Minneapolis ? A study by a University of Minnesota researcher found that over a six-year period the number of women choosing that aggressive approach increased by 150 percent – even though statistically the risk of developing cancer in the second breast is less than 1 percent. It’s far more common that cancer will spread to other parts of their body, experts said.

“What I hear frequently is, ‘I just want to be done with it,”‘ said Dr. Todd Tuttle, a breast cancer surgeon at the University of Minnesota and one of the authors of the study published Monday in the Journal of Clinical Oncology.

“Being diagnosed with breast cancer has to be one of the most stressful events in a woman’s life, and they don’t want to repeat that again.”

The research is significant because it comes at a time when cancer surgeons are trying to do less surgery, not more. That shift is driven by advances in drug treatments that can prevent new cancers, imaging technology that can detect tumors early, and a better understanding of the risks and disfigurement of surgery.

“Some would argue that the need for aggressive surgery should be going down, not up,” said Beth Virnig, an associate professor of epidemiology at the university and another of the study’s authors.

The researchers found that between 1998 and 2003 the number of women who opted for a double mastectomy, though quite small, increased at a rapid rate. They used a database that provides information on a fourth of the cancer patients in the United States but does not include Minnesota.

During the six years about 153,000 women were diagnosed with breast cancer on one side and treated with surgery. The majority had either a lumpectomy, in which part of the breast is removed, or they had only the affected breast removed.

But the number choosing to have both breasts removed when they had cancer on one side increased from 1.8 percent in 1998 to 4.5 percent in 2003. Tuttle said he thinks that the rate has continued to climb.

Women younger than 40 were much more likely to choose a double mastectomy than those in their 70s; an average of 6.7 percent compared with 1.3 percent, the study showed. Tuttle said younger women were more likely to choose the more aggressive approach because they still had long lives in front of them and wanted to minimize their risk.

Dr. Lynn Hartmann, a breast cancer researcher at the Mayo Clinic, said that for younger women, a double mastectomy might be the appropriate choice. Many who have cancer at such a young age are at high risk for carrying the breast cancer gene. About 5 to 10 percent of women who get breast cancer do carry the gene, she said. For them, the risk of recurrence in the other breast is quite high, she said.

Tuttle decided to do the research because he and other surgeons kept hearing from women who opted for double mastectomies, he said. But he was surprised, he said, at how the numbers of have grown.

“Lots of women have thought this out,” he said.

However, experts say women who get cancer in one breast each year have 0.5 to 0.75 percent chance of the cancer reappearing in the second breast.

The aggressive approach does not improve their chances overall.