Hundreds of more breast cancer patients should be tested for the BRAC1 gene mutation test. What exactly is the BRAC1? It is is a human caretaker gene that produces a protein called breast cancer type 1 susceptibility protein, responsible for repairing DNA. BRCA1 is expressed in the cells of breast and other tissue, where it helps repair damaged DNA,
or destroy cells if DNA cannot be repaired. If BRCA1 itself is damaged,
damaged DNA is not repaired properly and this increases risks for
cancers.
A BRCA mutation is a mutation in either of the genes BRCA1 and BRCA2. Harmful mutations in these genes produce a hereditary breast-ovarian cancer syndrome in affected families. Mutations in BRCA1 and BRCA2
are uncommon, and breast cancer is relatively common, so these
mutations consequently account for only five to ten percent of all
breast cancer cases in women.
BRCA Testing Kit and Where the BRCA Gene is Located
The researchers – funded by Cancer Research UK and led by scientists
at The Institute of Cancer Research – looked at more than 300 women with TN breast cancer and found BRCA1 mutations in nearly one in five women diagnosed under 50.
But due to the cost of testing for the BRCA1 mutation, NICE guidance
recommends that BRCA1 should be offered if the likelihood of detecting a
mutation is greater than 20 per cent, although many testing centres
offer it if the likelihood is between 10-20 per cent.
Centres use a range of criteria and methods to determine if a patient
is eligible for testing. But this requires specialist knowledge and
software and potentially misses hundreds of women a year.
Based on their findings the researchers estimate more than one in
three women with TN breast cancer caused by BRCA1 mutations would not
have been tested using the current criteria.
Lead author Professor Nazneen Rahman, a Cancer Research UK funded
researcher at the Institute of Cancer Research and the Royal Marsden
Hospital, said: “Our findings show that women diagnosed with
triple-negative breast cancer under 50 should be offered BRCA1 testing.
Using a simple age criteria for testing will provide a clear and
understandable guide for doctors and women to follow, and should result
in many more women benefitting from the optimised care that genetic
information makes possible.”
Changing the current testing guidelines could mean an extra 1,200
tests a year, which the researchers acknowledge will place an extra
burden on current genetic testing services.
Professor Rahman added: “There are hurdles to overcome so that NHS
testing services can cope with more BRCA1 testing, but we’re moving
towards an era of faster and cheaper genetic testing, so it will soon be
possible.”
Women carrying the BRCA1 mutation have up to a 65 per cent chance of
developing breast cancer by the time they are 70. But only around one in
900 women in the general population carry a BRCA1 mutation.
Breast cancers with BRCA1 mutations can respond well to treatment
with platinum-based drugs, such as carboplatin and cisplatin, and also
to radiotherapy. But they can develop resistance to the treatment and
start to grow again.
Rowena Kincaid, 36, from Cardiff, was diagnosed with breast cancer in
July 2009 after finding a lump. It was confirmed as triple negative and
she underwent a lumpectomy followed by four months of chemotherapy and
radiotherapy. She is now doing well, is back at work and took part in
Race for Life in 2011.
She said: “I am interested to know about the genetic testing, as I know there has been cancer in the family. To be offered the chance to find out
if I carry the BRCA1 mutation would not only give me insight to my own
disease but also allow me and my family to discuss with our doctors if
we carry the mutation what the next steps would be.”
Professor Peter Johnson, chief clinician at Cancer Research UK, said:
“It’s important that we identify women and their families who carry
BRCA1 mutations. They’re more likely to develop breast and ovarian
cancer, so armed with this knowledge doctors can offer targeted
screening and tailored treatments to these women.
“The NHS needs to adapt so that tests for BRCA1 can be offered to
women who are likely to carry the mutation. This approach will be
cost-effective for the NHS in the long-term, leading to a substantial
reduction in the number of breast and ovarian cancers by offering
preventative treatments for those women and their families who are at
greatest risk.”
More information: L. Robertson et al BRCA1 testing should be offered to individuals with triple-negative breast cancer diagnosed below 50 years British Journal of Cancer (2012). doi:10.1038/bjc.2012.31
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