Can consensus guidelines defining adequate margins decrease unnecessary breast cancer surgeries?
Nearly 25% of all women who underwent initial breast conservation surgery (BCS) for breast cancer had a subsequent surgical intervention, according to a report in JAMA Surgery (2014; doi:10.1001/jamasurg.2014.926).
Complete surgical excision of breast cancer is the best way to reduce the risk of recurrence and improve survival rates. But a lack of consensus on what constitutes an adequate margin has led to variable rates of re-excision. Consequently, patients may undergo unnecessary additional surgeries ranging from completion lumpectomy to complete mastectomy.
Lee G. Wilke, MD, professor of surgical oncology at the University of Wisconsin School of Medicine in Madison, Wisconsin and co-authors studied factors that influenced repeat surgery rates in women undergoing BCS from 2004 through 2010. The study included 316,114 women with breast cancer stage 0 to II. Women who were treated with neoadjuvant chemotherapy to shrink their tumors before surgery and those whose diagnosis was made by excisional biopsy were excluded.
They found that 74,517 patients (23.6%) had at least one additional operation. Of the patients who had an additional operation, 46,250 (62.1%) had a completion lumpectomy and 28,267 (37.9%) underwent mastectomy.
The percentage of patients undergoing repeat surgery decreased from 25.4% to 22.7% during the study period. Tumor size and histologic subtype were the two most important patient factors associated with repeat surgeries.
Academic research centers had a 26% repeat surgery rate compared with a 22.4% rate at community medical centers. Medical centers in the Mountain region of the United States were less likely to perform repeat surgery compared with facilities in the Northeast (18.4% and 26.5% respectively).
"These data support the vitally important adoption of guidelines regarding re-excision after initial BCS. Adoption of the standard definitions of adequate margins set forth in the consensus guidelines by the Society of Surgical Oncology and the American Society for Radiation Oncology with the indications for re-excision will decrease the wide variation in repeat surgery rates. This will also decrease costs and patient anxiety surrounding tumor-positive margins," the authors stated.
In a related commentary, Julie A. Margenthaler, MD, of Washington University School of Medicine in St. Louis, Missouri and Aislinn Vaughan, MD, of the Sisters of St. Mary's Breast Care in St. Charles, Missouri wrote: "The Society of Surgical Oncology and the American Society for Radiation Oncology developed a consensus statement, supported by systematic review data, encouraging adoption of 'no tumor on ink' as the standard definition of a negative margin for invasive stage I and II breast cancer. It is time to put our biases aside. We have robust evidence that additional operations for close, but negative, margins do not result in better outcomes."
"However, additional operations increase health care costs, misuse of resources, patient anxiety, and delay in adjuvant therapy. With more than 200,000 new invasive breast cancers diagnosed each year, a staggering number of women are undergoing procedures that are unnecessary and simply wasteful. Our hope is that the Society of Surgical Oncology and the American Society for Radiation Oncology guidelines will be rapidly adopted by surgeons. Data from the study by Wilke [and colleagues]. provide an excellent historical reference for investigation of the success of this paradigm shift," the authors stated.
This commentary was published in JAMA Surgery (doi:10.1001/jamasurg.2014.950).