Could you get cancer by eating a cancerous tumour?

August 25, 2009 2:11 PM

Not that any human would ever do this, but what would happen if someone ate a cancerous tumor? Like, if they waited around a surgical room, and it was removed from someone's breast, or pancreas. Would the stomach acids kill it? Could the person get cancer by eating it?
posted by Sully to Health & Fitness (21 answers total)

As a cancer researcher... I have no idea.

I know there is a specific type of canine tumor that's sexually transmissable, but I think that's incredibly unique.
posted by Oktober at 2:16 PM on August 25, 2009

Your body would see it as an invader and kill it. The cancer that works for one person wont work for another. I dont believe cancer can be transmitted. You can transit a virus that may cause cancer, but the actual tumor is harmless. You can eat all the cancer you like.
posted by damn dirty ape at 2:22 PM on August 25, 2009

Well, Tasmanian Devils are in some serious trouble due to their bitey habits. That's definitely a transmissible tumor. And, in humans, a surgeon accidentally received a patient's tumor.

I'll bet that if you ate stomach tumors long enough, you probably could find something that would be adapted to the stomach environment and might "survive." Sounds like something very unlikely. I say chow down!
posted by adipocere at 2:25 PM on August 25, 2009 [4 favorites]

Could you get cancer by injecting someone else's cancerous cells?
posted by phrontist at 2:26 PM on August 25, 2009

Response by poster: Phrontist - isn't that how they give cancer to mice? Like, when they're testing for a cure?
posted by Sully at 2:33 PM on August 25, 2009

This is all speculative based on what I know, but here goes:

Cancer isn't a result of any particular chemical content in the cancerous cells. It is, rather, a manifestation of accumulated genetic errors to the replicating functionality of a cell. Cancer is when the normal limits on cell division and proliferation are removed and cell division runs amok.

It would logically follow that that you probably wouldn't get cancer from eating a tumor. In all likelihood, you'd simply break the tissue down into its components and digest it.
posted by dualityofmind at 2:41 PM on August 25, 2009

Phrontist - isn't that how they give cancer to mice?

Yeah, more or less.

There's a story, it might be apocryphal, that I've heard bandied about by molecular biologists about someone who managed to aspirate HeLa cells into their lungs and wound up with lung cancer. I can't find anything about it online, but as you might imagine, it's a difficult search to do.
posted by mr_roboto at 2:54 PM on August 25, 2009

To expand on what dualityomind said above, the cancer cells would have to find a way to get into your body without getting digested. Typically an entire cell would never be absorbed into your body, because it is broken down by the acids in your stomach and the enzymes in your mouth, stomach, and intestines. What you absorb are tiny, tiny, tiny building blocks of cells, nowhere near organized enough to be "cancer" anymore.

However, I can sort of imagine a scenario where an tumor could maybe manage to get into the bloodstream, IF the person who ate it had a bleeding ulcer or some other internal damage that allowed direct access to the blood from the GI contents. But you'd need the original tumor to be somehow resistant to acid digestion, and human cells typically aren't.
posted by vytae at 3:09 PM on August 25, 2009

You would not get cancer from eating (or injecting) a tumor from another person (except maybe your twin?). This is essentially the same situation as an organ transplant where immunosuppressive drugs need to be taken otherwise your immune system will attack and destroy the transplant. In the case of cancer research, nude mice are used, which means they have genetically compromised immune systems.
posted by Durin's Bane at 3:13 PM on August 25, 2009

Even if the tumor survived the digestive track, it would typically be rejected by the host in the same way that a transplanted organ is attacked and rejected by the immune system.
posted by The Bishop of Turkey at 3:17 PM on August 25, 2009

Phrontist - isn't that how they give cancer to mice? Like, when they're testing for a cure?

The mice in question are all inbred so that they are genetically identical. They won't have a rejection reaction to cells from other mice in the same genetic lineage because they all look like "self" to one another.
posted by Chocolate Pickle at 3:27 PM on August 25, 2009

99.99% nothing.

Exceptions:

* identical twins. You body would likely not be able to identify the tumor as "foreign" tissue.
* Some tumors have a viral background. There might be a tiny chance that you could catch something.
* As already mentioned, there are tumors that can be transmitted in the animal kingdom like a infectious disease.

http://www.sciencedaily.com/releases/2008/01/080128173735.htm

IMHO the risk of catching another disease like HIV, Hepatitis that the patient might have had in addition are FAR HIGHER!
posted by yoyo_nyc at 5:29 PM on August 25, 2009

Response by poster: Yoyo_Nyc, so what I'm getting is that IF your twin had a tumor, and IF you managed to get a hold of it, and IF you ate it, and IF your mouth had a huge gash in it because, say the night before while eating dinner you aimed your fork wrong, and IF the particular cancer your twin had was maybe not your regular garden-variety cancer, but one verging on the viral, there is a SMALL chance you could get cancer yourself from a strange case of the munchies?
posted by Sully at 6:47 PM on August 25, 2009

yoyo_nyc is pretty much right, based on the literature I've read. The few cases of human-to-human tumor transmission have generally included near blood relatives or people with surpressed immune systems. Lab mice are both incredibly inbred and (in many experiments) have surpressed immune systems; this makes it very easy to implant bits of mouse tumors (or even implanted tumors from other animals) in other mice from the same lineage and be sure that they will grow. Viruses do not need to be involved in this (viral transmission is generally stuff like HPV; transmissible cancers do not necessarily involve viruses.) There are no known tumors that are widely transmissible in humans.

Eatingat tumor is not going to be a particularly good way to catch cancer, even if you've got AIDS and are eating your identical twin's very malignant tumor. Now there's a sentence I never expected to write. Your body is pretty damn good at digesting things, which essentially tearing the cells apart and using up their components - and cancer cells are still cells. Sticking a needleful of your twin's tumor somewhere in your body (thus evading those digestive enzymes) would be much more likely to result in cancer, as long as your immune system was not really working.

(I looked into this rather... avidly following a needlestick with some (lysed) HeLa cells, and it's really a very unlikely thing. Though if I get finger cancer, I'll let you know and we'll get the literature updated.)

Bonus question: would a tumor taste good?
posted by ubersturm at 8:55 PM on August 25, 2009

As has been pointed out it's the immune system that deal with this, just as it deals with any other non-self invasion. Cancer cells growing in your body are quite good at evading the immune system by various means (generally some form of hiding) but even then, if the cells come out of hiding, your body is generally capable of recognising them as foreign even if they originated from your own cells. Cancer cells from someone else will be even more different, won't have the same avoidance mechanisms in place, and will be recognised and destroyed. The intestine has a bunch of different mechanisms for recognising foreign invaders and letting the immune system know they're there, both cancer antigens and foreign cell antigens will trigger an immune response at the intestinal mucosa before any cell material is absorbed into the body.

When giving mice cancer for research it's actually more likely to be a human cancer cell line, since we're interested in killing human tumours much more than mouse ones. In those cases the mice are always either immune deficient or fully immune suppressed. When injecting them with mouse cancer cells the same strain is used, as has been mentioned, and they're so inbred they are basically clones. And even then, with the inbreeding or the immune deficiency, you sometimes get spontaneous regressions where the mouse's body manages to kill the tumour cells so it doesn't 'take'. So even the best laboratory conditions with cells injected directly into the body and no immune system doesn't guarantee success, so I think the chances of transfer by eating a tumour are pretty non-existent. You'd have to do all the things suggested upstream, inject the cells, have them come from a clone, have a suppressed immune system, and even then it would be somewhat unlikely.

(as an aside I injected my finger with SiHa cervical cancer cells about four years ago, nothing happened except a very embarrassing incident report)

(as another aside, there's no evidence that the Tasmanian Devil's transfer mechanism has ever been seen in humans, it's very specific and weird)
posted by shelleycat at 9:54 PM on August 25, 2009

Some tumors have a viral background. There might be a tiny chance that you could catch something.

This is a good point actually, but keep in mind you'd catch the virus not the cancer. Of course some viruses cause cancer so it might be an indirect mechanism. (I realise yoyo_nyc a gets this but not sure if the distinction was clear to the OP).
posted by shelleycat at 9:57 PM on August 25, 2009

Response by poster: AmbroseChapel - Actually, this question was inspired because I once saw a photograph of a cancerous tumour and it was all shiny and puffy and reminded me of this pastry I used to eat as a kid at dim sum. It surprised me that a tumour could actually look "pretty". For some reason I had it in my head that a cancer tumour would be awful looking. And I know some are. But this particular photograph wasn't.

Shelleycat - I am glad that it's really hard to get cancer from ingesting it. It's true I don't really understand the nuances - I'm not a cancer researcher, just someone who has weird questions pop into his head every once in a while. Thank you for the clarification! I like that all these particular circumstances have to be in place for the one in a trillion chance of catching cancer by eating. It's a question that's nagged at me for a while.
posted by Sully at 10:44 PM on August 25, 2009 [1 favorite]

As has been pointed out, the accidental transplantation of a tumour is uncommon, but there are several documented cases, involving either injection or the transplantation of organs. In some of these, it was a surgeon who was infected during an operation, and some of the origional case reports don't mention immuno-compromise.

So, conceivably, you could contract cancer from eating the tumor of a non-relative, if you had a cut in your mouth that allowed cancerous cells into your bloodstream - but it would be extremely unlikely.

Many of these cases up to 1971 are reviewed here
posted by James Scott-Brown at 1:53 AM on August 26, 2009

Incidentally, Sully, there's a comic story by the late Dori Seda (in the one-shot Cannibal Romance, reprinted in the collection Dori Stories, if you've a good comics shop near you, they might have it) that's based on a similar premise. The story also features sex.
posted by Halloween Jack at 8:19 AM on August 26, 2009

Stangest CanIEatThisFilter ever.
posted by anagrama at 10:45 AM on August 26, 2009 [4 favorites]

As other people have already pointed out, even if the tumor cells made it into your bloodstream, they would still more than likely be recognized as foreign antigens and destroyed by the immune system, in the same way that organ transplantation fails in people who are not syngeneic.
posted by sciencemandan at 11:02 AM on August 26, 2009