Screening for breast cancer genes 'is cost-effective'

Friday January 19 2018

"Testing all women for the 'Angelina Jolie gene', even if not considered at risk, would prevent cancers, save lives and is cost-effective, say doctors," BBC News reports.

The actress Angelina Jolie helped raise awareness of the genetic risks of both breast and ovarian cancer after tests showed she had "faulty" BRCA1 and BRCA2 genes.

Both mutations are known to significantly increase the risk of a woman developing breast or ovarian cancer (or, in some cases, both).

UK researchers found that testing for these types of genes is more cost-effective than current family history-based screening if offered to every woman over the age of 30.

Thanks to advances in technology, these types of genetic tests are a lot cheaper than they used to be, now costing around £175.

Researchers calculated that if 71% of women took up testing, up to 17,500 ovarian cancers and 64,500 breast cancers could be prevented, and 12,300 lives saved.

They also estimated that 64,493 breast cancer cases and 17,505 ovarian cancer cases could be prevented using the new range of genetic tests.

The total cost of screening all 27 million women over 30 in the UK was estimated to be around £3.5 billion.

BBC News reported: "The UK's National Screening Committee said it would look at the findings 'with interest'."

Women concerned about being a carrier because of a family history of breast or ovarian cancer should contact their GP.

Where did the story come from?

The study was carried out by researchers from the Cancer Research UK Bart's Centre at Queen Mary University London, and was funded by The Eve Appeal charity.

It was published in the peer-reviewed Journal of the National Cancer Institute.

The UK media's reporting of the study was generally accurate.

What kind of research was this?

In this modelling study, researchers aimed to compare the lifetime costs of current screening tests available for detecting breast and ovarian cancer, and the subsequent treatment, with the lifetime costs of new genetic tests and treatments.

Cost-effectiveness is thought of in terms of quality adjusted life years (QALY), which estimates both the quality and quantity of life lived.

The current benchmark used by the NHS is that an intervention that costs less than £30,000 may be cost-effective if it's expected to add at least 1 year to a person's QALY.

The researchers used 29 estimates in their model, including one for the prevalence of the gene in the population (about 7 people in 100,000).

What did the research involve?

Two approaches to identify people carrying these genes were compared with each other in terms of their cost-effectiveness.

Currently, women with strong clinical criteria and a family history of cancer greater than 10% are offered gene testing (BRCA1/BRCA2 testing).

The researchers compared this with:

  • adding new gene tests to those identified using the same clinical criteria or family history-based screening
  • testing all women aged 30 and over with the new panel of tests for BRCA1/BRCA2/RAD51C/RAD51D/PALB2

In theory, carriers of these genes (who are at higher risk) could be identified earlier and be offered various options to help diagnose cancer should it occur, or prevent its onset.

Information on the prevalence of gene mutations in the population was gathered from various scientific publications and national guidelines in the UK and the US, such as Cancer Research UK and the US National Cancer Institute.

Costs were primarily taken from NHS reference costs documents and National Institute for Health and Care Excellence (NICE) guidelines.

The researchers compared the cost-effectiveness and QALY in both the UK and US populations, as these countries have different screening practices and approaches to cost-effectiveness.

They took account of the costs of genetic counselling (genetic testing and associated advice), and assumed this would be taken up by 71% of people having the test – previous experience has shown not everyone offered a test will accept it.

They also considered the risk of cardiovascular mortality, which is a side effect for women who experience premature loss of ovarian function.

What were the basic results?

The researchers found that screening all 26.65 million women over 30 in the UK with the new genetic tests:

  • population screening was a cost-effective strategy compared with current policy, and would cost an additional £21,600 per year to save a year of additional life (quality adjusted)
  • for an individual, the benefit averaged out at between 7.5 and 9.3 days of extra life
  • could prevent 523 deaths from breast cancer for every million women
  • could prevent 461 deaths from ovarian cancer for every million women
  • the test alone costs £175, so would cost approximately £3.5 billion for 20 million women

How did the researchers interpret the results?

The researchers stated that this kind of population-based genetic testing is more cost-effective than any clinical criteria or family history strategy.

They went on to say that for the first time, this analysis addresses the important topical issue of the cost-effectiveness of a population-based strategy for testing moderate- to high-risk carriers of the ovarian or breast cancer gene mutation in the general population.

Conclusion

This study provides promising evidence to help guide policy decisions for allocating healthcare resources to help prevent breast and ovarian cancer.

The researchers estimated that routine clinical criteria and family history tests are missing around 50% of mutation carriers. It's encouraging that the new testing strategy might significantly increase detection rates.

But it's worth bearing in mind that as the first step, it won't be possible to offer the test to the general population immediately.

Policymakers still need to understand the balance of these benefits with the known harms of population screening, such as the risk of overdiagnosis, false alarms and whether any cases could be missed.

It's also not clear how best to tackle the practical challenge of offering genetic counselling to all women being tested so they're adequately informed about, and prepared for, the consequences when their individual risk of carrying these genes are so low.

Being identified as a carrier of a mutated gene doesn't automatically mean the treatments to prevent the development of ovarian and lung cancer will be effective.

Identifying the mutation is just the initial step, and many discussions with a consultant will follow, all of which can be very stressful.

Despite these limitations, this study provides promising evidence that the new genetic test may help identify more people with breast and ovarian cancer.

Find out more about genetic tests for cancer risk.

Analysis by Bazian
Edited by NHS Choices