AURORA, Colo., Jan. 28 (UPI) -- A study challenges the U.S. Preventative Service Task Force recommendations made in 2009 for breast cancer screening to begin at age 50, researchers say.

R. Edward Hendrick of the University of Colorado School of Medicine and Dr. Mark Helvie of the University of Michigan Comprehensive Cancer Center used the same modeling data the task force considered and compared task force guidelines to American Cancer Society guidelines, which recommend screening every year in women ages 40-84.

U.S. Preventative Service Task Force recommends breast cancer screening every other year in women ages 50-74 because of the potential harms mammography can cause -- including pain during the screening and the anxiety from false-positives, which can lead to additional imaging or biopsy.

The study, scheduled to the published in the February American Journal of Roentgenology, found, on average, women ages 40-49 screened annually will have a false-positive mammogram once every 10 years, be asked back for more tests once every 12 years and will undergo a false-positive biopsy once every 149 years.

The researchers found if women begin annual mammograms at age 40, it reduced breast cancer deaths by 40 percent. Screening beginning at age 50 and conducted every other year reduces breast cancer deaths 23 percent.

The difference between these two screening strategies comes down to 71 percent more lives saved with yearly screening beginning at 40, the researchers say.