Angelina Jolie's double mastectomy puts genetic key to breast cancer in the spotlight

The developing science of DNA profiling helped the actress decide to have a double mastectomy

Angelina Jolie during the G8 Meeting which she attended with William Hague in April (Getty Images)

Video: The Foreign Secretary William Hague praises Angelina Jolie

Even celebrities are mortal. They share our genes and, like us, cannot escape their inheritance. Angelina Jolie’s graceful and dignified account of her encounter with her own mortality in The New York Times will inspire millions.

It will also shine a light on the developing science of genetic diagnosis and DNA profiling which is increasingly allowing patients at high risk of inherited diseases to be identified so that they can take preventive action.

The BRCA1 and BRCA2 genes were the first to be identified in breast and ovarian cancer more than 20 years ago. The presence of faulty versions of the genes increases the risk of the diseases by at least 50 per cent, the exact proportion depending on other factors. Just as the risk varies from woman to woman, so does the response.

In Ms Jolie’s case it was radical surgery to remove her breasts. About 3,000 women in the UK have done likewise. But for other women the decisions required may be less radical and distressing, involving modifying lifestyle, having regular mammograms or MRI scans or starting a course of preventive drugs.

Only last January, the UK’s National Institute for Clinical Excellence recommended for the first time in draft guidance that women at high risk of breast cancer be prescribed the drug tamoxifen or a related drug as a preventive measure. Tamoxifen has been established as a treatment for the disease for decades.

Ms Jolie, however, opted for surgery with its more certain outcome. Doctors told her that her risk was raised by 87 per cent and reduced to 5 per cent by the removal of her breasts. Take away most of the tissue where the cancer develops and you take away most of the risk.

She chose nipple preserving surgery – one of the toughest choices women in her position have to make. It meant that some breast tissue was left behind. But after reconstruction with implants, her breasts would look normal following the operation – which was important to reassure her children.

“They can see my small scars and that’s it. Everything else is just Mommy, the same as she always was,” she wrote.

The maximum protection from the surgery is achieved by removing the maximum amount of tissue. But removal of the nipple is a disfiguring operation and a step too far for many women.

Genetic testing of the kind Ms Jolie underwent is becoming increasingly common. Testing for the presence of specific mutations is already available for a range of cancers, including those of the womb, bowel, stomach and bladder, where the presence of an inherited faulty gene may increase the risk by between 10 and 60 per cent

The next stage is genetic profiling which offers patients personal risk analyses, predicting their chance of developing disease and enabling doctors to tailor treatments to their genetic inheritance.

An early example was provided by Greg Lucier, chief executive of Life Technologies, the Californian company that makes machines for reading the human genome who submitted himself as a guinea pig to test the technology he promotes.

His genetic profile revealed several surprises, including that he carried a mutation linked with breast cancer, which could be important to his teenage daughter. He also carried a mutation linked with Parkinson’s disease, which his mother suffered from.

But while the threat of breast cancer can be dealt with through regular screening, drugs or surgery, there are no preventive measures that can be taken against Parkinson’s, highlighting one of the drawbacks of genetic testing. Is it helpful to know you are at high risk of a terminal disease about which you can do nothing?

Ms Jolie’s public declaration of her medical history will be a huge boost for breast cancer prevention, and the charities that seek to improve it. She joins former X-factor judge Sharon Osborne and Liberty X singer Michelle Heaton who both had double mastectomies and have written and spoken about their experience.

Celebrity endorsement can have a transformative effect. When former Big Brother contestant Jade Goody was diagnosed with cervical cancer in 2008 and chose to “die in the public eye” screening rates for the disease rose by up to 50 per cent.

The Government launched a review to examine the age at which screening should start. The disease, which claims more than 750 lives a year in the UK, had not had so much attention for a generation.

Case study: ‘I said I wanted the operation’

Jane Netherton, 58, lives in Plymouth, with her husband, Stephen. Like Jolie, she underwent a double mastectomy

“My grandmother and mother had breast cancer, and when my sister was diagnosed in her early 40s, it was found that she had the faulty gene. I also had BRCA2, and I had an 85-90 per cent risk of getting breast cancer. You’re given a counsellor, but I said straight away I wanted the operation. I had only just got married. In 2007, I had a double mastectomy. I can imagine that for many it isn’t an easy decision. My husband has been brilliant.”

Raising awareness: Celebrity sufferers

Jade Goody

The Big Brother contestant was told she had cervical cancer while appearing on the Indian version of the reality show in 2008. Her struggle and death at 27 in 2009 prompted a marked rise in women having smear tests.

Michael J Fox

Since being diagnosed with Parkinson’s disease in 1991, the Back To The Future actor has been at the forefront of efforts to raise awareness. In 2006, he starred in a powerful political advert advocating stem cell research.

Terry Pratchett

In 2007, the Discworld author announced that he was suffering from early-onset Alzheimer’s. As well as fundraising and campaigning, he is a leading voice in the movement for assisted suicide.

Christopher Reeve

Reeve was paralysed in 1995 when he broke his neck after being thrown from a horse. The Superman actor became an advocate for research on spinal cord injuries. His death in 2004 led to arguments over stem cell therapies to become a major campaign issue.