The study, published in the journal Open Medicine, tracked Canadian women with the BRCA1 or BRCA2 genes that predisposes them to an 87 percent lifetime risk of developing breast cancer. Women with the gene have several options for cancer prevention including prophylactic surgery, chemo prevention and screening.

Lead author Kelly Metcalfe identified 672 Canadian women with the genes and found after four years 342 women were without breast cancer and 46 percent had not undertaken any cancer prevention option such as a mastectomy, oophorectomy or tamoxifen or raloxifene -- drugs used in chemo prevention. Thirty-nine percent of women with the genetic mutation in Ontario did not take preventive measures; 34 percent in Western Canada and 62 percent in Quebec.

"The numbers show a huge discrepancy, with women in Quebec being the least likely to elect for a preventive option," Metcalfe said.