Map of life expectancy at birth from Global Education Project.

Wednesday, October 21, 2009

Remember, you read it here first

The American Cancer Society finally admits that they have been overhyping the benefits and underplaying the adverse effects of breast and prostate cancer screening.

"We don’t want people to panic,” said Dr. Otis Brawley, chief medical officer of the cancer society. “But I’m admitting that American medicine has overpromised when it comes to screening. The advantages to screening have been exaggerated.”


Abstract of the JAMA article is here. Since you are too low-borne and no account to read it, I will summarize for you. When you start widespread screening, you will, obviously, have a sudden jump in the incidence rate of cancer, because you're detecting more of it. What you want to happen is that after time, the incidence of serious disease and death goes down, because early detection has prevented many cancers from becoming serious.

What has actually happened is that the incidence of prostate and breast cancer have doubled; but the incidence of serious disease and death has declined little for both types of cancers, perhaps not at all due to screening. Periodic screening may be good at detecting early stage lesions that will never develop into meaningful disease before the person dies of something else; but tend not to find more dangerous cancers early enough to make much of a difference. And that appears to be what is happening. A large burden of morbidity and treatment for innocuous lesions that would never have caused a problem, in exchange for a very small reduction in the rate of serious disease and death, if any.

Mass screening would be much more useful if we could distinguish the dangerous lesions from ones that just bear watching, but as of now, we really can't. The shameful truth is, however, that without having good evidence that screening really does save lives or that the benefits outweigh the costs, the ACS and disease-specific organizations have undertaken mass campaigns over decades to try to get everyone to be screened. Of course there is money to be made at every stage, from radiography to lab to surgery and chemotherapy. Is that why they jumped the gun on the evidence? Who would think such a thing.

And while we're on the subject of what you read here first:

As I and others have been saying for some time now, the influenza surveillance data which has been used to describe the novel H1N1 pandemic is based, not on actual confirmed cases, but merely on the number of people who present with flu-like illnesses. For some reason, the public has been told to assume that most of these are in fact cases of novel H1N1 influenza, but that has not been established. CBS News now reports that the overwhelming majority of people who have been tested did not have novel H1N1 influenza, or even, in most cases, have any form of flu. Hmm.

Update: Kathy's comment reminds me that I should clarify something. The new position from the American Cancer Society refers only to mass screening of the general population. If you are at high risk -- for example, because you have a "first order relative" (parent or sibling) who has had breast cancer, especially at a relatively early age, your cost/benefit profile is very different, and mammography makes much more sense for you. I'm not here to give individual medical advice, but to talk about broad policy. You should make your own informed decisions, hopefully in consultation with your physician.

13 comments:

kathy a. said...

well, i was interested in the report of the jama article. and it is a good thing that some cancers are caught early and eradicated, but from what i can gather, the promise of mass screening catching it all at an early point is not panning out. the routine prostate and breast screenings are not catching more serious forms of disease any earlier than testing done because of symptoms or other indications, from what i gather.

this is just my view from my personal experiences: it's good to have a baseline mammogram, and followups maybe periodically but certainly when there are changes.

i've had 3 rounds of mammography this year, since my sister was diagnosed with an aggressive stage II cancer. the last one was at a cancer center, really because of staffing issues and i think because the medical foundation spent shitloads on building this new cancer place. but after round 3, i finally got enough info that i think the "suspicious" bits on film are actually fibroids that have been there for about ever. [on round 2, i was told they were in a different place than my longstanding lumps, but that wasn't accurate info.] they lost my old mams, by the way -- which were dated, but hopefully they will be able to keep the digital images safe someplace for future reference.

my sister with the stage II cancer was pretty diligent about mams, particularly since she had an earlier breast concern. she sought help when she found a new mass.

Anonymous said...

Revere on CBS story that you refer to:
http://scienceblogs.com/effectmeasure/2009/10/cbs_news_on_swine_flu_testing.php#more

Cervantes said...

Kathy -- because you have a first order relative who has had breast cancer, you are in a different situation. Your risk is higher, therefore it probably makes sense for you to have regular mammography. These recommendations refer to general population screening only. I should probably put an update on the post to make that clearer.

Anonymous: Revere's post is quite wonky as usual, but the main point most of us should take from it is that the flu surveillance system is not designed to give us any sort of reliable numbers on overall incidence; it's a sentinel surveillance system designed to raise red flags that something may be occurring that bears investigation and possibly response.

What I want everyone to understand is that all of the reports of "widespread flu activity" and schools closing because of "flu" outbreaks and so on are very likely wrong. We don't know if the people presenting at doctors' offices or staying home from school have flu at all, let alone novel H1N1 - in fact, most of them don't.

gribley said...

I haven't had the time to sort through Revere's comments yet. But the health people at my small PA college tell me that we send a few samples, taken from cases diagnosed as flu based on symptoms, to CDC each week as part of a CDC surveillance project, and that 2/3 of those are coming back as H1N1. I'm surprised it's that high, and maybe I need to start trying to get my hands on that data, but it's interesting.

Cervantes said...

The testing criteria have no doubt become more stringent, so a higher pct. will test positive. You may also happen to be in a high prevalence area. Nevertheless the qualitative point remains: it is impossible to make a definitive flu diagnosis clinically.

kathy a. said...

i'm just not that interested in what strain of flu is going around, since H1N1 doesn't seem to be particularly virulant or deadly. naturally, complications should be investigated.

my friend's daughter was at a summer program, and tons of people got sick -- not so unusual for kids in close quarters -- and everyone recovered in a few days. but they did testing, who knows who paid for it, and lots of the kids had H1N1, sending their long-distance parents into palpitations until the fever went down.

gribley said...

kathy: yes, the hype is real, but to say that H1N1 is "not particularly virulent or deadly" is stretching things a bit. It does seem that we are much further along into a higher-mortality flu season than we'd like, and it's still very early.

Not meaning to hijack the thread for flu -- I know Cervantes is, to put it mildly, disinterested in it -- but check Revere's post here.

Token on-topic contribution: Cervantes, I *have* been reading it here first for years, and it's nice to see JAMA catching up. It will be interesting to figure out how to respond when, in a year or two, I start hitting the recommended PSA screening age bracket.

Nathan said...

Cervantes, I don't rely on CBS news for my health information, especially when devoid of any real data and when parts of this story include fear-mongering. Yes, most cases are not confirmed, but plenty of lab testing continues to happen. There is more than just "assuming" going on here. Part of the science behind this is here: http://www.cdc.gov/flu/weekly/

Bix said...

Yes, especially that 5th paragraph.

An unfortunate outcome from this aggressive testing - all the good body parts that have been excised or damaged, needlessly, and all the needless risky radiation exposure.

There's something almost barbaric about how we approach cancer - all this cutting out.

We need to spend (we need to have spent) a commensurate amount of money characterizing and staging tumors, so we're comfortable choosing no-action. (I know no-action isn't profitable in our system. Maybe the proposed Comparative-Effectiveness Institute would address this.)

It's like ... okay, we have a tumor, now what? Even a wait-and-see approach is costly, tests cost, there is a cost in risk from the test itself, not to mention the cost in emotional health. (Which is a whole other area that doesn't get addressed - mental health.)

kathy a. said...

bix, i'm interested in learning more about your perspective -- are you speaking to end of life? basically incurable cancers? or very invasive biopsies to even see if there is cancer? or what?

Bix said...

I'm speaking to all of those, and more. I don't believe that more interventions necessarily lead to better health. Regarding cancer, I think there are some healthcare environments that are quick to remove and disrupt healthy tissue, at a cost, without good understanding of how much health or time it buys.

Every intervention - be it a an x-ray, a scope, a blood test, surgery, a drug - comes with costs.

I read a NYTs story over the weekend that made me consider...

http://www.nytimes.com/2009/10/25/health/research/25anderson.html?_r=1

... How, for many, cancer is a chronic condition. As such, we might want to elevate quality-of-life (mental and physical) in the treatment equation.

This probably gets back to QALYs.

kathy a. said...

interesting article, bix.

i certainly agree about the importance of quality of life issues with cancer [and probably other illnesses, too, but a lot of people in my life have had struggles with cancer].

on the opposite end from extreme medical intervention at all costs, i heard recently that suzanne sommers has put out a book along the lines of "i had cancer and refused chemo, and i'm just dandy! try these alternative approaches by quacks!" and i think that is reprehensible. apparently her breast cancer was early stage, with a high survival rate for those getting surgery alone -- so her situation is far different from that of many others. and i hate quack medicine more than i hate overly-aggressive traditional medicine.

Bix said...

Re: Somers' book. Coincidentally, after you posted this, someone also named Kathy got on my blog and recommended it. I don't know the book, but it seems to have a following.