Slashdot Mirror
Re-evaluating the Benefits of Cancer Screening
uncleO writes "An article in the NY Times describes two studies that weigh the harm caused by cancer screenings against the benefits they provide. From the article, 'Two recent clinical trials of prostate cancer screening cast doubt on whether many lives — or any — are saved. And it said that screening often leads to what can be disabling treatments for men whose cancer otherwise would never have harmed them. A new analysis of mammography concluded that while mammograms find cancer in 138,000 women each year, as many as 120,000 to 134,000 of those women either have cancers that are already lethal or have cancers that grow so slowly they do not need to be treated. ... In recent years, researchers have found that many, if not most, cancers are indolent. They grow very slowly or stop growing altogether. Some even regress and do not need to be treated — they are harmless."
Justin Bieber has stopped growing, but that doesn't make him harmless.
When the foot seeks the place of the head, the line is crossed. Know your place. Keep your place. Be a shoe.
And the UK is now reviewing the entire breast screening programme it runs to see whether the evidence continues to show that, on balance, good outweighs harm. Tough decisions for all concerned, and an excellent demonstration of just why science is hard to do right.
Among the options:
1) Continue as-is
2) Use more selective screening with (hopefully) greater specificity -- eg familial history, gene markers, etc
3) Stop screening
I'm curious why blood tests aren't peformed regularly. You can certainly request Alpha-fetoprotein (AFP) any time you like, but it is not commonly recommended on a regular basis. AFP can indicate tumors growing in the body. Very high levels of AFP can indicate advanced cancer. In the case of a co-worker who was found to have advanced cancer, on first diagnosis, why not have this marker checked every 6 months?
I've been told a normal reading is about 100-120. Values over 10,000 should be investigated. Lance Armstrong, had levels of over 100,000 when he was diagnosed, with tumors spread throughout his body.
It seems a low impact test, why is it not advised as part of a standard checkup? We'll look for chelesterol, why not Alpha-fetoprotein?
A feeling of having made the same mistake before: Deja Foobar
Deaths caused by cancer (US numbers, 2009): 562,875
Deaths caused by heart disease (US, 2009): 616,067
We know more about Heart Disease, but it gets less press - mainly because the treatments for it are not as painful.
You know, I bet if someone created a painful, dramatic, balding cure for Heart Disease that in 10 years we would cure it entirely.
excitingthingstodo.blogspot.com
The problem is they have difficulty, with prostate cancer, in telling which are slow growing and which are aggressive.
Seems like someone is driving a huge PR campaign for "let's not have people visit doctors and get cancer screening". It's likely actually just costing a group of HMO insurers more money to have lots of people treat cancers early and undergo lengthy treatment, and then survive, rather than have a smaller number of people detect it too late, do a short treatment, and then just die.
After all, health services are a business. We understand. You can't just have insured people liviing a long time and making businesses lose money.
Build your own energy sources from scratch. http://otherpower.com/
"have cancers that are already lethal"
--> People that have lethal cancer can be treated nevertheless.
--> how do you know if a persons cancer will be lethal or not?
Well, you'll find out sooner or later, right?
Space game using normal deck of cards: http://BattleCards.org
So ... what kind of idiot wrote that pretentious article
One who understands that cost/benefit calculations have to, you know, include the costs as well as the benefits?
If attempting to treat supposed cancers causes debilitating harm to thousands of people but benefits another few thousand people, then it's far from clear whether treatment is beneficial to the majority.
I know in the case of prostate cancers, there are fast-growing tumors and there are slow-growing tumors. My father-in-law was diagnosed with a slow-growing tumor in his mid-70s and his doctor advised him to basically live with it, because something else would kill him first, and six or seven years later he died after a stroke.
The world's burning. Moped Jesus spotted on I50. Details at 11.
Another approach is to find an imaging technique that is cheap and harmless enough that you could image someone's whole body every week. Then you could compare week to week to monitor growth and spread of the tumors, and only target tumors that are fast growing, or persist beyond a certain threshold size.
I've seen these and similar studies crop up recently. They really bother me because while they are technically right, I don't think their conclusions are helpful. One problem they point out is that once you've been diagnosed, so many times it is "too late". Their conclusion? Screening test are not as important as we thought. WRONG. If anything this points to MORE FREQUENT screening of assorted cancers. It's easy to be so dismissive of cancer when you are thinking about these things statistically...it's entirely different if you know anyone who has had cancer or if you yourself get it. I am starting to get "older" and am approaching an age where I personally believe I should start getting screened. When I start, I plan on doing this very often. To me, it is worth having a finger up my ass and some amount of money not to die a slow, painful death from something I could have caught and treated. If you want to take the gamble and bet with the statistics, then by all means do. I, however, plan on living as long and healthy as possible.
One who understands that the government cannot afford the level of care we have become accustomed to, but wants the government to pay for everybody's health care anyway.
The truth is that all men having power ought to be mistrusted. James Madison
They rob pharmaceutical companies of revenue streams that are rightfully theirs.
Well, if cancer is found during the screening, chances are all kinds of products made by pharmaceutical companies will be unleashed onto the patient full-force.
It's a fair bit more complex than that.
Genetic damage accumulates _all_ the time, however you have DNA-repair mechanisms of rather amazing complexity that constantly patch things back into their original shape, and in the case they fail they still face down the checkpoints in the mitotic cycle that halts cell divison until damage is either repair or the self-destruct/apoptosis kicks in.
And there's more, if a cell starts to produce foreign proteins these will appear in fragments on its surface, which the immune system will latch onto, and then the cell will face down the subtly named Natural Killer cells which have methods to force the aptotic machinery into action even if the intial stages have somehow mutated into uselessness.
Also, cancer that grows fast will displace itself to the point where necrotic lesions appear, these will result in inflammation, a state usually not very conductive to growth, which may self-limit the cancer(not to mention that inflammation means the presence of immune mediators, a lot of them).
As for chemo, it's not that black and white, there's a very large difference between cancer cancer and chemo and chemo. Certain lymphoma(enormous proliferation of immune cells, circulating) have very close to 100% survival rate, if you enter chemo treatment. Testicle cancer also have a very good prognosis even if metastatized. For a perspective, take a look here http://en.wikipedia.org/wiki/Chemotherapy_protocol
If the cancer kills you anyway, then you went through a whole lot of pain and trouble for nothing. I'd rather not be put through all that for nothing.
You wait until they've died from it. Then you mark in your notes that the cancer was lethal. Pretty simple really. But only useful for generating statistics.
Again, you wait until they die, then you look and see if the cancer killed them, or if it was something else. Again, only really useful for generating statistics.
Some people know not to argue with the truth. That's the kind of person who would write this article. You can live your life however you want.
You really think "Obamacare" is driving this? It would be happening regardless, driven by the insurance companies.
But people were complaining recently that health insurers drive people to have too many tests and unneccesary treatments, so that they can push up premiums.
Then today they're not paying for enough.
Seems they're damned either way.
as many as 120,000 to 134,000 of those women either have cancers that are already lethal or
There are a lot of cancers that are incurable, but can still be controlled for a while. Statements like this make it sound as though catching these cancers early and controlling them for a while is a worthless endeavor.
My wife is one year into a battle with a cancer that she has only roughly a 25% chance of surviving with treatment. Without treatment, she would have been dead a few weeks after diagnosis. She is grateful to have spent the past year alive instead of dead, and of course the children and I are also grateful. I guess the point that I'm trying to make here is that treating a cancer that will most likely be lethal still has significant value. None of us would have been very happy if some government bureaucrat had told us that since the cancer was so likely to kill her, they wouldn't bother treating.
They don't grade fathers, but if your daughter's a stripper, you fucked up. --Chris Rock
I guess the question is how do you tell the ones that need treatment from the ones that don't before it it too late to treat the ones that do
Histology at the moment. What a trained pathologist can tell from a slide of stained cells is incredible. In the near future, genomic sequencing is what experts seem to be saying. You find a tumor, you get a biopsy, look at it under the microscope and also sequence the DNA of the cancer. Between what the cells look like and the DNA sequence, they'll be able to tell how likely it is to kill you.
There are a number of well-characterized things a cancer cell must do to be really bad, and genomic sequencing will allow a good diagnosis as to what a cancer is doing exactly. If it's just that the cells are growing more than they should, but are otherwise playing by the rules (IE, unlikely to metastasize or start increasing the bloodflow to the tumor, and not in a critical location) keep an eye on it but it may not become a problem ever. If it is expressing several genes that will allow the cells to get into the bloodstream and take root elsewhere, chemotherapy now. Chances are much better that it will spread to critical areas like your lungs or brain and kill you.
Some diagnostic tests (breast cancer screening, for example) increase the risk of contracting the disease you are screening for.
In the case of the prostate cancer study, it seems that treatment of detected, but actually benign, tumors was causing more mortality than just living in ignorance of them.
Government care would be cheaper, for evidence look around the world.
This is about not torturing people with pointless treatments, not saving a couple bucks.
There's the fast growing terrible cancer variety.
And then there's hyperplasia, this only insults you by increasing the duration of the average urination by ~1000%, and UTI rate by similar numbers.
The problematic part is that there's a relationship between hyperplasia and malignitiy, and for prostates this is an eternal headache.
Sure, it's cheaper because with government care, sick people don't live as long. Just look at the prognosis for someone with a specific serious illness around the world.
The truth is that all men having power ought to be mistrusted. James Madison
People read these articles and too many come away with "we shouldn't be screening for cancer". That's not what it's saying at all. It's saying "we shouldn't rely on our current screening tests". That's the key. Screening isn't a problem. Early detection isn't a problem. Inaccurate screening tests that encourage treatment when none would be necessary is the problem. That's what the US Preventive Services Task Force is trying to say: shitty tests create shitty outcomes.
It's like trying to use just a thermometer to diagnose H1N1 or Ebola. Well, you'd also catch the standard flu, or a head cold, or appendicitis, or a thousand other things that cause a fever. The prostrate screening test just tests for the known prostrate cancer antigen... but it's not very specific to the type of cancer present. That's the problem. Doctors and patients are stuck in the mindset of If (Cancer == True) { CancerTreatment(); }. That said, cancer treatment involves really dangerous and destructive things to the human body. Many cancer patients die from treatment as much as from the disease. They're akin to poisoning the whole body and hoping that you kill the cancerous bits before you kill the patient. This means that that Cancer == True test better damn well be pretty reliable and accurate. It's a reminder of the basis of medical ethics: primum non nocere -- first, do no harm. The data says doctors are doing a lot of harm if 120,000 of 138,000 cases (87%) have unwarranted treatments.
So, again, they're not saying "don't screen". They're saying "don't screen with shitty tests; get better tests, then screen."
The road to tyranny has always been paved with claims of necessity.
Whether the cancer was going to end up harmless or end up killing a person, it's better that they at least know if its existence and have the choice of whether or not they want treatment.
Thank you for giving President Obama credit for the most dramatic overhaul in the nation's history. When Obamacare becomes as popular as Medicare and Social Security, it will be nice to know people will remember who was responsible for it.
Strive to make your client happy, not necessarly give them what they ask for
The change in policy stems from good mathematics, namely good statistics. Where the number of people who are subjected to a test may suffer from one of two failures,
a) false negative - that is the test fails to detect the presence of a disease and thus incorrectly reports a negative results, and
b) false positive, the test incorrectly reports a positive result, but the disease is not actually present.
The problem is that with a large pool of test population and a small affected sub-population, the misleading results are counter-intuitive, and can end up causing more harm (otherwise healthy individuals undergoing unnecessary biopsies, radiation, and chemotherapy increase mortality rate) to the overall population.
See The dangers of false positives by Dr. Dave Richeson, don't take my word on it.
Let's see if I have this right:
When people receive bad news about their health, they often make poor decisions about treatment.
Solution: Stop screening and therefore, there won't be any bad news to report.
What? Unless the testing itself is a hazard, we shouldn't be cutting off a potentially life saving source of information. We should be working on improving the decision making process. If most prostate cancers should not be treated then recognize this and develop an alternative response. Perhaps more extensive tests for those who come up positive. Perhaps more frequent tests. Maybe just wait and see if it has grown by the time next years test rolls around.
The general arguement is that 'screening comes with harms as well as benefits' (from TFA), which is false unless you believe that listening to the heart leads to side effects from open-heart surgery because too many false positive heart diseases or indolent heart conditions are overly treated. The problem lies within understanding the results and the possible outcomes from different treatments. For example, if cancer is found that is possibly slow growing or indolent, then go into a "watchful monitoring" treatment of more frequent and different checks. Because we have great screening systems that will be able to detect disease earlier and earlier, we need to understand that there is a point at which a disease is so early it is not worth treating. But it does not mean we should not look.
In othehr words, because bad actions can be taken as a result of getting the correct diagnosis information, then we need to fix our analysis and recommendation for treatments. Lets not stick our heads in the sand and not even look for the disease.
Bzzt, wrong.
The USA has one of the shortest life expectancies in the first world.
They rob pharmaceutical companies of revenue streams that are rightfully theirs.
Well, if cancer is found during the screening, chances are all kinds of products made by pharmaceutical companies will be unleashed onto the patient full-force.
Knowingly or not, you've just touched upon my issue with privatized medical treatment: the industry has incentive to "diagnose" any number of "maladies," real or imagined, in order to drum up business and boost profits. I wonder how many of these "illnesses" that magically popped into existence in the past 20 years are actual, physical conditions.
... and don't even get me started on the incentives to "treat" illness as opposed to curing it...
An enigma, wrapped in a riddle, shrouded in bacon and cheese
Isn't this another instance of the 'Fallacy of the Commons'? Maybe it's true that the cost of full community screening is not matched by the net benefit of all outcomes. But for me, I sure want to pay the cost of anything that might give me more life or comfort. It's clearer if you don't expect 'the community' to pay (or the insurer who mutualises community risks). How does your own money vote? And would that optimise community benefit?
You can blame this on Obamacare IFF you can prove without a doubt your exact same exact scenario would NOT happen in the era immediately preceding Obamacare (you know, the Golden Age of Private Insurance.)
One who understands that the government cannot afford the level of care we have become accustomed to, but wants the government to pay for everybody's health care anyway.
We cannot afford the level of care we have been accustomed to, period. Medicare OR through private insurance.
Health care premiums doubled between 1996 and 2006. I dare you to blame Obamacare for that.
here are already bureaucrats sitting between you and your doctor--the private insurance companies--and you already have limited mobility between providers
So the answer is to REDUCE mobility even further by having essentially just one provider? 99% of us have no preexisting conditions that would prevent us from moving, but plenty of regulations in the way like the ones barring me from purchasing insurance across state lines.
I have never understood the course of philosophy that thinks you can make something better by distilling the essence of what is wrong and making it 1000x more potent a concern.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
My colonoscopy at 53 (3 years late) detected the start of malignant cancer. My gastro guy described my situation as "having *just* missed being hit by the bus. Without treatment, I'd have been dead in less than 5 years, give or take a year.
So, better safe than sorry has become my new motto. The social and economic cost, in the scheme of things, is trivial (That is, if you have health insurance. If you don't, unofficial government policy is the usual de facto homicide applied to the poor).
Please do not read this sig. Thank you.
without the test you never have the choice between treating and not treating. This sounds like a study conducted by wealthy @$$es to discourage middle class people from seeking medical treatment. I don't see Senators turning down treatment. What was that qoute? "In America, If you get sick better die quick!".
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
"illnesses" that magically popped into existence in the past 20 years
?
The efficacy of a medical test is determined by three numbers.
1) The real incidence rate - what percent of the population (after the fact) actually has the condition.
2) The false positive rate.
3) The false negative rate.
The problem with the PSA test is that while the real incidence rate is relatively high, the false positive and false negative rates are extremely high.
1) The incidence rate varies with age and ethnicity. According to the CDC (and wikipedia, for what it's worth), (http://www.cdc.gov/cancer/prostate/statistics/race.htm), the age-averaged rate is 100 per 100,000 for asians, 160 per 100,000 for white and 250 per 100,000 for black men. But they don't recommend the test for men under 45. And age really is the determining factor. (http://seer.cancer.gov/publications/prostate/inc_mort.pdf). So, let's assume an incidence rate of 10% for 55 year old men for purposes of this exercise. - for 75 year old men, it's probably closer to 90%, for 20 year old men, essentially zero.
2) According to the National Cancer Institute (http://www.cancer.gov/cancertopics/factsheet/detection/PSA), the false positive rate is 65-75%. Giving the test the best chance, I'll take the lower limit of 65%.
3) I haven't found a definitive source for the false negative rate, but wikipedia cites a paper giving a 25% false negative rate. Let's give it the benefit of the doubt and call it 20%.
Source...
^ Thompson IM, Pauler DK, Goodman PJ, Tangen CM, Lucia MS, Parnes HL, Minasian LM, Ford LG, Lippman SM, Crawford ED, Crowley JJ, Coltman CA (May 2004). "Prevalence of prostate cancer among men with a prostate-specific antigen level or 4.0 ng per milliliter". N. Engl. J. Med. 350 (22): 2239–46)
So - give a population of 1 million men a PSA test and here's what you get.
100,000 men have prostate cancer
900,000 do not have prostate cancer.
Of the 100,000 men who DO have prostate cancer...
a) 20,000 test negative (a problem, but what are you going to do? This was my father's case (see below))
b) 80,000 test positive (okay, but do you need treatment? Odds are you'll die of something else first (see below))
Of the 900,000 who do NOT have prostate cancer.
c) 585,000 test positive (the real problem)
d) 315000 test negative. (good on yer.)
The real problem is that honking huge false positive rate. If you test positive, there's still less than a 50% chance that you actually have prostate cancer, and even if you do, it's probably not going to make a damn bit of difference over the course of your life, but it's still very very scary and you get a biopsy or have radiation treatment and risk impotence and/or incontinence and possibly seriously reduce your quantity of life for the rest of your life for no good reason. It's even more complicated by the fact that the PSA level goes up naturally as you age. If your level goes from 4 to 10 over 10 years, what does it mean? Flip a coin.
That said, given that my father, both his brothers and my paternal grandfather all died from prostate cancer (between the ages of 90 and 94, I'll grant you - that's the thing. The vast majority of men will die of something else before the prostate cancer kills them), my doctor recommends continuing to take the test every 5 years.
You might have a point, but what are those
"illnesses" that magically popped into existence in the past 20 years
?
ADD and Fibromyalgia come immediately to mind...
Another big part of the problem is that "doctors" (i.e. pharmaceutical salesmen) have developed this nasty habit of treating symptoms (using expensive drugs), instead of trying to find the actual disease causing the symptoms. Thus, the condition never gets cured, and the patient spends their life taking expensive drugs they probably don't need.
An enigma, wrapped in a riddle, shrouded in bacon and cheese
"Histology" - stripped bare, it's essentially heuristic eyeballing, isn't it. So screening can tell if there are tumor cells but cannot tell how they will progress.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
I recall reading that a ridiculously high proportion of men that die in old age have prostate cancer, something like 75% of males over 75, iirc. Usually without posing symptoms / problems, relative to old age at least.
First world problems I guess, as historically they wouldn't have lived long enough for it to show up.
Sent from my PDP-11
Another 'the pharma companies are hiding the cures' tinfoil nut?
I'll remind you of the ~$30 Billion a year the NIH spends for researchers on their own D.C. area campus and at universities around the nation to do medical research. Those folks aren't hiding cures.
Doesn't matter what actual studies find. ABC News will film someone who'll definitively state "The only reason I'm alive today is because the prostate/breast/colorectal/whatever screening caught my cancer. I just can't understand those doctors wanting to stop the test that saved my life!" Intercut the scientifically illiterate telegenic reporter nodding sympathetically. Then go back to Diane Sawyer in the studio giving the network's medical expert 37 seconds to explain how on earth *NOT* finding cancers is a good idea. And he'll just say "Uh, it's complicated... go talk to your doctor."
This stuff is just too hard for people, they don't have the math skills for it. But that doesn't prevent them from "knowing" what's right.
=S
So what's the solution? I think its to research more so you can come up with a reliable, cheap way to differentiate between all the 4 below. preferably with minimal side effects "1. You find a cancer that will eventually kill you AND that particular cancer has a treatment that works better when started earlier. (True Positive result) 2. You don't find a cancer that you don't have. (True Negative result) 3. You find a cancer or something that looks like a cancer however it will grow so slowly or regress so it won't cause any harm, but then you don't really know which is which so you elect to be treated for same with some morbidity or mortality. (False Positive result) 4. You don't find the cancer that existed and goes off to knock you off just before you design the next iPad killer. (False negative result)." properly Identifying which tumors are slow growing and which patients are too late would solve a lot of problems. of course this is easier said than done
Death panels. Liberal jobby chasers
The new right fascists are bilingual. They speak English and Bullshit.
Bzzt, reading comprehension fail.
The U.S. generally has the best prognosis for someone diagnosed with a particular serious illness (specific type of cancer, diabetes, etc). That is, the five year survival rate for people diagnosed with most life-threatening diseases is better in the U.S. than in most of the rest of the first world. There are many reasons why U.S. life expectancy is shorter that have nothing to do with quality of care. For example, in many first world countries, if a child dies within the first 24 hours after birth it is considered stillborn. In the U.S., such an incident is counted as infant mortality (and thus lowers average life expectancy). As another example, the life expectancy for Japan is higher than for the U.S., yet the life expectancy for a Japanese American is higher than the life expectancy for Japan.
The truth is that all men having power ought to be mistrusted. James Madison
No, I blame Medicare and Medicaid for that. Obamacare will just make medical care inflation worse. If you look at the cost of medical care over time you discover that the cost of medical care rose at basically the same rate as inflation until the year after both Medicare and Medicaid were in force. At which point, the cost of medical care began rising much faster than inflation.
The truth is that all men having power ought to be mistrusted. James Madison
Whether it is the defense industry, the corrections industry or the healthcare industry big money and the promise of lucre cause the industry to bloat well past any benefit to society. Basic to this process is the incessant selling of FUD: "You're going to be enslaved by communists." "You're going to be victimized by criminals." "You're going to die of cancer". And so on ...
Both the National Cancer Institute and several pharmaceutical companies declined to pay for the research. Neither applicants nor funders discuss the reasons an application is turned down.
And I'm supposed to be the nut... riiiiiiiiight...
An enigma, wrapped in a riddle, shrouded in bacon and cheese
I'll second that. It's bad odds for the majority of the population who don't contract prostate cancer, but for those of us who have had it and have caught it early due to the PSA, it's a good deal. I've had my winning lottery ticket, thank you!
"Who controls the past controls the future. Who controls the present controls the past." -- George Orwell
Yeah, Social Security and Medicare are real popular until they start bankrupting us due to foreseeable demographic changes. Kind of like cancer that doesn't do much harm until it gets out of control and kills a person.
Except for ending slavery, the Nazis, communism, & securing American independence, war has never solved anything.
and then we run out of other people's money for real. whats then?