Stuart Bradford

For decades, advocates have fought to protect women from disfiguring breast cancer surgery, arguing that it was just as effective to remove only the cancerous tissue rather than the whole breast.

But today, a growing number of women with breast cancer are pushing surgeons in a startling new direction. Not only do they want the cancerous breast removed, but they also want the healthy breast cut off.

“I just didn’t want to worry about it,” explained Liliana Holtzman, 50, an art director in Ann Arbor, Mich., who had both breasts removed after a cancer diagnosis five years ago. “It was for my own peace of mind. I wanted to do everything I could.”

The percentage of women asking to remove both breasts after a cancer diagnosis has more than doubled in recent years. Over all, about 6 percent of women undergoing surgery for breast cancer in 2006 opted for the procedure, formally known as contralateral prophylactic mastectomy. Among women in their 40s who underwent breast cancer surgery, one in 10 opted to have both breasts removed, according to a University of Minnesota study presented last week in St. Louis at the annual meeting of the Society of Surgical Oncology.

Surprisingly, the practice is also more popular among women with the earliest, most curable forms of cancer. Among women who had surgery for ductal carcinoma in situ, sometimes called Stage 0 cancer or precancer, the rate of double mastectomy rose to 5.2 percent in 2005, from 2.1 percent in 1998, according to a 2009 study in The Journal of Clinical Oncology.

Women with a known genetic risk for breast cancer can lower the chances of developing it by having both breasts removed before cancer appears. But for most women given a diagnosis of breast cancer, cutting off a healthy breast does not improve the odds of survival.

A new study in The Journal of the National Cancer Institute reviews data on 108,000 women who underwent mastectomy, including 9,000 who chose to remove a healthy breast along with the cancerous one. It found that for most women, having a healthy breast removed after a cancer diagnosis had no effect on long-term survival.

The study found a slight survival benefit among a small subset of breast cancer patients — women under 50 with early stage estrogen-receptor-negative tumors, which don’t respond to risk-lowering drugs like Tamoxifen.

“A lot of patients coming into my clinic are asking for it,” said Dr. Isabelle Bedrosian, a surgical oncologist at M. D. Anderson Cancer Center in Houston, who conducted the new study. “Part of the reason women are frightened is we haven’t given them good information. Part of my hope with this study is to tell most breast cancer patients that it’s O.K. not to do this.”

The data are confusing, because a diagnosis of breast cancer or ductal carcinoma in situ does carry a slightly higher risk (about 0.6 to 1 percent a year) of developing a new, unrelated cancer in the second breast — although many women wrongly believe this means their cancer has “spread” to the other breast. And because of more vigilant screening among breast cancer survivors, second breast cancers are more likely to be detected at an early, more curable stage. As a result, the higher risk for a second cancer does not mean a higher risk of dying.

Doctors say that the highest risk to a woman is not from a future cancer, but from the potential spread of the cancer she already has. Removing a second healthy breast doesn’t change those odds.

“Women say the reason they’re going to have both breasts removed is because they want to see their children graduate or watch their grandchildren grow up,” said Dr. Todd M. Tuttle, chief of surgical oncology at the Masonic Cancer Center at the University of Minnesota. “But having that other breast removed doesn’t help them at all in being able to survive another 10 or 20 years.”

But women who have opted for the procedure say it’s not about the statistics. Once they receive a breast cancer diagnosis, they never again want to experience the stress of a mammogram or biopsy.

“Why would you want to risk getting cancer a second time?” asked a 46-year-old marketing executive in New York City who had both breasts removed last year after learning she had early stage breast cancer. (She asked that her name not be used to protect her privacy.)

“I think the risks were pretty well presented to me, but I didn’t care,” she continued. “I told the doctor, ‘Just take them.’ ”

Patients also say they opt for a double mastectomy to make sure that their breasts after reconstruction surgery are more symmetrical. Even so, many women don’t realize that reconstruction surgery is not like getting cosmetic implants. After a traditional mastectomy and reconstruction, women lose all sensation across their chest.

“When you’re lying next to someone, skin on skin, it’s sort of sad,” the New York woman said. “It’s not implants, and you have to make sure people understand that. But I wouldn’t do it differently.”

Dr. Susan Love, the breast surgeon and women’s health advocate who wrote the best-selling “Dr. Susan Love’s Breast Book” (Da Capo, 2000), fears that women are making decisions about prophylactic mastectomy without having all the facts.

Compounding the issue, she said, plastic surgeons usually prefer to remove both breasts. So they tend not to argue with women who ask to have a healthy breast removed as well. Dr. Love emphasized that doctors needed to listen to women’s reasons for choosing the more aggressive surgery.

“To a certain degree, women are right, because it’s their choice,” she said. “They need to choose the one that feels right for them.”