My last blog post was about alternative medicine in cancer treatment. That piece was about patients who refuse all other treatment, and thankfully that is still a relatively rare occurrence. Usually, patients use alternative medicine alongside their regular treatment. As a result, studying patients who refuse all regular treatment isn't necessarily the most informative thing.Because of this distinction, researchers from Yale decided to have a look at patients who do this, and they published their results this month. It is not encouraging reading.The research showed that if patients used alternative medicine at the same time as conventional medicine, they were twice as likely to die in the 5 years after diagnosis. I will get into the details and the numbers below, but first I want to repeat that statement. If patients used alternative medicine at the same time as conventional medicine, they were twice as likely to die in the 5 years after diagnosis. That is a shocking toll.Before I get into the study itself, I want to briefly explain this result. Essentially, if someone uses alternative medicine, they are more likely to refuse other parts of the treatment. So this terrible loss of life is probably not because a specific alternative medicine was causing a problem, but because the belief in pseudoscience has corroded and undercut the public’s trust in medicine. People believe that their alternative treatment is viable replacement for conventional therapy.This belief has not sprung out of nowhere; an entire industry has been built on the idea that medicine is “toxic”, and that if something is “natural” it is automatically better for you.I know so many people who use alternative medicine, from acupuncture, to supplements, to homeopathy, and they often say “what’s the harm?”. Well, this is the harm. Because of the normalisation of this kind of thinking, patients are making bad medical decisions, and are dying as a result. I will say it again: patients who used alternative medicine at the same time as conventional medicine were twice as likely to die in the 5 years after diagnosis.So what does the science actually tell us? Research from a few years ago showed that if someone uses alternative medicine, they are more likely to skip certain parts of their treatment. However, that study didn’t look at how this impacted their survival. This new paper takes that finding and looked at a larger population of patients to see if the use of alternative medicine alongside conventional treatment had any affect (good or bad) on cancer.Firstly, the authors confirmed that in their population of patients, those who used alternative medicine were far more likely to refuse or skip part of their treatment. This included surgery, radiotherapy, chemotherapy and hormone therapy.For example, 7% of patients who used alternative medicine refused surgery, while only 0.1% of other patients did. 34% of alternative medicine using patients refused part of their chemotherapy, while only 3% of other patients did. In a way, this is understandable: these treatments are hard, and make people feel awful. If you already believe that your side effect free alternative medicine is a viable replacement for your chemo, then skipping a round of chemo doesn’t seem like that big a deal.Just to be clear, interventions like surgery, radiotherapy or chemotherapy are not used because we think they improve survival; they are used because we know it. Huge numbers of clinical trials have been done to figure out what allows patients to live longer, and these treatments do that. And refusing some of these seems to be what is doing the damage in patients taking alternative medicine.There is not much more I can really say about this study, apart from the usual caveats. A lot of patients lie to their doctors about their use of alternative medicine, so that could be a confounding factor. The authors were very strict with their criteria, so as a result, the study was relative small, with only 258 alternative medicine-using patients. That being said, it is the biggest study we have on the topic, and the analysis was very rigorous.What this study really shows is the harm that the “natural” industry is doing. Vaccination rates are falling all around the western world. Species are being wiped out because of the popularity of traditional Chinese medicine. But perhaps most damagingly, a third of the American population regularly use alternative medicine without any evidence that is has any effect, spending nearly $200 billion in the process. With such a huge number of people using it, and with the credulous treatment it receives in Hollywood and other media, it is no wonder that people assume it works. It has been marketed and accepted by a large number of people as a true alternative to medicine, and as a result, people are dying for no reason.This is why it is so important to call out pseudoscience when it comes up. We live in a world where medicine is advancing on a daily basis. We can live longer, healthier lives, but people are increasingly taking that for granted and turning towards pseudoscientific ideas, because they are more "natural". The reality is that the more people who understand that alternative medicine does nothing, the better.
How improved cancer screening can make us think we are doing better than we really are
This blog post is a follow on from this post I wrote about cancer survival, and is about some really interesting quirks we encounter when we try to study it. These problems arise when we increase our ability to detect the cancer at earlier stages.
Lead time bias
The first of these is known as lead time bias. Because of better technology, we can now diagnose cancer earlier. So imagine a case where a new screening technique lets us catch a cancer 1 year earlier. The catch is that no matter how early we catch it, in this case the disease is going to progress and ultimately kill the patient.
So before the introduction of this new technology the patient might only survive 1 year after diagnosis, because we are catching it late. After the introduction, we can now catch the disease early, and the patient will survives 2 years after diagnosis.
If we were just looking at the numbers, we might think that we are making significant progress with this disease, because patients are now surviving for 2 years rather than just 1. However, we have done nothing to increase the patient's lifespan. If we hadn’t caught it at all, the patient would have died on the same day.This is known as lead time bias. Because we are catching a disease earlier, it can look like patients are surviving longer, when in fact they are not. It is an easy mistake to make, but a very important bias to consider when we are talking about cancer survival.
Length time bias
The second problem appears when you realize that if we detect a cancer early, it is possible that we are detecting a cancer that might never have progressed at all. It isn't well-known, but there are cancers that never progress to a dangerous level. If we look at autopsies, nearly half of all men have prostate cancer when they die. However, only a small proportion of them actually die from prostate cancer. The rest have the cancer, but it will never progress. So the men are dying with prostate cancer, but not from prostate cancer. Most of these men will never have symptoms, so will never be diagnosed.If a patient has symptoms, then it is quite likely that the cancer will progress if we don't treat it. However, if we use a screening technology and catch the cancer before symptoms appear, then it is possible (likely) that some of those cancers were never going to progress to a dangerous level.For example, before a screening technology is developed, survival from a particular cancer might be quite low, because we don't detect the cancer until symptoms appear. Then we develop the new screening technology, and suddenly we are detecting all the cancers, regardless of whether they have symptoms or not.If we were just looking at the numbers it would look like the incidence of that cancer is increasing (we now detect extra cancers that we wouldn’t have before), but it would also look like we are successfully treating these additional patients. Even though those cancers would never progress, patients would still get (un-needed) chemotherapy, and it would look like the treatment was successful.The result of this is that we would think that the survival is increasing, but in reality, we are just identifying cancers who we wouldn’t have previously.This is just two examples, but understanding this kind of bias helps us realise just how easily we can be fooled into thinking the wrong thing. This lets you look more critically at studies, and hopefully means we are less prone to bias when carrying out these kind of studies.
Disparities in cancer survival
In my last post I published some good news about cancer survival rates, so I thought it was important to highlight a big problem with our recent success against this disease. This issue is flagged up in a study published at the end of January.It addresses the fact that the gains we have made in cancer diagnosis and treatment are very unevenly spread around the world. To analyze this is greater detail, the scientists studied the differences in survival in different countries, and the results are somewhat predictable.If, for example, you are an Australian or American with breast cancer, you have a 90% chance of surviving. If you are Indian however, you only have a 66% chance.If a child is diagnosed with acute lymphoblastic leukaemia in Finland, they have a 95% chance of beating the disease; in Ecuador, the rate is only 50%.So, over the period of this study (2000 to 2014) roughly 200,000 Indian women died from breast cancer who wouldn’t have died if they were living in the US. Almost 1,000 Ecuadorian children died from acute lymphoblastic leukaemia who wouldn’t have if they were in Finland. The same pattern is seen for all cancers, so it is clear that millions are dying from cancer in less developed countries who would not be if they were born somewhere else.This is even more staggering when you realise that this study did not even include countries at the bottom end of the global poverty index. This excluded nearly one third of the global population, as the records and reporting from these areas is just too unreliable to use.It is clear from the numbers that if you are from a less well-off country, you are far more likely to die after being diagnosed with cancer. This isn’t entirely surprising, as the detection and treatment of the disease changes quickly and can prohibitively expensive.Unfortunately, it is also likely get worse in the coming years. Due to a lack of tobacco regulation in poorer countries, lung cancer is set to increase. The WHO has pointed out that smoking still appears to be increasing in Middle Eastern and African regions, and it is known that the tobacco industry has actively been targeting young people in these countries.Additionally, as our treatments for cancer get more sophisticated, they also get more expensive, something I have written about in the past. When combined with less well supported health systems, and other more pressing public health issues, the picture looks bleak for cancer patients in many low- and middle-income countries.Of course, there are plenty of other public health improvements that can be made around the world that would have a bigger impact on people’s lives than providing better access to cancer treatments. Access to clean water, anti-malarial programs, and HIV and TB treatment programs would be far wiser investments than cancer therapeutics. However, as we in cancer research congratulate ourselves on our successes, it is always worth keeping in mind just how unevenly that success is distributed.
Vitamin supplements: unexpected consequences
Over the last number of years, the vitamin and nutritional supplement market has grown phenomenally. It is estimated to be worth over $36 billion in the US, up from $17 billion in 2000. It is thought that nearly 70% of the US population take some kind of dietary supplement, and there is much said and written about their use. One thing that cannot be debated however, is the lack of evidence that they do any good. A prime example of this comes from a study published recently about vitamin B supplements.
The study looked at vitamin B use and lung cancer. They decided to do this because a previous study had reported an increase in these cancers in people taking vitamins B12 and B9, but that study wasn't designed to look specifically at this, so more work was needed.This study looked at over 77,000 people between the ages of 50 and 76, over a number of years. The results were striking. Vitamin B6 or vitamin B12 use was associated with a doubling in lung cancer risk in men, if taken at above the recommended daily allowance. Since people generally have no idea what the recommended daily allowance is, and the levels of these vitamins can be very high in supplements, there may be many people putting themselves at risk. Indeed, the majority of people taking vitamins unknowingly exceeded the recommended daily allowence.There are a few details that are worth noting. First, the effect was only seen in men and not in women. Second, the association was even stronger in smokers, who are already prone to lung cancer. Third, this effect was present for B6 and B12, but not for people taking B9 (also known as folic acid). Finally, the authors found no beneficial effects of vitamin B supplements in any group.So what does this mean in real terms? Of the 37,049 men in this study, 1966 where found to be taking the highest dose of vitamin B. Of that 1966, 36 were ultimately diagnosed with lung cancer. If they had not been taking vitamin B supplements, this would be expected to be 18 lung cancer diagnoses. That suggests that high vitamin B use was associated with roughly an additional 18 cases of lung cancer. When you consider that this study had over 77,000 people enrolled, 18 additional cases of lung cancer may seem quite small, and these numbers are indeed dwarfed by the additional cases caused by smoking, but it is still significant.As always, I have to point out that this study did not show that vitamin B supplementation caused these extra lung cancers, just that men taking high doses were more likely to get it. As I have previously described, correlation is not the same as causation. However, this was a well carried out study, and the authors controlled for as many variables as they could, making it more believable that the vitamin supplementation is contributing to the cancers.What is clear however, is that vitamin B pills give no benefit on any health outcome. Considering that they may even be doing some harm, it emphasises that we should be cautious when supplementing our diet with unnaturally high levels of vitamins. It is generaly assumed that the more vitamins the better, but as this study points out, that is not the case. A healthy, varied diet more than meets our vitamin needs. Why spend money on supplements if we don't need them?
Alternative medicine as a placebo
I recently wrote a post about the decision by NICE to no longer recommend acupuncture for lower back pain. This decision was made because, like most alternative medicine, acupuncture hasn’t been shown to work any better than a placebo. However, plenty of people use and get benefit from such treatments. This raises an interesting question: is there a place for complementary and alternative medicine (as a placebo) in the clinic?
The ethics of prescribing placebos is a complicated topic. People are perfectly entitled to use alternative medicine, and if they get a benefit, that’s obviously good. However, whether a doctor should prescribe alternative medicine is a different matter.As I have previously written, most complementary and alternative medicine works purely on the placebo effect. People argue that alternative medicine should be allowed to be prescribed, because if the placebo effect helps someone, then that justifies its use. Indeed, here in Glasgow we have an NHS funded “homeopathic hospital”, and if it helps people, why should we stop that?Unfortunately it’s not that simple. If a doctor prescribes such a therapy, it has the effect of offering a medical credibility to the therapy that doesn’t work. This may not sound like a big problem, but it is. There are many examples of people eschewing mainstream medicine for “natural” alternatives and herbal remedies.A court in Canada, for example, recently convicted the parents of a child who died from meningitis after they consulted a naturopath rather than a medical professional. The naturopath recommended the parents give ecinachia to their dying child. This isn’t an isolated case; it’s worth visiting the What’s the Harm website to see the toll that belief in pseudoscience can have.The reality is that if a doctor prescribes acupuncture for pain, then a patient is more likely to believe the plethora of false claims that an acupuncturist may make (including it being effective against diabetes, heart attacks, cancer and even ebola). This in turn increases the risk of patients postponing or declining evidence-based conventional treatment when it is needed. It was recently shown that women who were using certain alternative therapies were less likely to start chemo for their breast cancer. Regardless of whether someone benefits from the placebo effect given by an alternative therapy, it is simply not ethical to legitimise it as a practice. Furthermore, it is perfectly possible to give a placebo that does not come with the added nonsense, which brings me on to my next point.In 2008, the American Federal Trade Commission made a ruling on the use of the Q-Ray Ionised Bracelet in medicine. The makers argued that they could claim it was a cure for chronic pain because, like acupuncture and other alternative medicine, it exhibited the placebo effect. In his ruling on the case, the judge said the following:
“Like a sugar pill, it alleviates symptoms even though there is no apparent medical reason. Since the placebo effect can be obtained from sugar pills, charging $200 for a device that is represented as a miracle cure but works no better than a dummy pill is a form of fraud.”
When we can get the same or similar effects from a far cheaper placebo, then a doctor prescribing alternative medicine is ripping off their patient or the NHS. With already stretched resources, it is scandalous that the NHS pays £1.33 million per year to the Glasgow Homeopathic Hospital. People spend a huge amount of money on alternative medicine (it’s a $34 billion industry in the US), a product that doesn’t work, and is also completely unregulated.The unregulated nature of the industry is something that people are generally unaware of. Numerous studies have shown that alternative remedies regularly contain contaminants like toxic metals, pharmaceuticals, insects, rodents, parasites, fungi, pesticides and other fillers. These contaminants have led to serious illness is many cases, and several deaths. Prof. Edzard Ernst (former Chair in Complementary Medicine at the University of Exeter) has written extensively about this topic and is a good place to look for more information.The placebo effect has a significant role to play in health care. It can undoubtedly improve subjective symptoms in a number of contexts. However, while any effect alternative medicine has can be explained by placebo, the industry claims that it does much more than that. Couple this with the unregulated nature of the products and the expense involved, and it is clear that alternative medicine should never be given legitimacy by the mainstream medical community. I’ll leave you with this quote from Tim Minchin:
"By definition", I begin"Alternative Medicine", I continue"Has either not been proved to work,Or been proved not to work.Do you know what they call "alternative medicine"That's been proved to work?Medicine."
https://www.youtube.com/watch?v=HhGuXCuDb1U
Royal College of Physicians recommends e-cigarettes for smokers
A few months ago I wrote here about the rise of e-cigarettes. In that post I pointed out that e-cigarettes are far less harmful than tobacco, and should be marketed as a safer alternative to smoking. There has been an interesting update on this topic today, with the Royal College of Physicians (RCP) recommending that all smokers be offered and encouraged to use e-cigarettes.You can read my previous post for some of background, but put simply, e-cigarettes vaporise nicotine to allow it to be inhaled (hence it being known as “vaping”). This differs from smoking, where tobacco is burned and the smoke inhaled. This accounts for the primary difference between vaping and smoking; tobacco burning creates thousands of chemicals, 10% of which are known to cause cancer. People inhale far fewer chemicals when vaping, making it 95% safer than smoking.The RCP released a report today (April 28th) stating that
"e-cigarettes are likely to be beneficial to UK public health. Smokers can therefore be reassured and encouraged to use them, and the public can be reassured that e-cigarettes are much safer than smoking"
They go on to state that current evidence shows:
- E-cigarettes are not a gateway to smoking.
- E-cigarettes do not result in the normalisation of smoking.
- E-cigarette use is likely to lead to quit attempts that would not otherwise have happened.
- The dangers of long-term e-cigarette are unlikely to exceed 5% of those associated with smoked tobacco products, and may well be substantially lower than this figure.
An excellent Cancer Research UK blog post on this topic points out that this reduced harm of vaping is something we should focus on. They emphasise that a significant number of people may be unable, or simply not want, to give up smoking. For these people, the aim should be to reduce the danger of their habit by encouraging them to use e-cigarettes rather than traditional cigarettes. This harm reduction strategy has worked well in other cases, such as needle exchanges for intravenous drug users.This is what the NHS already recommends, in the form of nicotine replacement therapy. It has been shown, however, that the delivery of nicotine to the brain via vaping is far more similar to smoking than in nicotine replacement therapy. As a result smokers seem to prefer vaping, and e-cigarettes have now replaced nicotine patches and gum as the most popular aid in quitting smoking in the UK.It has been shown that an overwhelming majority of e-cigarette users are ex-smokers, or current smokers who are trying to cut down or quit. Considering the human toll of smoking (270 deaths in the UK every day), it is commendable that the RCP have recommended e-cigarettes to smokers. While there are still problems with vaping (particularly in marketing to children), the advantages for current smokers are undeniable. The use of alternative sources of nicotine is safer, and should be part of any strategy to reduce the harm of tobacco.
The placebo effect
The recent decision by NICE to no longer recommend acupuncture for lower back pain got me thinking about the placebo effect. It is a bizarre phenomenon: any treatment (regardless of whether it is a real treatment or not) will improve symptoms in some people simply because the recipient believes that it will work. So if we give someone a placebo (a sugar pill for example) and tell them that it can work for their illness, a proportion of patients will feel better. There are so many interesting things about the placebo effect it’s difficult to know where to start.The more the placebo, the bigger the effectTake this observation: if we give someone sugar pills as a placebo, then they might see improvement in their symptoms. However, if we give them four sugar pills instead of two, then we will see a bigger improvement. And if a placebo injection is used, then this is more effective again.It matters what a placebo looks likeSugar pills with a brand name stamped on them will have a stronger placebo effect than those that don’t. Researchers have also found that sugar pills with a $2.50 price tag ease pain much more effectively than identical pills with a10 cents tag. We actually see the same effect with wine; people rate a wine highly if they think it is more expensive.You don’t necessarily have to deceive peopleBizarrely, there is still a placebo effect even when the patients know they are getting a placebo. When researchers told people who were on a trial for an irritable bowel syndrome that they were receiving “placebo pills made of an inert substance”, they found that patients still experienced a reduction in symptom severity, even though they knew they were on a placebo. In another study, researchers gave patients a fake pain-relieving gel for 4 days, and then told them the truth, that it was it was actually just dyed vaseline. However, the pain relieving effect still persisted after this, suggesting that conditioning is part of this effect.The placebo effect is getting stronger with timeResearchers analysing 20 years of clinical trials for pain have noticed a weird pattern: the placebo effect has been increasing over that time (but only in the US). Several explanations for this have been suggested, including that patients are getting more attention and encouragement now compared to the past, so their overall experience in the trial is better. It has also been pointed out that over this time pharmaceutical companies have turned to private companies to run their trials. As these companies are paid to recruit more people, they may inadvertently include less ill patients on the trial in order to boost numbers. This has been shown to result in an apparent treatment effect in patients, contributing to the placebo effect.There is a placebo effect on animalsThis is a really confusing one: animals experience the placebo effect! If this effect is driven by the expectation that the treatment will work, how do we explain that? More about that below.Placebos can cause side effectsWhen patients are aware of the side effects of a treatment, they can also experience these while on placebo. For example, if a patient has previously taken opioid pain relief (one related to opium, such as morphine, codeine or vicodin), which can result in respiratory depression, they are then more likely to experience the same symptoms when on a placebo. Furthermore, if someone has been on hormone replacement therapy (HRT) placebo and this is then discontinued, they can experience the same withdrawal symptoms as someone who has actually been on HRT.And placebos aren’t just a medical thingThe placebo effect exists in other areas of life too. After drinking placebo vodka, people’s IQ drops and they have impaired judgement. This is demonstrated with predictably funny results in a video of a non-alcoholic keg party that you can find here.The above examples all point to the fact that while the placebo itself is an inert substance, it can still result in real physiological effects through suggestion, expectation and other mental processes.We really don’t have a good grasp on how the placebo effect works. We know that it usually affects subjective symptoms like pain, depression, hot flushes, and insomnia, but that it very rarely improves the underlying disease mechanisms. Survival from serious forms of cancer has little observable placebo effect for example. However, we do know that it is made up of a mix of different biological and psychological factors.First and most obvious of these is that mood and belief can have a significant effect on subjective symptoms, both through our perception of those symptoms, but also through real biological mechanisms. When studying the placebo effect in pain research, scientists found that a drug called naloxone, which inhibits opioids, could also inhibit the placebo effect, suggesting that placebo and opioid pain relief share a common mechanism. Other scientists then used brain imaging to suggest that placebo and opioid pain relief both seem to work via the same pathways in the brain, showing that for pain relief at least, part of the placebo effect is caused by a real biological mechanism.Such biological mechanisms are also at play in systems where mood really matters. The placebo effect can lower the release of stress hormones (through altering someone’s mood) and as such can have an effect on the heart and the immune system. The influence of a placebo in this context is mild, but almost certainly real.These biological explanations are in the minority however; it is thought that most of the placebo effect is as a result of cognitive biases that we are all prone to. Before I get into that however, I will point out that, placebo or not, if someone feels better after taking something, then it may have legitimate use in medicine. I won’t address this issue here, but will in my next post on this blog. The use of alternative medicine falls into this category, and is an interesting topic.Back to the placebo effect; the most common cognitive bias that falls into this category is called regression to the mean. The many so-called “cures” for the common cold (echinacea, hot lemon, etc.) are a great example of this. We can show that these none of these remedies have any effect above the placebo. However, when people get better they credit whatever treatment they have taken for this natural improvement in their symptoms. Often, by the time someone starts their herbal remedy (or whatever they decide to go with) their body has already dealt with the illness and they are on the mend. It is very natural for us to see cause and effect where there is none, but most improvements like this are as a result of the placebo effect, specifically regression to the mean.The animal placebo effect mentioned above can be explained by another bias we are prone to called the caregivers effect. This occurs because animals cannot directly report their subjective symptoms, so people have to observe the animals and decide whether they are responding to the therapy. Often, the humans will perceive improvement even when objective measures show none.In human trials, other biases occur. People taking a treatment want to get better and want the time and money they have invested to be worthwhile, so when they are asked to rate their symptoms, they tend to over-estimate their improvement. This is known as reporting bias, and also affects scientists, who want their treatments to work and will tend to over-estimate the positive effect in their trial.It is also known that simply being in a clinical trial can contribute to the placebo effect. Participants tend to take better care of themselves than normal, and also get more medical attention than people not in trials. This causes improvements in people on the trial, not because of any biologically “real” placebo effect, but simply because they are part of the trial. This is known as the clinical trial effect.The placebo effect is an incredibly fascinating thing. It shines a light on how much we do not understand about our bodies, but also on how much tricks of the mind can affect our perception of ourselves. I began this article by talking about acupuncture, but the role of the placebo effect in alternative medicine is not one I will address in this post. However, I will tackle this, and the question of whether it is ethical to prescribe a placebo, in my next piece on this topic.
Why screening is hard
It’s a simple fact that the most effective thing we can do to cure more cancers is to catch them earlier. If we find bladder cancer at an early stage, the five year survival is 88%; if we catch it at a late stage, when it has started spreading around the body, it drops below 15%. This is why we screen for certain diseases, including breast, bowel and cervical cancer. These large-scale screening programs are the best hope we have for majorly reducing the toll cancer takes on our lives.Screening, however, is hard. The main problem we face is accuracy. An ideal test would flag up 100% of sick people and 0% of healthy people. However, these tests are never perfect. There is always a percentage of sick people who are not flagged up (false negatives) and a percentage of healthy people who are incorrectly labelled as sick (false positives). And these problems can get pretty bad pretty quickly.The following diagram illustrates this issue. It shows the results of a test that is quite accurate (one that has 90% accuracy) applied to a common disease that is present in 1% of the population.
As you can see above, what sounds like a good screening test results in 10 times more false positives than true positives, while it also tests one person as negative while they are actually positive.In a large population, even a small percentage of error translates into a large number of misidentified patients. This can result in a crippling financial burden on the health system, as well as unnecessary worry, stress and pointless treatment for perfectly healthy people.As a result, only extremely accurate tests can be used in the clinic, which is the reason we screen for so few diseases. So how do we get around this? Well, obviously we have to develop more accurate tests, and a lot of effort is currently being invested in this field.Additionally, we can also improve things by being more selective about the people we screen. If a disease is present in 1% of the general population, but present in 5% of people over 65, then we can screen just the over 65s.So using the above the example of a test with 90% accuracy, if the prevalence is 5% instead of 1%, then rather than 10-times more false positives than true positives, there is just over 2-times. If the test were 98% accurate, then we would have far more true positives than false positives. This increased accuracy in a specific population is what we are working towards.
However, while significant research is being carried out in the development of new tests, it is disappointing to note that this is still a small percentage of cancer research funding. According to the National Cancer Research Institute, in 2011 (the most recent year I could find numbers for), research into early detection, diagnosis and prognosis received just 12.6% of cancer research funding.While it is understandable that research into a “cure” is more attractive than research into early diagnosis, the potential benefits of early diagnosis far outstrip that of drug development. Encouragingly, this level of funding is increasing steadily, and rose from 8.1% in 2002 to 12.6% in 2011. If this research can result in more viable screening programs, this will provide a significant clinical benefit to cancer patients.For more information about screening, I’d recommend having a look at the sense about science website, which does a great job of describing not just this problem, but also many others that arise in screening populations for diseases.
Can Wi-Fi make you sick?
A French court recently awarded a disability grant to a woman claiming to suffer from electromagnetic hypersensitivity. Sufferers define this as an illness caused by the radiation given out by everyday objects (Wi-Fi routers, mobile phones and power lines, for example), resulting in a wide range of non-specific symptoms, including headaches, fatigue and irregular heartbeats. There have been several lawsuits in the US from people claiming that their health has been affected by Wi-Fi (unsuccessful so far), and just this week in Massachusetts parents have sued a school, claiming that the Wi-Fi there made their son ill.
While sufferers may have very real symptoms, we can be extremely confident that they are not as a result of exposure to electromagnetic radiation, and all reliable evidence suggests that electromagnetic hypersensitivity does not exist as an illness. Many studies have now been conducted to test whether the everyday electromagnetic radiation is causing the symptoms that sufferers display.For example, trials have exposed sufferers to either electromagnetic radiation or not, and tested whether the patients can tell the difference (they can’t), or whether there are increased stress hormones in their blood (there isn’t). Alternatively, study participants’ can be given protective netting designed to shield them from electromagnetic fields, sham netting or no netting, and tested to see if their symptoms get any better when shielded (they don’t).A 2010 review of the literature gathered evidence of 46 published papers on electromagnetic hypersensitivity and stated that the authors were “unable to find any robust evidence to support the existence of (electro-magnetic hypersensitivity) as a biologic entity”. Furthermore, the WHO took into account a staggering 25,000 articles, published over the last 30 years, analysing the biological effects and medical applications of non-ionizing radiation and concluded that “current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields”.The most likely explanation is that these symptoms are caused by the nocebo effect. This is the opposite of the placebo effect, so rather than people feeling better when they think they have been given a treatment, they feel worse when they think they have been exposed to something harmful. The symptoms that they feel may be entirely real, but they are almost certainly psychological. In an experiment carried out in 2013, scientists showed half of their subjects an episode of the BBC series “Panorama,” which alleged that WiFi signals were harmful. They then exposed the whole group to a fake Wi-Fi signal and waited to see who would get sick. The ones who watched the documentary were far more likely to develop electromagnetic hypersensitivity symptoms, providing strong evidence that the nocebo effect plays a large role in this syndrome.The judge in the case in France accepted that the woman’s symptoms prevented her from working, but stopped short of recognising electromagnetic hypersensitivity as an illness. This however hasn’t stopped believers from claiming this as a major breakthrough which proves that it is not a psychiatric illness. It doesn’t help when so many news outlets report so credulously on this story. Unfortunately, this court case has given legitimacy to believers in this syndrome, which could have much wider consequences. An industry has sprung up, selling products that claim to protect people from this harmless radiation, exploiting sick and vulnerable people. Unfortunately, this court case will only make this easier.
