KUALA LUMPUR, March 8 — Cancer Research Malaysia has developed a tool called the Asian Genetic Risk Calculator (ARiCa) that enables women with breast cancer to determine their likelihood of inheriting a faulty BRCA1 or BRCA2 gene.
BRCA1 and BRCA2 are tumour suppressor genes that help keep breast, ovarian and other types of cells from growing and dividing too rapidly or in an uncontrolled way.
ARiCa was developed based on a study that analysed BRCA1 and BRCA2 in more than 8,000 breast cancer patients from Malaysia and Singapore.
When it comes to breast cancer, data shows that one in 25 patients inherited a faulty BRCA gene. Prior to this research, breast cancer patients are only offered a test if they were diagnosed at a young age or have close relatives with breast or ovarian cancer.
However, age and family history alone do not accurately predict the likelihood of carrying a faulty gene. As such, many gene carriers are not offered the genetic test. This could cost them in terms of life-saving treatments and prevention strategies for their close relatives.
Although a number of mutation prediction tools have been developed, most of them are designed for European women and are less accurate for women of Asian descent.
As a result, Asian patients and their family members miss out on the opportunity to be aware of their genetic risk status, thereby losing the possibility for cancer prevention and accurate treatment selection.
“Using criteria such as age and the presence of family history of breast cancer, we estimate that each year, nearly 4,000 newly diagnosed breast cancer patients in Malaysia would need genetic counselling and testing, but they often don’t consider a genetic test because most assume that they are unlikely to have inherited a faulty gene,” said Prof Dr Teo Soo Hwang, chief scientific officer at Cancer Research Malaysia, who led the study.
“With ARiCa, we can now give each woman their individual likelihood of being a BRCA carrier so that they can be empowered to make informed choices about their health and health care practitioners can provide more accurate treatment plans for their patients.”
The study was conducted by Cancer Research Malaysia in collaboration with University of Cambridge, Universiti Malaya, Subang Jaya Medical Centre, the University of Nottingham, the Genome Institute of Singapore, National University of Singapore, National University Hospital, KK Women’s and Children’s Hospital, Tan Tock Seng Hospital, National Cancer Centre Singapore, Singapore General Hospital, and Changi General Hospital.
“From the clinical perspective, knowing that a patient has a BRCA mutation may alter their surgical management. For instance, a patient with a BRCA mutation has a 50 per cent likelihood of developing breast cancer on the opposite breast. An acceptable prevention strategy is to remove both breasts with an option of immediate breast reconstruction,” said Dr Yip Cheng Har, consultant breast surgeon at Subang Jaya Medical Centre.
“But because a BRCA carrier also has a 30 to 40 per cent risk of developing ovarian cancer, removal of the ovaries can be done at the same time.
“In addition to changing the available surgical options, medical practitioners can also prescribe the patient with a new class of drugs called PARP inhibitors that targets the BRCA mutation to improve survival in carriers with early and late stages of breast cancer.
“Since we cannot provide cancer genetics services for all patients, ARiCa can help us to identify patients that need to be referred for genetic counselling and testing.”