A scanning electron micrograph of a blood clot. Image credit: Steve Gschmeissner/Science Photo Library (http://www.sciencephoto.com/media/203271/enlarge#)
On Monday January 1st, I overheard my dad telling my mom how his left arm was numb and that he had no strength in his left hand. I immediately ran into the medicine cabinet, grabbed two aspirin, practically shoved them down my dad’s throat, and told him to get his coat. He was going to the ER.
As it turns out, my dad was having a stroke, which is basically the cessation of blood flow to an area in the brain. Luckily, my dad only suffered a very mild stroke, and after several days of monitoring and a battery of tests, he was released from the hospital.
While we are all relieved that he dodged what could have been a fatal bullet, I came to realize that there was only a superficial understanding of what was actually happening. So, to help demystify the process for my dad (and anyone else in this situation), I’ve decided to write a mini-guide on strokes. Below you will find some handy information about strokes, including what they are, as well as a glossary of relevant terms.
Why we need blood flow in the brain
Before I get into what happens to the brain when a stroke occurs, it is important to first understand why unrestricted blood flow in blood vessels in the brain is important. The brain is a type of tissue, and like all tissues in our body, it needs a constant access to nutrients and oxygen. Furthermore, tissues produce waste, and this waste needs to be removed.
The human cardiovascular system. Image Credit: Wikipedia.
Evolution’s solution to this problem is the development of a vast network of blood vessels existing within our tissues. For instance, take a good look at your very own eyeballs. Especially when we are tired, we can see tiny blood vessels called capillaries, which help to deliver key nutrients and oxygen, keeping our organs of sight healthy and happy. Now consider that this type of blood vessel network exists in all tissues in our bodies (because it does). Depending on the needs of the tissue, these vessels vary in size and number. Sometimes the blood vessels are large, like the aorta, and sometimes they are super tiny, like the capillaries in our eyes. However, all serve the same function: to make sure that cells can breath, eat, and get rid of waste.
When blood is prevented from traveling to a specific area within a tissue, the cells in that area will not get enough fuel and oxygen and will begin to die. For instance, the restriction of blood flow to the heart leads to the death of heart tissue, causing a heart attack. Similarly, the interruption of normal blood flow within the brain causes the affected cells in the brain to essentially starve, suffocate, and die, resulting in a stroke. The medical term for a lack of oxygen delivery to tissues due to a restriction in blood flow is ischemia. In general, the heart, brain, and the kidneys are the most sensitive to ischemic events, which, when occurring in these organs, can be fatal.
So, what exactly is a stroke?
Some strokes can be categorized as being ischemic. As mentioned above, an ischemic stroke occurs when blood flow (and the associated oxygen supply) is restricted in an area within the brain, leading to tissue death. A major cause of ischemic strokes is a progressive disease called atherosclerosis, which can be translated to mean “the hardening of the arteries.”
Severe atherosclerosis of the aorta. Image Credit: Wikipedia.
Affecting the entire cardiovascular system, atherosclerosis is the result of cholesterol build-up inside of our blood vessels, causing their openings to become narrower. These cholesterol plaques can eventually burst, leading to the formation of a blood clot. Ischemic strokes occur as a result of a blood clot, medically known as a thrombus, that blocks the flow of blood to the brain, a phenomenon often related to complications from atherosclerosis. A ruptured cholesterol plaque and resulting blood clot can occur in the brain, or it can occur elsewhere in the body, such as in the carotid arteries, and then travel to the brain. Either way, the blood clot will block blood flow and oxygen delivery to sensitive brain tissue and cause a stroke.
Strokes that result from the bursting of a blood vessel in the brain can be categorized as being hemorrhagic. In this situation, there may be a pre-existing condition rendering the blood vessels in the brain defective, causing them to become weak and more susceptible to bursting. More often than not, a hemorrhagic stroke is the result of high blood pressure, which puts an awful lot of stress on the blood vessels. Hemorrhagic strokes are less common than ischemic strokes, but still just as serious.
How do you know if you’ve had a stroke?
The symptoms of a stroke can vary depending on which part of the brain is affected and can develop quite suddenly. It is common to experience a moderate to severe headache, especially if you are hemorrhaging (bleeding) in the brain. Other symptoms can include dizziness, a change in senses (hearing, seeing, tasting), muscle tingling and/or weakness, trouble communicating, and/or memory loss. If you are experiencing any of these warning signs, it is important to get to the hospital right away. This is especially important if the stroke is being caused by a blood clot since clot-busting medicationsare only effective within the first few hours hours of clot formation.
Once in the hospital, the caregiver will likely give anyone suspected of having a stroke a CT scan. From this test, doctors will be able to determine if you had a stroke, what type of stroke you had (ischemic versus hemorrhagic), or if there is some other issue. However, as was the case with my dad, a CT scan may not show evidence for a stroke. This issue can arise as a result of timing (test performed before brain injury set in) or size of affected area (too small to see). When not in an emergency situation, doctors may also or instead choose to prescribe an MRItest to look for evidence of a stroke.
If a stroke has been confirmed, the next steps will be to try and figure out the underlying cause. For ischemic strokes, it is important to find out if there is a blood clot and where it originated. Because my dad had an ischemic stroke, he had to undergo a series of tests that searched for a blood clot in his carotid arteries though ultrasound, as well as in the heart, using both an electrocardiogram(EKG) and an echocardiogram(ultrasound of the heart). The patient might also be asked to wear a Holter Monitor, which is a device worn for at least 24 hours and can detect potential heart abnormalities that may not be obvious from short-term observations, like those obtained via an EKG. If a stroke is due to a hemorrhagic event, an angiogramwould be performed to try an pinpoint the compromised blood vessel.
A stroke you did have. Now what?
Once a stroke has been confirmed and categorized, the patient will most likely be transferred to the stroke unit of the hospital for both treatment and further observation. If a clot has been detected, a patient will receive clot-busting medications (assuming this detection occurs within several hours of clot formation). Alternatively, a clot can be mechanically removed with surgery (animation of clot removal, also known as a thrombectomy). Patients might also be given blood-thinning medications to either ensure that clots do not increase in size or to prevent new clots from forming. As for secondary prevention, meaning preventing another stroke from happening, patients might be given blood pressure and cholesterol lowering medications.
If a disability arises due to stroke, a patient might need to undergo rehabilitation. The type and duration of stroke rehabilitation is dependent on the area of brain that was affected, as well as the severity of the injury.
Major risk factors and predictors of stroke
There are many situations that could predispose one to having a stroke, and many of these conditions are treatable. The absolute greatest predictor of a stroke is blood pressure. High blood pressure, also known as hypertension, will significantly raise your risk of having a stroke. Other modifiable stroke risk factors include blood cholesterol levels, smoking, type 2 diabetes, diet, alcohol/drug use, and a sedentary life style. However, there are also risk factors that you cannot change including family history of stroke, age, race, and gender. But that shouldn’t stop one from practicing a healthy lifestyle!
In conclusion, strokes are no joke. I am glad that my dad is still here (yes, dad, if you are reading this, we are in fact friends) and that he escaped with relatively no real consequences. Let’s just not do this again, ok?
Anti-coagulants:These are medications that help to reduce the incidence of blood clotting. The repertoire includes aspirin, Plavix, Warfarin, and Coumadin. Also called blood thinners.
Atherosclerosis:Literally translated as “hardening of the arteries,” this condition is hallmarked by the build-up of cholesterol inside of blood vessels. Atherosclerosis can lead to many complications including heart disease and stroke.
Cardiovascular System: The network of blood vessels and heart that works to distribute blood throughout the body.
Carotid Arteries: Arteries that carry blood away from the heart toward the head, neck, and brain.
CT Scan: Cross sectional pictures of the brain using X-rays.
Echocardiogram:An ultrasound of the heart. In stroke vicitms, electrocardiography is used to detect the presence of a blood clot in the heart.
Electrocardiogram (EKG or ECG): The measurement of the electrical activity of the heart. It is performed by attaching electrodes to a patient at numerous locations on the body, which function to measure electrical output of the heart.
Embolic Stroke: A type of ischemic stroke, an embolic stroke occurs when a blood clot forms (usually in the heart) and then travels to the brain, blocking blood flow and oxygen delivery to brain tissue.
Hemorrhagic Stroke: A type of stroke that results form the bursting of a blood vessel in the brain.
Hypertension:High blood pressure, defined as having 140/90 mmHg or above.
It’s not easy being green. First, you have decide which green to be. (Source)
[We at Double X Science had been considering a "toxins" post but then found the following post by Jennifer Mo, a happily childfree vegetarian who lives in California with a cat named Brie but variously nicknamed Walnut "for her brain capacity" or Toxokitty for her history of toxoplasmosis--which, as it turns out, turns up in Jennifer's guest post, below. This post first appeared at Jennifer's blog, It's Not Easy to Be Green, where she writes about environmental issues as a "rationalist and a pragmatist." You can also follow Jennifer on Twitter @noteasy2begreen. We appreciated the pragmatics of this particular post quite a bit and thank Jennifer for allowing us to host it at Double X Science. We are particularly taken with the fact that she asks if we'd ever wanted to call our own brain a troglodyte.]
It’s a common demand from the public to scientists: prove to us something is safe before unleashing your monster on the world. And on one hand, it’s a totally fair, reasonable request to not be treated as lab rats. I get that. I hate the idea of having big chemical corporations profiting off their creations that create long term problems for ordinary people and the environment. On the other, whether you’re talking about GMOs or synthetic chemicals, it’s a problematic request for a couple of key reasons:
It assumes a binary between safe and unsafe without regard to exposure level or other circumstances. Just about everything can be harmful under the right (or perhaps I should say wrong?) conditions. Take water, for example.TonsContinue reading →
Stayin’ Alive. The heart is a muscle that must beat in good timefor you to remain alive.
Cardiac deaths reach their peak during December and January, the experts say, and it’s important for anyone to know what to do in the event of either experiencing a heart attack or witnessing one. Below is a post that initially appeared at The Biology Files, but given the season, we think it’s important information to have front and center.
Last spring, a man who had come to our house to deliver a box for storage/moving died of a either a heart attack or sudden cardiac arrest in the street in front of our home. The story of what happened with him and our response is available here. What I’d like to blog here is simply a health warning of sorts, an alert for anyone who reads this in the hope that maybe that one person can avoid an early, sudden death like this one.
The man who died was only 56. But from what we experienced, he had at least three of the risk factorsfor having heart disease:
·he was male
·he was over age 45
·he had central obesity
I’d infer from his physical condition that he likely also had another risk factor, a sedentary lifestyle. Even though his work had been for many years delivering these boxes–with a smile and a lovely friendliness, I add–it was not necessarily physically demanding work, as it primarily involved using a forklift to load and unload the crates.
The thing is, I learned from one of his co-workers that he had come in the previous day complaining about feeling unwell in an odd, indescribable way and of unusual fatigue. I wish–I’m sure everyone who knew him wishes–that he’d taken that as a sign to get checked out. With his risk factors, it would have been a reasonable thing to have done.
Complicating his situation was the fact that he had asthma. The symptoms of an asthma attack and of a heart attack can seem very similar and difficult to tease apart. The key distinction seems to be that asthma doesn’t involve a feeling of chest pressure, and a heart attack does not respond to the use of inhaled asthma medication.
Add to that that his asthma may also have been a risk factor for heart disease, and you’ve got someone who had four or five risk factors for a heart attack. He was certainly a good candidate for a full health workup had he presented the previous day with his symptoms of “not feeling quite right” and “fatigue” and his risk factors.
His death was a terrible loss for his family. It’s also terrible to think that recognition of some of the risk factors compounded by what may have been some warning signs went unheeded and ended in this loss. These issues aren’t close to my heart only because this man died at our home. My grandfather also died at a relatively young age and without warning, lying in bed, reading a news magazine. He also had a number of risk factors for heart disease, including a family history, smoking, and other lifestyle factors. His visits to the doctor were few and far between, and he likely had never had a workup for heart disease. The night before he died in his bed, he’d complained about not feeling quite right, an upset feeling in his stomach. And then he…just died.
Everyone is going to die. Obviously, we can’t get away from that. But an awareness of risk factors and of lifestyle factors you can modify can mean the difference between dying suddenly and all too young or dying in your sleep at a grand old age with your life in order and some expectation that Death is on its way.
·Discomfort in the torso/upper body (this is what my grandfather had)
·Shortness of breath
Because this is Double X Science, we note that heart attack symptoms in women can differ from those in men. There is some overlap, including feeling strangely fatigued, something like indigestion, anxiety, dizziness, shortness of breath, and weakness. Women may also experience sleep disturbance, arm weakness, and indigestion more than men do, while not showing what have been considered the classic chest-gripping signs of a heart attack.
Another form of sudden death related to heart problems can be sudden cardiac arrest. We were told that the man who died did so of a heart attack, but I’m not sure if that was a term arising from a layperson’s understanding or because that was the final medical determination. A sudden cardiac arrest results from electrical misfiring in the heart muscle. It differs from a heart attack, which results from blockage of blood flow to the heart so that the heart tissue dies. Either can cause sudden death. The fact that he may have been having some sort of prodrome the previous day could have indicated either. If he was fibrillating, he also would have felt “odd” and “fatigued.”
Some things about what happened make me think that the man who died may have experienced sudden cardiac arrest. He was unresponsive and not breathing when we found him, and after the EMTs arrived, they continued the CPR we’d begun and tried de-fib on him three times. Given these factors, it sounds to me as though he’d had sudden cardiac arrest, rather than a heart attack. The risk factors for the two are similar. And the outcome in this case, regardless, was death.
Finally, there is the matter of what a bystander can do who finds themselves in our position. Call 911. Push hard and fast. Someone had already called 911, so we immediately began chest compressions. No mouth-to-mouth is necessary. Further, the compressions really need to be deep enough. In essence, you are trying to be the heart for the victim, to imitate what the heart, a powerful, muscular pump, would be doing.
So, the current response to a sudden cardiac death is pretty simple: Chest compressions only, 100 times a minute. Count them out loud as you go. It’s a fast clip. Some people recommend doing it to the beat of the Bee Gees’ song, Stayin’ Alive, if you’re familiar with that. For more information on what you can do in an emergency situation like this one, see the Red Cross guidelines (pdf). Learning these may someday help you save a life, in any season.
On using the Stayin’ Alive technique (amidst many other story threads and information), from RadioLab:
Here’s a video of comedian Ken Jeong demonstrating the hands-only Stayin’ Alive technique. The basics: Call 911. Push hard and fast.
[Editor's note: We are pleased to be able to run this post by Dr. Kate Clancy that first appeared at Clancy's Scientific American blog, the wonderful Context and Variation. Clancy is an Assistant Professor of Anthropology at the University of Illinois. She studies the evolutionary medicine of women’s reproductive physiology, and blogs about her field, the evolution of human behavior and issues for women in science. You can follow her on Twitter--which we strongly recommend, particularly if you're interested in human behavior, evolutionary medicine, and ladybusiness--@KateClancy.]
Over the course of my training to become a biological anthropologist with a specialty in women’s reproductive ecology and life history theory, or ladybusiness expert, I have learned a lot about miscarriage. Only it wasn’t miscarriage, it was spontaneous abortion. Except that some didn’t like the term spontaneous abortion and used intrauterine mortality (Wood, 1994). Or fetal loss. Fetal loss is probably the most common.
There is also pregnancy loss (Holman and Wood, 2001). You can use that term, too. Oh, or aContinue reading →
“You wanna do WHAT?!” Photo courtesy of Justyna Furmanczyk at sxc.hu.
By Tara Haelle, DXS contributor
[Tara Haelle (www.tarahaelle.com) is a health and science writer and a photojournalist based in Peoria, IL after years as a Texan, where she earned her undergraduate degrees and MA in journalism at UT-Austin. She’s the mental health editor for dailyRx.com in addition to reporting on pediatrics, vaccines, sleep, parenting, prenatal care and obesity. This post first appeared on her blog, Red Wine & Apple Sauce focuses on health and science news for moms (www.redwineandapplesauce.com), and you can follow her on Twitter at @health_reporter and @tarasue. She’s also swum with 9 different species of sharks, climbed Kilimanjaro and backpacked in over 40 countries, but that was in the years of B.C. (Before Children). She finds that two-year-olds are tougher to tussle with than tiger sharks.]
I am grateful that their statement was issued with the sensitivity and caution needed for such a controversial practice and decision. Some of the headlines have been frustrating, implying that the AAP said “Circumcision is better.” Um, no. That’s not what they said. They said that the “preventive health benefits of elective circumcision of male newborns outweigh the risks of the procedure.” (To be fair, most headlines basically ran with “benefits trump risks” or some variation thereof.)
In other words, if you choose to do this procedure, the benefits you will gain are greater than the risks involved in the procedure. This is very different from saying “It’s better to be circumcised.” In fact, their policy explicitly points out that they do not officially “recommend” the procedure routinely: “Although health benefits are not great enough to recommend routine circumcision for all male newborns, the benefits of circumcision are sufficient to justify access to this procedure for families choosing it and to warrant third-party payment for circumcision of male newborns.” (That last part just means yes, insurance companies, you should pay for it.)
An analogy: A child with obstructive sleep apnea can have a tonsillectomy/adenoidectomy (called an adenotonsillectomy) to remove their tonsils and adenoids for treatment. The tonsils and adenoids (lumps of issue behind the nose) generally cause the blockage that interferes with a child’s breathing while asleep, so removing them can usually cure the sleep apnea (in 75 to 100 percent of the cases).
There are risks to adenotonsillectomy, namely infection and excessive bleeding. There are risks to sleep apnea, including obesity, heart disease, diabetes, depression and death. For a child with obstructive sleep apnea, the benefits generally outweigh the risks of the procedure. A parent can still elect not to give their child the surgery.
Is it better for the child with sleep apnea to have the surgery? Probably. But perhaps not. It depends on the situation and the child. Is it better for a child without obstructive sleep apnea to have the surgery? Of course not. Why take any risk when there’s no benefit?
Now consider the two primary benefits conferred by circumcision: lower risk of urinary tract infections during the first year and reduced risk of HIV and a several other sexually transmitted infections during heterosexual sex. The risks of circumcision are most commonly bleeding, infection or the wrong amount of tissue snipped off, and this happens in about 1 of every 500 newborn boys (0.2 percent). Other studies found the rates higher, up to 2 to 3 percent, but these complications were still just minor bleeding. They even offered a comparison of a similar surgery as the one I discussed above: complications involving severe bleeding from tonsillectomies occur about 1.9 percent of the time in kids age 4 and under.
For parents with wild imaginations about horror stories, fear not: “The majority of severe or even catastrophic injuries are so infrequent as to be reported as case reports (and were therefore excluded from this literature review). These rare complications include glans or penile amputation, transmission of herpes simplex after mouth-to-penis contact by a mohel (Jewish ritual circumcisers) after circumcision, methicillin-resistant Staphylococcus aureus infection, urethral cutaneous fistula, glans ischemia and death.” Basically, yea, there’s a bunch of really bad stuff that can happen, but it’s really, really, really, really rare. Probably rarer than being struck by lightning. Twice. But that happens too.
So, the risks are pretty low. How beneficial are the benefits? Here’s a condensed run-down from the AAP’s technical report:
Circumcision reduces the odds of contracting HIV during male-female sex by 40 to 60 percent… in Africa. When the CDC calculated that figure with the rate of contracting HIV by heterosexual sex in the U.S., they came up with a 15.7 percent reduction here. It’s something, but nowhere near as good as a condom. Plus, if your kids turns out to be gay, there’s not much evidence that circumcision helps him avoid contracting HIV. (And on the other side of the coin, circumcision can make it a little easier for women to contract HIV from a man, per one study cited in the AAP review.)
Circumcised men are about 30 to 40 percent less likely to get any type of human papillomavirus (HPV), including both the relatively harmless strains and the ones that can lead to cervical cancer or raise your risk of cancer of the mouth, throat, penis and anus. Now, the CDC has recommended that boys get the HPV vaccine, but the vaccines available do not cover all the strains. Gardasil takes care of four of them, including the two responsible for about 70 percent of cervical cancer (HPV-16 and HPV-18) and the two responsible for 90 percent of genital warts. Cervarix only takes care of HPV-16 and HPV-18. So, circumcision would offer some protection against getting the HPV strains that the vaccines don’t cover, most of which — but not all — are not linked to cancer or warts.
There’s some evidence that circumcision reduces risk of herpes (HSV-2) by about 28 to 34 percent, based on two studies in Africa.
Evidence for protection against syphilis is weak. There’s no evidence that circumcision decreases the risk of contracting gonorrhea or chlamydia.
There’s good evidence that uncircumcised boys get more urinary tract infections that circumcised boys, in part because bacteria can hang out in that moist area under the hood. The AAP estimates that 7 to 14 of every 1,000 uncircumcised boys will get a UTI before their first birthday, compared to 1 to 2 out of 1,000 circumcised boys. With such a low rate overall, in either population, the AAP notes that “the benefits of male circumcision are, therefore, likely to be greater in boys at higher risk of UTI, such as male infants with underlying anatomic defects such as reflux or recurrent UTIs.” (These are mostly the boys that get UTIs anyway.)
So, those are definitely some benefits to circumcision, especially if your little guy will have sex one day (which, presumably, you want him to do at some point in the far off, I-don’t-want-to-think-about-it future). It’s also fair to say that good sex education and condom use would make those benefits almost moot (not the UTIs, which are pretty low risk, and not all HPV strains, which sometimes infect even with condom use).
In any case, these two benefits, a lower risk for UTIs and some STIs, then become the risks of not being circumcised. The former is — usually — not very serious. There are some very serious urinary tract infections, and untreated ones can damage the kidneys. And they’re certainly not fun. They aren’t, however, usually life or death situations. HIV (somewhat still) is. Of course, boys are still at a pretty high risk for getting HIV if they sleep with someone who has it and don’t use a condom, circumcised or not. But every bit of protection helps, right?
Unless it requires lopping off part of a little boy’s penis. There. I said it. Because that’s what many parents are simply uneasy about, regardless of the health benefits, which are great or marginal, depending on your perspective. And that’s why the AAP stopped short of recommending circumcision as a routine procedure.
They did include in their review several studies related to sexual satisfaction and sensitivity, one of the complaints that “intactivists” bring up. The AAP summarizes it pretty nicely: “The literature review does not support the belief that male circumcision adversely affects penile sexual function or sensitivity, or sexual satisfaction, regardless of how these factors are defined.”
But it’s not possible to take into consideration, in scientific, mathematical terms, the primary complaint of those who oppose circumcision, which is that the man these little boys become may have wanted that little flap over the tip. And this is one of those gray areas that give parents pause. Once you cut that hood, you can’t put it back. How many circumcised men regret what their parents did? Well, probably not vast numbers, or circumcision rates would have plummeted.
So, this is where we end up. There are some decent benefits. There are very few and mostly minor risks to the procedure. And there’s big, giant, gray unknown area of “what if’s” and “could have been’s” for the boys who get snipped. It’s disingenuous to compare the practice to female circumcision, as some do, since neither its intent nor its effect is to influence sexual satisfaction. But whether it’s the right thing to do…? The AAP says it’s up to mom and dad. (Which, in many households, like mine, probably means mostly dad.)
“Parents ultimately should decide whether circumcision is in the best interests of their male child,” they wrote. “They will need to weigh medical information in the context of their own religious, ethical, and cultural beliefs and practices. The medical benefits alone may not outweigh these other considerations for individual families.”
What are those other considerations? Well, whether you want your little guy to have a foreskin. Or, whether you don’t know if he does or doesn’t want it and figure he should decide that in 18 years. Maybe daddy’s not circumcised and you both want him to look like daddy. (I know many people who circumcised for this reason alone.)
About the only certain thing that can be said about circumcision, based on the AAP’s policy statement and research and what we know about opposition to the practice, is that this controversy will be with us for years to come.
The opinions in this post do not necessarily reflect or disagree with the opinion of the DXS editorial team.
The stormy landscape of the breast, as seen on ultrasound. At top center (dark circle) is a small cyst. Source: Wikimedia Commons. Credit: Nevit Dilmen.
By Laura Newman, contributor
In a unanimous decision, FDA has approved the first breast ultrasound imaging system for dense breast tissue “for use in combination with a standard mammography in women with dense breast tissue who have a negative mammogram and no symptoms of breast cancer.” Patients should not interpret FDA’s approval of the somo-v Automated Breast Ultrasound System as an endorsement of the device as necessarily beneficial for this indication and this will be a thorny concept for many patients to appreciate.
If the approval did not take place in the setting of intense pressure to both inform women that they have dense breasts and lobbying to roll out all sorts of imaging studies quickly, no matter how well they have been studied, it would not be worth posting.
Dense breasts are worrisome to women, especially young women (in their 40s particularly) because they have proved a risk factor for developing breast cancer. Doing ultrasound on every woman with dense breasts, though, who has no symptoms, and a normal mammogram potentially encompasses as many as 40% of women undergoing screening mammography who also have dense breasts, according to the FDA’s press release. Dense breast tissue is most common in young women, specifically women in their forties, and breast density declines with age.
The limitations of mammography in seeing through dense breast tissue have been well known for decades and the search has been on for better imaging studies. Government appointed panels have reviewed the issue and mammography for women in their forties has been controversial. What’s new is the “Are You Dense?” patient movement and legislation to inform women that they have dense breasts.
Merits and pitfalls of device approval
The approval of breast ultrasound hinges on a study of 200 women with dense breast evaluated retrospectively at 13 sites across the United States with mammography and ultrasound. The study showed a statistically significant increase in breast cancer detection when ultrasound was used with mammography.
Approval of a device of this nature (noninvasive, already approved in general, but not for this indication) does not require the company to demonstrate that use of the device reduces morbidity or mortality, or that health benefits outweigh risks.
Eitan Amir, MD, PhD, medical oncologist at Princess Margaret Hospital, Toronto, Canada, said: “It’s really not a policy decision. All this is, is notice that if you want to buy the technology, you can.”
That’s clearly an important point, but not one that patients in the US understand. Patients hear “FDA approval” and assume that means a technology most certainly is for them and a necessary add-on. This disconnect in the FDA medical device approval process and in what patients think it means warrants an overhaul or at the minimum, a clarification for the public.
Materials for FDA submission are available on the FDA website, including the study filed with FDA and a PowerPoint presentation, but lots of luck, finding them quickly. “In the submission by Sunnyvale CA uSystems to FDA, the company stated that screening reduces lymph node positive breast cancer,” noted Amir. “There are few data to support this comment.”
Is cancer detection a sufficient goal?
In the FDA study, more cancers were identified with ultrasound. However, one has to question whether breast cancer detection alone is meaningful in driving use of a technology. In the past year, prostate cancer detection through PSA screening has been attacked because several studies and epidemiologists have found that screening is a poor predictor of who will die from prostate cancer or be bothered by it during their lifetime. We seem to be picking up findings that don’t lead to much to worry about, according to some researchers. Could new imaging studies for breast cancer suffer the same limitation? It is possible.
Another question is whether or not the detected cancers on ultrasound in the FDA study would have been identified shortly thereafter on a routine mammogram. It’s a question that is unclear from the FDA submission, according to Amir.
One of the problems that arises from excess screening is overdiagnosis, overtreatment, and high-cost, unaffordable care. An outcomes analysis of 9,232 women in the US Breast Cancer Surveillance Consortium led by Gretchen L. Gierach, PhD, MPH, at the National Institutes of Health MD, and published online in the August 21 Journal of the National Cancer Institute, revealed: “High mammographic breast density was not associated with risk of death from breast cancer or death from any cause after accounting for other patient and tumor characteristics.” –Gierach et al., 2012
Proposed breast cancer screening tests
Meanwhile, numerous imaging modalities have been proposed as an adjunct to mammography and as potential replacements for mammography. In 2002, proponents of positron emission tomography (PET) asked Medicare to approve pet scans for imaging dense breast tissue, especially in Asian women. The Medicare Coverage Advisory Commission heard testimony, but in the end, Medicare did not approve it for the dense-breast indication.
PET scans are far less popular today, while magnetic resonance imaging (AKA MR, MRI) and imaging have emerged as as adjuncts to mammography for women with certain risk factors. Like ultrasound, the outcomes data is not in the bag for screening with it.
In an interview with Monica Morrow, MD, Chief of Breast Surgery at Memorial Sloan-Kettering Cancer Center, New York, several months ago concerning the rise in legislation to inform women about dense breasts, which frequently leads to additional imaging studies, she said: “There is no good data that women with dense breasts benefit from additional MR screening.” She is not the only investigator to question potentially deleterious use of MR ahead of data collection and analysis. Many breast researchers have expressed fear that women will opt for double mastectomies, based on MR, that in the end, may have been absolutely unnecessary.
“There is one clear indication for MR screening,” stressed Morrow, explaining that women with BRCA mutations should be screened with MRI. “Outside of that group, there was no evidence that screening women with MR was beneficial.”
At just about every breast cancer meeting in the past two years, the benefits and harms of MR and other proposed screening modalities come up, and there is no consensus in the field. It should be noted, though, that plenty of breast physicians are skeptical about broad use of MR– not just generalists outside of the field. In other words, it is not breast and radiology specialists versus the US Preventive Services Task Force – a very important message for patients to understand.
One thing is clear: as these new technologies gain FDA approval, it will be a windfall for industry. If industry is successful and doctors are biased to promoting these tests, many may offer them on the estimated 40% of women with dense breasts who undergo routine mammograms, as well as other women evaluated as having a high lifetime risk. The tests will be offered in a setting of unclear value and uncertain harms. Even though FDA has not approved breast MRI for screening dense breasts, breast MR is being used off label and it is far more costly than mammography.
When patients raise concerns about the unaffordability of medical care, they should be counseled about the uncertain benefit and potential harms of such a test. That may be a tall bill for most Americans to consider: it’s clear that the more is better philosophy is alive and well. Early detection of something, anything, even something dormant, going nowhere, is preferable to skipping a test, and risking who-knows-what, and that is something, most of us cannot imagine at the outset.
[Today's post is from Patient POV, the blog of Laura Newman, a science writer who has worked in health care for most of her adult life, first as a health policy analyst, and as a medical journalist for the last two decades. She was a proud member of the women’s health movement. She has a longstanding interest in what matters to patients and thinks that patients should play a major role in planning and operational discussions about healthcare. Laura’s news stories have appeared in Scientific American blogs, WebMD Medical News, Medscape, Drug Topics, Applied Neurology, Neurology Today, the Journal of the National Cancer Institute, The Lancet, and BMJ, and numerous other outlets. You can find her on Twitter @lauranewmanny.] Ed note: The original version of this post contains a posted correction that is incorporated into the version you’ve read here.
The opinions in this article do not necessarily conflict with or reflect those of the DXS editorial team.