good question. And it's when I have been thinking a lot about, um, I found this, uh, lovely quote, uh, from w H O's 2020 guide on, on screening. Um, uh, and it's from raffle and gray and they say all screening programs do harm. Some do good as well. And of these, some will do more good than harm at a reasonable cast. So that's quite profound cuz they're putting it up there front and center that this can, they is a, an activity causes harm. And, and we should be very aware of that, but we can, once the evidence is established, you know, the, uh, screening can be used in a way that it's beneficial to the population. So to answer your question, just because we have the technology, it doesn't necessarily mean we should use it for screening. No. Um, there are loads of things that need to be considered, um, before you set up a screening program and it's really context specific, like, you know, what the prevalence of the, uh, the disease is in your country, how many resources, um, are available in that country for, uh, a screening program, how strong or how integrated is your, your health system? Because you know, it's important to remember screening is not just a simple test. We often think about it just as you know, you you're called up and you walk in, you go and get your test, but that's actually only the very beginning of a whole pathway that goes right way through from testing to potential treatment. And there are kind of ethical principles that underpin screening and, and, and the most important one I believe is, is the, the principle that says you should not, uh, set up a screening program if you cannot deliver all of those steps along the pathway. And that makes sense, you, you, you shouldn't test for something that if, if there isn't treatment and diagnosis readily, uh, available, um, and then, you know, as I mentioned, screening itself can be, um, harmful.
Speaker 1:So you speak about a care pathway. I mean, what, what is a care pathway in, in the first instance and, um, when might screening usually come in and how can we improve early diagnosis instead of relying on screening?
Speaker 2:Great, great questions. So there's a lovely diagram in our new screening guide and it sets out all of the steps in what we call the screening pathway. And it starts with identifying the population eligible for a screening, um, because the evidence shows, you know, um, uh, that often a targeted approach to screening is more effective. You know, if there isn't high prevalence of a disease is for example, amongst a younger, uh, population, there is no point putting them through screening because screening causes stress and anxiety as well. Cuz you know, you're taking healthy people and you're trying to, um, I identify, uh, you know, pre-cancerous or, or cancers before they come, um, dangerous. So I'm just touching that. I'll go back to the harms in, in, in a few minutes, but just to go back to the screening pathway, your initial step is identifying the population eligible for a screening and then you, um, the screening program sends out an information with all of the information. So, uh, participants can make an informed decision and then the, um, service user, the participant will go along for, for, for screening. And, um, if there is a positive result, they will be referred on, uh, and that will be followed ideally by diagnosis, uh, intervention, uh, follow up and, you know, reporting of, of the, um, within that. And again, this falls under the bracket of harm, this theme of harm. And, and this is a real focus of this screening guide because it's something that hasn't been fully addressed before. Um, we are more familiar with the concepts of false positives and false negatives. Now I think an kind of, um, our COVID antigen testing and it's similar with, um, screening, you get false, uh, positives and false negatives, but of course the implications here are, are far more serious. So those harms have to be born in mind, uh, as well. So that's the, the screening pathway
Speaker 1:On effectiveness. Can you explain, we mean, when we speak about effectiveness and cost effectiveness of screening, so
Speaker 2:When we're assessing kind of, um, whether screening for a certain cancer is worthwhile or not. Yes, we look at effectiveness and cost effectiveness. So effectiveness is essentially is the screening doing what it was designed to do I E is it reducing sickness and death from cancer in the population by early detection and, and early treatment, for example, uh, breast cancer screening or, or is it, uh, succeeding in reducing the incidence of cancer by identifying and treating its precursors? And that's the case with cervical and colorectal screening. So they, they have slightly different aims there. So, um, that, um, that is how we measure effectiveness cost effectiveness kind of looks at, you know, compared to other ways that this money could be spent. You know, all of the demands in healthcare does this particular expenditure represent good value from money, a in terms of, uh, the health return and B its positive impact, uh, on the population. And this is very important because in, for example, in resource limited settings, uh, in countries where they have high rates of late cancer diagnosis, in fact, it's better to target resources at early diagnosis than it is, uh, in investing it in setting up a screening program. I know that sounds kind of surprising. You were like, why would you not catch it like early on the other? I think really important point here. And I, I nearly came to it is, is this, this statistic for every one woman whose life is saved by breast cancer screening three are going to undergo treatment for cancers that would never have harmed them. So the technology is picking up on cancers, but there a lot of cancers never develop. You have tigers and Pussycats. And the problem with cancer screening is you don't know when you do the screening, it's not gonna tell you if it's gonna develop into a tiger or a pusycat. So, so you treat it, but a lot of them will never become harmful, um, to the person. A lot of people, um, get sick or die with cancer, not of cancer. Um, and that's not a small statistic that three will undergo treatment that is invasive. That can cause other huge harms to health. Again, like these, uh, these are the harms. Um, and, and it's very important to remember, you know, with this technology, uh, there is the risk of overdiagnosis and as a result of that over treatment,
Speaker 1:The statistic that may have mentions that for every woman whose life is by breast cancer, screening three undergo treatment for cancers that would never have harmed them, comes from a study of breast cancer screening in England, which purported an overdiagnosis in the English program, depending on rates of breast cancer. This figure may differ other countries, but it shows how screening can result in overdiagnosis may have explains more, but to put you on the spot, we recommend screening for breast cancer, despite that statistic
Speaker 2:Yes, for certain cohorts for, for, for certain cohorts and in certain, um, countries, it will be different because as, uh, Sue Cohen is one of the main authors of the report, she, she made the important point actually prevalence of breast cancers is different in different countries. The rates of breast cancer are not kind of standard across countries. That that's kind of surprising. I, I hadn't, you know, know fully, uh, thought about that. So, um, so again, this goes back to the point that yeah. Screening it's, so context specific, um, your country, your resources, your, your rates of the disease. Um, there's another great example she gave of the, the dangers they of a diagnosis, um, in a, in a lower income country where there is, um, where there are high smoking rates and a high rate of lung disease. There are proposals to bring in, um, screening for lung cancer. But if you go back to the principles, the principles are, you have, you have to, you know, you should have exhausted all, uh, uh, strategies for prevention before you get to screening. And again, that second principle that you need to have the resources to treat if you're going to screen. Um, so you can see where it gets, where it becomes, this is all very complicated and not straightforward. Um, and, and it's why I would encourage and invite people to, um, be you policymaker or member of the public. I, I think this new guide is a very accessible, uh, easy to read, um, summary of, uh, of kind did the concepts behind screening and some of the issues as well.
Speaker 1:Thanks me. I'm sorry to put you on the spot in that last one, but I think from what you're saying, it sounds, um, like you, and I think it was in your first answer or your second possibly about the cohorts and the, the context you find yourself within. So that again, I mean, I would imagine with, with something like breast cancer, if you have a, and I'm totally generalizing here, I'm not basing this on any knowledge, but if you were to have say an older, um, population, your rates of breast cancer are probably higher than if you had a younger population and maybe there's certain risk factors. Like you say, with smoking, I think is a brilliant example. If you're gonna have, uh, a higher rate of, of smoking, then it's not that surprised, and you're gonna have higher rate of lung cancers. So actually, maybe it is a good idea to screen for lung cancers in that country where smoking is high.
Speaker 2:Actually, no, just on the last point, they're saying, they're saying the opposite. They're saying if you are population, if, if lung cancer is so prevalent and that means they're, they're past the stage of screening as in. So if you have limited resources screening is, is for where you already have a really good health system and you're already catching your symptomatic people, then it's like, oh, okay, now we can move to presymptomatic people and try and catch them in the early days, but it's not a, um, a substitute for prevention. And if a country doesn't have strong tobacco control policies in place, and yet are proposing to we light screening for long, I say that that will totally train public resources like to set up a screening program is a massive investment. Because as I said, you, you have to have all of the, the treatment, um, capacity available as well. Um, so there's a lot of reasons why you would not set up a screening program in that scenario. It's some of this is quite counterintuitive.
Speaker 1:It definitely is, but that's, that's really interesting. I hadn't thought about it in those terms that, yeah, if you think the prevalence is that high, why would you even bother screening cuz um, because the prevalence is high. You, you
Speaker 2:Need, you wanna target on, uh, prevention and uh, early diagnosis. That's the guide is very clear on that in low income settings where there aren't many resources focus your resources on early detection, which is catching people who are symptomatic at the early stages, rather than using your resources on a population who, who are not symptomatic.
Speaker 1:That's all we have time for special, thanks to Mave for taking part. In this episode, if you'd like to find out more about cancer screening, you can do so on our website or via the show notes, make sure to leave the rating. And if you'd like what you've heard, recommend us to a friend colleague, thanks for listening until next time, stay safe and stay healthy.