There's been a vast amount of money spent on research into cancer - what makes you think that more money would suddenly achieve the breakthrough? Finding a cure to cancer would be an absolute goldmine for a company, so there is a clear incentive for companies to spend money on research if there is much of a prospect of success. Meanwhile you'll have various charities also with an interest, regardless of the chances of success, and hence there will be at least some research taking place. Meanwhile that extra money could save far more lives if spent on other areas, so I'm not sure increasing cancer research would be (or have been) the most effective. It's a bit like the lottery - sure it'd be nice to get all those millions, but ultimately you have to weigh up the likelihood of that happening and the cost or you'll end up throwing money away, as well as the cost of alternatives.