Breast Cancer Screening Should be Tailored to Individual Risk

Women at high risk of breast cancer may benefit from shorter mammography screening intervals

medwireNews: The frequency of mammography screening should be adjusted according to a woman’s individual risk of developing breast cancer, UK researchers propose.

Currently, the UK’s NHS Breast Screening Programme recommends that women between the ages of 50 and 70 years undergo mammography at 3-year intervals, with pilot schemes examining the benefits of initiating screening at 47 years and continuing up until 73 years of age.

Now, however, Gareth Evans from The University of Manchester and fellow Predicting Risk Of breast Cancer At Screening (PROCAS) study investigators say that high-risk women should undergo screening more frequently. They suggest that annual mammograms are more appropriate for patients found to have an 8% risk of developing breast cancer over the next 10 years.

The team used a questionnaire detailing lifestyle factors and family history of breast cancer, genetic testing of saliva where appropriate and a visual assessment score of mammographic breast density to assess 53,467 women undergoing breast screening from 2009 onwards.

When the questionnaire and breast density results were combined, 2.4% of women were identified as being at high risk of developing breast cancer in the next 10 years. High risk was defined as an 8.0% or higher risk of developing breast cancer over 10 years. A further 27.5% had an above average 10-year risk (>3.5%) and 68.7% had an average or below average risk (≤3.5%), with 6.4% of these women found to have a low (<1%) risk of developing the disease in the upcoming decade.

During follow-up, 634 women were diagnosed with breast cancer, with 2.3%, 1.8%, 1.0% and 0.3% of the high, above average, average and low-risk patient groups diagnosed with breast cancer over 4 years of follow-up, respectively.

Of note, just three women per 100,000 women screened each year with a low or average risk were diagnosed with breast cancer involving the lymph nodes, compared with 11 cases per 100,000 women a year for those with an above average risk. And higher stage cancers occurred in significantly more high-risk patients than those with a low-to-average risk, at 32% versus 19%.

“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,” Gareth Evans said in a press release issued to coincide with the study data being presented at the 9th European Breast Cancer Conference, held in Glasgow, UK.

Hilary Dobson, chair of the conference organising committee and Clinical Lead of the West of Scotland Breast Screening Service, also commented on the findings. “As our understanding of the contribution of familial risk has improved, there has been a move to align such cases with the national screening programme. This study takes the process one step further towards the concept of more personalised screening - a model taking account of a range of personalised risk factors resulting in an individualised screening frequency.

“Longer follow-up of the affected individuals will add weight to any future requirement to change from the current delivery model of the national screening programme."

References

Evans G, Stavrinos P, Dawe S, et al. Assessing individual breast cancer risk within the UK National Health Service Breast Screening Programme: First prospective results from PROCAS. Abstract number 8. 9th European Breast Cancer Conference; Glasgow, UK: 19–21 March 2014.
Conference site: http://www.ecco-org.eu/Events/EBCC9.aspx

Press release based on abstract

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