As of 2004 the global cancer research budget
was about 17 billion dollars.
The largest single research funder in the world is the US government's National Cancer Institute, the oldest institute within NIH.
In 2004 the NCI accounted for about 73% of all US cancer research funding. (public and private combined)
The US (from all sources) spends the most per capita on cancer research. The UK has a similar rate. Those are the global stand-out nations.
Europe (ex-UK) spends about half as much pre capita as the US and UK. Cancer research funding in Europe is about 50-50% public and private.
Just some stuff that stuck in my head reading around on the topic.
http://kcl.academia.edu/RichardSullivan/Papers/263427/Trends_in_the_global_funding_and_activity_of_cancer_research
http://obf.cancer.gov/financial/factbook.htm
http://iom.edu/~/media/Files/Activity%20Files/Disease/NCPF/Fund.pdf