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AkioDAccolade t1_iw5bl5o wrote

Reply to comment by Veni_Vidi_Legi in How do medical researchers obtain lab animals with diseases like specific forms of cancer which arise spontaneously? Do they raise thousands of apes and hope some eventually develop the disease? by userbrn1

Isn't it possible that most cancers are transmissible given the right scenario?

I vaguely remember reading an article about a medical professional who died of skin cancer despite never having skin cancer, but she did experience an accident where she accidentally sliced herself with a scalpel that was being used to excise a cancerous growth in an elderly patient?

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15MinuteUpload t1_iw5nowu wrote

In immunocompetent individuals it's unbelievably rare for a traditionally non-infectious cancer (i.e. all of them except the dog and Tasmanian devil ones) to be able to establish itself in another host, even if the cancer is directly implanted into the host. Part of the reason a natural/endogenous cancer can be so hard for the body to take care of is because it's composed of the host's own cells, which are obviously recognized as "self" and therefore less likely to come under attack by the immune system. Foreign cancers of course do not have this innate defense and so will almost always be very quickly killed off by the host's immune system.

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wulfoftheorderofbio t1_iw66eoy wrote

I was gonna say, seem to recall learning through immunology that the immune system does a pretty decent job fighting off most cancers that try to grow since the body considers them "foreign?" I need to brush up on immunology. It has been 8 years and my memory isn't what it used to be.

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Veni_Vidi_Legi t1_iw5qbzo wrote

> Isn't it possible that most cancers are transmissible given the right scenario?

Such a cancer would have to be able to survive exposure during the transmission process while also being in the right place and condition to transfer to a susceptible host site.

Once there, the immune system would almost certainly kill the more foreign looking cancer, as it almost always does for the more similar looking native cancers that arise in the host. But if it can evade the immune system, or if the immune system were missing, then it would have to find a suitable site and then maybe it can take hold.

So there would be a lot stacked against most cancers.

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Chemputer t1_iwoiwzh wrote

Not particularly, not in humans, no. It's even one of the misconceptions/myths on cancer.gov not specifically that story you mentioned (I googled my best and couldn't find it), but that cancers are contagious.

If what you remember reading is actually what you read and it's actually true (not a knock on you, just far more likely for your memory to be your brain trying to confabulate a story from something different, possibly vaguely related. Our memory sucks, especially fuzzy ones, and our brain just fills in the gaps), perhaps it was a cancer caused by a virus or bacteria (which is very possible, some decent percentage -- I've read 15-20% but can't find a citation for that exact number -- of cancers are linked to viruses or bacteria) and said pathogen spread, then causing cancer. The cancer itself would not spread in that manner.

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AkioDAccolade t1_iwok10y wrote

So I looked it up when I remembered it but I'm having difficulty finding the case study for a third time, but in the case I was remembering it was indeed a nurse that contracted it, however she was HIV+ (that she acquired during another accident, guess she would have taken the hint) which is the part I was missing. It was sometime in the early 90s

That pretty well makes anything possible.

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