Researchers say that regular mammograms can reduce the chances of a patient dying from breast cancer by nearly 30 percent, and that national screening programs should continue, according to a large Canadian study.

"What my study is showing is that high-risk women should be screened earlier, beginning at the age of 30," said study researcher Anna Chiarelli, a senior scientist at Cancer Care Ontario. "They should be screened often -- every year -- and they should be screened with both a breast MRI and a mammogram every year."

Chiarelli and her colleagues followed 2,207 women, aged 30 to 69, all at high risk of breast cancer, to determine the effect of the two screenings. The women were enrolled in the Ontario Breast Screening Program, which expanded in July 2011 to screen high-risk women in a special program that uses both tests -- MRI and digital mammography.

The study is published in the June 16 online edition of the Journal of Clinical Oncology.

The findings of the Canadian study apply only to high-risk women, not the majority of women. About 5 percent to 10 percent of breast cancers are linked to genetic defects, the society estimates.