Women with a family history of breast cancer should have mammogram screening from the age of 35, new research suggests. 

The major UK trial concluded annual screening for younger women aged 35-39 who have a family history of breast cancer would be effective in detecting tumours earlier and potentially save thousands of lives. 

Currently, women in England are invited for breast cancer screening every three years on the NHS from the age of 50, while NICE guidelines currently recommend annual screening for women aged 40-49 who are identified as being at moderate or high risk of the disease. 

In the trial led by Professor Gareth Evans at the University of Manchester, almost 3,000 women aged 35-39 at moderate or high risk of breast cancer due to their family history were offered annual screening across 34 UK centres between 2006 and 2015.

In total, 50 breast cancers were detected (in 49 women), of which 35 were invasive tumours. Of the 35 invasive breast cancers, 80% were detected by screening when the tumour was 2cm or smaller in size, and only 20% had spread to the patients’ lymph nodes.

The trial compared the results to an unscreened cohort of women aged 35-39 and at increased risk  – with annual screening being shown to nearly double the proportion of tumours detected before they were over 2cm in size.

In unscreened women, just 45% of breast cancers were detected when the tumour was 2cm or smaller in size and 54% of cases had already spread to the lymph nodes.

Based on the findings, leading UK clinicians and researchers suggest that regular screening in women identified at moderate or high risk of breast cancer could be lowered to women aged 35-39.

While more women are now surviving the disease than ever before, breast cancer remains the leading cause of death in women under 50 in England and Wales – more than 920 women under 50 lost their lives to the disease in 2017.

Breast cancer is the UK’s most common cancer, with around 55,000 women and 350 men being diagnosed each year in the UK – and it is estimated that around 5-15% of cases are linked to a family history of the disease.

Women with a significant family history of breast cancer can be referred by their GP to specialist services for an assessment of their risk, as well as support including information about available monitoring and risk-reducing options such as chemo-prevention, lifestyle advice or preventive surgery.

Lead author Professor Evans described the results of the trial as “very promising”. 

“These are the first significant data on the benefits of screening in women aged 35-39,” he said. “Our trial shows that mammography screening is effective in detecting tumours earlier in this younger age group, and lays the groundwork for extending this screening in women at moderate or high risk down to women aged 35-39 from ages 40-49.”

He said more research is now needed to determine the impact of this screening on women’s overall survival. 

Baroness Delyth Morgan, chief executive at Breast Cancer Now, which funded the trial, described the results as an “enormous breakthrough”.

“In the absence of screening, it is so important for women at increased risk to remain breast aware and to report any unusual changes in your breasts to your doctor,” she said. “Please do speak to your GP if you have any concerns at all or if you’d like to discuss the options available to you in more detail.”