A new study concludes that some women over 50 may be able to have a mammogram every two years rather than once a year without increasing their risk of developing advanced breast cancer.

The researchers evaluated nearly one million women.

They report, women aged 50 to 74, who got a mammogram every other year, had a risk of developing advanced breast cancer that was similar to those who got the test every year.

Screening every two years was also associated with a lower risk of having a false-positive result.

The study’s conclusions are drawing mixed reactions.