Mammogram samples from a screening programme in the Netherlands showed that a quarter of women aged 50 to 69 had the 'dense'[1] mammographic breast patterns more normally associated with younger women. Among 50 to 54-year-olds the proportion was 44%.
Radiologist Dr Fred van der Horst said no one really knew why the change had occurred. It was unlikely to be due entirely to HRT as its use never exceeded 15% in the Netherlands. But, it could partly be due to the changes in childbearing patterns.
Dr van der Horst will be presenting the findings at the 4th European Breast Cancer Conference to a special meeting of the European Group for Breast Cancer Screening.
He said that breast cancer screening in postmenopausal women is effective but cancers can still go undetected. High mammographic density partly accounted for these missed cancers.
The study set out to see what impact breast density had on screening performance. Researchers chose a random sample of 2,000 from among the 54,500 women who are screened every two years in a screening programme. They classified the mammograms as dense if more than a quarter of the breast was composed of dense tissue. If less than a quarter of the breast comprised dense tissue the mammograms were classified as lucent[1].
They found that 25% of 50 to 69-year-olds overall had dense breasts 44% of 50 to 54-year-olds reducing to 17% of 65 to
69-year-olds. They then calculated the ratio of screen-detected cancers to the total number of screen-detected cancers plus those cancers arising in the interval between scr
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Contact: Margaret Willson
m.willson@mwcommunications.org.uk
44-153-677-2181
Federation of European Cancer Societies
15-Mar-2004