Can you imagine having major parts of your body removed even though your doctor says you're perfectly healthy?

The procedure is known as prophylactic surgery -- thousands of women are doing it, and the surgery can be a life saver.

Sandra Cohen refers to herself, not as a cancer survivor, but as a "pre-vivor."

Cohen made the difficult decision to have her ovaries and her breasts removed, even though she was never diagnosed with breast or ovarian cancer. But the lives of her mother and grandmother were cut short by it, and Cohen carries the gene.

"It's kind of like you are sitting on a time bomb waiting for cancer to occur and it really does a number on you mentally to deal with that every single day," she explained.

Cohen's decision to have the radical surgery before there's evidence of cancer was backed-up by a new study published in the Journal of the American Medical Association.

Researchers looked at nearly 2,500 women with the BRCA 1 or 2 genetic mutations and found the removal of the ovaries almost eliminated ovarian cancer risk and reduced breast cancer risk by two-thirds.

Removal of breasts reduced the risk of breast cancer by 85 percent. Either procedure eliminated the risk of death by at least two-thirds.

"We've known for several years that removing ovaries decreases the risk of ovarian cancer and breast cancer. But what we've been able to clearly demonstrate now is that, that reduction in risk translates to women living longer," said Dr. Susan M. Domchek, a researcher at the University of Pennsylvania's School of Medicine.

One of the most important implications of this study is that women who have a family history of breast or ovarian cancer should consider genetic testing to learn whether they have the gene.

Once Cohen learned she had the gene, she consulted other women who have it, too, and who had their breasts and ovaries removed as a precaution. This helped her decide to have the surgery.

"When you can actually see someone who's gone through it and they look great and they feel great, it gives you the empowerment to move on and to take action," she said.

Cohen said since she was finished having children, her main concern was making sure they had a mother for many years to come.