BRCA1/2 gene mutations and cancer prevention: What you need to know

7,400 women are diagnosed with ovarian cancer in the UK each year. Approximately 15% of these diagnoses are linked to a BRCA1/2 gene mutation.

As March is Ovarian Cancer Awareness Month, it’s the perfect time to get clued up about hereditary ovarian cancer and BRCA gene mutations – specifically why BRCA awareness is a potentially life-saving clinical tool.

What are BRCA1/2 gene mutations?

BRCA1 and BRCA2 are tumour suppressor genes: they help to repair damaged DNA and regulate the growth and division of cells. When either gene is mutated, their ability to function properly is impaired. As a result, damaged and abnormal cells may be allowed to build up to form a cancerous tumour. BRCA1/2 gene mutation carriers have an increased risk of ovarian, breast, pancreatic and prostate cancers.

On average, women have a 2% chance of developing ovarian cancer. However, women with a mutated BRCA2 gene have a 40% - 60% lifetime risk of developing ovarian cancer, and women with an impaired BRCA1 gene have a 10% - 20% lifetime risk of the disease.

Who’s at risk?

In the general population, only between 1/400 – 1/800 people will carry a BRCA1/2 mutation. However, this risk is much higher in certain populations. 1 in 40 people from an Ashkenazi Jewish background has this genetic impairment. It’s also thought BRCA1/2 mutation prevalence is greater in Dutch, Icelandic, Norwegian, Swedish, Polish and Pakistani populations.

Whichever population group you’re presented with, one fact remains the same: those who carry the “faulty” gene have a 50% chance of passing it on to their child. In fact, men have just as much chance of inheriting and passing on these genetic mutations as women.

When to offer testing

The NHS offers BRCA testing to those whose risk of carrying a mutation is judged by a geneticist to meet or exceed a 10% risk threshold. This is calculated by assessing the individual’s personal and familial cancer history.

NICE Guidelines state a woman with high-grade serous epithelial ovarian cancer automatically qualifies for testing. Otherwise, a geneticist will consider a combination of factors such as the number and types of potentially BRCA-related cancer cases in the family, the age at which these cancers occurred, etc. to determine the likelihood a mutated BRCA gene is present.

If a woman qualifies for testing, it is imperative that she receives genetic counselling before and after the test, as the results can have far reaching physical and emotional implications for her and her family.

Why is BRCA testing important?

However, there are positive points to consider. Identifying a BRCA1/2 gene mutation gives a woman a number of clinical advantages against ovarian cancer, a disease that otherwise has very poor outcomes.

1. Prevention. Ovarian cancer is the deadliest gynaecological cancer; only 35% of women survive five years beyond their diagnosis. Women who are aware of an elevated ovarian cancer-risk can consider preventative, potentially life-saving options such as risk-reducing.

2. Tailored treatment. BRCA positive ovarian cancer patients respond better to some therapies than those without the mutation. Knowing your BRCA status means patients can receive personalised and more effective treatment.

3. Alerting the family. BRCA1/2 gene mutations can be inherited. If someone has a BRCA1/2 gene mutation, there’s a chance other family members have the variation as well. Mutation carriers can alert family members to their BRCA-risk so that they too can decided whether or not to be tested and take preventative action.

Alongside these positives, it’s important to remember the results may hold difficult emotional consequences for the person in question.

BRCA positive: A patient’s perspective

Laura Moses discovered she had inherited a BRCA1 gene mutation when she was 26 years old. She knows all too well the dangers of ovarian cancer: even by the standards of BRCA mutation carriers, Laura developed the disease unusually young, aged just 27.

Laura’s BRCA journey began with a distant relative’s cancer diagnosis.

“My great aunt in Australia was diagnosed with breast cancer. Discussions regarding her family’s history of breast and ovarian cancer prompted her oncologist to suggest genetic testing. She tested positive for the BRCA1 mutation and was advised to inform the rest of the family.

“My grandfather tested positive, and so did my father. My three siblings and I decided to get tested too: I was the only one to test positive for a BRCA1 mutation. I remember the day when I answered the phone and received the news. I did not know what to think or feel. In a strange way it felt like I had been told I had cancer.”

Laura decided to take control immediately. She had her breasts screened every six months and had her ovaries and CA-125 levels checked once a year.

Despite the emotional impact of her results, Laura does not regret her choice to get tested – particularly when she was diagnosed with ovarian cancer the next year.

“There is not one minute where I question my decision to get tested. It was tough to find out about the mutation so young, but it allowed me to make choices about my body. It meant I was able to get regular health checks. My ovarian cancer was diagnosed early and when it was, knowing about the BRCA1 mutation helped.”

In fact, Laura’s oncologist told her that patients with BRCA1 mutations are often more sensitive to platinum-based chemotherapy. This knowledge meant her medical team could develop a personalised treatment plan.

Now in remission, Laura works with medical research charity Ovarian Cancer Action to advocate BRCA awareness.

Ultimately, BRCA testing is a vital cancer prevention tool. It can empower women and their families to make informed medical choices and safeguard their health. In Laura’s words: “We have to remember knowledge is power.”

To find out more about BRCA gene mutations and hereditary cancer visit Ovarian Cancer Action’s online BRCA Hub at ovarian.org.uk/ovarian-cancer/brca/