Mammography is the standard technology for routine breast cancer screening-but it's not fit for purpose. It's missing cancers in women who have dense breast tissue and who are more likely to develop tumours, a new study has found.
It fails to detect around four cancers per 1,000 women with dense breast tissue, which affects one in three women.
Instead, these women should be offered ultrasound, say researchers from the Hospital of Central Connecticut, which was one of the first to pioneer the use of routine ultrasound scans for breast cancer.
In a four-year study, the researchers screened around 13,000 women with dense breast tissue with mammograms and ultrasounds. The ultrasounds picked up between three and four cancers per 1,000 women screened-so around 52 cancers in total-that mammography had missed. Extrapolating those figures to the UK's breast screening programme, around 2,400 cases of breast cancer are missed every year by mammography.
Mammography also picks up more 'false-positives'-seeing cancers that aren't there-than genuine cancers, which causes unnecessary treatment and distress.
Dr Jean Weigert, a clinical radiologist at the Connecticut hospital, thinks more hospitals don't offer ultrasound as an alternative "because we're afraid of finding too many things". However, finding a large cancer, when earlier screening could have detected it when it was much smaller, is scarier still, she says.
(Source: proceedings of the San Antonio Breast Cancer Symposium, December 9, 2014)