Women at higher risk of developing breast cancer might benefit from more frequent mammograms, a study of over 50,000 women has found.
However, three-yearly screening is appropriate for the majority of women participating in the NHS Breast Screening Programme, researchers from the University of Manchester have found.
Using a questionnaire, the researchers collected information on important breast cancer risk factors such as family history and lifestyle; where appropriate, genetic information was collected by analysing saliva samples; breast density was measured from the mammogram and given a “visual assessment score” (VAS), which indicated the percentage of dense tissue in the breast.
When researchers combined results from the risk factor questionnaire with VAS they found that 1,280 (2%) of women had over an 8% risk of developing breast cancer. Out of these women, 2.3% (29) developed breast cancer.
And of the 14,720 women with an above average risk (over 3.5%) of developing breast cancer in the next ten years 267 (1.8%) had developed breast cancer in the four-year period from 2009.
This left 36,748 women with average or below average risk of developing breast cancer, and, of these, only 371 (1%) developed breast cancer.
Professor Gareth Evans, who is the chief investigator for the study and also part of Manchester Cancer Research Centre, said: “Our results suggest that three-yearly screening is very effective for around 70% of the female population, but that those women who have a higher than average risk of developing breast cancer probably require more frequent screening, particularly as more advanced cancers were detected in these women. Screening should be annual for the small proportion of women who have an eight percent or greater risk of developing cancer over the next ten years.
“This is the largest study of its kind in the UK, and the results could have an impact on the whole NHS Breast Screening Programme. By incorporating this process of personal risk assessment into routine screening practice we can predict and prevent more breast cancers in the future.”
The study was presented at the 9th European Breast Cancer Conference.