Three sisters, Mary, Sandra and Kerry Lloyd all developed breast cancer within 15 months of each other. They joined the 100,000 Genomes Project at Leicester’s Hospitals, which is part of the East of England NHS Genomic Medicine Centre. They were very keen to participate in the project – to understand more about their cancer, to understand if it was inherited and what the risks to other family members might be.
The Lloyd family
The three sisters are not the only ones affected by cancer in their family. Their late mother had also been affected, as well as two other female relatives over three generations.
They had already undergone genetic testing for changes in the BRCA1 and BRCA2 genes – which can be a cause of breast cancer. But these tests didn’t find anything. The sisters donated a small amount of blood and have had their genomes sequenced. Bioinformaticians will analyse the sequences to see if there are any changes in their 3.2 billion letters of DNA code that could be a cause of their cancer.
Familial breast cancer
Breast cancer affects approximately 1 in 8 women in the UK. Around 5-10% of breast cancers are thought to be hereditary, caused by abnormal genes passed from parent to child. This is called ‘familial breast cancer’. Families that have familial breast cancer may have men with breast cancer and sometimes have other cancers, such as ovarian cancer or prostate cancer. In these families, cancers may develop at a younger age than usual.
Most inherited cases of breast cancer are associated with specific changes in two genes: BRCA1 (BReast CAncer gene one) and BRCA2 (BReast CAncer gene two).
Everyone has BRCA1 and BRCA2 genes. The function of the BRCA genes is to repair cell damage and keep breast cells growing normally. But when these genes contain abnormalities or mutations, the genes don’t function normally and breast cancer risk increases.
Not all familial breast cancer is due to mutations in BRCA. Changes in other genes have also been found which have a role in causing familial breast cancer.
How does identifying a mutation help?
By identifying the gene changes that are causing someone’s cancer a specific chemotherapy or other treatment may be able to be recommended. For example, newly developed drugs are already benefitting patients with a specific genome change in their skin cancer.
This is the case with testing in breast cancer too. Doctors are increasingly likely to use information about a patient’s BRCA status, together with lots of other information, to help determine which drug to prescribe. We hope that, one day, treatments based on the specific characteristics of the tumour, including the genetic make-up, can be offered to all patients.
Finding an inherited mutation responsible for a cancer means that other family members could then be tested for it, if they wished to be. This would help predict their risk, and preventative surgery may be an option for some people.
By taking part in the 100,000 Genomes Project, the Lloyd sisters are contributing to research. Their de-identified data, together with data from other participants, is available to researchers through our secure database.
There is great interest in understanding the genomic factors which might be connected to breast cancer risk. These factors could include changes in the way known risk genes (like BRCA1 and BRCA2) are regulated, or switched on and off.
Several other genes have already been identified that may increase the risk of breast cancer. And research might identify still more. There is also a lot of research into how to use genomic testing to predict long term prognosis for breast cancer patients, and how it could be used to guide treatment and screening.
By taking part in the 100,000 Genomes Project, the Lloyd sisters are part of research like this. Find out more about research in the 100,000 Genomes Project.
Cancer in the 100,000 Genomes Project
There are two ways that patients with cancer can join the project. Families with particular types of cancer in many close relatives, often at a young age, can join the programme together in the way the Lloyd sisters did, by giving blood samples.
People who have very recently been diagnosed with certain types of cancer, but don’t necessarily have a family history of cancer, are also being invited to join the Project. These patients can join by donating blood samples and a sample of their tumour. Find out more about cancer genomics and sequencing tumour samples.
Find out more about what feedback and results participants can expect in our taking part section.
Support and advice
The following organisations can give information, support and advice about breast cancer and familial breast cancer.
Breast Cancer Now, 08080 100 200 www.breakthrough.org.uk
Breast Cancer Care, 0808 800 6000 www.breastcancercare.org.uk
CancerHelp UK – the patient information website of Cancer Research UK, 0808 800 4040 www.cancerhelp.org.uk
Macmillan Cancer Support, 0808 808 00 00 www.macmillan.org.uk
Target Ovarian Cancer, 020 7923 5470 www.targetovariancancer.org.uk