Annual screening for women aged 35–39 who have a family history of breast cancer may be highly effective in detecting tumors earlier, according to findings published by Evans et al in The Lancet’s online journal EClinicalMedicine. The FH02 trial found that annual mammograms for women aged 35–39 at moderate or high risk of breast cancer detected tumors when they were significantly smaller in size and less likely to have spread to the lymph nodes than in an unscreened control cohort.
Based on the findings, clinicians and researchers suggest that regular screening in women identified at moderate or high risk of breast cancer could be extended from ages 40–49 to also include women aged 35–39.
In the new prospective FHO2 trial in younger women, led by Gareth Evans, MD, FRCP, of The University of Manchester, 2,899 women aged 35–39 at moderate or high risk of breast cancer due to their family history were offered annual screening across 34 UK centers between 2006 and 2015.
In total, 50 breast cancers were detected (in 49 women), of which 35 were invasive tumors. Of the 35 invasive breast cancers, 80% (28 of 35) were detected by screening when the tumor was 2 cm or smaller in size, and only 20% (7 of 35) had metastasized to the patients’ lymph nodes.
The trial compared the results to an unscreened cohort of women aged 35–39 and at increased risk in the POSH trial, with annual screening being shown to nearly double the proportion of tumors detected before they had grown to 2 cm in size. In unscreened women, just 45% (131 of 293) of breast cancers were detected when the tumor was 2 cm or smaller in size and 54% (158 of 290) of cases had already spread to the lymph nodes.
Further health economic analysis will now be needed to determine the full benefits and risks in this age group, including whether this screening may be limited to those with a high chance of developing breast cancer (rather than high and moderate), as well as longer-term follow up to understand any impact of the radiation dose on women’s risk of future cancers.
Lead author Dr. Evans, Professor in Medical Genetics and Cancer Epidemiology at The University of Manchester, said in a University of Manchester press release, “These are the first significant data on the benefits of screening in women aged 35–39 who are at increased risk of breast cancer due to a family history, and the results are very promising.”
“Our trial shows that mammography screening is effective in detecting tumors earlier in this younger age group, and lays the groundwork for extending this screening in women at moderate or high risk from ages 40–49 down to women aged 35-39.”
“Overdiagnosis is also far less likely to be a major issue in such a young age group. For women with a family history, removing a noninvasive tumor so early in their lives is likely to be a cancer preventive. You only need to look at current long-term survival outcomes in this group to see just how important new early detection methods could be.”
“Longer-term follow-up is now required to determine the impact of this screening on women’s overall survival and any impact on their future risk of primary breast cancer, while health economic analysis will be needed to assess whether such screening could be extended to both [women at] moderate and high risk [for breast cancer].”
Disclosure: The FH02 trial was funded by Breast Cancer Now, with additional support from the NIHR Manchester Biomedical Research Centre. The study authors' full disclosures can be found at thelancet.com.
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