Posts Tagged Cancer

“Liquid biopsies” for cancer screening: Life-saving tests, or overdiagnosis and overtreatment taken to a new level?

Could a blood draw be all you need to diagnose cancer and identify the best treatment for it? Not so fast...

Could a blood draw be all you need to diagnose cancer and identify the best treatment for it? Not so fast…

I’ve written many times about how the relationship between the early detection of cancer and decreased mortality from cancer is not nearly as straightforward as the average person—even the average doctor—thinks, the first time being in the very first year of this blog’s existence. Since then, the complexities and overpromising of various screening modalities designed to detect disease at an early, asymptomatic phase have become a relatively frequent topic on this blog. Before that, on my not-so-super-secret other blog, I noted that screening MRI for breast cancer and whole body CT scans intended to detect other cancers early were not scientifically supported and thus were far more likely to cause harm than good. That was well over ten years ago. Now we have a company offering what it refers to as a “liquid biopsy” for the early detection of cancer. I fear that this is the recipe for the ultimate in overdiagnosis. I will explain.

The problem, of course, is that disease progression, including cancer progression, is not always a linear process, in which the disease progresses relentlessly through its preclinical, asymptomatic phase to symptoms to complications to (depending on the disease) death. There is such a thing as disease that remains asymptomatic and never progresses (at which point it’s hard to justify actually calling it a disease). As I pointed out in my first SBM post on the topic, at least three-quarters of men over 80 have evidence of prostate cancer in autopsy series. Yet nowhere near three-quarters of men in their 80s die of prostate cancer—or ever manifest symptoms from it. This is what is meant by overdiagnosis, the diagnosis of disease that doesn’t need to be treated, that would never cause a patient problems.

When teaching medical students and residents, I frequently emphasize that overdiagnosis is different from a false positive because overdiagnosis does diagnose an actual abnormality or disease. For example, ductal carcinoma in situ (DCIS) diagnosed by mammography leading to a biopsy is a real pathological abnormality; it is not a false positive. We just do not know which cases of DCIS will progress to cancer and which will not, leading to a question of how DCIS should be treated or at the very least whether we should treat it as aggressively as we do now, particularly given that the apparent incidence of DCIS has increased 16-fold since the 1970s, all of it due to mammographic screening programs and the increased diagnosis of DCIS and early stage breast cancer has not resulted in nearly as much of a decrease in the diagnosis of advanced stage breast cancer as one would expect if early diagnosis were having an impact in reducing the diagnosis of late stage disease.

Overdiagnosis would not be such an issue if it didn’t inevitably lead to overtreatment. DCIS, for instance, is treated with surgery, radiation, and anti-estrogen drugs. Early stage prostate cancer used to be treated with radical prostatectomy, but now more frequently with radiation. Many of these men and women didn’t actually need treatment. We just don’t know which ones. This is why over the last six or seven years a significant rethinking of screening for breast and prostate cancer has occurred. There has been a backlash, of course, but the rethinking seems to have taken hold.

Not everywhere, of course. (more…)

Posted in: Basic Science, Cancer, Diagnostic tests & procedures, Public Health

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An aspirin a day to prevent heart attacks, strokes, and cancer?

Low dose aspirin is now recommended to prevent heart disease and cancer.

Low dose aspirin is now recommended to prevent heart disease and cancer.

Despite the remarkable advances in medicine over the past 20 years, cardiovascular disease and cancer will still kill half of us. Beyond the deaths, millions survive heart attacks, strokes and cancer, but many are left with disability and a reduced quality of life. While lifestyle changes can improve our odds of avoiding these diseases, they do not eliminate our risk. Finding ways to medically prevent these diseases before they occur, a term called “primary prevention”, is a holy grail in medicine. Primary prevention can be a tough sell, personally and medically. It means taking medicine (which may cause side effects) when you’re well, with the hope of preventing a disease before it occurs.

The US Preventative Services Task Force (USPSTF) released draft guidelines on the primary prevention of cardiovascular disease and colorectal cancer last week. The USPSTF is now recommending daily aspirin in some age groups who have at least a 10% risk of cardiovascular disease in the next 10 years. This isn’t the first guideline that’s recommended aspirin for primary prevention of cardiovascular disease, but it is the first major guideline to endorse aspirin to prevent colorectal cancer. Given these recommendations will apply to millions of people, they have attracted considerable controversy. Is this strategy going to reduce deaths and disability? Or are we about to start “medicalizing” healthy people inappropriately? (more…)

Posted in: Public Health, Science and Medicine

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The Woo Boat, or: How far Andrew Wakefield has fallen

Sadly, this is not the crew of the Woo Boat, which is not the Love Boat. It would be awesome if that were the case, but it's not. I wonder if they'll be letting the astrologist navigate. The trip might end up being longer than expected.

Sadly, this is not the crew of the Woo Boat, which is not the Love Boat. It would be awesome if that were the case, but it’s not. I wonder if they’ll be letting the astrologist navigate. The trip might end up being longer than expected. Oh, and I couldn’t resist crossposting this from another blog because this is so damned hilarious.

File this one under the category: You can’t make stuff like this up. (At least, I can’t.)

Let’s say you’re a diehard all-conspiracy conspiracy theorist and alternative medicine believer (a not uncommon combination). You love Alex Jones and Mike Adams and agree with their rants that there is a New World Order trying to suppress your rights. You strongly believe that vaccines not only cause autism, sudden infant death syndrome, a shaken baby-like syndrome, autoimmune diseases, premature ovarian failure, and even outright death, but are a depopulation plot hatched by Bill Gates and the Illuminati who support his agenda. Heck, you even believe that black helicopters are keeping an eye on those who have discovered this plot. To you, genetically modified organisms (GMOs) are part of the same plot, pure poison and pure evil. And, of course, you just know that there is a cure for cancer—nay, cures for all diseases—out there but those evil pharmaceutical companies are keeping them from the people, the better to bolster their profits, just as they are preventing Brave Maverick Doctors like Andrew Wakefield, Mark Geier, and Sherri Tenpenny from telling the world the truth about vaccines. Heck, you just know that these same nefarious forces are even going so far as to kill vaccine “skeptic” heroes like Jeff Bradstreet (and, of course, make it look like a suicide) and holistic “pioneers” like Nicholas Gonzalez (and make it look like a heart attack).

And you like cruises.

So where do you go when you want to go on a cruise? Normal cruises are filled with people who just want to have a good time and tend to roll their eyes when you regale them with your ideas about how there is a shadowy conspiracy out there that is promoting toxic pharmaceuticals and vaccines and preventing natural cures from being used by the people, while simultaneously promoting GMOs to make people sick so that they think they need more of those pharmaceuticals and vaccines and more pliable so that their New World Order agenda faces less opposition. By the time you get to how they’re also using chemtrails as another means of control, AIDS is not caused by HIV, and Ebola can be cured with homeopathy, in other words, by the time you’ve been on the cruise a couple of days, you’ll find yourself basically shunned, eating alone at dinner, and drinking alone at the bar. When you sit down at a table, everyone suddenly finds a reason to be elsewhere.

Fear not! There is now a cruise for you. See the Conspira-Sea Cruise next January, embarking in Los Angeles and taking you on a cruise through the Mexican Riviera:

Posted in: Science and Medicine

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Let food be thy medicine and medicine be thy food? The obsessive worship of “medicinal foods”

Let food be thy medicine and medicine be thy food? The obsessive worship of “medicinal foods”

Let food be thy medicine and medicine be thy food.

– attributed to Hippocrates

Who said anything about medicine? Let’s eat!

– attributed to one of Hippocrates forgotten (and skeptical) students


Who hasn’t seen or heard Hippocrates’ famous quote about letting food be your medicine and your medicine your food? If you have Facebook friends who are the least bit into “natural” medicine or living, you’ve almost certainly come across it in your feed, and if you’re a skeptic who pays the least bit of attention to what’s going on in the quackosphere you will almost certainly have seen it plastered on a picture as a meme, either using a picture of Hippocrates or pictures of plates of green, leafy vegetables, or both. I like to view the fetishization of “food as medicine,” to cite Hippocrates, as one of the best examples out there of the logical fallacy known as the appeal to antiquity; in other words, the claim that if something is ancient and still around it must be correct (or at least there must be something to it worth considering).

Of course, just because an idea is old doesn’t mean it’s good, any more than just because Hippocrates said it means it must be true. Hippocrates was an important figure in the history of medicine because he was among the earliest to assert that diseases were caused by natural processes rather than the gods and because of his emphasis on the careful observation and documentation of patient history and physical findings, which led to the discovery of physical signs associated with diseases of specific organs. However, let’s not also forget that Hippocrates and his followers also believed in humoral theory, the idea that all disease results from an imbalance of the “four humors.” It’s also amusing to note that this quote by Hippocrates is thought to be a misquote, as it is nowhere to be found in the more than 60 texts known as The Hippocratic Corpus (Corpus Hippocraticum).

As Diana Cardenes argues:

But Hippocratic doctors clearly saw a difference between food and medicines. In fact, food was considered as a material that could be assimilated after digestion (e.g. the air was also food) and converted into the substance of the body. For example, food was converted into the different parts of the body such as muscles, nerves, etc. By contrast, the concept of medicines at the time was a product which was able to change the body’s own nature (in terms of humor quality or quantity) but not be converted into the body’s own substance. Thus a food wasn’t considered a medicine. A possible root of the food-medicine confusion is the following cryptic phrase found in the work On Aliment: “In food excellent medication, in food bad medication, bad and good relatively”.3 This text is nowadays attributed to the Hellenistic period, but was considered to be Hippocratic in Antiquity by Galenus in particular.

Now, it is certainly true that Hippocrates and his followers used diet to treat many illnesses, it’s not really clear what sort of success they had. However, this ancient idea that virtually all disease could be treated with diet, however much or little it was embraced by Hippocrates, has become an idée fixe in alternative medicine, so much so that it leads its proponents twist new science (like epigenetics) to try to fit it into a framework where diet rules all, often coupled with the idea that doctors don’t understand or care about nutrition and it’s big pharma that’s preventing the acceptance of dietary interventions. That thinking also permeates popular culture, fitting in very nicely with an equally ancient phenomenon, the moralization of food choices (discussed ably by Dr. Jones a month ago).

Posted in: Cancer, Nutrition

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As in 2014, “right-to-try” laws continue to metastasize in 2015

As in 2014, “right-to-try” laws continue to metastasize in 2015

Last year, I did several posts on what I consider to be a profoundly misguided and potentially harmful type of law known as “right-to-try.” Beginning about a year and a half ago, promoted by the libertarian think tank known as the Goldwater Institute, right-to-try laws began popping up in state legislatures, which I likened to Dallas Buyers Club laws. Both Jann Bellamy and I wrote about how these laws are far more likely to do harm than good, and that is a position that I maintain today. The idea behind these laws is to give terminally ill patients access to experimental drugs—in some cases drugs that have only passed phase I testing—that might help them. It’s an understandable, albeit flawed argument. After all, it’s perfectly understandable why terminally ill patients would fight for drugs that give them hope, and it’s just as understandable why politicians and the public would see such a goal as a good thing. In practice, as I will explain again in the context of this update, such laws are far more likely to harm patients than help them. Indeed, as you will see, in the year since the first wave of right-to-try laws have passed, not a single patient that I can find has obtained access to experimental drugs under a right-to-try law, much less been helped by them.

Unfortunately, given how effectively “right to try” has been sold on grounds of providing terminally ill patients hope and as a matter of personal freedom, it’s clear that this wave is not going to abate. Since Colorado passed the very first right-to-try law almost exactly a year ago today, a total of 17 more states now have passed passed similar legislation, the most recent being Tennessee, and 22 others have introduced legislation. It’s a good bet that right-to-try will pass in all of those states, because, as I’ve explained many times before and in many interviews, if you don’t understand clinical trial ethics and science, opposing the concept of right-to-try comes across like opposing Mom, apple pie, and the American flag, and leaves opponents open to false—but seemingly convincing—charges of callousness towards the terminally ill on the order of enjoying drop kicking puppies through flaming goalposts.

Posted in: Clinical Trials, Pharmaceuticals, Politics and Regulation

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Vitamins and Cancer Risk

One of the greatest triumphs of marketing over evidence was the incredible rise of vitamin supplement use in the 20th century. Supplement makers successfully created a “health halo” around vitamins, and taking your vitamins became a virtue, something mothers told their children to do. The evidence, however, does not tell such a simple story.

In recent years it has become increasingly apparent that there are unintended consequences to taking vitamin supplements, and in fact there may be a net negative health effect. This is especially true for those who are healthy and don’t need vitamins, and for those who exceed the recommend dosages.

A recent review of the last 20 years of literature on the subject, presented at the American Association for Cancer Research 2015 meeting, found an overall increased risk of cancer among vitamin users. Dr. Tim Byers presented the study, which echoes the result of a 2012 review that he and others published. He specifically refers to two famous studies showing an increased risk of cancer from vitamins.

The 2011 SELECT trial found an overall increased risk of prostate cancer among men taking vitamin E. (more…)

Posted in: Herbs & Supplements, Nutrition

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Ken Burns Presents Cancer

Note: I wrote two posts today to alert readers to two upcoming television events in time for them to plan their viewing. See the second post for an announcement about a film on scientology, along with an article about Scientology’s War on Medicine that I wrote for Skeptic magazine.

Ken Burns

Filmmaker Ken Burns

Ken Burns has made a lot of outstanding films. His The Civil War has been listed as second only to Nanook of the North as the most influential documentary of all time. I was delighted to learn that he had applied his exceptional skills to a topic that is very important to us on the Science-Based medicine blog, cancer. His film is based on the Pulitzer Prize-winning book by Siddhartha Mukherjee, The Emperor of all Maladies: A Biography of Cancer.

I reviewed Mukherjee’s book in 2010. He is an oncologist and cancer researcher and also a superb writer. I characterized his book as:

a unique combination of insightful history, cutting edge science reporting, and vivid stories about the individuals involved: the scientists, the activists, the doctors, and the patients. It is also the story of science itself: how the scientific method works and how it developed, how we learned to randomize, do controlled trials, get informed consent, use statistics appropriately, and how science can go wrong.

I continue to think it is the best book ever written on cancer.

The film interviews Mukherjee and many of the researchers and patients whose stories appear in the book. If you haven’t read the book, it will give you an idea what it’s about. If you have read the book, you will enjoy it even more as you meet the people you have read about. It covers the history of cancer as well as the most recent scientific developments and is very optimistic about the future.

The movie is scheduled to premiere March 30 – April 1 at 9 PM EST on PBS, in 3 parts with a total duration of 6 hours. You can watch the trailer online. The producers sent me a press preview 1-hour highlight reel and I was very impressed. I can’t wait to watch the whole thing. I hope you will be able to watch it too.

Posted in: Announcements, Book & movie reviews, Cancer

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On the “right” to challenge a medical or scientific consensus

Jenny McCarthy flaunting her "expertise" at the antivaccine "Green Our Vaccines" rally in Washington, DC in 2008

Jenny McCarthy flaunting her “expertise” at the antivaccine “Green Our Vaccines” rally in Washington, DC in 2008

The major theme of the Science-Based Medicine blog is that the application of good science to medicine is the best way to maintain and improve the quality of patient care. Consequently, we spend considerable time dissecting medical treatments based on pseudoscience, bad science, and no science, and trying to prevent their contaminating existing medicine with unscientific claims and treatments. Often these claims and treatments are represented as “challenging” the scientific consensus and end up being presented in the media—or, sadly, sometimes even in the scientific literature—as valid alternatives to existing medicine. Think homeopathy. Think antivaccine views. Think various alternative cancer treatments. When such pseudoscientific medicine is criticized, frequently the reaction from its proponents is to attack “consensus science.” Indeed, I’ve argued that one red flag identifying a crank or a quack is a hostility towards the very concept of a scientific consensus.

Indeed, I even cited as an example of this attitude a Tweet by Jane Orient, MD, executive director of the American Association of Physicians and Surgeons (AAPS). This is an organization of physicians that values “mavericky-ness” above all else, in the process rejecting the scientific consensus that vaccines are safe and effective and do not cause autism or sudden infant death syndrome (SIDS), that HIV causes AIDS, and that abortion doesn’t cause breast cancer, to name a few. Along the way the AAPS embraces some seriously wacky far right wing viewpoints such as that Medicare is unconstitutional and that doctors should not be bound by evidence-based practice guidelines because they are an affront to the primacy of the doctor-patient relationship and—or so it seems to me—the “freedom” of a doctor to do pretty much damned well anything he pleases to treat a patient.

Posted in: Critical Thinking, Science and the Media, Vaccines

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Medical marijuana as the new herbalism, part 3: A “cannabis cures cancer” testimonial

Medical marijuana as the new herbalism, part 3: A “cannabis cures cancer” testimonial

It’s been a while since I discussed medical marijuana, even though it’s a topic I’ve been meaning to come back to since I first dubbed medical marijuana to be the equivalent of herbalism and discussed how the potential of cannabinoids to treat cancer has been, thus far, unimpressive, with relatively modest antitumor effects. The reason I refer to medical marijuana as the “new herbalism” is because the arguments made in favor of medical marijuana are very much like arguments for herbalism, including arguments that using the natural plant is superior to using specific purified cannabinoids, appeals to how “natural” marijuana is, and claims of incredible effectiveness against all manner of diseases, including deadly diseases like cancer, based on anecdotes and testimonials. Now, as I pointed out before, not only am I not opposed to the legalization and regulation of marijuana for recreational use, even though I’ve never tried it myself, but I support it. What I do not support are claims for medical effects that are not backed up with good scientific evidence, and for medical marijuana most claims fall into that category. That’s why I tend to view medical marijuana as a backdoor way to get marijuana legalized. Personally I’d rather advocates of marijuana legalization drop the charade, argue for legalization, and stop with the medical nonsense.

The last time around, I discussed the evidence supporting claims that “cannabis cures cancer” and found them to be wanting based on science. I didn’t however, discuss the “cannabis cures cancer” testimonial machine that drives the claim that marijuana is useful for treating cancer; at least, I only touched on it by discussing briefly Rick Simpson, who claims that his hash oil cures approximately 70% of patients with terminal cancer and a published anecdote in which it was claimed that hemp oil was effective in treating acute lymphoblastic leukemia. (It wasn’t. At least, the evidence presented was not convincing.) Since then, I’ve wanted to revisit the topic of “cannabis cures cancer” testimonials, and, for whatever reason, now seems like a good time to do it.

Posted in: Cancer, Herbs & Supplements

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The Gerson protocol, cancer, and the death of Jess Ainscough, a.k.a. “The Wellness Warrior”

The Wellness Warrior website now redirects to this photo.

The Wellness Warrior website now redirects to this photo.

Less than four days ago, a young Australian woman died of a very rare type of cancer. Most of my American and probably many of my European readers have never heard of her, but in Australia she had become quite famous over the last seven years as a major proponent of “natural health.” Her name was Jess Ainscough, but, like a certain American woman who has become famous for promoting dubious science, she was better known by her “brand” name. That brand name was The Wellness Warrior.

I first encountered Ms. Ainscough about a year and a half ago and have been intermittently following her career ever since. I’ve even blogged about her three or four times during that period over at my not-so-super-secret other blog. However, for whatever reason, even though it was my intent to write about her here on Science-Based Medicine, I never got around to it. Her death prodded me to write now, because her tale is a cautionary one important enough that I believe there should be something written here about it. Given that, those of you who follow my cubical other self will find some of this post repetitive. However, think of it as the first opportunity I’ve had to tell the story from beginning to end, along with a major deconstruction of the Gerson protocol. (Yes, unfortunately the Gerson protocol figures heavily in this story.) It’s a story that has led to the deaths of at least two people, and whose harm to others is impossible to quantify, given that the reach of The Wellness Warrior was long, at least in Australia.

Posted in: Cancer, Herbs & Supplements, History, Science and the Media

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