Every other year may be enough for women over 50 to undergo a mammogram, U.S. researchers said on Tuesday. A study of nearly 8,000 women showed that those who let a two-year interval slip in between mammograms were no more likely to have advanced cancer if they did develop a tumor than women who had mammograms every year. But in women in their 40s, when cancer may be more aggressive, there was a higher risk that when a tumor was detected it would already be at an advanced stage.
"Mammography screening may reduce breast cancer mortality by detecting cancers at an earlier stage," Emily White of the Fred Hutchinson Cancer Research Center in Seattle and colleagues wrote in their report, published in the Journal of the National Cancer Institute. "However, certain questions remain, including the ideal interval between mammograms," they added.
They studied women to see if those who had mammograms only every other year were more likely to have advanced cancer when diagnosed. They compared 2,440 women who had been diagnosed with breast cancer after a two-year interval between mammograms with 5,400 women diagnosed with breast cancer after a yearly scan. "In summary, we found little evidence that indicates that women who undergo mammography screening every two years have an increased risk of late-stage breast cancer compared with women who undergo annual screening, except for women in their 40s," they wrote. "However, because breast cancer incidence among women aged 40 to 49 years is less than half that among women 50 years of age or older, the benefit of annual screening for younger women is small and the cost per year of life saved is high," they added.
The U.S. Preventive Services Task Force recommends mammograms every one to two years, while the American Cancer Society recommends every year. In Europe, most countries recommend that women be screened every two years and concentrate their recommendations on women age 50 and older. About 1.2 million people a year are diagnosed with breast cancer globally, and the disease kills 40,000 women and men in the United States every year. (Reuters)