Mammograms may not reduce breast cancer deaths: Study

In a significant study, Canadian researchers have found that yearly mammograms in middle-age women do not reduce breast cancer deaths but these tests are essentially as good as physical examination alone.

The new findings suggest that the rationale for screening by mammography should be urgently reassessed by policy makers.

The study, which included nearly 90,000 women ages 40 to 59, is the latest to question the value of routine mammography.

The researchers found the same number of women died of breast cancer over 25 years, regardless of whether they underwent yearly mammograms or not.

"The majority of breast cancers are detectable by mammography, but whether or not this is beneficial has now become very controversial," said study researcher Anthony Miller, professor emeritus at University of Toronto.

Mammography is performed routinely to screen women for breast cancer, with the goal of early diagnosis.

But it is highly debated whether this screening saves lives.

In some cases, early detection does not necessarily mean the cancer can be cured, and in some others, treatments work even if cancer is discovered at later stages.

The new study found that about 22 percent of breast cancers detected by mammograms were what researchers call over-diagnosed.

It means the mammograms revealed tumours that didn't cause disease symptoms, and would not have reduced a woman's life span if left undetected, said the study published in the British Medical Journal (BMJ).