Actress Christina Applegate (2008) and television personality Sharon Osbourne (2012) both opted for double mastectomies after discovering breast cancer in one breast. They wanted to reduce their chances of developing cancer in the unaffected breast when genetic testing showed that they were at an increased risk.

And they've done a great deal to reduce the fear of having what is called contralateral prophylactic mastectomy (CPM).

But CPM is not necessarily the right move for women who have breast cancer but are not at increased risk for recurrence in the unaffected breast. Increased risk comes from a familial history of breast or ovarian cancer, a genetic mutation or predisposition, or exposure to mantel field radiation during childhood.

Nonetheless, from 2002 to 2013, CPMs tripled. And that's a shame, say researchers from Brigham and Women's Hospital in Boston, who analyzed eight years of data on almost 500,000 women with unilateral stage-one to stage-three breast cancer.

They found that the majority of women in the U.S. who have CPM don't have genetic risks, and are at a low risk for developing breast cancer in the unaffected breast. And having it removed does not increase long-term survival rates.

So if you're diagnosed with breast cancer, talk to your oncologist about risk factors for developing cancer in the unaffected breast and the benefits and risks of CPM.

After treatment, join a shared medical appointment program for post-breast cancer patients.

You'll really reduce your risks through a good diet change, exercise and stress management.