Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Most cancer screenings don’t extend life, study finds

cnn.com

Post reply on HN
Print view View original

81–90 of 149 posts

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

#81

Post by DonsDiscountGas »

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…

I can see why insurance companies might not want to pay, but the people selling the screenings absolutely would want you to get screened.

I dunno about all types of cancer (and screening methods), but mammograms definitely are not helpful and this has been known for a long time [0]

[0] https://www.vox.com/2015/7/6/8900751/breast-cancer-overdiagn... (2015)

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

#82

Post by arisAlexis »

There is a really weird connotation with this: if when malignancy is found and then actions are taken and when it's found earlier actions are taken earlier but they still don't survive means that when you treat a cancer early is the same as treating it late. But that is contrary to all studies ever done. So either there is some mistake or stage I with stage 3 cancer have the same survival. Look like someone fucked up some math imo.

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

#83

Post by DonsDiscountGas »

highwayman47 wrote: post #51
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…

Ya exactly, I’ve had 2 family members catch pancreatic cancer early and be cured. It’s typically the most fatal cancer.

This study did not look at pancreatic cancer.

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

#84

Post by andrekandre »

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…

  > I often wonder how different public attitudes would be towards treatment and prevention if the US healthcare system wasn’t profit driven.
in japan some prefectures or cities will send you leaflets/guides about how to get prescreening for cancer markers and early treatment for people past a certain age

i seem to also remember seeing they offer incentives like first screening only 700 yen (about 5 bucks) etc

so, yea, different systems, different incentives i guess

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

#85

Post by NoZebra120vClip »

arisAlexis wrote: post #68
haltingproblem wrote: post #61

Earlier quoted context omitted.

This is the negative expectation part of most medical screening that most analyses miss. - Medical screenings themselves have iatrogenic effects, - the false positives interventions resulting from screenings have further negative effects and - finally the true positive interventions don't necessarily prolong life. All in all very difficult (confounding) tradeoffs that are impossible to quantify and understand especia…

Do you really believe your third point? That most medical interventions for cancer do not prolong life? Or the word necessarily means your argument is null like "not all interventions prolong life". Yeah , we knew that already. It's never 100%.

I'd rather die of cancer than die of chemotherapy.

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

#86

Post by wnissen »

hedora wrote: post #35
kazinator wrote: post #14

> But experts say this doesn’t mean you should cancel that colonoscopy or mammogram appointment. That can only be that these experts disagree with the study, because if it were properly conducted such that its findings are true, then in fact its conclusions do add up to skipping colonoscopies and mammograms. The study is saying that the diagnostic procedures have no effect on outcome. You should not waste time on pro…

The article dismisses a population-wide life expectancy increase of 4 months from one of the screens. If that's your bar, then most preventative screening is probably not worthwhile.

It would really help me to use the same methodology but compare it to people smoking like they did in the 1980s.

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

#87

Post by DennisP »

idopmstuff wrote: post #80
DennisP wrote: post #76

Earlier quoted context omitted.

So work the numbers. Put together the chance of false positives, false negatives, rate of negative effects from treatment, and rate of death with and without treatment. Tell the patient the risk of each outcome. The math is easy. If we don't have the numbers for it, then get them. Plenty of people get prostate cancer and some of them choose to just monitor. We should have plenty of information to make a rational deci…

> Tell the patient the risk of each outcome. This isn't a simple problem of calculating EV. Telling somebody that there's a 40% chance that the positive test is actually wrong and in the 60% case that it's right, 40% of the time it's going to be benign, but if it's not benign it might kill them but if it is benign and they do surgery they might be left wearing diapers is not a simple thing for a person to evaluate. A…

No, I mean you take the test and if it's positive then present options like this:

Risk of death: X% with treatment, Y% without treatment.

Risk of side effect A: X% with treatment, Y% without treatment.

Those numbers take into account the rate of false positives and false negatives. They are clear and understandable.

There are definitely situations in which you shouldn't test: where the rate of the cancer is low, the false positive rate is high, and the risk of treatment is high. In that case, the numbers can show that risk of death is higher with treatment than without, so while (noninvasive) testing doesn't make things worse if we're giving clear numbers, it doesn't help either; we might as well not test at all. But that's not true for everything. As for side effects, we should give patients clear numbers like this so they can make informed decisions.

Adding up the number of false positives and negatives, and the number of patients with various outcomes, is not comparable to using AI.

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

#88

Post by kccqzy »

pessimizer wrote: post #40
orblivion wrote: post #11

Earlier quoted context omitted.

I mean, you could interpret that as "most cancer screenings don't extend life, because they come back negative". It's the "not most" case you're testing for in the first place.

Not all positive tests are cancer. In some cases, actual cancers could be a tiny minority of positive tests. The tests themselves are a dangerous tool, and the way we minimize that danger is through statistics.

Then you are just changing one form of bad communication with another form. When a test indicates that there is cancer, the physician is not supposed to say "you have cancer" but rather "there is X% probability that you have cancer." If the test comes back negative, it should be "there is Y% probability that you have cancer" where presumably Y<X.

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

#89

Post by burnished »

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…

Ok, you've convinced me. This article could have given more information and context so that folk without that benefit would walk away with a more nuanced understanding of screening and its seemingly paradoxical costs. A short article that glosses over the details was not appropriate for this subject. Seeing plenty of evidence for that in this comment section.

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

#90

Post by Retric »

rocmcd wrote: post #75
Retric wrote: post #16

Earlier quoted context omitted.

Those numbers seem really off. The US has 3,464,231 deaths per year with cancer killing just over 600k, so 17.3%. https://www.cdc.gov/nchs/fastats/deaths.htm https://www.cancer.org/research/cancer-facts-statistics/all-... Also cancer screenings happen in the US. Thus 750k deaths without screenings and 80% of that = 600k deaths with screenings and 150k deaths postponed. Are they using some unusual definition or someth…

The 4% GP quoted was in reference to individual cancers (since there is no "cancer" screening, each screening is specific to a type of cancer). I'm having trouble finding numbers, but the comment by Vinay was basically saying that each screening is testing for something that has 1-4% chance of killing you. Not that 4% of all cause mortality is cancer, which is incorrect. In the context of individual screenings per ca…

There are also plenty of screening tests that catch multiple kinds of cancers. But focusing on individual tests misses the forest for the trees. Sure when you look at ever smaller subsets the benefits can seem smaller in each subset, however that’s directly offset by there being more groups.

Critically, these studies are backward looking they can tell you want taking such a test in 2017 followed by getting treatment in 2017 might do, but that doesn’t directly translate to what taking a test in 2024 would be worth.

As to changing all-cause mortality, when you’re talking 8 billion people even moving the needle by a single day represents another 5 years for 4 million people. That’s a big deal.

Treatments for the young tend to move the needle more because the young are likely to live longer. However in the developed world we’ve mostly plucked the low hanging fruit. That’s more or less the definition of a developed country, the obvious routes for development have already happened.

Post reply on HN