Around 1 in 8 women in United States (12 percent) develop aggressive breast cancer over the course of their lifetime. About 40,000 women in the U.S. died in 2010 from breast cancer.

However, there is good news for everyone in danger of getting breast cancer according to The American Society of Clinical Oncology.

The latest study conducted by Canada's NCIC Clinical Trials Group revealed that a drug called Exemestane, sold under the brand name Aromasin, now used to prevent recurrences of breast cancer can also prevent it from occurring in the first place. The drug cuts the risk of development breast cancer by more than half in women who were past menopause without any lethal side effects.

The findings were the result of an huge international clinical trial, which included almost 250 Canadian women from 13 cities, including Vancouver, Winnipeg, Montreal, Ottawa and Toronto.

The randomized, double-blind, phase three clinical trial studied 4,560 women throughout the U.S., Canada, France and Spain over a five-year period.

There are two drugs that are already being using to prevent breast cancer (Tamoxifen and Raloxifene). However, these two drugs are known for side effects such as causing blood clots and uterine cancer.

The Canadian Cancer Society's vice-president, Dr. Michael Wosnick, said the results of the study were very exciting because they had the possibility to influence thousands of women.

The findings were published in the New England Journal of Medicine on Saturday.