Future cancer therapies could be tailored to suit individual patients, but because the drugs are so expensive and will have a limited market, they may never be made.

There are already a few drugs on the market that target specific protein receptors in cancer and thanks to the decoding of the human genome more could be on way.

But an expert at Britain’s Institute of Cancer Research warned Tuesday that breakthroughs in research may not lead to new treatments because the costs will be too high for drug companies.