Today there are numerous in vitro tests, as they're called--laboratory studies quite aside from animal studies based on cell cultures. A lot of the time carcinogens and of course drugs used against cancer are tested on cell lines in the petri dish or on cells implanted into animals.
Our techniques here are really quite sophisticated, but there are also numerous examples showing that when a substance you found to be cytotoxic and showing some form of danger in cell culture has been tested on an animal, it just hasn't done anything--or it does something worse than you found. The animal is far more complex that just single cells.
To answer your question, there are certainly tests available today that are being implemented; many decisions are based upon that. Whether to go ahead with researching a new drug, for example, will depend on what you find initially in cell culture; based on that, you may decide to go ahead or not go ahead, but it's still not 100% indicative of what can happen in a living system.