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Most cancer screenings don’t extend life, study finds

cnn.com

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

#131

Post by haldujai »

Gibbon1 wrote: post #64
idopmstuff wrote: post #54

Earlier quoted context omitted.

> Given that screening is arguably benign for most people You're 100% wrong here, this is not a given. Prostate cancer screenings, which are very common, can have both false positives as well as findings of cancer that is and would remain completely benign. These can both lead to unnecessary treatments that cause serious negative health effects, including incontinence and erectile dysfunction. https://www.cdc.gov/can…

Also read that death rates from thyroid cancer hasn't changed in 50 years. Despite huge numbers of thyroid screenings and treatment. An ultrasound of the thyroid often leads to finding a nodule. Which leads to a biopsy. Which comes out indeterminate. Which leads to a thyroidectomy and life long dependence on thyroid hormones. Another one is ductal carcinoma in situ. Read somewhere there is a 1% chance that will evolv…

Absolutely no one is getting a bilateral mastectomy or chemotherapy for DCIS.

This is by far the most inaccurate medical claim I've ever seen on HN. Where on earth did you get this from?

The whole point of diagnosing DCIS on screening mammography is that it avoids systemic therapy and mastectomy. It also wouldn't be bilateral.

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

#132

Post by throwaway290 »

DennisP wrote: post #102
throwaway290 wrote: post #96

Earlier quoted context omitted.

Better odds to live longer or have good life? Looks like this study says it's definitely not the former?

Untreated cancer is not without its effects on quality of life. As I said above, with a positive test, work out the numbers for death and other unpleasant outcomes, with or without treatment, and let the patient decide. If those numbers would say not to treat regardless of test results, then don't test. The study just says that most , not all, cancer screenings don't extend life. And it doesn't say whether doctors ar…

Sure, but cancer != positive test because of false positives. Therefore the question of odds.

I like your idea of working these things out statistically but by your phrasing it's not necessarily what's being done (as in there are no reliable enough numbers for odds that matter).

But even if those odds were available, no matter what patient chooses, once you tell then there is a positive result, the fact that false positive is possible and odds are not in favor of treatment so they make a choice to do nothing does not mean they get to live a normal life from now on. Patients are not pure bayesian choice machines. The choice you make will affect you in big unknown ways and the existence of such choice already affects you until your EOL and has repercussions. That cancer was detected in your body cannot be "unheard" or "unread" back. Maybe you manage to deal with it, maybe you will live in constant stress. and of course chronic stress is connected to tissue inflammation, sleep disruption and other issues.

Therefore your argument that screening is automatically good does not seem to be convincing to me

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

#133

Post by throwaway02sfv »

somenameforme wrote: post #13
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…

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…

I can confirm these findings. My father, aged 63, passed away just 3 days ago because of blood cancer. He was totally fit and fine until 8 months ago when we first noticed his abnormal blood counts.

He did regular screening, nothing came up in it. When suddenly in one blood report, his counts were low that's when we did some extensive testing. Even with extensive testing, the diagnosis kept changing. From Myelofibrosis to MDS to AML to AEL.

Whole aspects around testing and related studies are very confusing. Tests are not at all accurate and testing is very expensive.

It seems like a scam when it comes to testing industry and pharma industry for such disorders. Bottomline is nothing helped in my father's case and we lost him after spending tons of money.

The fact that medical system remains such an inefficient system till date indicates to me that world leaders doesn't want to solve for health problems. It's an industry for them with lots of money. Everyone seems to be motivated to keep population seek and be subscribed to their drugs.

Sorry for the rant.

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

#134

Post by DennisP »

throwaway290 wrote: post #132
DennisP wrote: post #102

Earlier quoted context omitted.

Untreated cancer is not without its effects on quality of life. As I said above, with a positive test, work out the numbers for death and other unpleasant outcomes, with or without treatment, and let the patient decide. If those numbers would say not to treat regardless of test results, then don't test. The study just says that most , not all, cancer screenings don't extend life. And it doesn't say whether doctors ar…

Sure, but cancer != positive test because of false positives. Therefore the question of odds. I like your idea of working these things out statistically but by your phrasing it's not necessarily what's being done (as in there are no reliable enough numbers for odds that matter). But even if those odds were available, no matter what patient chooses, once you tell then there is a positive result, the fact that false po…

Right the numbers for "positive test" should include false positives. That's part of my point. I've worked out a sample calculation if you want to see it. We could get fancy with error bars but I don't think that's necessary for any common cancer, and rare cancers shouldn't be tested for anyway since you'll mostly have false positives.

As I said above, I don't think that screening is automatically good because in some cases, working out the above numbers will tell you not to treat even if you had a positive test. Those cases should not be tested since they're not actionable anyway. That would likely be the case for a rare cancer.

I agree that a false positive is not great. But if you have the data, then the impact of false positive tests is already included in your data. You're comparing the total rates of death and other unpleasant outcomes for a tested population vs. an untested population.

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

#135

Post by csours »

stevehawk wrote: post #130
csours wrote: post #128

Earlier quoted context omitted.

Someone else linked to https://thennt.com/nnt/screening-mammography-for-reducing-de... Quote: > "Two recent data reviews deserve further mention. The United Kingdom commissioned an independent review after dissenting voices swelled, for the purpose of better informing shared decision making and educational materials about the harms and benefits of screening.6 Unfortunately the review concluded that screening mammogra…

so this is almost like a Goodhart's Law problem

I think it is a tricky measurement problem for sure. In this case, it feels like there is an obvious measurement (individual outcomes) that you have to deliberately step around to see the better measurement. That deliberate decision to ignore individual success stories feels very callous.

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

#136

Post by haltingproblem »

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%.

Sorry for the delay in responding.

I actually do and most of it based on what I have have directly experienced with what, especially older doctors, counsel their patients.

There is a lot of literature on how doctors die [1], which also drives my beliefs.

I am also influenced and how weak the statistical significance is on evidence based literature on interventions and how often the interventions are difficult to replicate.

As always, please do your own research :)

1- https://www.thehappymd.com/blog/bid/295228/how-doctors-die

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

#137

Post by vc8f6vVV »

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…

Have you read the original article, not the CNN interpretation? They are talking about harm vs benefits of screening. In simple words: you performed colonoscopy, got colon perforation and died of complications. Was colon cancer prevented? Absolutely! You didn't die of colon cancer! Is it any easier? No, it's not. The chance of dying of breast cancer is around 2.5%, so 1 women in 39 will die from that. OTOH annual X-rays affect the other 38 too, how many of them will die from X-ray exposure (which can cause e.g. another type of cancer, not necessary breast)? For the sake of discussion let's say 1 in 380. Congratulations, you've just increased breast cancer related death by 10%! Only it won't be in statistic as deaths from breast cancer.

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

#138

Post by vc8f6vVV »

throwway120385 wrote: post #18
amanaplanacanal wrote: post #8

Earlier quoted context omitted.

It looks like they were comparing a group that got screening vs a group that didn’t get screening. If the group that got screening didn’t live longer than the group that didn’t get screening, that seems like a lot of wasted dollars.

Life expectancy is really only one dimension of "health," and it's probably the most shallow dimension. If I'm quadriplegic and confined to a ventilator but I live to 80, that's the same in this metric as if I'm not paralyzed and able to breathe on my own until I die. What if some people in the group that didn't get screening had fewer high-quality years? It might simply be that the last 5 years of life for people wh…

There is another consideration:

1. You have an aggressive (i.e. non-treatable) cancer, maybe you feel slightly off, but you go on with your life, until you finally got worse and die. Or you performed screening, focus on treatment, bankrupt your family and ... die anyway,

2. You have a slow growing cancer (e.g. prostate), live your life and die of some other causes. Or you performed screening, got surgery, got tons of problems and die of myocardial infarction (yes, that's one of complications after prostate surgery).

If you read the original JAMA publication you would notice that there is a research on quality of life metric. That metric for breast cancer is higher among non-screened women.

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

#139

Post by vc8f6vVV »

haldujai wrote: post #131
Gibbon1 wrote: post #64

Earlier quoted context omitted.

Also read that death rates from thyroid cancer hasn't changed in 50 years. Despite huge numbers of thyroid screenings and treatment. An ultrasound of the thyroid often leads to finding a nodule. Which leads to a biopsy. Which comes out indeterminate. Which leads to a thyroidectomy and life long dependence on thyroid hormones. Another one is ductal carcinoma in situ. Read somewhere there is a 1% chance that will evolv…

Absolutely no one is getting a bilateral mastectomy or chemotherapy for DCIS. This is by far the most inaccurate medical claim I've ever seen on HN. Where on earth did you get this from? The whole point of diagnosing DCIS on screening mammography is that it avoids systemic therapy and mastectomy. It also wouldn't be bilateral.

Yes, they do. I have a friend who did just that. Was it justified? I don't know, but it's very real.

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

#140

Post by vc8f6vVV »

DennisP wrote: post #87
idopmstuff wrote: post #80

Earlier quoted context omitted.

> 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…

You are also presented with a choice: you take a test and you die in X% because of the test itself (there are no non-invasive tests, even IV is potentially dangerous), or you may be diagnosed with cancer with Y% chance of right diagnosis and Z% of lethality. Math is getting much more complicated. Now consider that only 2.5% women will die from breast cancer, but 97.5% others will get X-ray exposure once a year (with 100% test coverage of course). X-rays are know to cause mutations and thus cancer. Add to this money spent on tests that can be used to find a cure (we don't have unlimited resources).
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