A new study is questioning the validity of routine mammography screenings.
According to HealthDay, mammography screening is much more likely to find insignificant breast tumors than it is to catch life-threatening cancer in its early stages.
Are breast cancer screenings not as effective or important as was once believed?
The study takes a look at cancer statistics to try to determine how effective mammography screening has been since it became widely used in the 1980s.
The research shows that large breast tumors - 2 centimeters or more - among women in the U.S. has declined. But the findings also estimated that the number of small tumors found and diagnosed has seen an increase.
Most of the smaller tumors never would have progressed to be life-threatening, according to researcher Dr. H. Gilbert Welch from the Dartmouth Institute of Health Policy and Clinical Practice in Lebanon, New Hampshire.
Dr. Welch says mammography is more likely to "over-diagnose" breast cancer than to catch the dangerous tumors early.
Research from the study also shows that the declining number of breast cancer deaths since the 1970s is mainly due to better treatment, not screenings.
Some cancer and radiology experts say there are flaws with this research and defend current screening guidelines.
Welch says the problem with screening is not being able to determine which small tumors will progress and which will remain harmless.
This means that some women are receiving treatments for a cancer that really isn't there. They face "real harm" with surgery, radiation and possibly hormone therapy with no benefit, says Welch.
Still, a mammography is useful in catching the tumors that will become life-threatening.
Research shows that about an extra 162 small breast tumors for every 100,000 women are caught through screenings versus the pre-screening era. However, only 30 of those 162 tumors would likely have grown larger and harmful.
The study was published October 13 in the New England Journal of Medicine.