Women should be offered genetic testing to detect a breast cancer that affects thousands of people each year but 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 detect in its early stages.
A new study suggests that 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 begins to grow.
Similar tests are available for genes linked to other types of breast cancer. Hollywood star Angelina Jolie underwent a double mastectomy after BRCA gene testing revealed she was at high risk.
Now a charity has asked the health service to consider testing women for the rare CDH1 gene.
BBC presenter Victoria Derbyshire, 55, was diagnosed in 2015 after researching the cause of an inverted nipple online.
Hollywood star Angelina Jolie underwent a double mastectomy after BRCA gene testing revealed she was at high risk.
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 detect in its early stages. In the photo: a mammogram (archive image)
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 difficult to find using existing imaging systems.
‘Because of the way lobular breast cancer grows and presents, it is very difficult to detect on a mammogram. When women are finally diagnosed, the cancer is often at a much more advanced stage.’
He added: “Testing that identifies a possible genetic risk factor could be beneficial, as it could allow it to be monitored and diagnosed much earlier.”
“It’s something we would appreciate because the current imaging system is not appropriate for lobular breast cancer.”
The disease begins in the milk-producing glands and accounts for approximately 15 percent of diagnosed breast cancer cases.
If diagnosed early, it can be treated successfully. But because the tumors grow in a “spider web” shape rather than forming a lump, they are harder to detect with a mammogram, ultrasound, or biopsy.
Symptoms may include an inverted nipple, thickening of the breast tissue, a pulling sensation, or a dent in the breast.
BBC presenter Victoria Derbyshire, 55, was diagnosed in 2015 after researching the cause of an inverted nipple online.
She was diagnosed with stage 2 invasive lobular breast cancer and underwent a right-sided mastectomy and reconstruction, followed by chemotherapy and radiation therapy.
The link between lobular breast cancer and defective genes was pointed out by Italian academics in a study of more than 5,000 women with lobular breast cancer, published last month.
The researchers found that one in 66 had a pathogenic variant of the CDH1 gene, mainly women who had developed the disease before age 45 or who had a family history of breast cancer.
The gene has been linked to some cases of stomach cancer. It has also been suggested that patients at risk for stomach cancer are more likely to develop lobular breast cancer.
However, this study is the first to conclude that there is a clear link between CHD1 and lobular breast cancer. Crucially, it also found that one-fifth of CDH1 patients who developed the disease had no family history. Neither carried the cancer-related BRCA gene.
Doctors in the UK believe that CDH1 screening would likely detect lobular breast cancer cases early, but question whether the NHS has enough resources to implement such a programme.
“In the current circumstances of the National Health Service, it is unlikely to be introduced,” says Vosia Miedzybrodzka, professor of medical genetics at the University of Aberdeen. “But as genomic testing becomes more common, this could be one of the genes studied.”
One patient who believes she could have benefited from genetic testing 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 detect the disease.
The former NHS white-collar worker was finally diagnosed in 2018 and is receiving oral chemotherapy. While Ruth’s condition is stable, the cancer cannot be cured and has spread to the liver, bones and lining of the brain.
“The BRCA gene is well known and it is recognized that if you have a family history of breast cancer you should be more aware and can get tested,” she says.
“If there is another gene that we should be aware of that could be a risk factor for lobular breast cancer, then testing should be done.
‘If I had been tested when I had my first mammogram when I was 40, it could have made a big difference. They could have followed me closely and detected it sooner.’