I'm not an expert, just an interested layperson, but from what I read, I am starting to wonder whether cancer cures might be more basic than we realize, we're just not looking at the right things.
The example that keeps coming to mind is HPV - it can cause cervical cancer etc. And, since there is an immunization for HPV, the disease is preventable, and to the extent it is the "only" cause of certain cancers, would also prevent those cancers.
So is HPV the "only" virus which causes cancer? Seems unlikely. I just don't know how much research is focused on bacterial or viral origins. Maybe it is not glamorous or mysterious enough to justify funding.
The 2005 nobel in physiology went to Barry Marshal for discovering that stomach ulcers, long a mystery, were caused by Helicobacter pylori bacteria. And in fairness to history, he wasn't even the first person to discover it, just the most recent person in western society.
I used to work in anti-infectives research and if you talked to virologists long enough they would all insist that huge numbers of human ailments were caused by as yet undiscovered viruses. I admit that I'm a bit biased toward this myself. But I also have worked with people who are mitochondrial experts and they are convinced that huge amounts of disease are caused by mitochondrial defects. Lots of microbiologists think undiscovered bacteria are to blame.
The bottom line is that they are likely all correct. There is a staggeringly large amount of biology that we just don't know anything about. The complexity of it all is almost fractal. Just when we think we've got our heads around something, we peel another layer off the onion to reveal an entire landscape of which we were previously unaware. The best example of this is the recent findings in epigenetics. Before Darwin, Lamarck argued that acquired characteristics could be passed on to offspring. This was widely discredited. I learned about how it was patently false in high school. Now, we are finding that DNA methylation patterns (which work sort of like commenting out blocks of your DNA code) are modified and passed on to offspring. In some studies, if a mother is stressed, her offspring have stress response genes turned on by default at birth. In another, if there is starvation, the animal has starvation survival genes enabled at birth. It's quite remarkable and it means that in addition to our DNA which is fairly static, we have this parallel inheritance pattern that can be shaped and molded by the environment and passed to our offspring. The old "nature vs nurture" debate gets a whole lot more confusing (and might even be the wrong question entirely) with that in play.
Viruses are only one potential cause of cancer, and there are several known tumorigenic viruses (HPV, adenovirus, EBV, polyomavirus, etc.). There are still researchers that believe that all remaining cancers are caused by yet undiscovered viruses (the "viral hypothesis"), but these researchers are becoming scarce.
It seems more likely that cancer can also be a disease of aging and degeneration. As we get older, things break. Cellular division is liable to be one of those things. There are identified mutations that dramatically predispose people to cancer, because one of the genes controlling cellular division is already broken (the "Knudson hypothesis").
Some researchers do prefer to use the viral cancers as a model for studying the others, because they luckily have a singularly identifiable cause, and therefore seem more likely to point to the causative mutations behind cancer as a general process. This is the premise for a paper that I helped author: http://www.nature.com/nature/journal/v487/n7408/full/nature1...
Nitpick: in the same vein, not all gastric ulcers are caused by H. pylori. Another common cause is chronic NSAID (e.g. ibuprofen) use.
Your link lost me at the first sentence. But the word "phenotype" reminded me of this 11 minute Khan Academy video. Maybe I'm just repeating the same thing. But I thought Sal's video was worth sharing and easily digestible.
For whatever reason, Breast Cancer prefers to metastasize bone (which is a phenotype). Something as simple as giving cured Breast Cancer victims a calcium supplement can significantly reduce remission. Phenotypes >= Genotypes?
Prevention of cancer is not a cure, and it would not prevent all types of cancer. Cancer can appear anywhere in the body without any significant "cause". Regular safe sun radiation can be enough to alter certain DNA part during regular cell divide and immune cells might fail to spot the cell and it can start reproducing. Unlike infectious diseases, cancer is the result of evolution within body, it is fundamental to every multicell organism.
"Finally, that one of the simplest of diseases managed to utterly confound us for so long, at the cost of millions of lives, even after we had stumbled across an unequivocal cure. It makes you wonder how many incurable ailments of the modern world - depression, autism, hypertension, obesity - will turn out to have equally simple solutions, once we are able to see them in the correct light. What will we be slapping our foreheads about sixty years from now, wondering how we missed something so obvious?"
To be fair to him (and co-discoverer/recipient Robin Warren), it's one thing to notice something; another thing to prove it. And he proved it by drinking the bacteria himself.
[ An interesting criticism of modern science is that by demanding proof, it rejects all truths that are not proven. ]
Cancer may be similar, though I suspect it's a syndrome i.e. not a single cause and cure; but many causes, and therefore many treatments.
The example that keeps coming to mind is HPV - it can cause cervical cancer etc. And, since there is an immunization for HPV, the disease is preventable, and to the extent it is the "only" cause of certain cancers, would also prevent those cancers.
So is HPV the "only" virus which causes cancer? Seems unlikely. I just don't know how much research is focused on bacterial or viral origins. Maybe it is not glamorous or mysterious enough to justify funding.
The 2005 nobel in physiology went to Barry Marshal for discovering that stomach ulcers, long a mystery, were caused by Helicobacter pylori bacteria. And in fairness to history, he wasn't even the first person to discover it, just the most recent person in western society.
http://westhunt.wordpress.com/2012/02/22/low-hanging-fruit/