Kim stressed that there is no evidence to support the idea that removing both breasts after a diagnosis of breast cancer increases survival rate. And indeed, one recent University of Michigan study found that 70 percent of women who had both breasts removed following a breast cancer diagnosis did not get any benefit from the procedure because their risk of developing cancer in the healthy breast was no greater than in women without cancer.
"For a woman with a gene mutation or a family history, the surgery makes sense," Kim said. "For most other women who are opting to have it, it is very controversial."
Kim said that breast cancer survival is less affected by how much of the breast tissue is removed than by how aggressive the cancer is and how much it has spread at the time of surgery. If the disease has spread into lymph nodes and the blood stream by the time of surgery then removing more breast tissue will not affect a patient's outcome, he noted.
But Kim said he does understand why a low-risk patient might opt for a mastectomy.
"In my mind, if a patient is well informed about risks of having or not having the surgery, it's often more than just survival that influences a person's decisions," he said.
And even when it's a proven cancer-avoidance tactic, Horn said the decision to remove your breasts is not an easy one.
"I wasn't sure if my breasts would ever feel like mine again or how my future boyfriends would feel or if I would feel like I was lacking in any way," she said.
Her doctor told her she could monitor her health with frequent screening to put off the surgery but ultimately Horn felt it was the only choice she could make.
"Ultimately, I had no second thoughts because with my mom having cancer, I had played out the numbers in my head and knew what I had to do," she said. "I have no regrets. And I really like my new breasts."