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Virtually all deaths from solid cancers are preventable with routine scans to find tumors before they metastasize. Doctors have for decades refused to learn to

Virtually all deaths from solid cancers are preventable with routine scans to find tumors before they metastasize. Doctors have for decades refused to learn to use this technology.[1-4][5-9] * Meanwhile, population studies like the one this article is based on[10] are horseshit because they are subject to unknown degrees of sampling bias, rely on enormous assumptions (such as linear relationships which may not hold at all being applied over many orders of magnitude), and cannot in any case establish causality. [1] https://www.pocus.org/ https://www.pocus.org/ [2] https://www.butterflynetwork.com/ https://www.butterflynetwork.com/ [3] https://www.exo.inc/ https://www.exo.inc/ [4] https://vavehealth.com/ https://vavehealth.com/ [5] https://ezra.com/ https://ezra.com/ [6] https://www.halodx.com/ https://www.halodx.com/ [7] https://www.prenuvo.com/ https://www.prenuvo.com/ [8] https://www.simonone.com/ https://www.simonone.com/ [9] https://www.lifeimagingfla.com/ https://www.lifeimagingfla.com/ * Compare the experience of getting an x-ray from a dentist to getting one from a doctor. Or getting an ultrasound from an OB to getting one from any other doctor. [10] https://pubmed.ncbi.nlm.nih.gov/35988567/ https://pubmed.ncbi.nlm.nih.gov/35988567/

picture 4y ago
Routinely scanning people without symptom or otherwise cause for concern is not a good idea. The human body is very messy and variable, and it's hard for anyone or anything to reliably spot thing that are actually worth acting on. If the doctor spots a vague blob - how can they know what it is without any symptoms? The course of action is then "come back in three months for another scan." Subjecting a population to unnecessary routine full body scans, especially with radiation, will cause harm statistically. There are also countless examples of people undergoing unnecessary operation and suffering complications, like losing a perfectly fine healthy heart and requiring transplant.
- dan00 4y ago
  Yes, the breast cancer screening already has quite questionable results.
- landryraccoon 4y ago
  Wouldn’t the skill of analyzing scans improve if they were done more frequently? It seems like you’re promoting a self fulfilling prophecy. Doctors aren’t good at reading scans, so scans will cause false positives. But doctors are capable of learning and improving their skills. They will surely rapidly learn to screen a lot of false positives, thereby saving lives.
  - MauranKilom 4y ago
    You seem to assume that radiologists currently see patient scans too rarely to deliver accurate diagnosis. That seems very unfounded to me. "More frequent scans per patient" != "More scans seen per clinician". You would just end up having to hire more clinicians. (Yes, your family doctor might end up seeing more scans in this scheme, but it is implausible that they would be better at evaluating them than a trained radiologist, which is who this would almost surely be deferred to anyway.)
    - landryraccoon 4y ago
      Is the argument then that scans are intrinsically error prone, as in the noise level is so high that even a team of highly trained radiologists can’t accurately determine if cancer is present from a scan?
      - MauranKilom 4y ago
        It's not the quality of the scan (although that can certainly be a factor). It's that there is a lot of variation in human anatomy, and "these pixels are brighter than the rest" can mean any of many things. Relatedly, for many types of brain tumors, you simply don't know what exact kind of tumor it is until you actually do a biopsy (= you undergo surgery). This can be important information ("how aggressive is it?"), so in some hospitals it is common practice to send a tissue sample for identification and get back the result while the surgery is still going on.
  - moonchrome 4y ago
    This is a very naive argument, it assumes the entire problem is lack of skill and that early intervention on positive diagnosis is always a good thing. Mammography is a really good candidate for random screening and it's still debated because of false positives and the impacts of misdiagnosis.
- valenterry 4y ago
  We need yearly scans or even monthly scans (MRI) for everyone. Privacy concerns aside, I think we would learn an awesome lot. We could then monitor changes over time and machine-learning could probably get really good at recognizing what changes are harmless and which are harmful and need a doctor to look into. It's a dream scenario, but maybe some day it will be like that. Or it will be like that and be dystopia. :)
  - discardable_dan 4y ago
    MRIs would need to take a fraction of the time for this to be viable.
    - derefr 4y ago
      Or, y'know, we could have 10x more MRI machines, thus incentivizing them to be cost-optimized in ways they absolutely aren't today.
      - Broken_Hippo 4y ago
        That's not really going to help. For an MRI, you have to lay there being still, and for some you have to hold your breath, all while in a loud little tube. I have to get a couple every year, and I*m lucky not to find them too uncomfortable. Some folks, though, would have serious issues with the cage over your head when you get your brain scanned: Your brain and spinal column will take 45 minutes, as will other areas. You will need to be repositioned often, adding and removing things to get the pictures of all the areas. In other words, you'll need an entire day off to do this if it is even possible for you to lay there for so long in one event, even if you get breaks. And for some folks it is going to be hours of torture. More MRI machines won't solve the issue.
    - likeabbas 4y ago
      Not necessarily, we just need cheaper ones. I interviewed at Hyperfine last year and they seemed to have a promising product https://hyperfine.io/ https://hyperfine.io/
    - 4y ago
- ssivark 4y ago
  > especially with radiation, will cause harm statistically. Ultrasound is not radiation (as in photons). To the best of our understanding (from a physics/engg perspective) ultrasound imaging capped by appropriate energy/etc limits is expected to be perfectly safe. Likewise with MRI. If we want more pointed study to be sure of this, that's fair, but let's be clear & specific about it and commit to figuring it out one way or another so we don't repeat the same discussion a couple of decades down the line. (We have to think of moving the state of the art forward, instead of festering in unresolved disagreements) Further, if you're concerned about under-studied possible side-effects of radiation from occasional diagnostic testing, what do you plan to do about being blanketed by mm waves once 5G gets deployed more ubiquitously? > There are also countless examples of people undergoing unnecessary operation and suffering complications This sounds far more serious (and fixable) compared to the physics/biology interaction of diagnostic testing. Why do we continue to bury our heads in the sand collectively, instead of trying to fix this with better decision-making tools?
  - DanBC 4y ago
    > Likewise with MRI MRI isn't radiation, but is sometimes used with contrast dye. People can be allergic to the dye. For one person this is a small risk. Across a population we'd be causing harm. We'd balance the risks of harm against the benefits, and so far no-one can find a benefit to routine whole body MRI scans. And if the benefit was there the MRI machine companies probably would have found it by now because it'd massively increase the numbers of machines they could sell.
    - robocat 4y ago
      MRI uses electromagnetic radiation. MRI uses a magnetic field with a radio-frequency pulse and then the protons emit a radio-frequency response - that response location is used to synthetically generate the image. MRI does not use ionising radiation. Nice overview here: https://www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri https://www.nibib.nih.gov/science-education/science-topics/m...
      - 4y ago
- voldacar 4y ago
  This is just silly. You are never disadvantaged by knowing more about what's inside your body. What you don't know can easily kill you, though. Hopefully in the long term future we will have extremely cheap & frequent MRI and blood testing so you can assemble a high resolution digital history of your body. Doctors are generally not very innovative people though and they will probably resist it to the end.
  - bagels 4y ago
    It's not silly. Look at how the mammogram guidelines are set. If the scans are too frequent, the harm done from false positives (unnecessary surgeries and risks from those surgeries) can become too great. The standards were relaxed to include fewer scans in the last few years because of this. Apply this to more invasive exploratory surgeries, and you see people dying from internal surgery complications for benign cysts and lumps.
    - derefr 4y ago
      That's because single datapoints are used to trigger intervention. We should be intervening based on growth trends from time-series data. Time-series data which can only be collected by... frequent scans.
      - Sebb767 4y ago
        Don't discount psychological stress. "You have something growing in your breast which might be cancer, just wait a few months and we'll scan again" is not something that gives people a good nights sleep.
        derefr 4y ago
        So don't tell them. Like I said, a single datapoint by itself is meaningless — so you wouldn't bring it to the patient's attention. Heck, the software shouldn't flag it for the doctor's attention. (Think: metrics-based alerting thresholds in software systems.)
      - 4y ago
- paulpauper 4y ago
  the screening guidelines take into account those risks and it's still deemed worthwhile because cancer can grow and become lethal despite being asymptomatic. colon cancer is the mid-life killer...plenty of ppl in their 50s or even 40s get it despite no risk factors. Screening is the only option to catch it early.
_qua 4y ago
What is your medical background? I am a physician and do not agree with your thesis. Linking to ultrasound websites is not really evidence of anything. There simply isn't good evidence that "all solid tumors caught early are curable." Some cancers, like localized breast cancers and certain renal cancers, are highly curable when caught early. Some other non-solid cancers like certain pediatric leukemias are also extremely responsive to therapy and highly curable. Conversely, some solid tumors, even when caught early, have dismal prognosis due to micrometastasis and the underlying biology of the tumor. I would recommend "The Hallmarks of Cancer" for a high level overview of the current understanding of what drives cancer: https://doi.org/10.1016/j.cell.2011.02.013 https://doi.org/10.1016/j.cell.2011.02.013
- bagels 4y ago
  Some of those devices are not decades old either, regardless of the other problems with the thesis.
- echelon 4y ago
  Does a physician have a globally optimal understanding? Do you actively read medical journals? Developments in biochemistry? Even amongst the best read physicians and researchers, I would bet my life that we're doing a lot of things suboptimally or have improper understanding of many diseases. I'm not trying to belittle your understanding or your credentials, which I understand to be far better than untrained laymen. The current state of medical care leaves a lot to be desired. We have a long way to go to detect and cure every disease state. If more money is spent on developing better tooling, assays, imaging, etc. we will undoubtedly improve patient outcomes.
  - PragmaticPulp 4y ago
    > Does a physician have a globally optimal understanding? I’m far more inclined to trust a trained physician than a random HN commenter whose first four citations are just random ultrasound device manufacturer websites. The parent comment makes bold claims and tries to overwhelm the reader with non sequitur citations, but it’s clear they don’t actually understand the subject matter.
oaktrout 4y ago
POCUS is used commonly in my experience and there are large amounts of curriculum devoted to it. We haven't had affordable access to POCUS for decades so I don't see how doctors have refused to learn it for decades.
- ssivark 4y ago
  Do you think that affordability is the biggest hurdle holding back POCUS from being used ubiquitously for diagnostic imaging, or is it something else?
  - oaktrout 4y ago
    Probably not. Costs have come down immensely, most HN users could afford a butterfly if they wanted to play around with it. Ultrasound has limited penetration for deeper tissues so you aren't going to see lung cancer with it (especially behind ribs), and overweight patients don't image as well, again because of limitations in imaging depth. Regardless of uptake it's not going to solve all our diagnostic challenges. It also takes skill to know what you are seeing and to know how to find what you're looking for. Anyone could learn, but it's a time investment and physicians have limited time as is. Still, it is becoming more popular and soon it won't be uncommon for your primary care doc to pull out the probe and see if your gallbladder is inflammed or if that abscess is going to be amenable to in office drainage.
loxias 4y ago
> Virtually all deaths from solid cancers are preventable with routine scans to find tumors before they metastasize. Fantastic. I take it from those links this would be detectable with a full body MRI? I already wanted an excuse to start getting those regularly. > Compare the experience of getting an x-ray from a dentist to getting one from a doctor. Or getting an ultrasound from an OB to getting one from any other doctor. Can you expand on this? It sounds like you're implying something (I might agree with), but am not sure.
- PragmaticPulp 4y ago
  > Fantastic. I take it from those links this would be detectable with a full body MRI? I already wanted an excuse to start getting those regularly. There is a lot of research on the topic but it doesn’t agree with the OP’s thesis. Full body scans can be purchased if you have the funds, but you are far more likely to get false positives than to actually catch a cancer this way. The ensuing medical costs and possibly even unnecessary surgeries are statistically likely to cause you more detriment than any benefit you might receive. This is counterintuitive to many, but the truth is that it’s not actually easy to spot nascent pre-symptomatic cancers from full body scans without incurring a massive number of false positives along the way. Something like 1 in 8 people will end up getting flagged for “warning signs of potential cancer” during these scans that turns out to be nothing upon further investigation. Few people continue to get the tests for this reason.
- aaaaaaaaaaab 4y ago
  >I already wanted an excuse to start getting those regularly. Psychotherapy can help with hypochondria.
  - loxias 4y ago
    Hahaha :) Close, but no. Regularly I mean "roughly yearly", and I'm a signals processing dork, not much of a health nut.
    - sgtnoodle 4y ago
PragmaticPulp 4y ago
Your first four links are just random ultrasound device companies. Doctors are very well-versed in ultrasound technology so your claim that doctors refuse to learn this is patently false. Full-body scans have been marketed for years by companies looking to drum up business for their machines, but they mostly lead to false positives. Notice how your fifth link clearly says it has helped people find “warning signs of potential cancer” instead of that it helps people find cancer? These machines are basically false positive generators in most cases. If someone had effectively infinite time and money to dedicate to routine cancer screenings from these machines, they are more likely to end up harmed by unnecessary procedures stemming from false positive results than they are to catch and remove a specific cancer occurring randomly in their bodies. Contrary to your claims, we do actually screen for certain cancers in cases where a clear net positive benefit can be demonstrated. Mammograms for breast cancer are one common example. Doctors definitely aren’t just burying their heads in sand. These are common research topics and the tradeoffs of false positives are constantly being investigated. Full-body screenings aren’t necessarily a net benefit.
- sigmoid10 4y ago
  There's also a lot of politics and social psychology involved in these things. From the government side, it can be decades between arranging, deploying and evaluating large scale, population-wide cancer screenings. These are timescales on which scientific consensus can easily change. Mammograms in particular are a touchy subject, since newer metastudies only show a statistically significant reduction in mortality for women above the age of 50 and below the age of 74 [1]. However, many policy makers still offer screenings starting at the age of 40 with no upper limit, despite evidence that annual mammograms will result in a false positive result over 10 years with up to 61% probability [2]. Below the age of 50, regular mammograms may even increase the risk of dying from breast cancer [3]. Ultrasound screenings on the other hand would be much safer from a radiation-exposure point of view and metastudies suggest they can detect cancers under difficult conditions more reliably, but they also suffer from more false positives [4]. This is where the social aspect comes in, where many woman fear getting their breasts removed for no reason. This is especially concerning when more than 50% of positive results are found to be false positives [5]. To summarize: It's really hard to figure out what amounts to "net positive benefit" when it comes to general public screenings. [1] https://www.aeaweb.org/articles?id=10.1257/jep.35.2.119 https://www.aeaweb.org/articles?id=10.1257/jep.35.2.119 [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209800/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209800/ [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189562/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189562/ [4] https://bmccancer.biomedcentral.com/articles/10.1186/s12885-020-06992-1 https://bmccancer.biomedcentral.com/articles/10.1186/s12885-... [5] https://ebmh.bmj.com/content/16/4/115 https://ebmh.bmj.com/content/16/4/115
deleted 4y ago
[deleted]
mfer 4y ago
There is a fair amount of scientific study that has linked diet to some cancers. Those same diet attributes that can make one obese also lead to higher rates of cancer. In cancer prevention, lifestyle matters.
mikotodomo 4y ago
Wait, so I've been avoiding McDonalds all this time for no reason? I literally lost a GF because I decided to skip eating one afternoon when the only place close to us was McDonalds!
n8henrie 4y ago
What in the world are you talking about? I'm a physician that uses ultrasound every shift, and I'm pretty darn good at it. I've even used one of the specific devices you linked to. Virtually every physician I know is foaming at the mouth to learn more ultrasound and to apply it to new indications and with new approaches. Inappropriate use of ultrasound for harebrained indications (for which we have far superior alternatives) is on of my pet peeves. I am not a cancer doc, but I am drawing a blank as to what solid tumors you could possibly be referring to for which ultrasound is the preferred screening or diagnostic technique, or what kind of conspiracy you're vaguely implying that prevents its use. IME, virtually everyone is (over?) eager to use ultrasound for every condition under the sun, and I am sincerely perplexed as to what experiences have led you to form your opinion on this matter.
Ovah 4y ago
"Doctors have for decades refused to learn to use this technology" In Sweden this is actually standard practice. It's used for patients who have syndromes that guarantee them to get cancer several times over in their lifetime. IIRC some get an MRI every 6 months. The reason it's not done to a wider population.. well you can't justify the cost in a state funded healthcare system. The health benefit just isn't justifiable when MRIs are so scarce and expensive to run.

picture 4y ago

Routinely scanning people without symptom or otherwise cause for concern is not a good idea. The human body is very messy and variable, and it's hard for anyone or anything to reliably spot thing that are actually worth acting on. If the doctor spots a vague blob - how can they know what it is without any symptoms? The course of action is then "come back in three months for another scan." Subjecting a population to unnecessary routine full body scans, especially with radiation, will cause harm statistically. There are also countless examples of people undergoing unnecessary operation and suffering complications, like losing a perfectly fine healthy heart and requiring transplant.

dan00 4y ago
Yes, the breast cancer screening already has quite questionable results.
landryraccoon 4y ago
Wouldn’t the skill of analyzing scans improve if they were done more frequently? It seems like you’re promoting a self fulfilling prophecy. Doctors aren’t good at reading scans, so scans will cause false positives. But doctors are capable of learning and improving their skills. They will surely rapidly learn to screen a lot of false positives, thereby saving lives.
- MauranKilom 4y ago
  You seem to assume that radiologists currently see patient scans too rarely to deliver accurate diagnosis. That seems very unfounded to me. "More frequent scans per patient" != "More scans seen per clinician". You would just end up having to hire more clinicians. (Yes, your family doctor might end up seeing more scans in this scheme, but it is implausible that they would be better at evaluating them than a trained radiologist, which is who this would almost surely be deferred to anyway.)
  - landryraccoon 4y ago
    Is the argument then that scans are intrinsically error prone, as in the noise level is so high that even a team of highly trained radiologists can’t accurately determine if cancer is present from a scan?
    - MauranKilom 4y ago
      It's not the quality of the scan (although that can certainly be a factor). It's that there is a lot of variation in human anatomy, and "these pixels are brighter than the rest" can mean any of many things. Relatedly, for many types of brain tumors, you simply don't know what exact kind of tumor it is until you actually do a biopsy (= you undergo surgery). This can be important information ("how aggressive is it?"), so in some hospitals it is common practice to send a tissue sample for identification and get back the result while the surgery is still going on.
- moonchrome 4y ago
  This is a very naive argument, it assumes the entire problem is lack of skill and that early intervention on positive diagnosis is always a good thing. Mammography is a really good candidate for random screening and it's still debated because of false positives and the impacts of misdiagnosis.
valenterry 4y ago
We need yearly scans or even monthly scans (MRI) for everyone. Privacy concerns aside, I think we would learn an awesome lot. We could then monitor changes over time and machine-learning could probably get really good at recognizing what changes are harmless and which are harmful and need a doctor to look into. It's a dream scenario, but maybe some day it will be like that. Or it will be like that and be dystopia. :)
- discardable_dan 4y ago
  MRIs would need to take a fraction of the time for this to be viable.
  - derefr 4y ago
    Or, y'know, we could have 10x more MRI machines, thus incentivizing them to be cost-optimized in ways they absolutely aren't today.
    - Broken_Hippo 4y ago
      That's not really going to help. For an MRI, you have to lay there being still, and for some you have to hold your breath, all while in a loud little tube. I have to get a couple every year, and I*m lucky not to find them too uncomfortable. Some folks, though, would have serious issues with the cage over your head when you get your brain scanned: Your brain and spinal column will take 45 minutes, as will other areas. You will need to be repositioned often, adding and removing things to get the pictures of all the areas. In other words, you'll need an entire day off to do this if it is even possible for you to lay there for so long in one event, even if you get breaks. And for some folks it is going to be hours of torture. More MRI machines won't solve the issue.
  - likeabbas 4y ago
    Not necessarily, we just need cheaper ones. I interviewed at Hyperfine last year and they seemed to have a promising product https://hyperfine.io/ https://hyperfine.io/
  - 4y ago
ssivark 4y ago
> especially with radiation, will cause harm statistically. Ultrasound is not radiation (as in photons). To the best of our understanding (from a physics/engg perspective) ultrasound imaging capped by appropriate energy/etc limits is expected to be perfectly safe. Likewise with MRI. If we want more pointed study to be sure of this, that's fair, but let's be clear & specific about it and commit to figuring it out one way or another so we don't repeat the same discussion a couple of decades down the line. (We have to think of moving the state of the art forward, instead of festering in unresolved disagreements) Further, if you're concerned about under-studied possible side-effects of radiation from occasional diagnostic testing, what do you plan to do about being blanketed by mm waves once 5G gets deployed more ubiquitously? > There are also countless examples of people undergoing unnecessary operation and suffering complications This sounds far more serious (and fixable) compared to the physics/biology interaction of diagnostic testing. Why do we continue to bury our heads in the sand collectively, instead of trying to fix this with better decision-making tools?
- DanBC 4y ago
  > Likewise with MRI MRI isn't radiation, but is sometimes used with contrast dye. People can be allergic to the dye. For one person this is a small risk. Across a population we'd be causing harm. We'd balance the risks of harm against the benefits, and so far no-one can find a benefit to routine whole body MRI scans. And if the benefit was there the MRI machine companies probably would have found it by now because it'd massively increase the numbers of machines they could sell.
  - robocat 4y ago
    MRI uses electromagnetic radiation. MRI uses a magnetic field with a radio-frequency pulse and then the protons emit a radio-frequency response - that response location is used to synthetically generate the image. MRI does not use ionising radiation. Nice overview here: https://www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri https://www.nibib.nih.gov/science-education/science-topics/m...
    - 4y ago
voldacar 4y ago
This is just silly. You are never disadvantaged by knowing more about what's inside your body. What you don't know can easily kill you, though. Hopefully in the long term future we will have extremely cheap & frequent MRI and blood testing so you can assemble a high resolution digital history of your body. Doctors are generally not very innovative people though and they will probably resist it to the end.
- bagels 4y ago
  It's not silly. Look at how the mammogram guidelines are set. If the scans are too frequent, the harm done from false positives (unnecessary surgeries and risks from those surgeries) can become too great. The standards were relaxed to include fewer scans in the last few years because of this. Apply this to more invasive exploratory surgeries, and you see people dying from internal surgery complications for benign cysts and lumps.
  - derefr 4y ago
    That's because single datapoints are used to trigger intervention. We should be intervening based on growth trends from time-series data. Time-series data which can only be collected by... frequent scans.
    - Sebb767 4y ago
      Don't discount psychological stress. "You have something growing in your breast which might be cancer, just wait a few months and we'll scan again" is not something that gives people a good nights sleep.
      - derefr 4y ago
        So don't tell them. Like I said, a single datapoint by itself is meaningless — so you wouldn't bring it to the patient's attention. Heck, the software shouldn't flag it for the doctor's attention. (Think: metrics-based alerting thresholds in software systems.)
    - 4y ago
paulpauper 4y ago
the screening guidelines take into account those risks and it's still deemed worthwhile because cancer can grow and become lethal despite being asymptomatic. colon cancer is the mid-life killer...plenty of ppl in their 50s or even 40s get it despite no risk factors. Screening is the only option to catch it early.

_qua 4y ago

What is your medical background? I am a physician and do not agree with your thesis. Linking to ultrasound websites is not really evidence of anything. There simply isn't good evidence that "all solid tumors caught early are curable." Some cancers, like localized breast cancers and certain renal cancers, are highly curable when caught early. Some other non-solid cancers like certain pediatric leukemias are also extremely responsive to therapy and highly curable. Conversely, some solid tumors, even when caught early, have dismal prognosis due to micrometastasis and the underlying biology of the tumor. I would recommend "The Hallmarks of Cancer" for a high level overview of the current understanding of what drives cancer: https://doi.org/10.1016/j.cell.2011.02.013 https://doi.org/10.1016/j.cell.2011.02.013

bagels 4y ago
Some of those devices are not decades old either, regardless of the other problems with the thesis.
echelon 4y ago
Does a physician have a globally optimal understanding? Do you actively read medical journals? Developments in biochemistry? Even amongst the best read physicians and researchers, I would bet my life that we're doing a lot of things suboptimally or have improper understanding of many diseases. I'm not trying to belittle your understanding or your credentials, which I understand to be far better than untrained laymen. The current state of medical care leaves a lot to be desired. We have a long way to go to detect and cure every disease state. If more money is spent on developing better tooling, assays, imaging, etc. we will undoubtedly improve patient outcomes.
- PragmaticPulp 4y ago
  > Does a physician have a globally optimal understanding? I’m far more inclined to trust a trained physician than a random HN commenter whose first four citations are just random ultrasound device manufacturer websites. The parent comment makes bold claims and tries to overwhelm the reader with non sequitur citations, but it’s clear they don’t actually understand the subject matter.

oaktrout 4y ago

POCUS is used commonly in my experience and there are large amounts of curriculum devoted to it. We haven't had affordable access to POCUS for decades so I don't see how doctors have refused to learn it for decades.

ssivark 4y ago
Do you think that affordability is the biggest hurdle holding back POCUS from being used ubiquitously for diagnostic imaging, or is it something else?
- oaktrout 4y ago
  Probably not. Costs have come down immensely, most HN users could afford a butterfly if they wanted to play around with it. Ultrasound has limited penetration for deeper tissues so you aren't going to see lung cancer with it (especially behind ribs), and overweight patients don't image as well, again because of limitations in imaging depth. Regardless of uptake it's not going to solve all our diagnostic challenges. It also takes skill to know what you are seeing and to know how to find what you're looking for. Anyone could learn, but it's a time investment and physicians have limited time as is. Still, it is becoming more popular and soon it won't be uncommon for your primary care doc to pull out the probe and see if your gallbladder is inflammed or if that abscess is going to be amenable to in office drainage.

loxias 4y ago

> Virtually all deaths from solid cancers are preventable with routine scans to find tumors before they metastasize. Fantastic. I take it from those links this would be detectable with a full body MRI? I already wanted an excuse to start getting those regularly. > Compare the experience of getting an x-ray from a dentist to getting one from a doctor. Or getting an ultrasound from an OB to getting one from any other doctor. Can you expand on this? It sounds like you're implying something (I might agree with), but am not sure.

PragmaticPulp 4y ago
> Fantastic. I take it from those links this would be detectable with a full body MRI? I already wanted an excuse to start getting those regularly. There is a lot of research on the topic but it doesn’t agree with the OP’s thesis. Full body scans can be purchased if you have the funds, but you are far more likely to get false positives than to actually catch a cancer this way. The ensuing medical costs and possibly even unnecessary surgeries are statistically likely to cause you more detriment than any benefit you might receive. This is counterintuitive to many, but the truth is that it’s not actually easy to spot nascent pre-symptomatic cancers from full body scans without incurring a massive number of false positives along the way. Something like 1 in 8 people will end up getting flagged for “warning signs of potential cancer” during these scans that turns out to be nothing upon further investigation. Few people continue to get the tests for this reason.
aaaaaaaaaaab 4y ago
>I already wanted an excuse to start getting those regularly. Psychotherapy can help with hypochondria.
- loxias 4y ago
  Hahaha :) Close, but no. Regularly I mean "roughly yearly", and I'm a signals processing dork, not much of a health nut.
  - sgtnoodle 4y ago

PragmaticPulp 4y ago

Your first four links are just random ultrasound device companies. Doctors are very well-versed in ultrasound technology so your claim that doctors refuse to learn this is patently false. Full-body scans have been marketed for years by companies looking to drum up business for their machines, but they mostly lead to false positives. Notice how your fifth link clearly says it has helped people find “warning signs of potential cancer” instead of that it helps people find cancer? These machines are basically false positive generators in most cases. If someone had effectively infinite time and money to dedicate to routine cancer screenings from these machines, they are more likely to end up harmed by unnecessary procedures stemming from false positive results than they are to catch and remove a specific cancer occurring randomly in their bodies. Contrary to your claims, we do actually screen for certain cancers in cases where a clear net positive benefit can be demonstrated. Mammograms for breast cancer are one common example. Doctors definitely aren’t just burying their heads in sand. These are common research topics and the tradeoffs of false positives are constantly being investigated. Full-body screenings aren’t necessarily a net benefit.

sigmoid10 4y ago
There's also a lot of politics and social psychology involved in these things. From the government side, it can be decades between arranging, deploying and evaluating large scale, population-wide cancer screenings. These are timescales on which scientific consensus can easily change. Mammograms in particular are a touchy subject, since newer metastudies only show a statistically significant reduction in mortality for women above the age of 50 and below the age of 74 [1]. However, many policy makers still offer screenings starting at the age of 40 with no upper limit, despite evidence that annual mammograms will result in a false positive result over 10 years with up to 61% probability [2]. Below the age of 50, regular mammograms may even increase the risk of dying from breast cancer [3]. Ultrasound screenings on the other hand would be much safer from a radiation-exposure point of view and metastudies suggest they can detect cancers under difficult conditions more reliably, but they also suffer from more false positives [4]. This is where the social aspect comes in, where many woman fear getting their breasts removed for no reason. This is especially concerning when more than 50% of positive results are found to be false positives [5]. To summarize: It's really hard to figure out what amounts to "net positive benefit" when it comes to general public screenings. [1] https://www.aeaweb.org/articles?id=10.1257/jep.35.2.119 https://www.aeaweb.org/articles?id=10.1257/jep.35.2.119 [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209800/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3209800/ [3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189562/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4189562/ [4] https://bmccancer.biomedcentral.com/articles/10.1186/s12885-020-06992-1 https://bmccancer.biomedcentral.com/articles/10.1186/s12885-... [5] https://ebmh.bmj.com/content/16/4/115 https://ebmh.bmj.com/content/16/4/115

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mfer 4y ago

There is a fair amount of scientific study that has linked diet to some cancers. Those same diet attributes that can make one obese also lead to higher rates of cancer. In cancer prevention, lifestyle matters.

mikotodomo 4y ago

Wait, so I've been avoiding McDonalds all this time for no reason? I literally lost a GF because I decided to skip eating one afternoon when the only place close to us was McDonalds!

n8henrie 4y ago

What in the world are you talking about? I'm a physician that uses ultrasound every shift, and I'm pretty darn good at it. I've even used one of the specific devices you linked to. Virtually every physician I know is foaming at the mouth to learn more ultrasound and to apply it to new indications and with new approaches. Inappropriate use of ultrasound for harebrained indications (for which we have far superior alternatives) is on of my pet peeves. I am not a cancer doc, but I am drawing a blank as to what solid tumors you could possibly be referring to for which ultrasound is the preferred screening or diagnostic technique, or what kind of conspiracy you're vaguely implying that prevents its use. IME, virtually everyone is (over?) eager to use ultrasound for every condition under the sun, and I am sincerely perplexed as to what experiences have led you to form your opinion on this matter.

Ovah 4y ago

"Doctors have for decades refused to learn to use this technology" In Sweden this is actually standard practice. It's used for patients who have syndromes that guarantee them to get cancer several times over in their lifetime. IIRC some get an MRI every 6 months. The reason it's not done to a wider population.. well you can't justify the cost in a state funded healthcare system. The health benefit just isn't justifiable when MRIs are so scarce and expensive to run.