The study, published in Cancer Epidemiology, Biomarkers and Prevention is the largest of its kind in Australia and one of the largest in the world. It followed about 4,000 women in a study of the BreastScreen program in Western Australia.

University of Melbourne Research Fellow Dr Carolyn Nickson and colleagues from the Melbourne School of Population Health said the findings reaffirmed the importance and efficacy of mammography.

The study focused on women aged 50-69 years, who are in the target age range for screening. It included 427 cases where women had died from breast cancer and 3,650 control women who were still alive when the other women died.

The research team compared screening attendance between the two groups and found screening was much lower among women who had died from breast cancer, a finding that is consistent with a similar study from South Australia and with numerous studies from around the world. Comparison with similar studies showed an average estimate of a 49% reduced risk of dying.

Some other studies including studies from Australia claim that screening doesn't reduce risk of dying from breast cancer. However, these studies do not compare outcomes for individual women.

"Sound research methods have been used in this study. I believe it is time to move on from the debate about whether screening reduces mortality and to instead direct research resources to help improve the program for women who choose to use it," Dr Nickson said.

"It is important that Australian women have accurate information about the pros and cons of participating in BreastScreen. The findings of this study may help women decide whether to participate."

"Early detection is the key to early treatment and the free BreastScreen program is the best health service available to detect breast cancers earlier in women aged 50-69 years."