Search for genetic markers for susceptibility to cancer are unlikely to succeed, two researchers have stated.
Writing in this week's British Medical Journal, Stuart Baker and Jaakko Kaprio claim that genes associated with cancer either do not exist or have little effect on the incidence of the disease.
"The search for common cancer susceptibility genes faces important methodological and practical challenges for cancer prevention, given the small chance that such genetic variants exist and the difficulty and expense of proving substantial clinical benefit if they do exist," they write.
Millions of pounds are spent worldwide on searching for a cure for cancer and genes related to it, with one US project recently being awarded $14 million to do so.
Instead of a genetic cause, the researchers say that environmental factors play a more significant part.
They point to studies of identical twins and of different generations in which they say that lifestyle played a bigger role.
Even if genes associated with cancer were identified, they claim that proof of clinical benefit would be difficult and would require large trial.
The article concludes by saying that "enthusiasm for [gene] research should not precipitate unwarranted expectations".