Telling women their breast density after screening was linked to higher anxiety and confusion than no notification, an Australian study suggests.

Breast density is the proportion of glandular and fibrous tissue compared with fat. Dense tissue is a risk factor for breast cancer and can make mammograms harder to interpret.

Women undergoing screening in Australia are already told their density, and the measure is being considered in the UK by the National Screening Committee.

Melanie Sturtevant, associate director of policy, evidence and influencing at Breast Cancer Now, said: “Knowing personal risk of breast cancer could allow people to make informed decisions about their own breast health.

“But studies like this one are really important to understand the impact of informing people about personal risk factors like breast density, including on a person’s mental health.

“The findings underline that learning they were higher risk left many women feeling more anxious and confused, and more likely to ask their GP for further information.”

Researchers at the University of Sydney studied 2,401 women screened between September 2023 and July 2024 who were classified as having dense breasts.

Participants were randomised to a control group (no density notice), a group notified with written information, or a group notified with a link to an explanatory video.

Eight weeks later, women were surveyed about their psychological response and whether they intended to speak to their GP or seek extra screening.

Those notified of their density were more likely to feel anxious and unsure what to do than the control group.

Intentions to talk to a GP were also higher among notified women: 22.8 per cent and 19.4 per cent in the written and video groups, compared with 12.9 per cent in the control group.

The NHS breast screening programme in England does not currently assess or record breast density on screening mammograms.

Sophie Brooks, health information manager at Cancer Research UK, said that having dense breasts could make it harder to detect cancer on a mammogram, but it was not something people could check for themselves or change.

She added: “This study suggests that telling women about their breast density has mixed results.

“Women who were told were more likely to seek advice from their GP, but they were also more likely to feel anxious and confused, highlighting the need for clear information and support.

“More research is needed to investigate whether informing women about their breast density could have a positive impact or not, and the UK National Screening Committee are currently looking into this.”

The study concluded that women notified of dense breasts “felt anxious and confused, did not feel more informed to make decisions about their breast health, and wanted to be guided by their general practitioners”.

Sturtevant said: “Currently in the UK, routine screening does not involve recording information about breast density, and a review into whether additional screening should be offered to women with dense breasts is ongoing.

“While we appreciate the need for a strong, evidence-driven process, we want to see the UK National Screening Committee conduct this with more urgency and transparency.”

A sperm donor carrying a cancer-linked TP53 mutation fathered at least 197 children across Europe, a cross-border investigation has found.

Some children have already died and, for those who inherit the mutation, only a minority will escape cancer in their lifetimes, the investigation by 14 public service broadcasters found.

The sperm was not sold to UK clinics, but a “very small” number of British families used the donor’s sperm while having fertility treatment in Denmark.

Prof Clare Turnbull, a cancer geneticist at the Institute of Cancer Research in London, said: “It is a dreadful diagnosis. It’s a very challenging diagnosis to land on a family, there is a lifelong burden of living with that risk, it’s clearly devastating.”

Denmark’s European Sperm Bank, which sold the sperm, said affected families had its “deepest sympathy” and admitted the sperm was used to make too many babies in some countries.

The anonymous donor was paid to donate as a student starting in 2005. His sperm was then used by women for about 17 years. He is healthy and passed donor screening checks.

A mutation arose in some of his cells before birth, damaging TP53, a tumour-suppressor gene that helps stop cells becoming cancerous.

Up to 20 per cent of his sperm carry the altered TP53.

Children conceived from affected sperm have the mutation in every cell, known as Li Fraumeni syndrome, which brings up to a 90 per cent lifetime cancer risk.

Dr Edwige Kasper, a cancer geneticist at Rouen University Hospital in France, said: “We have many children that have already developed a cancer.

“We have some children that have developed already two different cancers and some of them have already died at a very early age.”

Peter Thompson, chief executive of the HFEA, said affected British women “have been told about the donor by the Danish clinic at which they were treated.”