Women should be offered genetic screening to detect a breast cancer that affects thousands every year but which is routinely missed by mammograms, a charity has said.
More than 8,000 women a year in the UK are diagnosed with lobular breast cancer — which rarely forms a lump and is extremely difficult to spot in its early stages.
A new study suggests some cases are hereditary and caused by a faulty gene, meaning tests could have the potential to identify women at risk of the disease, even before the cancer starts to grow.
Similar testing is available for genes linked to other types of breast cancer. Hollywood star Angelina Jolie underwent a double mastectomy after tests for the BRCA gene revealed she was at high risk.
Now a charity has called for the health service to consider testing women for the rare CDH1 gene.
Claire Turner, chair of Lobular Breast Cancer UK said: ‘Twenty-two women a day are diagnosed with a type of breast cancer that is really hard to find using the existing imaging systems.
‘Because of the way lobular breast cancer grows and presents itself, it is very hard to be seen on a mammogram. When women are eventually diagnosed, often the cancer is at a far later stage.’
She added: ‘Tests that identify a potential genetic risk factor could be beneficial as they might allow them to be monitored and diagnosed far earlier.
‘It’s something we’d welcome because the current imaging system isn’t appropriate for lobular breast cancer.’
The disease begins in the milk-producing glands and accounts for about 15 per cent of diagnosed breast cancer cases.
Diagnosed early, it can be successfully treated. But because tumours grow in a ‘spider’s web’ pattern rather than forming a lump, it is harder to spot with a mammogram, ultrasound or biopsy.
Symptoms can include an inverted nipple, a thickening of breast tissue, a tugging sensation or a dent in the breast.
BBC presenter Victoria Derbyshire, 55, was diagnosed in 2015 after researching online what caused an inverted nipple.
Diagnosed with stage 2 invasive lobular breast cancer, she underwent a right-sided mastectomy and reconstruction, followed by chemotherapy and radiotherapy.
The link between lobular breast cancer and faulty genes was flagged by Italian academics in a study of more than 5,000 women with lobular breast cancer, published last month.
Researchers found one in 66 had a pathogenic variant of the CDH1 gene– mainly women who had developed the disease before the age of 45 or who had a family history of breast cancer.
The gene has been linked to some cases of stomach cancer. There have also been suggestions that patients at risk of stomach cancer are more likely to develop lobular breast cancer.
However, this study is the first to conclude there is a clear link between CHD1 and lobular breast cancer. Crucially, it also found that a fifth of patients with CDH1 who developed the disease had no family history. None carried the cancer-linked BRCA gene either.
UK clinicians believe screening for CDH1 would likely catch cases of lobular breast cancer early, but question whether the NHS has sufficient resources to roll out such a programme.
‘In the current circumstances of the NHS, it’s unlikely it would be brought in,’ says Vosia Miedzybrodzka, professor of medical genetics at the University of Aberdeen. ‘But as genomic testing becomes more commonplace, this could be one of the genes looked at.’
One patient who believes she may have benefited from genetic screening is Ruth Warden, 56, from West Yorkshire. The mother-of-two is being treated for incurable lobular breast cancer after two separate mammograms failed to spot the disease.
The former NHS administrative worker was finally diagnosed in 2018 and is undergoing oral chemotherapy. While Ruth’s condition is stable, the cancer cannot be cured and has spread to her liver, bones and brain lining.
‘The BRCA gene is well-known and it’s recognised that if you’ve got a family history of breast cancer you need to be more aware and you can be tested,’ she says.
‘If there is another gene we need to be aware of that could be a risk factor for lobular breast cancer, then tests should be put in place.
‘If I had been given a test when I had my first mammogram in my 40s, it could have made a huge difference. I could have had been closely monitored and it could have been picked up sooner.’