According to the research, women in screening programs have less than a 5 percent chance of dying. But women who don't get screened have a 56 percent chance of death.
Details of this new research will be presented later this week to a meeting of the American Society of Clinical Oncology.
Most cancer societies and many governments recommend women be screened regularly. But a few studies have questioned the worth of this screening tool, because they may detect false positives, possibly leading to unnecessary tests and anxiety.