The US Preventive Services Task Force (USPSTF) recommends that everyone aged 50-75 be screened for colon cancer with any one of three options: colonoscopy every 10 years, flexible sigmoidoscopy every 5 years, or fecal occult blood testing (FOBT) every year. Conventional colonoscopy is considered the “gold standard” since it allows for direct detection and biopsy of early cancers and removal of precancerous polyps. It involves passing a long colonoscope via the rectum through the full length of the colon and is also known as optical or visual colonoscopy. A newer and less invasive alternative, virtual colonoscopy or CT colonography, is being promoted by some as the test of choice. Others disagree. One area of controversy is that CTs frequently find “incidentalomas” that require further investigation. An article in the journal Radiology highlights this problem, describing “the clinical drama that follows screening or diagnostic tests.” (more…)
Archive for Cancer
Well, it’s been a tough month for herbs since my last monthly soiree here at SBM.
Just last week at the American Society for Clinical Oncology (ASCO) meeting, a group out of the Mayo Clinic presented data from a study showing that a well-characterized flaxseed extract was ineffective against hot flashes in postmenopausal women. But as Steve Novella noted here earlier this week, negative clinical trials data on supplements rarely influence the behavior of those who continue to advocate for their herbal use.
Flaxseed, known to contain phytoestrogen compounds such as secoisolariciresinol diglucoside (SDG) and enterolactone, has been purported to relieve hot flashes.
But I think the hypothesis was flawed in the first place: while these compounds bind the estrogen receptor, they have largely been shown to be estrogen receptor modulators that act in a negative manner. Work from the group of Dr. Lillian Thompson at the University of Toronto has repeatedly shown in an estrogen-dependent animal model of human breast cancer that flaxseed components act in a predominantly anti-estrogenic manner. One might suspect that hot flashes would be made worse by flaxseed, although this was not the case in the study presented as ASCO.
A friend asked me to look at the evidence for hash oil as a treatment for glioma. His teenage daughter was recently diagnosed with brain cancer: a grade 3 anaplastic ependymoma. It recurred very rapidly after surgery and radiotherapy and the latest tissue diagnosis shows an aggressive grade IV glioma. Her prognosis is not good. No further attempts at curative therapy are indicated; the oncologist prescribed only palliative therapy with temozolomide. Her father, who had recently lost his wife to cancer (breast cancer metastatic to lungs and brain), was understandably devastated. As he puts it, he remains “focused on the belief that just maybe a cure can be found.” He stumbled on what he calls “earth-shattering news” regarding hash oil. He and his friends established a private wiki website which they are constantly updating with information about THC (tetrahydrocannabinol, the active ingredient in marijuana and hash) and other possible cancer cures: everything from curcumin to diet. He asked me to look at the information he has accumulated. He said
I hope to convince you in the same way I have done with my daughter’s GPs and her neuro-oncologist at BC Children’s Hospital.
The oncologist was not exactly convinced. He didn’t say he thought hash oil was likely to work; he only said it would be reasonable to try it as a complementary therapy. He said
the data published so far appears very preliminary, most of its potential effectiveness in vivo so far appears in colonic disease, having said that there doesn’t appear to be any obvious down side as a complementary therapy and may have synergistic effect, so may be reasonable as add on to temodal if she tolerates it
I wasn’t convinced either.
I will discuss two issues here:
- What does the evidence say about gliomas and hash oil?
- When is it reasonable to try an unproven treatment as a last resort?
Here at Science-Based Medicine, we try to be relatively apolitical. We might not always succeed, but in general our main concern is not so much with right-wing or left-wing politics, but rather with how prevailing government policies and regulation impact the delivery of medical care, in particular whether they tend to prevent, do nothing about, or promote the proliferation of non-science-based medical care. Consequently, when Kimball or I call for the disbanding of the National Center for Complementary and Alternative Medicine (NCCAM), it does not matter one whit to us who is President or which party controls Congress. All that matters is that we see NCCAM as a government entity that, through credulously studying many “alternative medicine” modalities, ends up inadvertently promoting them and providing them with the imprimatur of government approval. The same concept applies to state medical licensing boards licensing pseudoscientific modalities, such as naturopathy, acupuncture, and homeopathy. By regulating these “disciplines,” states also provide them with an unmerited mantle of respectability through their imprimatur of regulating them as professions, just like medicine and nursing.
As far as political views, although all of us have them and they occasionally even come to the fore in disagreements (remember when Wally Sampson occasionally clashed with others with differing political viewpoints?), we generally subsume them for purposes of the SBM blog experience into our advocacy for basing medicine on the best science available. Sometimes, however, when a pundit or politician makes claims that are either contrary to or distort science for ideological or political advantage, I feel the need to discuss those claims, sometimes even sarcastically. Such was the case last week, when Ann Coulter wrote a blisteringly ignorant column, entitled A Glowing Report on Radiation. She wrote this article in the wake of the fears arising in Japan and around the world of nuclear catastrophe due to the damage to the Fukushima nuclear power plant caused by the earthquake and tsunami that hit northern Japan on March 11. Coulter was subsequently interviewed by Fox News pundit Bill O’Reilly on The O’Reilly Factor on Thursday evening:
Yes, according to Coulter, radiation is good for you, just like toxic sludge! Even more amazing, in this video Bill O’Reilly actually comes across as the voice of reason, at least in comparison to Ann Coulter. He’s very skeptical of Coulter’s claims and even challenges her by saying, “So by your account we should all be heading towards the nuclear reactor.”
So, fellow SBM aficionados, is Coulter right? Are all those scientists warning about the dangers of even low-level radiation all wrong? Should we start hanging out in radioactive mine shafts, as Coulter mentions in her column (seriously) in order to boost our health and decrease our risk of cancer?
Last Friday, Mark Crislip posted an excellent deconstruction of a very disappointing article that appeared in the most recent issue of Skeptical Inquirer, the flagship publication of the Committee for Skeptical Inquiry (CSI). I say “disappointing,” because I was disappointed to see SI (Skeptical Inquirer, not Sports Illustrated) publish such a biased, poorly thought out article, apparently for the sake of controversy. I’m a subscriber myself, and in general enjoy reading the magazine, although of late I must admit that I don’t always read each issue cover to cover the way I used to do. Between work, grant writing, blogging, and other activities, my outside reading, even of publications I like, has declined. Perhaps SI will soon find itself off my reading list. Be that as it may, I couldn’t miss the article that so irritated Mark, because it irritated me as well. There it was, emblazoned prominently on the cover of the March/April 2011 issue: Seven Deadly Medical Hypotheses. I flipped through the issue to the article to find out that this little gem was written by someone named Reynold Spector, MD. A tinge of familiarity going through my brain, I tried to think where I had heard that name before.
And then I remembered.
Dr. Spector, it turns out, first got on my nerves about a year ago, when he wrote an article for the January/February 2010 issue of SI entitled The War on Cancer: A Progress Report for Skeptics. I remember at that time being irritated by the article and wanting to pen a discussion of the points raised but don’t recall why I never actually did. It was probably a combination of the fact that SI doesn’t publish its articles online until some months have passed after the paper version has been released and perhaps my laziness about having to manually transcribe with my own fingers any passages of text that I might want to cite. By the time the article was available online, I forgot about it and never came back to it–until now. I should therefore, right here, right now, publicly thank Mark (and, of course, Dr. Spector) for providing me the opportunity to revisit that article in the context of piling on, so to speak, Dr. Spector’s most recent article. After all, Deadly Hypothesis Seven (as Dr. Spector so cheesily put it) is:
From a cancer patient population and public health perspective, cancer chemotherapy (chemo) has been a major medical advance.
Dr. Spector then takes this opportunity to cite copiously from his 2010 article, sprinkling “(Spector, 2010)” throughout the text like powdered sugar on a cupcake. There’s the opening I needed to justify revisiting an article that’s more than a year old! And what fantastic timing, too, hot on the heals of my post from a couple of weeks ago entitled Why haven’t we cured cancer yet?
Last week David Gorski wrote a excellent post about why we have not yet cured cancer. It turns out, cancer is a category of many individual diseases that are very challenging to treat. We have made steady progress, and many people with cancer can now be cured – but we have not discovered the one cure for all cancer. I personally am not convinced that we will discover a single cure for all cancer, at least not with any extrapolation of current technology. But if we continue to make progress as we are cancer will become an increasingly treatable and even curable type of disease.
This topic also brings up a meme that has been around for a long time – the notion that scientists have already cured cancer but the cure is being suppressed by the powers that be, to protect cancer as a source of income. In the comments to David’s article, Zuvrick writes:
So we can find a cure. It has probably happened multiple times. But nobody wants to cure cancer. Too many researchers earn a living seeking a cure by remaining inside a narrow, restricted channel of dogma. Their institutions get grant money and survive from the funding. Big Pharma makes big bucks selling chemotherapy drugs, surgeons remove tumors and various radiation devices employ radiologists and firms making these machines. MRI and CT scans would not be needed for cancer if Rife technology were available today.
I have heard or read some version of this claim since before I entered medical school. Superficially it may sound like profound wisdom (cynicism is a cheap way to sound wise) – but the idea collapses under the slightest bit of logical scrutiny.
Why haven’t we cured cancer yet?
If we can put a man on the moon, why can’t we cure cancer?
If we can harness the atom, why can’t we cure cancer?
How many times have you heard these questions, or variants thereof? How many times have you asked this question yourself? Sometimes, I even ask this question myself. Saturday was the two year anniversary of the death of my mother-in-law from a particularly nasty form of breast cancer, and, even though I am a breast cancer surgeon, I still wonder why there was nothing in the armamentarium of science-based medicine that could save her from a several month decline followed by an unpleasant death. That’s why, to me at least, the timing of the publication of a study examining the genome of prostate cancer that was published in Nature and summarized in this Science Daily news story was particularly apt. Performed as part of the National Cancer Institute’s Cancer Genome Project, the study undertook complete genome sequencing of seven advanced and aggressive prostate cancers. The results, as ERV put it, revealed what can be describe as a “train wreck.”
Personally, I’d describe it as looking as though someone threw a miniature grenade into the nucleus of a prostate epithelial cell. You’ll see what I mean shortly.
Of course, although that image does give you an idea of the chromosomal chaos in the heart of prostate cancer cells, it is inaccurate in that it implies a sudden explosion, after which the damage is done, and if there’s one thing we know about cancer it’s that in most cases it takes many years for a normal cell to progress to a cancer cell fully capable of metastasizing and killing its host. I’ve written in detail about the complexity of cancer before, of course, and have even pointed out before that when President Nixon launched the “war on cancer” 40 years ago scientists had no idea how difficult it would be. Indeed, before I discuss the current study, it’s probably useful to reiterate a bit why, in order to put the study in context.
A number of news outlets (e.g. Bloomberg Business Week, MSN.Com, US News, etc) have recently reported that use of complementary and alternative therapies (CAT) is widespread in hospice care facilities. This is based on a report from the Centers for Disease Control, Complementary and Alternative Therapies in Hospice: The National Home and Hospice Care Survey, Untied States, 2007. According to most news reports, about 42% of hospice care providers offer some kind of CAT.
I was initially inclined to find this a little worrisome. In my own field of veterinary medicine, advocates of alternative therapies are prominent among the organizers of the nascent hospice care movement. And while I am strongly supportive of better and more available veterinary hospice care, the involvement of CAM advocates raises the concern that animals at the end of their life might receive ineffective palliative care, or be denied the benefits of conventional treatments by some CAM providers, who often characterize “allopathic” treatments as “unnatural” and harmful.
Dr. H. Gilbert Welch has written a new book Over-diagnosed: Making People Sick in the Pursuit of Health, with co-authors Lisa Schwartz and Steven Woloshin. It identifies a serious problem, debunks medical misconceptions and contains words of wisdom.
We are healthier, but we are increasingly being told we are sick. We are labeled with diagnoses that may not mean anything to our health. People used to go to the doctor when they were sick, and diagnoses were based on symptoms. Today diagnoses are increasingly made on the basis of detected abnormalities in people who have no symptoms and might never have developed them. Overdiagnosis constitutes one of the biggest problems in modern medicine. Welch explains why and calls for a new paradigm to correct the problem. (more…)