MELBOURNE, June 21 (Xinhua) -- A study published on Wednesday has brought Australian researchers a step closer to understanding gene mutations that can cause breast cancer.
Scientists from the University of Melbourne and Peter MacCallum Cancer Centre have for the first time accurately established the likelihood that carriers of the BRCA1 and BRCA2 gene mutations will contract cancer.
The BRCA mutations are hereditary issues whereby chromosomes within the BRCA1 or BRCA2 genes, both of which are tumour-suppressing genes, are misplaced, drastically increasing the likelihood of developing breast or ovarian cancer.
The study found that women with the BRCA1 mutation had, on average, a 72 percent chance of developing breast cancer by the time they were 80 years old and a 44 percent likelihood of contracting ovarian cancer.
For women with the BRCA2, the chances were slimmer at 69 and 17 percent respectively for breast and ovarian cancer.
Almost 10,000 women from around the world with the mutations were assessed over 20 years for the landmark study.
John Hopper, lead researcher from the University of Melbourne, said that the fact that researchers were able to analyze the participants and their risk factors over the course of 20 years rather than assess retrospective data made the study the most reliable one done yet.
"Our study looked at women and followed them forward in time. Previous studies had looked backwards, and those studies are prone to getting the wrong answer," Hopper told Xinhua on Wednesday.
"Our estimates were thankfully close to past estimates, but were more accurate, precise and believable."
He said that once women with either mutation had hit the highest risk age group, the risk stayed consistent for the rest of their lives.
"An important finding was that carrier's risk was virtually the same from age 50 years on, meaning that carriers should continue to be vigilant with screening," Hopper said.
Researchers found that women with the mutations were at a relatively low risk until they hit their 30s.
Hopper said the research should make women around the world with the mutations to have constant checks for breast and ovarian cancer.
"They need not undertake extensive screening at young adult ages unless there were other indications, such as strong family history of early onset disease, but need to be vigilant once their risk have achieved their maximum plateau - and maintain screening," he said.
"That is, our study has provided information on the risk as it changes with age and this can be used to hopefully make screening and prevention more effective."