What is genetic testing for breast cancer?
Genetic testing screens for mutations in genes that increase cancer risk. Two common tumour suppressor genes are BRCA1 and BRCA2. Mutations to either gene affect their DNA-repair function, potentially leading to uncontrolled cell growth, and ultimately, cancer, said breast surgeon Dr Celene Ng.
Don’t rush to get genetic testing
Most breast cancers are sporadic – only 5 to 10 per cent are due to genetic abnormalities, said Dr Celene Ng.
Doctors generally recommend genetic testing for patients diagnosed with breast cancer at a relatively young age of below 45 to 50 years old, have triple negative breast cancer below the age of 60, have multiple cancers, or have multiple first-degree relatives with breast, ovarian, prostate or pancreatic cancer, Dr Celene Ng explained.
Weigh the pros and cons carefully
Patients should see a counsellor at a genetics clinic to understand the medical and personal implications of genetic testing, including how it might affect family members, insurance coverage and employment, advised gynaecologic oncologist Dr Joseph Ng.
However, Singapore’s insurance rules stop companies from asking for – or using – predictive genetic-test results (like a positive BRCA finding) for nearly all policies. They may only consider such results if you are applying for an exceptionally large life, total permanent disability, long-term care, critical illness and disability income insurance.
Gene testing empowers patients to make better choices
There are targeted drugs that work on gene-positive breast cancers in patients diagnosed at later stages, but the main advantage of genetic testing is the ability to mitigate risk with more frequent screening. A woman can also opt for preventative surgery (removing breasts and ovaries), which reduces the risk significantly but does not eliminate it, Dr Celene Ng added.
Consider the consequences of preventative surgery
Removing ovaries in pre-menopausal women triggers sudden menopause, warned Dr Joseph Ng. This raises long-term risks of heart disease, osteoporosis and various other health conditions.
Keeping her natural breasts also carries emotional value; women eligible for lumpectomy or other breast-conserving surgeries should consider it first, said Dr Celene Ng.
If the whole breast has to be removed, it can be reconstructed immediately or later either with a silicone implant or the patient’s own tissue taken from another area of the body, said plastic surgeon Dr Yap.
