Most cancer screenings don’t extend life, study finds • Hacker News Board

Re: Most cancer screenings don’t extend life, study finds

#141

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:11 PM UTC

kazinator wrote: post #15

kccqzy wrote: post #3

This is the pertinent quote: > “Cancer screening was never really designed to increase longevity. Screenings are really designed to decrease premature deaths from cancer.” Explained another way, Dahut said, if a person’s life expectancy at birth was 80, a cancer screening may prevent their premature death at 65, but it wouldn’t necessarily mean they’d live to be 90 instead of the predicted 80. Personally I think this…

If we decrease premature deaths from any cause, particularly a common cause of premature deaths, we increase life expectancy. Or just what do the authors think life expectancy means? It's an average. Every premature death drags down average life expectancy. If we say that cancer screening has no effect of life expectancy, that's exactly the same as saying that it doesn't prevent premature deaths. If cancer screening…

You may be decreasing premature deaths from cancer but increasing premature deaths from other causes related to screening, thus you don't increase life expectancy. Read the original article in JAMA.

Re: Most cancer screenings don’t extend life, study finds

#142

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:13 PM UTC

teleforce wrote: post #70

kccqzy wrote: post #3

This is the pertinent quote: > “Cancer screening was never really designed to increase longevity. Screenings are really designed to decrease premature deaths from cancer.” Explained another way, Dahut said, if a person’s life expectancy at birth was 80, a cancer screening may prevent their premature death at 65, but it wouldn’t necessarily mean they’d live to be 90 instead of the predicted 80. Personally I think this…

There's only two things that are certain in this world, death and taxes - Benjamin Franklin. The main purpose of screening for early disease or genetic condition detection regardless of the diseases or illness, cancer, heart attack, stroke, etc, is not really to prolong longevity, even though that's a wonderful side effect, but the main thing to prevent complication(s) that may arise from the late detection. Apparent…

Just curious, have you read the original article in JAMA?

Re: Most cancer screenings don’t extend life, study finds

#143

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:33 PM UTC

hn_throwaway_99 wrote: post #24

somenameforme wrote: post #13

Earlier quoted context omitted.

The paper [1] is more well written and clear than the CNN article. They were comparing the aggregate life expectancies of people who went through regular screenings vs those who did not, and there was near zero difference except for colorectal screenings where the difference was about 4 months of difference. The paper is indeed presenting strong evidence that regular screenings have minimal value. [1] - https://jaman…

Thanks for posting that. I read the article but not the paper, but I still feel like this may be a case where scientists "treat all time equally" in a way that most people do not, resulting in differing conclusions even though the data is the same. That is, putting aside monetary costs for the moment (which I know is not a good idea in reality, but want to focus on another issue), you often hear about how false posit…

X-ray is not just adding anxiety, it's harmful, and it's affecting all women who get screening, not only those who actually get cancer. Magic of numbers.

Re: Most cancer screenings don’t extend life, study finds

#144

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:48 PM UTC

twoodfin wrote: post #79

burnished wrote: post #71

Earlier quoted context omitted.

I see! Who are you arguing against? The article gives zero indication that any of this is actionable, seems to advocate not changing anything with respect to your regular medical care. But to answer your question; 'nothing'. This is interesting but it isn't actionable.

I thought the article was pretty sloppy in its description of the results. Here’s the lede: Most cancer screenings don’t ultimately give someone extra time beyond their regular lifespan, according to a new review of clinical trials involving more than 2.1 million people who had six kinds of common tests for cancer. This is trivially misreadable as “an individual with cancer who catches it early via screening doesn’t…

If you add "on average" that's exactly what the original paper says. The averaging is over "someone who doesn't get cancer but died of screening complications", "someone who got false positive and decreased their lifespan with unnecessary treatments", and of course "someone who got true positive and increased his lifespan due to treatment". Are you sure you will be in the last group?

Re: Most cancer screenings don’t extend life, study finds

#145

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:51 PM UTC

porcoda wrote: post #47

(Note: very US centric comment here) I’ve become skeptical of the motives behind any article that seems to seed some level of doubt about health screenings and any preventative or treatment measure that involves the healthcare system itself. They always stink of the insurance and for-profit healthcare system and their aversion to paying anything out beyond the absolute bare minimum to get people the care they need. I…

Only the author of the paper is from Europe?

Re: Most cancer screenings don’t extend life, study finds

#146

Post by vc8f6vVV » Thu, Aug 31, 2023, 3:56 PM UTC

xp84 wrote: post #122

I am still disturbed by this though. The alternative I see to "get screenings" is "get no screenings." If you're one of the ones who actually do have an aggressive cancer, and you don't find out about it until it's like Stage Four, then you just definitely die, badly and soon. You, specifically, might have been helped if screened when you had a little baby tumor. So, while I see the "statistically" part, asking every…

> You, specifically, might have been helped if screened when you had a little baby tumor.

Or your screening might have caused that tumor? X-rays are not harmless and they can cause cancer. Other screenings have their respective complications. Aren't you disturbed by a thought that maybe you wouldn't have any cancer if not for screening? Or you would have a healthy colon if not for the intern who perforated it during colonoscopy?

Re: Most cancer screenings don’t extend life, study finds

#147

Post by vc8f6vVV » Thu, Aug 31, 2023, 4:06 PM UTC

amluto wrote: post #60

The actual study is (after some URL sanitization): https://jamanetwork.com/journals/jamainternalmedicine/fullar... and I do not like it. It suffers from what I consider an extremely common problem in statistics: if you define the question poorly, then your output is garbage no matter how fancy or careful your analysis is. We can start with the beginning of the abstract: > Importance Cancer screening tests are promote…

> Colorectal cancer screening is not all that unpleasant

Also not that harmless as you think. Only you suggest to perform it on 24 other patients who won't ever have a colon cancer. And that might be you, right? With the real risk (albeit small, but you need to multiply it by 25) of having a serious complication which eventually may result in a premature death.

Re: Most cancer screenings don’t extend life, study finds

#148

Post by vc8f6vVV » Thu, Aug 31, 2023, 4:10 PM UTC

aydyn wrote: post #20

> explained that if breast cancer caused 3% of all female deaths and screenings reduced these deaths by 35%, that’s a good result on its own. But screenings may change mortality overall by only about 1% This statement makes it clear what's going on. In ML terms: class imbalance. 99.9% of people won't ever get colon cancer, and therefore won't ever benefit from a colonoscopy. It won't make any statistical difference i…

> 99.9% of people won't ever get colon cancer, and therefore won't ever benefit from a colonoscopy.

But they may have complications from a colonoscopy, that's the idea. No test is completely harmless, even a blood work. You save some lives but may loose others, that's the point of the paper. And of course you waste resources that can be used to find a cure.

Re: Most cancer screenings don’t extend life, study finds

#149

Post by vc8f6vVV » Thu, Aug 31, 2023, 4:26 PM UTC

haldujai wrote: post #125

Flatcircle wrote: post #98

Breast cancer screens def save lives. Can't speak to all screenings but some def work.

I don't know why you're downvoted. The commenters below are misunderstanding things, the NNT page is old and even then it's being mis-cited. I won't go into it but read the caveats section for the author's own explanation. Screening mammography unequivocally improves cancer-specific mortality. Making the leap to overall mortality is hard, and even a meta analysis is likely too underpowered given the very low overall…

> 1. Screening mammography has been proven to reduce cancer specific mortality in many studies.

So let's assume that an annual X-ray caused another cancer in women who would never develop breast cancer (i.e. 87% of them). You are saying "we don't know", but the authors of that paper are trying to answer exactly that. We may have saved lives in 13% group (that would be < 2.5% of those dying from breast cancer), but may have lost some lives in 87% group. According to the paper the net outcome is around 0.