jjtheblunt 20 hours ago

Another example from a few years ago that extends back over time decades

https://www.chicagomag.com/chicago-magazine/september-2018/c...

  • dmix 18 hours ago

    Interesting. In that case six people had the same rare type of cancer which caused a settlement. The five nurses have three different kinds.

    • SoftTalker 4 hours ago

      It’s not cancer in TFA though. “The tumors, all benign, are three different types.” Sorry that just sounds random to me.

      I’m not disputing that there are literally toxic workplaces or environments that do correlate with cancer clusters.

bluGill 20 hours ago

No reason to think this is anything other than normal stastical variation - at least at this time. not the same type of cancer even.

when there are billions of people in the world it is expected that some where several get cancer at the same time.

  • genter 20 hours ago

    I'm also curious if there's an increase of diagnosis because they work in a medical setting. Either they recognize the symptoms, or casual conversation with a doctor.

    • mixdup 20 hours ago

      These are benign tumors that were asymptomatic, and they only found them because people in the unit complained about some other health concern, and screenings began

      So, you're probably not far off

  • tengbretson 20 hours ago

    If you start with the assumption that brain cancer's occurrence is randomly distributed, then sure I guess.

    • Retr0id 20 hours ago

      If you assume it isn't randomly distributed, those odds only go up.

      • mmooss 19 hours ago

        Which odds go up, if you would clarify?

        • Retr0id 19 hours ago

          The odds "that some where several get cancer at the same time". (And by odds I mean probability, strictly speaking)

      • throwaway290 15 hours ago

        nope. they go down for some people and up for other people. if these nurses are the second kind then that is interesting.

    • surgical_fire 11 hours ago

      The nurses did not have cancer. They had benign tumors.

  • mmooss 19 hours ago

    > when there are billions of people in the world it is expected that some where several get cancer at the same time.

    That would be the answer if we asked whether such a coincidence ever happens in the world. In this specific case, the question is, 'what are the most likely causes?'

  • clircle 20 hours ago

    What’s the pvalue ?

    • TheBen1 15 hours ago

      You can't really put a useful p-value on that.

      To calculate a p-value (roughly spoken), you need to start with a single hypothesis. Then you gather data and the p-value gives you the probability that your data occurs while your hypothesis is false. When you start with a finite set of multiple hypotheses, you need to take that in to account when calculating your p-value.

      When you start with data and come up with a hypothesis afterwards, you would have to find the whole potential space of all hypotheses. So, for example, how many hospitals are there? Do you only consider US? Do you only consider nurses or other employees as well? What about only four nurses would that have made it to the news? What about other forms of cancer? What about time? Do you consider the time period of the last 50 years? As you think about what might have made the news, the set of hypotheses grows bigger and bigger and as it approaches infinity, the p-value for any data would approach one. Because when you have a very large set of unlikely hypotheses, the probability that your data accidentally supports one of them is quite large.

      That's what parent was talking about.

  • defrost 20 hours ago

    The article closes with that note.

      The American Cancer Society says that in order to meet the definition of a cancer cluster, occurrences must be the same type, in the same area, with the same cause, and affecting a number of people that's "greater than expected" when a baseline for occurrences is established.
    
      “Nearly 4 out of 10 people in the United States will develop cancer during their lifetimes," the society said on its cancer clusters webpage. "So, it’s not uncommon for several people in a relatively small area to develop cancer around the same time."
    
    The unstated numbers that matter here are many, how many people were thoroughly investigated here, was it the entire staff of the hospital (as many as a thousand, perhaps)? When X many people are thoroughly scanned how common is it for five people to have benign cancers that aren't doing anything, aren't growing, are just there?

    If (for example) twenty percent of the time 500 people were scanned, five at least had benign brain cancers, would this report be unusual or suspicious in itself?

    • klipt 20 hours ago

      Right but five people all getting brain cancer is certainly more suspicious than five people getting any cancer.

    • card_zero 18 hours ago

      > with the same cause

      That seems circular, like it's not a cancer cluster until we find out that it's a cancer cluster, or it's not a cancer cluster because we didn't determine a common cause, so don't worry too much about there maybe being a common cause that would make it count as a cancer cluster.

      This underlines how stats are no substitute for reasoning about mechanisms.

    • SubiculumCode 19 hours ago

      You know, if a bunch of nurses got their heads exposed to a radiation burst in an event, would they all get the same type of cancer? Probably not.

      • giantg2 19 hours ago

        It seems unlikely all 5 would only have their heads exposed. It seems it would be more likely they might develop various other cancers.

keepamovin 20 hours ago

Many cancers are definitely caused by pathogenic vectors.

  • bglazer 19 hours ago

    Which ones?

    • hobs 19 hours ago

      Cervical cancer is an obvious one that comes to mind.

      • chongli 19 hours ago

        And the cancer devastating the Tasmanian Devil [1]. It’s awful!

        [1] https://en.wikipedia.org/wiki/Devil_facial_tumour_disease?wp... (content warning)

        • card_zero 18 hours ago

          Evolution is saving them, it seems. The ones that survive spread a tumor immunity gene. (Probably irrelevant as a strategy for nurses.)

        • Ey7NFZ3P0nzAe 14 hours ago

          It's not. It's just that their immunity is very tolerant to other members of their specie so having a cancer of the face in a specie that frequently bites each other in the face is transmissible. Afaik there is no pathogen involved.

  • fnord77 19 hours ago

    ok, but the article said all the tumors were benign

SoftTalker 20 hours ago

Randomness is clumpy

  • Willingham 20 hours ago

    Wow this is a profoundly unsettling and truthful fact, thanks for sharing.

    • throwaway290 15 hours ago

      it also sneaks in a hideen assumption "cancer is random" in a way that tries to avoid a "citation needed". I hate those sorts of comments, worse than propaganda (at least that one obvious)

  • OutOfHere 19 hours ago

    Even so, most of the times, when there is a clump, it's likely causal, not random.

    • Solstinox 17 hours ago

      I suggest you go to random.org and play with the coin flipper or dice roller for a couple of hours.

      [edit] I just rolled 60 dice and got a string of 7 2’s in a row. Can someone calculate the odds of that happening for me?

      • OutOfHere 17 hours ago

        Randomness can be clumpy, but clumpiness does not have to be random. Clumpiness is typically causal. Your experiment won't tell you what you need to know.

      • throwaway290 15 hours ago

        "repeated number 2 out of 5 on a dice" vs. "repeated brain tumour out of infinite other things that can happen in dynamic system you don't even know all the parts" rly?

        run an RNG that doesn't quantize to an integer and see how many repeats you get then:)

d342d32d3d 20 hours ago

Shift work increases the cancer rate.

zekenie 19 hours ago

I’m surprised the hospital said they were confident it was safe. I wonder what gave them confidence? I’m struggling to think of what data I could have on hand that would convince me it was really safe. Also, to folks saying that randomness is clumpy… did you read the article? I think a bunch of nurses that notice they are all getting sick (and then FIVE of them getting brain tumors) should be taken quite seriously. I’d start with the assumption that there IS an environmental problem and then figure out what it is.

  • linsomniac 19 hours ago

    >I wonder what gave them confidence?

    I'd guess it was their lawyers...

  • giantg2 19 hours ago

    They said there weren't any environmental factors. However, we don't know that much about brain cancers and the only real environmental factor would be radiation and some meds (like the mini pill). Checking the water supply is fine, I guess, but it takes years for the cancers to form (usually). Who knows if whatever they would look for would still be there. I think there's little chance of finding a new environmental factor. I think it's likely some unknown factors exist. I just don't think it's likely they'll find one this time.

  • OutOfHere 19 hours ago

    Nurses near pathology or surgical areas may be exposed to carcinogenic VOCs like formaldehyde, xylene, and toluene.

RONROC 19 hours ago

Just a coincidence! Nothing to see here!