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from the should-have-switched-to-an-e-cig dept.
Cancer is often viewed as a fundamentally modern and monolithic disease. Many people think its rise and spread has been driven almost exclusively by the developed world's toxins and poisons; by our bad eating habits, lifestyles, and the very air we breathe.
Actually, cancer is not a single disease. It is also far from modern. New fossil evidence suggests that its origins lie deep in prehistory.
We recently published two papers in the South African Journal of Science that describe the discovery and diagnosis of the earliest benign tumour and earliest malignant cancer to affect the human family.
Tumours and cancers are collectively known as neoplastic diseases. Until now, the oldest evidence of neoplasia in the hominin fossil record dated back 120,000 years. This was found in a rib fragment of a Neanderthal from Krapina in Croatia.
But our discovery, in two South African cave sites, offers definitive evidence of cancer in hominins – human ancestors – as far back as 1.7 million years ago.
(Score: 5, Insightful) by ledow on Friday September 16 2016, @08:01AM
OK, I get tired of this. I'm not a qualified scientist, just a very keen amateur and mathematician. But I happen to live with a geneticist, a Dr, who works in London hospitals and tells you whether your sample is cancerous or not, whether your child has Down's or not, etc. If you live in London and have ever needed a test for a genetic condition or whether a sample is cancerous, likely she's one of the people who touched it and offered her diagnosis to your doctor.
Cancer is not a "disease" as such. It's not something you catch, it's not something in the air, it's not something floating around in cigarettes and campfire smoke.
Cancer is - quite literally - what happens to you if NOTHING else happens to you. It's caused, almost exclusively, by a random DNA flip in your cells which causes them to NOT stop reproducing. Normally, they reproduce as necessary until they get a signal to stop and then they're done. Cancer is, to give a computer analogy, a flipped bit on the hard drive that causes the cell to run over it's normal allocated boundaries and replicate endlessly - like a bad flipped bit in a file can cause an overflow and a cascade of errors resulting in a BSOD. The body has checks and measures (e.g. something almost akin to a DNA checksum!) because such things happen all the time.
Given enough time, every cell in your body would die of cancer. It's why they are killed off by the immune system and replaced on a regular basis (remember that "your skin cells are replaced every X days" statistic?). The immune system is capable of detecting some of the errors in some cells before they start down this path, and kill them off before they get out of hand. It's doing it now, in your body, right this moment. In effect, we all "have" cancer all the time.
The problem is when the immune systems own cells are corrupted, or they aren't able to "detect" a corruption in another cell. It's fairly hard for the immune system to spot everything - given that it's just shaped molecules fitting into other shaped molecules - so occasionally it misses one. And when that one is missed, it replicates and all its clones are also missed and you get a tumour / cancer.
What causes that flip is random chance. Literally, does this molecule in the cell / the DNA get hit by a photon or a gamma ray or a radiated electron and change its structure? It's statistical, and random. There are things that INCREASE the number of interactions that could each lead to cancer (e.g. radiation exposure, UV, etc.), but there's little you can do to stop it happening or predict it. Some people might be exposed to the chance a billion times and get nothing, others might get cancer before they even make it out of the womb.
But because of what cancer is, there's no "cure". You can't immunise yourself against it. It's always there and if you die of nothing else, statistically you will end up dying of cancer. Because it's just a flip, a corrupt bit, in one of billions of different cells of everything from bone to blood to muscle to skin, it's impossible to counteract in all its forms. Which is why the treatment is generally "zap it or cut it out" upon detection.
Cavemen, early humans, they had exactly the same kinds of exposures, the same kind of risks, the same kind of cancers. They always have. We probably always will (but maybe one day we'll find a definitive "treatment" so that when we get cancer, we can get rid of it most of the time).
We live a long time now. We tend not to die of a broken ankle which stops us hunting our prey, or of not being able to keep up with the tribe after the age of 30. Cooking our food means we don't die of simple things like diarrhoea. But cooking - especially open campfire - produce lots of particles that might end up flipping a bit and giving a cell cancer too. It's a game of statistics and probability. As such, our incidence of cancer is higher than those early people. But it's not a "modern" disease, it's always been around. It's just that it's the thing that ends up killing us more often now that we live twice or three times as long as those early humans and don't die because we cut our foot and get sepsis.
It gets me that people think of cancer as something you "catch", almost. That's why I don't like the word disease here, whether it's a medical term or not. Cancer is body-death. It's cell failure. It's the component that blows up randomly for no reason the day after the warranty gives out. It's brought forward by being in harsh environments and doing risky things. It's often pushed back by not doing those. And if we see it early, we can cut out those "dead" bits and live longer before they take us over. In absence of anything else, cancer will be what kills you. We might learn to treat it reliably but we can't cure it permanently or eradicate it.
Sure, we can "give" people cancer. It's easy. But "not giving" it doesn't mean they won't get it. If fact, it's almost a given if you live long enough.
Cancer is body-death, the mechanical failure of a cell that has been bashed too much by particles and photons and suchlike, or which has lived too long to stay intact. It's entirely different to almost every other way that we can die. It's that cog that one day, after much abuse or just sheer bad luck, jumps and smashes a tooth and then runs out of control through more sensitive parts of the body and causes complete system failure.
As such, it isn't surprising to find cancer this far back. It's in every species that has cells in its body. It has been since the first cells based on DNA split apart. And a great deal of the DNA and cell-cloning mechanisms in the body are designed to do nothing more than detect errors and eliminate them - which suggests millions of years of dealing with this problem and evolving ways to combat it.
(Score: 2) by maxwell demon on Friday September 16 2016, @08:26AM
Just because something is random does not mean there is no influence from the environment. To take the computer bit flip analogy: If you put your computer in an environment with higher radiation, you'll get a higher probability of a bad bit flip (that is, one that cannot be corrected by error correction, and that actually affects critical structures), simply because there are more gamma photons around to flip your bits. If you'd put it right besides a reactor core, it probably would instantly die. And it is nonsense to say that is not caused by the radiation of the reactor core.
And a disease is not necessarily something you "catch". A disease is simply when something in your body goes wrong. Cancer clearly is something in your body going wrong, therefore it is a disease.
And BTW, there are forms of cancer that can be transmitted.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Friday September 16 2016, @01:27PM
It's entirely different to almost every other way that we can die.
Autoimmunity is similar in some ways. Cancer happens because immune surveillance is under-responsive to self-tissue that is different and autoimmunity is when the immune system is over-responsive to self-tissue that is normal. Your immune system will eventually make this mistake as immune tolerance breaks-down with age (if you don't die of something else).
An immunology professor that I knew once said that autoimmunity is the price we pay for our immune system to be so good at detecting and destroying cancer cells.
Other non-random mutation causes of cancer include infectious disease (HPV, HTLV, EBV, etc.) and genomic instability (Philadelphia chromosome).
(Score: 0) by Anonymous Coward on Saturday September 17 2016, @04:48AM
Nothing you said contradicts the supposition that cancers may be getting more common due to damage to germline DNA (DNA damage passed down across generations)