Study paints clearer picture of cancer risk

Matt Woodley

21/06/2019 12:39:44 PM

A new study has reportedly identified nearly 100 genetic variants that increase the risk of breast cancer, but how useful will it be for GPs?

Dr Alia Kaderbhai
Dr Alia Kaderbhai says while the study’s findings sound promising, it is still ‘very early’.

The study, led by Queensland’s QIMR Berghofer Medical Research Institute, collated research and clinical data from around the world for a large number of BRCA1 and BRCA2 genetic variants of unknown clinical significance.
Aside from identifying 94 genetic variants that increase the risk of developing breast, ovarian, prostate and pancreatic cancers, it also revealed hundreds of others that did not.
However, the significance of thousands of those variants is still unknown, which is problematic for management of families carrying those variants.
According to senior author and head of QIMR Berghofer’s Molecular Cancer Epidemiology Group, Associate Professor Amanda Spurdle, the study is the largest of its type to date.
‘If we can narrow down which variants pose a danger, we can reduce concern for clinicians and patients, and avoid unnecessary testing that unfortunately sometimes occurs for individuals with a variant of uncertain significance,’ Associate Professor Spurdle said.
‘It’s like separating the wheat from the chaff.
‘These findings will help doctors give advice on the frequency of early screening such as breast scans, preventive measures such as risk-reducing surgery or medication, and even personalised treatment with specific drugs [PARP-inhibitors] for people with those cancers.’
But Dr Alia Kaderbhai, GP and coordinator of the RACGP Specific Interests Breast Medicine subgroup, told newsGP while the results sound promising and testing can be useful in the right context, GPs shouldn't lose sight of the importance of risk reduction.
‘This is one test, but it’s not the be all and end all in determining risk. As primary healthcare professionals our key role is in risk reduction, in particular with regard to lifestyle modifications,’ she said.
‘We still really need to be focusing on preventive health, such as exercise, weight control, limiting alcohol consumption, not smoking, and the other factors that increase the risk of breast cancer.’
Dr Kaderbhai explained that even though the majority of breast cancers are spontaneous, around 3–5% of cases are associated with the BRCA gene and as such high risk patients should always be referred to familial risk assessment clinics.
‘We should welcome genetic testing as it can be very useful and is promising for the management of diseases,’ she said.
‘The largest impact we might see is patients asking about the test and whether they can have it, as well as how we should refer for that if we think it’s appropriate and even though BRCA testing is commercially available, you need to do a proper assessment about risk before you use it.'
GP resource
The RACGP’s Genomics in general practice provides key information to help GPs assess and manage common genetic conditions in the general practice setting.

breast cancer genetics research


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