LONDON – Mammograms aimed at finding breast cancer might actually raise the chances of developing it in young women whose genes put them at higher risk for the disease, a study by leading European cancer agencies suggests.

The added radiation from mammograms and other types of tests with chest radiation might be especially harmful to them and an MRI is probably a safer method of screening women under 30 who are at high risk because of gene mutations, the authors conclude.

The study can't prove a link between the radiation and breast cancer, but is one of the biggest ever to look at the issue. The research was published Thursday in the journal BMJ.