MINNEAPOLIS/ST. PAUL (October 7, 2009)—More women in the greater Twin Cities region who are diagnosed with breast cancer in one breast are choosing also to have the healthy breast surgically removed. These women tend to be younger, have a larger tumor, a family history of the disease, and a female surgeon for their doctor. Those are the findings of a new study from the University of Minnesota's Masonic Cancer Center and Medical School.

Todd Tuttle, M.D., cancer surgeon and researcher, led the research team on this study. Their purpose: find out what factors as associated with the increasing rates of contralateral prophylactic mastectomy (CPM) – surgery to remove the healthy breast to prevent the occurrence of cancer – in Minnesota and throughout the United States.

This study involved the review of records of 571 patients who underwent surgery for breast cancer in 2006 and 2007 at the six hospitals operated by Fairview Health Services, including the University of Minnesota Medical Center; 290 of the women had breast removal surgery. It also is the first study to look at surgeon characteristics associated with CPM use. The findings are published this week in the Annals of Surgical Oncology journal.

"Our findings provide further insights into the factors associated with more aggressive breast cancer surgery," said Tuttle, who led two previous research studies on CPM, including the study that found CPM rates have increased nationally about 150 percent among patients with invasive breast cancer and ductal carcinoma in situ (DCIS) since 1988.

"Over the last several decades, treatment for breast cancer found in one breast has progressed from the radical mastectomy to less invasive breast-conserving surgery," he noted. "Breast-conserving surgery has been endorsed by the National Cancer Institute as the preferred treatment of early stage breast cancers since 1991. We also now have effective medicines-- Tamoxifen and aromatase inhibitors-- that significantly reduce the rate of cancer in the healthy breast. Nevertheless, the proportion of patients electing to undergo CPM has markedly increased in recent years.

"These findings are concerning because while CPM significantly reduces the risk of cancer in the healthy breast, it does not eliminate the risk and does not improve breast cancer survival rates," Tuttle said. "Further, CPM is not risk-free and complications are more common among patients undergoing immediate reconstruction surgery."

Overall study findings

The 571 patients ranged from 18 to 80 years of age and underwent surgery for treatment of either cancer in one breast or DCIS, a non-invasive condition in which abnormal cells are found in the lining of a breast duct. Tuttle and his colleagues found:

• 165 patients (28.9 percent) underwent mastectomy and CPM surgery.
• 130 patients (22.8 percent) chose to have the affected breast removed.
• 276 patients (48.3 percent) elected not to have their breast removed and chose breast-conserving surgery, such as a lumpectomy.
• 46.2 percent of the patients younger than age 40 underwent CPM, compared with 13.2 percent of patients older than age 70.
• While only 5 of 13 patients tested for BCRA, a gene associated with increased risk of breast cancer, were found to have the BCRA mutation, all of the patients chose CPM regardless of their test results.

Female surgeons and increased CPM use

Surgeons performing these operations included 20 male surgeons and 3 female surgeons. In this case, Tuttle and his colleagues found:

• The overall rate of CPM surgery performed by female surgeons was 46.5% compared with 23.2% for male surgeons.
• When the three female surgeons, all under the age of 50, were compared to the male surgeons under age 50, the female surgeons continued to have significantly higher rates for performing CPM.

"Female surgeon gender was one of the strongest predictors of CPM use," Tuttle said. "Several other research studies have established that the surgeon is a critical factor contributing to the decision of surgical treatment for breast cancer.

"However, it was not clear in our study whether female surgeons recommend CPM more often than their male counterparts, or if patients diagnosed with breast cancer may be more receptive and comfortable talking about CPM with a female surgeon," he said. "Because of the small number of female surgeons in this study, more research is needed to confirm these findings."

Reconstructive breast surgery after CPM

Tuttle and his colleagues further found that 62.4 percent of patients who underwent CPM chose to have immediate reconstructive surgery to create new breasts. He notes that immediate reconstruction is a substantial operation, irreversible, and not risk-free. Severe complications, he said, may delay the patient receiving the recommended therapy after the breast surgery.

"I believe this study clearly shows that further research is necessary to examine the factors affecting the patients' decision-making process and to develop better educational resources to help patients with this difficult decision," Tuttle said.

This study was sponsored with a grant from the National Cancer Institute. Working with Tuttle to conduct this research were Amanda Arrington, M.D., Stephanie Jarosek, M.P.H., Beth Virnig, Ph.D., and Elizabeth Habermann, Ph.D.

Masonic Cancer Center, University of Minnesota is part of the University's Academic Health Center. It is designated by the National Cancer Institute as a comprehensive cancer center for cancer research, treatment, and education. For more information, call 612-624-2620 or visit www.cancer.umn.edu.

Media contacts:

Mary Lawson, Masonic Cancer Center 612-203-0819, mlawson@umn.edu

Sara Martin, Academic Health Center 612-626-7037, buss@umn.edu