Wow, I'm actually a little offended by those statements. It's like conspiracy theorists are accusing people like me of faking the seriousness of cancer just so we can make a quick buck. We don't make a lot of money at this BTW, since I work in academic research and don't profit from any drug development. Your typical computer programmer makes more money than my boss, and he's already got an NIH grant.
It's not your fault though, since you're here being open-minded and asking for information. It's just that it's downright frustrating that so many people are being cynical and spreading misinformation that could really harm others. I mean, being cynical about 9/11 is one thing, but being cynical about cancer treatments? Completely another, because that information could affect you or a family member or even your child who has no say in their medical treatments. Not to mention that if enough people speak up, they could affect how research is funded and then treatments could be delayed in their development.
The thing that makes cancer so hard to figure out is that it's not one disease, it's almost a symptom. A
gazillion things (really, a gazillion) could cause one of your cells to go nuts and start dividing like mad. There are many, many genes where if something's deleted or copied over wrong or switched (see how many options there are?), could turn this dividing mode on. Once it starts, it's hard to stop because obviously these cells do not stop dividing and once they get into your bloodstream, they can hide anywhere and you can't just blast the body haphazardly with radiation to try and get them. What kills cancer cells also kills normal cells, which is why chemotherapy is such a b**ch and makes you sick. It's like trying to kill replicants in Blade Runner with nuclear bombs instead of Deckard's neat gun.
Doctors have been focusing more on treatments that target just these cancer cells and leave normal cells alone, but it's hard because each individual cancer case is basically different. Each case of cancer started with one cell with any myriad of mutations. There are definitely mutations that can be common between the kinds of cancer we hear about, but I wouldn't be surprised (since I'm not sure if anyone's definitively proved this) if all cancer cases were individually different. Like snowflakes.
There are definitely certain things you can do to prevent the probability you will get cancer, but even if you do everything right, there's no telling whether one of your cells will betray you in a freak mutation anyway.
What helps most is preventing inflammation, because inflammation induces rapid cell turnover as well as the "help we're dying!" mode that I will explain below Spoon's quote. The more your cells divide, the higher the chance one of these divisions will produce an error that causes the runaway division that causes cancer. (Even scientists in the early 1900's noticed that tumors seemed to occur more in areas where there had been chronic inflammation, so we've known this for a long time.) This means avoiding alcohol and smoking, because they kill cells. I know there have been lots of studies about how wine is good for you and such, so the body can take a little beating from alcohol and be okay. Just don't go crazy with it.
As for the food thing, who knows. There are definitely things about food that we don't know about, especially fruits and veggies that are rich in antioxidants and prevent DNA damage from affecting cells. The thing is that each person's metabolism is different, not to mention their cancer, so what totally works for one person may not work for another. So I definitely wouldn't tell someone with cancer to stop all of their treatments and start eating blueberries.
But a diet rich in these foods certainly doesn't hurt you either, so eat up!
As for the local fruit thing, it's better for you and environment to eat fruit local to your area. It's had less time for its nutrients to degrade and takes less fuel getting it to you. So that's basically win/win.
I totally believe that pharmaceutical companies and doctors are catering more toward the quick fix when all the patient has a symptom but nothing truly wrong with them. I mean, my doctor preliminarily diagnosed me with Irritable Bowel Syndrome when I told him I felt sick after eating, but that's just something doctors tell patients when there's a symptom but no major physical signs of anything actually wrong, you know what I mean? A lot of these symptoms can be alleviated with stress-management. The body will do a lot of weird things that you don't like when you're stressed and anxious. But believe me, cancer is very real. The tumor is not going to go away if you do yoga.
As for your second thought: Yup, pretty much. Notice how most people who get cancer are 50 and older? Not a coincidence.
I actually attended a seminar about cancer and aging, where the scientist (pretty much the most renowned in our field) argued that the things that keep us cancer-free when we're young works against us when we get old. What makes this hard to study is that it involves so many systems. My particular lab focuses just on DNA, but this scientist has had to expand her knowledge to stuff happening inside and outside the cells, and now has to study the immune system because it involves that!
It's a little complicated for the layperson, but here goes: (ooh, you've got me started here, this is a slippery slope!)
Cancer is basically caused by the fact we're alive and we're multicellular and need to live for a relatively long time. Multicellular organisms need to divide their cells eventually, because individual cells can be harmed and you need a way to replace them, right? Not to mention that cells just get old and start to accumulate relatively harmless mutations through their multiple cell divisions and the body would rather be sure that these cells won't get cancerous in the next go round. So when a cell gets old, it can stop dividing. (The other possibility is programmed suicide.) It doesn't die, it keeps doing whatever job it's doing, but it doesn't make copies of itself. When it does that, it produces a bunch of chemicals that tells the body that it's stopped dividing, so a few stem cells should come over and make sure there are still some dividing cells over there so you don't end up with a shortage of tissue in a particular area. With enough of these nondividing cells, immune cells will come in and take them out eventually to be replaced with the new stem cells.
This works fine when it's just one cell doing the signal and the body can handle it, which is why childhood cancers are relatively rare. But when there are many of these nondividing cells around (as it would be in an older person), massive amounts of signal can actually hide cells from the immune system and a cancerous can get away under the radar.
It's actually a very cool concept since it's pretty big-picture compared to what we're doing, but it's also harder because there are so many things (that we don't know about) happening at one time.
Speaking of which, I don't believe in a cancer "cure." We researchers all sorta go
when charities try to get money by touting that we're so close to a "cure." (I understand why they do it, but it's still amusing.) We're not close to a cure, because cancer is so complex and it's a symptom anyway so how can you "cure" a symptom, let alone develop a cure for any gazillion genetic possibilities of what the cancer might be caused by?
All he is is a good talker. I watched part of an informercial of his once and was 
)
You guys are hilarious.
.....Just kidding! 
t:
