Mastectomy surgeries for early-stage breast cancer appear to have increased among women who had undergone MRI, a Mayo Clinic study has found.
The researchers conducted the study on 5,414 women who had surgery for early-stage breast cancer at Mayo Clinic between 1997 and 2006.
"We found that if a woman undergoes an MRI before surgery, she is about 10 percent to 15 percent more likely to have a mastectomy, compared to women who did not undergo MRI," said the Dr Rajini Katipamula, study's lead author and a senior clinical fellow in hematology/oncology.
The team found that mastectomy rate declined from 44 percent in 1997 to 30 percent in 2003, but then had risen to 43 percent in 2006.During this time, the percentage of women who had breast MRI more than doubled, from 11 percent in 2003 to 23 percent in 2006.
The mastectomy rate was significantly higher in women who had a presurgical MRI (52 percent) compared to women who did not have the test and chose breast removal (41 percent).
"Our study is the largest to examine the association between MRI and mastectomy rates at a single institution and may reflect national trends," said Dr Matthew Goetz, study's senior author and assistant professor of oncology at Mayo Clinic.
He said that MRI, which easily detects both cancerous and non-cancerous breast lesions, may prompt a woman or her physician to choose total breast removal instead of lumpectomy, even though both procedures have long been proven to offer the same survival benefit.
"What we don't know from this study is whether the higher rate of mastectomy observed in our patients undergoing MRI is related to the detection of additional disease, or whether the uncertainty raised by MRI leads to greater anxiety for the patient and physician, thus leading patients and physicians to choose mastectomy over lumpectomy," he said.
Goetz said that while MRI was associated with an increased mastectomy rate, the mastectomy rates also increased in women who did not undergo MRI, suggesting other factors are playing an important role in the decision-making process of patients and physicians.
"Although MRI was associated with a higher mastectomy rate, we cannot assume it is a cause-and-effect relationship," said Dr Amy Degnim co-author, a breast surgeon at Mayo Clinic and an assistant professor of surgery.
"More investigation at an individual level is needed to understand better how MRI may impact personal choices for breast cancer surgery," she added.
The results will be presented May 31 at the 44th Annual Meeting of the American Society of Clinical Oncology (ASCO).