Study finds breast cancer over-diagnosed

COPENHAGEN, Denmark, July 10 (UPI) -- One in three women shown to have breast cancer undergo unnecessary surgery and chemotherapy, scientists in Europe said.

Results from mammograms that screen for breast cancer lead to over-diagnosis and unnecessary treatment, scientists at the Nordic Cochrane Center in Copenhagen said in a story published Friday in the British Medical Journal.

Some breast cancers are inconsequential, but once they are detected women usually undergo traumatic and potentially harmful treatment, said Gilbert Welch, a professor of medicine who reviewed the study of over-diagnosis of breast cancer in Britain, Canada, Norway, Sweden and Australia.

Mammography is one of medicine's "close calls," a balance between benefit and harm, in which different people in the same situation might reasonably make different choices. Welch said.

"Mammography undoubtedly helps some women but hurts others," Welch said.

The Nordic Cochrane study examined breast cancer trends seven years before and after mammograms were introduced in the five countries, The Guardian reported Friday.