Articles

Posts Tagged ultrasound

Reclassifying thyroid cancer and the willful misunderstanding of overdiagnosis

This is a panel showing some of the pathologic criteria for distinguishing invasive encapsulated follicular variant of papillary thyroid carcinoma from noninvasive. This is real science. Sayer Ji's rant is not.

This is a panel showing some of the pathologic criteria for distinguishing invasive encapsulated follicular variant of papillary thyroid carcinoma from noninvasive. This is real science. Sayer Ji’s rant is not.

If there’s one lesson that we here at Science-Based Medicine like to emphasize, it’s that practicing medicine and surgery is complicated. Part of the reason that it’s complicated is that for many diseases our understanding is incomplete, meaning that physicians have to apply existing science to their treatment as well as they can. The biology of cancer, in particular, can be vexing. Some cancers appear to progress relentlessly, meaning that it’s obvious that all of them must be treated. Others, particularly when detected in their very early stages through screening tests, have a variable and therefore difficult to predict clinical course if left untreated. Unfortunately, some people, such as Sayer Ji, don’t understand that. They like their medicine black and white, and if physicians ever change guidelines in order to align them more closely with scientific understanding, they write blisteringly ignorant articles like “‘Oops… It Wasn’t Cancer After All,’ Admits The National Cancer Institute/JAMA.”

Not exactly. An expert panel recommended reclassifying a specific thyroid lesion as not cancerous based on recent science. It’s called medicine correcting itself. Admittedly, this reclassification was probably long overdue, but what would Mr. Ji rather have? Medicine not correcting itself in this situation? In any case, when last I met Mr. Ji, he was happily abusing the science of genetics to argue that Angelina Jolie and other carriers of deleterious cancer-causing mutations don’t need prophylactic surgery because lifestyle interventions will save them through epigenetics, which to “natural health” enthusiasts like Mr. Ji seems to mean the magical ability to prevent any disease. Most recently, he has appeared on the deeply dishonest “documentary” about alternative medicine cancer cures, The Truth About Cancer, to expound on how chemotherapy is evil. His rant about the reclassification of a non-encapsulated follicular variant of papillary thyroid cancer as not cancer is more of the same, as you will see.
(more…)

Posted in: Cancer, Politics and Regulation, Public Health

Leave a Comment (0) →

Confusing overdiagnosis for an “epidemic” of thyroid cancer in Japan after Fukushima

A Japanese girl being screen for thyroid cancer.

A Japanese girl being screen for thyroid cancer.

One of my favorite topics to blog about for SBM is the topic of overdiagnosis and overtreatment. These are two interrelated phenomena that most people are blissfully unaware of. Unfortunately, I’d also say that the majority of physicians are only marginally more aware than the public about these confounders of screening programs, if even that.

Overdiagnosis has long been appreciated to be a major impediment to translating programs to screen for disease into better outcomes in a number of diseases but has only recently really seeped into the public consciousness, beginning in particular in 2009 when the United States Preventative Services Task Force (USPSTF) issued mammography recommendations that pushed back the recommended age to start screening to 50. Certainly, the concept of overdiagnosis is counterintuitive. After all, why do we screen for disease in asymptomatic people? The reason is simple—and maddeningly intuitive. We screen for disease based on the belief that catching potentially deadly diseases like cancer early, before they produce clinical symptoms, will allow earlier intervention and save lives. It seems blindingly obvious that this should be the case, doesn’t it? Unfortunately, real life biology and pathophysiology aren’t quite so neat and tidy, and the relationship between early detection and improved survival is muddied by phenomena such as lead time bias and the Will Rogers effect, in addition to overdiagnosis.

What is overdiagnosis? In brief, it is the detection of pathology or disease that, if left untreated, would never endanger the life of a patient or even harm him. Note that overdiagnosis is not the same thing as a false positive. A false positive occurs when a test detects disease that isn’t really there; in contrast with overdiagnosis there is definite pathology. The disease being screened for is there, at least in an early form. It’s just that, at the very early stage detected, it’s either not progressive or so indolent that the patient will grow old and die of something else before it would ever cause a problem. Indeed, it’s been estimated that as many as one in three breast cancers detected by mammography in asymptomatic women might be overdiagnosed and that one in five might spontaneously regress. However, because we don’t know which ones are unlikely to cause harm and haven’t worked out a safe method of observing them and intervening if they look as though they are progressing, we are obligated to treat them all when discovered. The problem of overdiagnosis has led to multiple alterations in what once were considered definitive recommendations for screening mammography, first by the USPSTF and most recently by the American Cancer Society.
(more…)

Posted in: Cancer, Epidemiology

Leave a Comment (0) →

Point-of-Care Ultrasound: The Best Thing Since Stethoscopes?

A bit of good news for a change: a “Perspective” article in the New England Journal of Medicine describes how point-of-care ultrasound devices are being integrated into medical education. The wonders of modern medical technology are akin to science fiction. We don’t yet have a tricorder like “Bones” McCoy uses on Star Trek, but we are heading in that direction, and the new handheld ultrasound devices are a promising development.

The stethoscope has become iconic, a symbol of medical expertise draped proudly around the neck by doctors and other medical personnel. Before it was invented, doctors could only try to listen to a patient’s heart by direct application of ear to chest. In 1816, Laennec interposed a tube of rolled paper between ear and chest, and the stethoscope was born. It quickly became an essential tool, allowing us to hear the distinctive murmurs produced by different heart valve abnormalities, to take blood pressures, to detect the wheezing of asthma or the collapse of a lung , to hear the bruits caused by atherosclerotic narrowing of blood vessels, to detect intestinal obstructions by listening for borborygmi (I love that onomatopoeic word!).

The stethoscope allows us to hear sounds produced by the body, but sound also allows us to see inside the body. Diagnostic ultrasound has a multitude of uses. With prenatal sonograms, we can determine the sex of a fetus, watch it suck its thumb, and even take its picture for the family album. With echocardiography we can evaluate heart valves, see fluid accumulation in the pericardium, observe the thickness and motion of the heart wall, and even quantify the efficiency of the pumping process. Ultrasound lets us see clots in blood vessels and stones in the gallbladder, evaluate abdominal organs, detect cysts, screen for carotid artery narrowing and abdominal aortic aneurysms, and guide needles into the body for therapeutic and diagnostic purposes. (more…)

Posted in: Diagnostic tests & procedures, Medical Academia, Medical devices

Leave a Comment (31) →

The End for CCSVI

Paolo Zamboni, proponent of the controversial and unlikely claim that multiple sclerosis is caused by chronic cerebrospinal vascular insufficiency.

Paolo Zamboni, proponent of the controversial and unlikely claim that multiple sclerosis is caused by chronic cerebrospinal vascular insufficiency.

A new study published in The Lancet provides the most definitive evidence to date that chronic cerebrospinal venous insufficiency (CCSVI), a hypothetical syndrome of narrowed veins draining the brain that some believe is the true cause of multiple sclerosis (MS), is not associated with MS.

In a science-based world, this study would be yet one more nail in the coffin of this failed hypothesis. But that’s not the world we live in.

CCSVI background

CCSVI was first proposed in 2009 by Italian vascular surgeon, Dr. Paolo Zamboni – that multiple sclerosis (MS) is caused by chronic blockage of the veins that drain the brain. The current scientific consensus is that MS is a chronic autoimmune disease, and the pathology is caused by primary inflammation. Dr. Zamboni believes that the venous anomalies he has discovered are the primary cause and the inflammation is secondary. (more…)

Posted in: Neuroscience/Mental Health

Leave a Comment (44) →

Are Prenatal Ultrasounds Dangerous?

Several questionable sources are spreading alarms about the possible dangers of prenatal ultrasound exams (sonograms). An example is Christine Anderson’s article on the ExpertClick website. In the heading, it says she “Never Liked Ultrasound Technology.”

[She] has never been sold on the safety using Ultrasounds for checking on the fetuses of pregnant women, and for the last decade her fears have been confirmed with a series of studies pointing to possible brain damage to the babies from this technology.

Should We Believe Her?

Should we avoid ultrasounds because Anderson never liked them? Should we trust her judgment that her fears have been confirmed by studies? Who is she?

“Dr.” Christine Anderson is a pediatric chiropractor in Hollywood who believes a lot of things that are not supported by science or reason. Her website mission statement includes

We acknowledge the devastating effects of the vertebral subluxation on human health and therefore recognize that the spines of all children need to be checked soon after birth, so they may grow up healthy.

It also states that “drugs interfere… and weaken the mind, body, and spirit.” Anderson is a homeopath, a craniosacral practitioner, a vegan, and a yoga teacher. She advises her pregnant patients to avoid toxins by only drinking filtered water and only eating organic foods. She sells her own yoga DVD. (more…)

Posted in: Diagnostic tests & procedures, Obstetrics & gynecology

Leave a Comment (57) →

Are one in three breast cancers really overdiagnosed and overtreated?

ResearchBlogging.orgScreening for disease is a real pain. I was reminded of this by the publication of a study in BMJ the very day of the Science-Based Medicine Conference a week and a half ago. Unfortunately, between The Amaz!ng Meeting and other activities, I was too busy to give this study the attention it deserved last Monday. Given the media coverage of the study, which in essence tried to paint mammography screening for breast cancer as being either useless or doing more harm than good, I thought it was imperative for me still to write about it. Better late than never, and I was further prodded by an article that was published late last week in the New York Times about screening for cancer.

If there’s one aspect of medicine that causes more confusion among the public and even among physicians, I’d be hard-pressed to come up with one more contentious than screening for disease, be it cancer, heart disease, or whatever. The reason is that any screening test is by definition looking for disease in an asymptomatic population, which is very different from looking for a cause of a patient’s symptoms. In the latter case, the patient is already being troubled by something that is bothering him. There may or may not be a cause in the form of a disease or syndrome that is responsible for the symptoms, but the very existence of the symptoms clues the physician in that there may be something going on that requires treatment. The doctor can then narrow down range of possibilities for what may be the cause of the patient’s symptoms by taking a careful history and physical examination (which will by themselves most often lead to the diagnosis). Diagnostic tests, be they blood tests, X-rays, or other tests, then tend to be more confirmatory of the suspected diagnosis than the main evidence supporting a diagnosis.
(more…)

Posted in: Cancer, Clinical Trials, Diagnostic tests & procedures, Public Health, Science and Medicine, Science and the Media

Leave a Comment (13) →

Ultrasound Screening: Misleading the Public

There is a new industry offering preventive health screening services direct to the public. A few years ago it was common to see ads for whole body CT scan screening at free-standing CT centers. That fad sort of faded away after numerous organizations pointed out that there was considerable radiation involved and the dangers outweighed any potential benefits.

Now what I most commonly see are ads for ultrasound screening. In fact, I am sick and tired of finding them in my mailbox and between the pages of my local newspaper. Ultrasound is certainly safe, with no radiation exposure. It sounds like it might be a good idea, but it isn’t.

Life Line Screening advertises itself as “America’s leading provider of quality health screenings.” They offer “4 tests in less than 1 hour – tests that can save your life.” They travel around the country, setting up their equipment in community centers, churches, and YMCAs. For $129 you get ultrasounds of your carotid arteries, your abdominal aorta, your legs, and your heel bone. They mail you your results 21 days later. (more…)

Posted in: Health Fraud, Medical Ethics, Public Health

Leave a Comment (21) →