Managing cancer risk without adequate data: a necessary evil.

While the French guidelines could be exhaustively deconstructed, to do so would be unlikely to produce a better justified set of guidelines. As is usually the case, the absence of data produces as many opinions as there are experts. However, the salient points are that data are not yet available and may not be available for several years. Clinicians and their patients want, and need, guidance now. The development of these guidelines, and the process used to do so, are to be applauded. Both serve as models for similar work in other countries.