Apparently pharmaceutical manufacturers are slowing, even halting, production of fluorouracil; one of the most commonly prescribed drugs for the treatment of colorectal and breast cancer as well as being used in treatment of other cancers.
http://www.thelocal.de/society/20121118-46239.html
It seems that it's unprofitable to manufacture and sell the drug. I'm wondering why pharma companies don't simply raise the prices but I have a feeling it has something to do with health care systems in Europe. No clue why they won't simply sell in the US.