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We Are Giving Ourselves Cancer

nytimes.com

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Re: We Are Giving Ourselves Cancer

#11

Post by skue »

refurb wrote: post #2

I have no doubt that patients are getting exposed to more radiation via imaging than they need to. However, every decision in medicine is (or should be) a risk-vs-benefit analysis. Cancer is not the only thing you can die from. If you suffer a head injury and end up in the ER and get a CT scan, you may increase your long-term risk of cancer, but you are also drastically reducing the risk of dying from a brain hemorrh…

Of course, no one would dispute ordering a CT for a trauma patient if the presentation warrants.

But the article was talking about the increase in CT usage over the past 20 years. That's largely been driven (in the US) by misaligned incentives that reimburse procedures at much higher rates that clinical decision making. Put simply, the person who owns the CT machine makes much more than the doctor who interprets the results. And so we have had a blossoming of imaging centers, and CT machines have moved into outpatient cardiology and even family care practices.

One of the major goals of Obamacare is addressing these misaligned incentives and shifting to a model where providers are paid to keep people healthy (outcome driven) rather than on volume (fee for service).

Another issue has been the difficulty of sharing/accessing existing imaging data, so tests are just repeated to save time (rather that save cost or adequately balance safety). Our long, painful journey to electronic record standardization should also help with that.

Re: We Are Giving Ourselves Cancer

#13

Post by latk »

petersellers wrote: post #6

The article's first sentence annoys me right off the bat: "Despite great strides in prevention and treatment, cancer rates remain stubbornly high and may soon surpass heart disease as the leading cause of death in the United States." This seems to be implying that cancer death rates are growing and will soon "surpass" those of heart disease. While the article is technically correct, this is due to the fact that death…

Indeed. I would also like to see that British study that claims a link between CTs and leukemia – I smell selection bias. It is however true that a CT does imply a significant radiation dose.

This article is especially frustrating in that the authors seem to be doctors in the appropriate fields. I assume they just went too far in dumbing down the matter, which together with their source-less references to a dazzling amount of numbers and studies ends up obscuring their main point: A culture of using the “best” medical tool available instead of the “appropriate” tool can have adverse health effects, and has to stop.

All in all, there is a reason this article was filed under Opinions, not Science.

Re: We Are Giving Ourselves Cancer

#15

Post by dnautics »

Big elephant in the room: Pre-test ban atmospheric nuclear tests.

Of course, there's nothing anyone can do about it. The somatic damage period is probably more or less over, but we are transitioning through the genetic damage period.

Re: We Are Giving Ourselves Cancer

#17

Post by pbreit »

DenisM wrote: post #3

>A single CT scan exposes a patient to the amount of radiation that epidemiologic evidence shows can be cancer-causing That does not look right to me. A single CT scan is 2-7 millisieverts, and exposures under 13 can not be linked to health effects - look for UNSCEAR in http://en.m.wikipedia.org/wiki/Sievert If you do the math by ICRP formulae, you end up with increase chance of cancer of 1 in 2600 over the next 20 y…

The Wikipedia article lists a full body CT scan at 10-30 mSv.

Re: We Are Giving Ourselves Cancer

#18

Post by redschell »

DenisM wrote: post #3

>A single CT scan exposes a patient to the amount of radiation that epidemiologic evidence shows can be cancer-causing That does not look right to me. A single CT scan is 2-7 millisieverts, and exposures under 13 can not be linked to health effects - look for UNSCEAR in http://en.m.wikipedia.org/wiki/Sievert If you do the math by ICRP formulae, you end up with increase chance of cancer of 1 in 2600 over the next 20 y…

The American Association of Physicists in Medicine seems to have your back:

http://www.usnews.com/science/articles/2012/01/17/phsycists-...

A full-body CT scan results in 12 mSv; a mammogram 0.13 mSv—a hundred times less. The risks from these procedures, according to AAPM, are too low to have been determined reliably, and may be "nonexistent."

Looks like this debate has been going on for a while now.

Re: We Are Giving Ourselves Cancer

#19

Post by latk »

darkxanthos wrote: post #9
petersellers wrote: post #6

The article's first sentence annoys me right off the bat: "Despite great strides in prevention and treatment, cancer rates remain stubbornly high and may soon surpass heart disease as the leading cause of death in the United States." This seems to be implying that cancer death rates are growing and will soon "surpass" those of heart disease. While the article is technically correct, this is due to the fact that death…

It also seems to imply that medical tests which expose us to radiation are the cause of supposedly increasing cancer rates... which _seems_ a bit alarmist?

That would actually be a sound argument: If we assume a linear damage model for radiation exposure (which is a generally accepted model for these circumstances), then there is no safe dose. Instead, any exposure increases your lifetime risk of cancer. It is therefore not useful to talk about how medical imaging causes an individual case of cancer.

But for a larger population we can figure out what the cancer risk without medical radiation exposure would be, and what the observed probability is. We can then ascribe the difference to these medical tests. Obviously there are a number of ways to fuck up this analysis. Geological differences in the natural radiation dose shouldn't be underestimated. However, almost half of the lifetime radiation dose of a human does come from medical applications, and it would certainly be good to reduce that.

Re: We Are Giving Ourselves Cancer

#20

Post by adrr »

Cancers rates are have been on the decline or remaining steady not rising. Look at the stats for the most common types of cancer.

http://seer.cancer.gov/statfacts/html/prost.html

http://seer.cancer.gov/statfacts/html/colorect.html

http://seer.cancer.gov/statfacts/html/breast.html

http://seer.cancer.gov/statfacts/html/lungb.html

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