A major trial has found that screening women, at an early age, who are of moderate or high risk of developing cancer can detect breast cancer at an early stage and is likely to be as effective in reducing mortality.
Of the approximately 55,000 women and 350 men diagnosed with breast cancer each year, 5–15% of cases are linked to a family history. Many women who are at increased risk of breast cancer due to a mother or sister diagnosed with breast cancer, aged under 40, do not currently qualify for surveillance before 40 years of age.
As early detection offers the best survival outcomes, the National Institute for Health and Care Excellence (NICE; London, UK) guidelines recommend annual screening for women aged 40–49 who are identified as ‘moderate’ or ‘high’ risk for breast cancer. Risk category is determined by a combination of family history, age and prior experience of cancer and is split into ‘general population’ (11% lifetime risk), ‘moderate’ (17–29% lifetime risk3) or ‘high’ (30% or higher lifetime risk).
In this trial, led by Gareth Evans of the University of Manchester (UK), it was found that annual screening of women aged 35–39 who have been identified as ‘moderate’ or ‘high’ risk can nearly double the proportion of tumors detected before they were over 2cm in size.
In a group of 2899 women, 49 were found to have cancer with 35 having invasive tumors. Eighty percent of these were detected when the tumor was less than 2cm in size and only 20% had spread to the lymph nodes. For comparison, in unscreened women just 45% on tumors smaller than 2cm were detected and 54% of cases showed spread to the lymph nodes.
“This could be an enormous breakthrough. We believe these findings could be practice-changing and urge the Government and NHS England to ensure the upcoming review of screening programs sets out what further evidence is needed to consider screening for women aged 35–39 who are at increased familial risk of breast cancer,” commented Delyth Morgan of Breast Cancer Now (London, UK).
If availability to annual screening is extended to women aged 35–39 with ‘moderate’ or ‘high’ risk, between 3–4% of the general population may be eligible, benefiting up to 86,000 women each year
“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 […] 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 non-invasive 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,” commented Evans.
Health economic analysis is needed to determine the benefit vs risk ration in this age group in addition to follow up, to identify any impact of radiation dose on risk of future cancers. Several risk prediction models are in development that may give an even more accurate estimate of risk, helping to alter the screening program to give more targeted and ‘risk-stratified’ screening.
“While we now need to understand the full balance of risks, costs and benefits of mammography in this group, we are extremely excited by the potential to adapt our world-class NHS screening services to prevent more deaths from breast cancer in younger women,” added Morgan. “In the meantime, we’d encourage any women concerned about their family history of breast cancer to speak to their GP, and to check their breasts regularly. Just get to know what looks and feels normal for you, check regularly, and report any unusual changes to your GP. It could save your life.”
Sources: Evans DG, Thomas S, Caunt J et al. Final results of the prospective FH02 Mammographic surveillance study of women aged 35-39 at increased familial risk of breast cancer. EClinicalMedicine. doi:10.1016/j.eclinm.2019.01.005 (2019) (Epub ahead of print); https://breastcancernow.org/news-and-blogs/news/annual-screening-detects-breast-cancers-earlier-for-women-aged-35-39-with-a-family-history-major-uk-trial-finds