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Scientists Ponder the Prospect of Contagious Cancer (cnbc.com)
Cancer causes many deaths each year, and anyone that's lost someone to cancer knows how painful and grueling it can be. The one saving grace is that it ultimately only kills the host. But is this changing? According to several recent papers, scientists have suggested that cancer could become contagious. Cancer cells could have the ability to metastasize, not just from organ to organ, but from person to person. While this is not an imminent threat, it has already happened in unusual circumstances.
Apparently the Tazmanian Devils in Tazmania are currently suffering for a contagious cancer outbreak. Devils get into fights and claw each other's noses, the cancer cells transfer into the wounds and multiply. Screws up their faces.
https://en.wikipedia.org/wiki/Devil_facial_tumour_disease
So for humans, it would be sorta like a zombie-like plague...
There is a nasty cancer which is decimating the population of Tasmanian Devils. It forms lumps and lesions in and around the mouth meaning the animal eventually starves to death. This cancer is spread through contact.
That said it is believed that a lack of genetic diversity is a major reason in why the healty devils body doesn't recognise the invading cancer cell as coming from another animal.
http://www.tassiedevil.com.au/...
One puzzle is why evolution has resulted in humans (and the vast majority of other organisms) having a limited lifespan with frequent breeding. Superficially, it would seem more efficient to invest less in the ability to procreate, but permit unlimited healthy lifespans. I have an hypothesis which I think fits with the content of TFA. Frequent breeding allows natural selection to counteract emerging diseases. Where a disease evolves that threatens to wipe out a species, genetic diversity provides an excellent chance that some individuals will be resistant. These resistant individuals can breed to aid species regeneration after being decimated by such a disease.
Um, nothing in the article said anything about cancer becoming airborne. I didn't think it was fear mongering at all. Instead, it suggested that cancer spreading from one host to another is within the realm of possibility and not that it's likely to occur in humans.
There are diseases that are transmissible in humans that can cause cancer. HPV is an example. The article makes it pretty clear that in just about every case there are enough defenses to make it impossible. For it to occur, it must be easy for cancer cells to pass from one person to another. Accidentally injecting oneself with cancer is a way for it to happen. The other example involved a person whose immune system was compromised and the source of the cancer was a parasite. Because conditions like this are rarely met, it's virtually impossible for cancer to be transmitted from one person to another.
It seems like there has to be an easy pathway for many cancer cells to move from one person to another. This is extremely rare. It also seems like compromising or fooling the immune system makes it far more likely to occur. This is far more likely to occur among animals than among humans. I think the article makes it clear that what's possible isn't likely nor is it a threat right now.
I don't get your criticism of the article.
Please mod the parent -1 redundant. All of the information in the above post was also in TFA.
The information that the information in the above post is in TFA, is already in TFA and the above post, which makes your post similarly redundant yet lacking any redeeming qualities.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
There's also a canine cancer that transmits through sexual contact:
...
...
https://en.wikipedia.org/wiki/...
"canine transmissible venereal sarcoma (CTVS), sticker tumors and infectious sarcoma is a histiocytic tumor of the external genitalia of the dog and other canines, and is transmitted from animal to animal during mating."
"The tumor cells are themselves the infectious agents, and the tumors that form are not genetically related to the host dog.[1] Although the genome of a CTVT is derived from a canid (probably a dog, wolf or coyote), it is now essentially living as a unicellular, asexually reproducing (but sexually transmitted) pathogen.[2] Sequence analysis of the genome suggests it diverged from canids over 6,000 years ago; possibly much earlier"
"believed to be the longest continually propagated cell lineage in the world"
Do you really think he bothered to read the article? Where do you think you are?
So, if my reading has been inadequate, educate me. I am currently under the (misguided?) impression that the evolutionary origin of senescence is still unknown. A favorite hypothesis has been that early death from all causes in nature drives the need for high fertility and (with few individuals living to old age) makes mutations leading to senescence irrelevant to species survival. Also popular is the notion that fertility is competitive, and it is more important to be good at procreation early in life than able to be long lived. The "disposable soma" theory that mechanisms for cellular repair would detract from those for fertility has never made much sense to me. If both can coexist when young, why must repair mechanisms deteriorate when we get older? I am aware that various evolvibility theories based upon group selection exist, but will be grateful if you would point me to the references where this is proven.
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There was a Russian scientist who claimed all cancers were caused by viruses, unfortunately I can't find the link on Ars and I'm lazy at this hour. But what if all cancers do come from a virus type that we don't have the ability to detect yet (and we aren't trying to)? It's fascinating to think about, but then look at AIDs, we've know the virus that causes it for decades and still can't cure it (although some will state it's a manageable illness now).
I read a while back that a surgeon accidentally got cancer from one of his surgical patients:
http://www.nejm.org/doi/full/1...
So, it appears that cancer can move between hosts in a mechanical fashion.
Contagious cancer is rare for the same reason that organ transplant is hard: your immune system already largely ignores your own cells, of which cancer is just a broken subtype of. Implanting random tissues from other individuals causes rejection of the tissue unless they are closely related to you and you take immunosuppressants. For this same reason, foreign cancer would be expected to be quickly destroyed unless you had AIDs or similar. I don't have a link handy, but I do recall reading a story about a man who had AIDs and contracted cancer from an ill intestinal worm (or other helminth... I can't recall). This would be especially unusual: cross species cancer should light up all the red flags in your immune system, but obviously his was especially degraded.