Over a million women have been diagnosed and treated for breast cancer that really didn't need a treatment, a new study found. The study also says that mammograms have hardly caught the really dangerous breast cancers.

Researchers found that 31 percent of breast cancer cases (nearly 70,000 early stage breast cancers) detected and treated in the year 2008 weren't really dangerous.

"There's been a dramatic increase in early-stage breast cancers that coincides with an increased use of mammograms. But it's not enough to find early-stage breast cancer; it must translate into fewer women being diagnosed at a later stage, and we found this decrease to be remarkably small," said Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Institute of Health Policy and Clinical Practice in Hanover, N.H. and co-author of the study, reports boston.com.

For the study, researchers examined trends of breast cancer and diagnosis between years 1976 and 2008.

Researchers found that with the introduction of mammography doubled early stage breast cancer diagnosis from 112 to 234 cases per 100,000 women while the rate of detection of late stage breast cancer has declined slightly from 102 to 94 cases per 100,000 women.

1.3 million women have been treated for cancers that would never be life-threatening and in 2008, 70,000 women were over-diagnosed, the research found.

Recent studies have shown that breast cancer screenings, especially before the age of 30, can actually increase the risk of the cancer. The risk is greater for women who are genetically predisposed to developing breast cancer as radiation from screening tests increases their chances of developing the cancer.

Some experts say that studies like these only create fear about being overt-treated and are designed to cut back healthcare costs.

"This is simply malicious nonsense. It is time to stop blaming mammography screening for 'overdiagnosis' and 'overtreatment' in an effort to deny women access to screening," said Dr. Daniel B. Kopans, a senior breast imager at Massachusetts General Hospital in Boston, reports Los Angeles Times.

The study is published in the New England Journal of Medicine.

An estimated 226,000 women and 2,000 men will be diagnosed with breast cancer in 2012 and nearly 40,000 women will die due to breast cancer, according to the National Cancer Institute.