A simple test could soon identify whether women with breast cancer would benefit from certain types of treatment, The Sun reported Tuesday.

Scientists at Queen's University in Belfast discovered that those with high levels of the gene FKBPL are more likely to respond to commonly-used drug tamoxifen.

It is estimated that only around two-thirds of those who use the drug actually benefit from it.

The breakthrough could stop thousands of women needlessly experiencing side effects when tamoxifen might not work.

"This is significant. It's very important to know if the breast cancer is going to respond because you wouldn't want to give tamoxifen unnecessarily," said The Sun's medical expert Dr. Carol Cooper.

Dr. Tracy Robson, who led the study, agreed.

"I believe that many women are being treated with tamoxifen without knowing whether it will benefit them," Robson said.

"This research is a step in the right direction towards personalized treatment, ensuring that appropriate therapies are given right at the point of diagnosis, avoiding unnecessary treatment."