Posts Tagged breast 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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“Precision medicine”: Hope, hype, or both?

The cost to sequence a whole genome has been plummeting impressively since 2007.

The cost to sequence a whole genome has been plummeting impressively since 2007.

I am fortunate to have become a physician in a time of great scientific progress. Back when I was in college and medical school, the thought that we would one day be able to sequence the human genome (and now sequence hundreds of cancer genomes), to measure the expression of every gene in the genome simultaneously on a single “gene chip,” and to assess the relative abundance of every RNA transcript, coding and noncoding (such as microRNAs) simultaneously through next generation sequencing (NGS) techniques was considered, if not science fiction, so far off in the future as to be unlikely to impact medicine in my career. Yet here I am, mid-career, and all of these are a reality. The cost of rapidly sequencing a genome has plummeted. Basically, the first human genome cost nearly $3 billion to sequence, while recent developments in sequencing technology have brought that cost down to the point where the “$1,000 genome” is within sight, if not already here, as illustrated in the graph above published by the National Human Genome Research Institute. Whether the “$1,000 genome” is truly here or not, the price is down to a few thousand dollars. Compare that to the cost of, for instance, the OncoType DX 21-gene assay for estrogen receptor-positive breast cancer, which costs nearly $4,000 and is paid for by insurance because its results can spare many women from even more expensive chemotherapy.

So, ready or not, genomic medicine is here, whether we know enough or not to interpret the results in individual patients and use it to benefit them, so much so that President Obama announced a $215 million plan for research in genomic mapping and precision medicine known as the Precision Medicine Initiative. Meanwhile, the deeply flawed yet popular 21st Century Cures bill, which passed the House of Representatives, bets heavily on genomic research and precision medicine. As I mentioned when I discussed the bill, it’s not so much the genomic medicine funding that is the major flaw in the bill but rather its underlying assumption that encouraging the FDA to decrease the burden of evidence to approve new drugs and devices will magically lead to an explosion in “21st century cures,” the same old antiregulatory wine in a slightly new bottle. Be that as it may, one way or the other, the federal government is poised to spend lots of money on precision medicine.

Because I’m a cancer doctor, and, if there’s one area in medicine in which precision medicine is being hyped the hardest, it’s hard for me not to think that the sea change that is going on in medicine really hit the national consciousness four years ago. That was when Walter Isaacson’s biography of Steve Jobs revealed that after his cancer had recurred as metastatic disease in 2010. Jobs had consulted with research teams at Stanford, Johns Hopkins, and the Broad Institute to have the genome of his cancer and normal tissue sequenced, one of the first twenty people in the world to have this information. At the time (2010-2011), each genome sequence cost $100,000, which Jobs could easily afford. Scientists and oncologists looked at this information and used it to choose various targeted therapies for Jobs throughout the remainder of his life, and Jobs met with all his doctors and researchers from the three institutions working on the DNA from his cancer at the Four Seasons Hotel in Palo Alto to discuss the genetic signatures found in Jobs’ cancer and how best to target them. Jobs’ case, as we now know, was a failure. However much Jobs’ team tried to stay one step ahead of his cancer, the cancer caught up and passed whatever they could do. (more…)

Posted in: Basic Science, Cancer, Clinical Trials, Science and the Media

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The uncertainty surrounding mammography continues

Screening mammography

Mammography is a topic that, as a breast surgeon, I can’t get away from. It’s a tool that those of us who treat breast cancer patients have used for over 30 years to detect breast cancer earlier in asymptomatic women and thus decrease their risk of dying of breast cancer through early intervention. We have always known, however, that mammography is an imperfect tool. Oddly enough, its imperfections come from two different directions. On the one hand, in women with dense breasts its sensitivity can be maddeningly low, leading it to miss breast cancers camouflaged by the surrounding dense breast tissue. On the other hand, it can be “too good” in that it can diagnose cancers at a very early stage.

Early detection isn’t always better

While intuitively such early detection would seem to be an unalloyed Good Thing, it isn’t always. Although screening for early cancers appears to improve survival, the phenomenon of lead time bias can mean that detecting a disease early only appears to improve survival even if earlier treatment has no impact whatsoever on the progression of the disease. Teasing out a true improvement in treatment outcomes from lead time bias is not trivial. Part of the reason why early detection might not always lead to improvements in outcome is because of a phenomenon called overdiagnosis. Basically, overdiagnosis is the diagnosis of disease (in this case breast cancer but it is also an issue for other cancers) that would, if left untreated, never endanger the health or life of a patient, either because it never progresses or because it progresses so slowly that the patient will die of something else (old age, even) before the disease ever becomes symptomatic. Estimates of overdiagnosis due to mammography have been reported to be as high as one in five or even one in three. (Remember, the patients in these studies are not patients with a lump or other symptoms, but women whose cancer was detected only through mammography!) Part of the evidence for overdiagnosis includes a 16-fold increase in incidence since 1975 of a breast cancer precursor known as ductal carcinoma in situ, which is almost certainly not due to biology but to the introduction of mass screening programs in the 1980s.

As a result of studies published over the last few years, the efficacy of screening mammography in decreasing breast cancer mortality has been called into question. For instance, in 2012 a study in the New England Journal of Medicine (NEJM) by Archie Bleyer and H. Gilbert Welch found that, while there had been a doubling in the number of cases of early stage breast cancer in the 30 years since mass mammographic screening programs had been instituted, this increase wasn’t associated with a comparable decrease in diagnoses of late stage cancers, as one would expect if early detection was taking early stage cancers out of the “cancer pool” by preventing their progression. That’s not to say that Bleyer and Welch didn’t find that late stage cancer diagnoses decreased, only that they didn’t decrease nearly as much as the diagnosis of early stage cancers increased, and they estimated the rate of overdiagnosis to be 31%. These results are in marked contrast to the promotion of mammography sometimes used by advocacy groups. Last year, the 25 year followup for the Canadian National Breast Screening Study (CNBSS) was published. The CNBSS is a large, randomized clinical trial started in the 1980s to examine the effect of mammographic screening on mortality. The conclusion thus far? That screening with mammography is not associated with a decrease in mortality from breast cancer. Naturally, there was pushback by radiology groups, but their arguments were, in general, not convincing. In any case, mammographic screening resulted in decreases in breast cancer mortality in randomized studies, but those studies were done decades ago, and treatments have improved markedly since, leaving open the question of whether it was the mammographic screening or better adjuvant treatments that caused the decrease in mortality from breast cancer that we have observed over the last 20 years.

Given that it’s been a while since I’ve looked at the topic (other than a dissection of well-meaning but misguided mandatory breast density reporting laws a month ago), I thought now would be a good time to look at some newer evidence in light of the publication of a new study that’s producing familiar headlines, such as “Mammograms may not reduce breast cancer deaths“.

Here we go again.

Posted in: Cancer, Public Health

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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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The Hippocrates Health Institute: Cancer quackery finally under the spotlight, but will it matter?

This is a screenshot from the website of the Hippocrates Health Institute, showing its grounds.

This is a screenshot from the website of the Hippocrates Health Institute, showing how high end its grounds and facilities are.

I first came across Brian Clement, the proprietor of the Hippocrates Health Institute in West Palm Beach, Florida, a little more than a year ago based on the story of Stephanie O’Halloran. Ms. O’Halloran was—word choice unfortunately intentional—a 23-year-old mother of an 18 month old child from Ireland who was diagnosed with stage IV breast cancer in 2013, with metastases to her lymph nodes, liver, lung, and leg. Unfortunately for her, she found Brian Clement at the Hippocrates Health Institute, who gave her false hope with his claims that a raw vegan diet and wheatgrass can treat just about everything. Unfortunately, but not unexpectedly, Ms. O’Halloran died in June 2014, less than nine months after having been diagnosed with metastatic breast cancer.

I didn’t write about Stephanie O’Halloran at the time (at least not here), but I did write about Brian Clement and the Hippocrates Health Institute (HHI) twice over the last several months in the context of the cases of two 11-year-old Aboriginal girls in Canada with cancer, specifically lymphoblastic leukemia. One was —word choice again unfortunately intentional—named Makayla Sault and the other is referred to as “JJ” in news reports to protect her privacy in her parents’ legal proceedings to assert their right to use traditional medicine to treat their daughter’s cancer rather than curative chemotherapy, which was estimated to have a 75% chance of curing Makayla Sault and an 85% to 90% chance of curing JJ. Unfortunately, both girls and their parents fell under the spell of Brian Clement and his cancer quackery. The result was one unnecessarily dead girl (Makayla Sault, who died last month) and one likely to be dead by the end of this year or not much longer (JJ). Such is the price of cancer quackery. In this case, even more puzzlingly, these girls’ parents seemed quite content to conflate the quackery of Brian Clement, a white man practicing in Florida, with “traditional Aboriginal medicine,” the sort of practices they were claiming to have a right to.

Posted in: Cancer, Health Fraud, Herbs & Supplements, Legal

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Screening for disease in people without symptoms: The reality

One of the most contentious questions that come up in science-based medicine that we discuss on this blog is the issue of screening asymptomatic individuals for disease. The most common conditions screened for that we, at least, have discussed on this blog are cancers (e.g., mammography for breast cancer, prostate-specific antigen screening for prostate cancer, ultrasound screening for thyroid cancer), but screening goes beyond just cancer. In cancer, screening is a particularly-contentious issue. For example, by simply questioning whether mammography saves as many lives lost to breast cancer as advocates claim, one can find oneself coming under fire from some very powerful advocates of screening who view any questioning of mammography as an attempt to deny “life-saving” screening to women. That’s why I was very interested when I saw a blog post on The Gupta Guide that pointed me to a new systematic review by John Ioannidis and colleagues examining the value of screening as a general phenomenon, entitled “Does screening for disease save lives in asymptomatic adults? Systematic review of meta-analyses and randomized trials.”

Before I get into the study, let’s first review some of the key concepts behind screening asymptomatic individuals for disease. (If you’re familiar with these concepts, you can skip to the next section.) The act of screening for disease is based on a concept that makes intuitive sense to most people, including physicians, but might not be correct for many diseases. That concept is that early intervention is more likely to successfully prevent complications and death than later intervention. This concept is particularly strong in cancer, for obvious reasons. Compare, for example, a stage I breast cancer (less than 2 cm in diameter, no involvement of the lymph nodes under the arm, known as axillary lymph nodes) with a stage III cancer (e.g., a tumor measuring greater than 5 cm and/or having lots of axillary lymph nodes involved). Five year survival is much higher for treated stage I than for treated stage III, and, depending on the molecular characteristics, the stage I cancer might not even require chemotherapy and can be treated with breast conserving surgery (“lumpectomy” or partial mastectomy) far more frequently than the stage III cancer. So it seems intuitively true that it would be better to catch a breast cancer when it’s stage I rather than when it’s stage III.

Posted in: Cancer, Clinical Trials, Epidemiology, Public Health

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Blaming breast cancer on autism

From the Wikimedia Commons, originally posted by Flickr user Alex E. Proimos (link)

From the Wikimedia Commons, originally posted by Flickr user Alex E. Proimos (link)

Gayle DeLong has been diagnosed with what she refers to as “autism-induced breast cancer”. She’s even given it an abbreviation, AIBC. Unfortunately, as you might be able to tell by the name she’s given her breast cancer, she is also showing signs of falling into the same errors in thinking with respect to her breast cancer as she clearly has with respect to autism. As a breast cancer surgeon, regardless of my personal opinion of DeLong’s anti-vaccine beliefs, I can only hope that she comes to her senses and undergoes science-based treatment, but I fear she will not, as you will see. Her brief post announcing her diagnosis and blaming it on autism, however, does provide what I like to call a “teachable moment” about cancer.

We’ve met DeLong before on this blog. For instance, she published an execrably bad study that—of course!—tried to link vaccine to autism and failed miserably, despite doing some amazing contortions of analysis, combining diagnoses willy-nilly, all in the service of the discredited vaccine-autism hypothesis. As I said at the time, it just goes to show that someone who is an associate professor of economics and finance shouldn’t be doing epidemiological research. As I also described at the time, if the sorts of analytical techniques she used in her study are acceptable in the world of economics and finance, no wonder our economy has been so screwed up for so long. Another time, DeLong wrote a broadside against the regulatory machinery that oversees vaccine development and safety that was full of the usual antivaccine misinformation, tropes, and pseudoscience and hugely exaggerated perceived “conflicts of interest” among the various parties.

Posted in: Cancer, Neuroscience/Mental Health, Vaccines

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Breast cancer myths: No, antiperspirants do not cause breast cancer


Four weeks ago, I wrote a post in which I explained why wearing a bra does not cause breast cancer. After I had finished the post, it occurred to me that I should have saved that post for now, given that October is Breast Cancer Awareness Month. The reason is that, like clockwork, pretty much every year around this time articles touting various myths about breast cancer will go viral, circulating on social media like Facebook, Twitter, Pinterest, and Tumblr like so many giant spider-microbes on the moon on Saturday. Sometimes, they’re new articles. Sometimes they’re old articles that, like the killer at the end of a slasher film, seem to have died but always come back for another attack, if not immediately, then when the next movie comes out.

So I thought that this October I should take at least a couple of them on, although I can’t guarantee that I’ll stick to the topic of breast cancer myths for the whole month. After all, our “atavistic oncology” crank (you remember him, don’t you?) is agitating in the comments and e-mailing his latest “challenge” to my dean, other universities, and me. It was almost enough for me to put this post on hold for a week and respond to our insistent little friend’s latest “evidence,” but for now I’ll just tell Dr. Frank Arguello, “Be very careful what you ask for. You might just get it.” Maybe next week. Or maybe on my not-so-super-secret other blog. Or maybe never. Because Dr. Arguello has officially begun to bore me.

In the meantime, I’m going to stick with the original plan, at least for now.

So, first up this week is a myth that I can’t believe that I haven’t covered in depth sometime during the nearly seven years of this blog’s existence, other than in passing a couple of times, even though it’s a topic that deserves its own post. I’m referring to the claim that antiperspirants cause breast cancer. I bet you’ve seen articles like this oldie but not so goodie from über-quack Joe Mercola entitled “Are Aluminum-Containing Antiperspirants Contributing To Breast Cancer In Women?” or this older and even moldier article from seven years ago entitled “Why women should avoid using anti-perspirants that could cause breast cancer” or this one from last year entitled “Attention Deodorant Users: New Studies Link Aluminum To Breast Cancer“. Surprisingly, I haven’t found that many from this year yet. (Maybe the Ebola scare is distracting the usual suspects and diverting their efforts.) The same ones, however, keep reappearing every year, and they’re all based on the same sorts of claims and the same studies. So let’s dig in, shall we? (more…)

Posted in: Cancer, Epidemiology, Public Health, Science and the Media

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One more time: No, wearing a bra does not cause breast cancer

A red bra


Besides being a researcher and prolific blogger, I still maintain a practice in breast cancer surgery. It’s one of the more satisfying specialties in oncology because, in the vast majority of cases I treat, I can actually remove the cancer and “cure” the patient. (I use the quotes because we generally don’t like to use that term, given that some forms of breast cancer can recur ten or more years later, but in many cases the term still fits, albeit not as well as we would like.) Granted, I get a little (actually a lot of) help from my friends, so to speak, the multimodality treatment of breast cancer involving surgical oncology, radiation oncology, and medical oncology, but breast cancer that can be cured will be primarily cured with surgery, with chemotherapy, hormonal therapy, and radiation therapy working mostly to decrease the risk of recurrence, either local in the breast or distant elsewhere in the body. Through this multimodality approach, breast cancer mortality has actually been decreasing over the last couple of decades.

However, as a breast cancer surgeon, I not infrequently have to deal with many of the common myths that have sprung up around breast cancer. Some are promoted by quacks; others are just myths that sound plausible but aren’t true. (That’s why they persist as myths.) One such myth has been in the news lately, in particular last week; so I thought now was a good time to take a look as any. Besides, I spent most of the weekend out of town visiting my wife’s family, and I didn’t have a lot of time for this post. So this week sticking to something I know well makes sense and inspired me to make like Harriet Hall and Steve Novella and keep my post to a reasonable length for a change. There’s also so much less mucking about on PubMed and Google that way to make sure I’m not missing something, too.

Posted in: Cancer, Epidemiology

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