Research and Development News

Record Breast Cancer Study: Mammography is Effective

By: Dan DiPietro-James | Thursday 30 June 2011 12:00 PDT

Breast cancer is one of the most prevalent forms of cancer in the U.S. and doctors advocate screening as one of the best defenses against the disease. The most common screening is mammography, and according to a new study on screening, regular mammograms actually prevent breast cancer deaths over time. 

The Swedish study, known as the Two-County Trial, was conducted by an international team of doctors and scientists. It is the largest and longest-running study ever done on breast cancer screening. It centered on mammography. 

Researchers studied 133,065 women in two groups. One received an invitation to get a screening and another received typical care on their schedules. Study results showed there were 30 percent fewer breast cancer deaths in the group invited to undergo a screening. 

"Mammographic screening confers a substantial relative and absolute reduction in breast cancer mortality risk in the long-term," said Stephen W. Duffy, M.Sc. and professor of cancer screening at Queen Mary, University of London. "For every 1,000 to 1,500 mammograms, one breast cancer death is prevented."

Screenings broke down like this: Women aged 40 to 49 were screened every two years, while women aged 50 to 74 were screened every 33 months. The study lasted almost 30 years. Study authors say the majority of the deaths prevented would have occurred ten years after the initial screening. Researchers say this shows that short-term follow-ups, while effective, are not nearly as effective as long-term follow-ups in breast cancer patients. 

Researchers say some follow-up times need to exceed 15 to 20 years, because the observed number of breast cancer deaths prevented increases with the passage of time. Many women stop getting a mammogram after a certain age. This research suggests they should continue to receive mammograms as part of a long-term regular screening process. 

Breast cancer is one of the most treatable forms of cancer thanks to years of research and technology. "Unfortunately, we cannot know for certain who will and who will not develop breast cancer," Duffy said. "But if you undergo a recommended screening regimen, and you are diagnosed with breast cancer at an early stage, chances are very good that it will be successfully treated."