
Breast MRI in cancer survivors results in more unneeded biopsies - howard941
https://www.healthimaging.com/topics/oncology-imaging/breast-mri-cancer-more-unneeded-biopsies-rsna
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nathan_f77
I strongly believe that more data is always better. (But more testing is not
always better if it's an invasive biopsy.)

If more data results in more unneeded biopsies, then just stop taking
biopsies! It seems very obvious that the answer is to perform a series of MRI
scans over a period of weeks or months, and track the size of the lump. If
it's growing rapidly (or more lumps appear), then you would perform a biopsy.
I don't even think you need machine learning for this. It just seems obvious
that a quickly growing lump is cancer (almost by definition), so you need
multiple scans over time to detect the rate of growth.

Is this a controversial opinion? Why is better to wear a metaphorical
blindfold instead of just being smarter about what you do with the data?

Is this because MRIs are expensive and are in high demand, so it's just not
practical to do this?

EDIT: I updated my comment to remove "more testing is always better".

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whatshisface
Last time I asked this question, the reasoning was that there are non-rational
(i.e. emotional, legal) reasons why an apparent lump on an MRI has to get
addressed, so the only acceptable point to say "don't operate" lies at the
point where the doctor decides whether or not to test. Apparently, doctors get
exactly one chance to say no.

~~~
nathan_f77
That makes a lot of sense. It also feels like a very solvable problem.

If I had the option to get annual MRI scans, but I had to sign a waiver that
prevents me from suing the doctor or the hospital, then I would gladly take
that deal. I'd rather have the data and an expert opinion, instead of no data
and no opinion. If they miss something and I die, then no problem (mainly
because I'm dead, but also because I would have died anyway). If they do a
biopsy and it turns out that it was nothing, then that's also no problem. It's
what I signed up for, and I understand that false positives can happen.
Hopefully I could find a level-headed doctor (or a black-box machine learning
algorithm), and just trust them to make the right call.

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mbell
A related issue is thyroid cancer. Diagnosis rates started increasing
dramatically almost everywhere in the world in the mid 80's. Diagnosis rates
in the US for example have tripled since 1980, in South Korea they have gone
up 13x since 1993. Meanwhile the mortality rate has been completely flat. The
most likely cause of this is increase in both screening and the sensitivity of
testing [1]. There is also a current debate about if we should be screening /
treating thyroid cancer the way we are, i.e. it seems like we're detecting a
lot of innocuous thyroid cancers and then operating without need resulting in
unnecessary life long complications for the person.

[1]
[https://www.bmj.com/content/355/bmj.i5745](https://www.bmj.com/content/355/bmj.i5745)

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lotu
From the article it sounds like most of the harm of false positives from the
MRI is the extra stress of the biopsy and/or waiting for biopsy results. As
such it feels rational to try to treat the stress/anxiety with well know
methods like talk therapy. Prescheduling an appointment for after the
MRI/Biopsy might greatly reduce the stress of patients. Of course this runs
into the cost "problem".

The rest is pure speculation based on how it appears these procedures are
portrayed.

Patients think of the MRI as yes/no for cancer and when comes back as yes they
get understandably upset. If instead the MRI biopsy are presented as a single
procedure (ideally done together, but money) the MRI is just getting targeting
information needed for the biopsy not providing a yes/no decision. If it turns
out there is nothing to biopsy the patient gets a happy surprise no-one is
ever upset about this. (Again problem of money)

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jedberg
It's the same results for starting mammograms at 40 vs 50. They're now
recommending to start at 50, unless you have a family history, because they
found a lot of false positives in women who started getting mammograms at 40
who didn't have high risk.

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makmanalp
I have two questions:

1) From the POV of the patient, how bad / invasive is getting a biopsy?
Wouldn't you always want the low-risk biopsy over having discovered a problem
too late? From a public health / insurance perspective, I get that you're
trying to lower costs and time wasted, which are sadly conflicting goals :-(

2) It's always been so shocking to me that the reaction to "we get false
positives" is not "we need to pour money for research into much better
diagnostic techniques yesterday" and instead it's "well I guess we'll just not
look then".

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bregma
> how bad / invasive is getting a biopsy?

About the same as getting a prostate biopsy, except you can lie on your back
instead of on your side while they shove several large hollow needles into
your flesh to cut out pieces of a very sensitive gland.

~~~
lotu
I don't think comparing it to prostate biopsy helps most people. I assume they
anesthetize you so you don't actually feel pain just really weird, possibly
upsetting tugging right? Afterwards you take some regular pain killers for a
few days. This doesn't feel like a big deal to me but I'm likely wrong. Maybe
it is only a big deal for some people like how how people who are
claustrophobic freak out in the MRI.

~~~
bregma
Prostate biopsies are usually done without any anaethesia, just a bug gun up
the bung that fires multiple needles and retracts.

Breast biopsies maybe use sedation and maybe a local bit of lidocaine, maybe
not, depending.

It doesn't make a lot of sense to stick a needle in so you don't feel a needle
sticking in, but they're different gauge needles.

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howard941
> Breast MRI had a cancer detection rate (CDR) of 10.8 per 1,000 exams
> compared to mammography’s CDR of 8.2 per 1,000 examinations. However, breast
> MRI had a biopsy rate of 10.1%, _double that of mammography’s 4% rate._
> [emphasis added]

What's going on with the biopsy rate? Is it something as simple/nefarious as
recouping the cost of the equipment?

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seren
I have not read the article but I believe that usually routine exams are done
with X Ray, because it is quicker and cheaper. However if something is a bit
worrying, doctor may ask for a different type of exam, MRI or Ultrasound, to
have some confirmation.

But since this is rarer people who have MRI are already people at risk, so it
makes sense to have a higher rate of biopsy in the end.

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arkades
Countdown to “but more data is always better.”

~~~
jdashg
Is it not the saddest thing that our outcomes are so poor that deliberately
starving ourselves of data is the safest course of action?

Sure, people will die of cancer we could have caught, but at least we wouldn't
kill a yet-larger group of false positives through mistreatment??

A system with this-perverse of an outcome is broken.

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arkades
It’s not a broken system. It’s a limitation of the current state of human
knowledge. Perfect information about X without the state of knowledge to
interpret that information prompts flawed action.

You are not living at the end of time, at the peak of human knowledge. There
are things we know enough about to interpret; there are things we don’t. The
former we test; the latter prompts scientific research.

