Nearly a quarter of all patients who underwent initial breast conservation surgery (BCS) for breast cancer had a subsequent surgical intervention, according to a report published online by JAMA Surgery.

Completely removing breast cancer is seen as the best way to reduce recurrence and improve survival. A lack of consensus on an adequate margin width has led to variable rates of reexcision and, as a result, patients undergo repeat or additional surgeries, according to background information provided in the study.

Lee G. Wilke, M.D., of the University of Wisconsin School of Medicine and Public Health, Madison, and fellow co-authors looked at patient, tumor and facility factors that influenced repeat surgery rates in U.S. patients undergoing BCS from 2004 through 2010. The authors' study included 316,114 patients with diagnosed breast cancer (stage 0 to II) who had initial BCS. Patients initially treated with chemotherapy to shrink their tumors (neoadjuvantly treated) or those who were diagnosed by excisional biopsy were excluded.

The study found 241,597 patients (76.4 percent) underwent a single lumpectomy and 74,517 patients (23.6 percent) had at least one additional operation. Of the patients who had an additional operation, 46,250 (62.1 percent) had a completion lumpectomy and 28,267 (37.9 percent) underwent mastectomy. The proportion of patients undergoing repeat surgery decreased during the study period from 25.4 percent to 22.7 percent. Tumor size and histologic subtype were the two most notable patient factors associated with repeat surgeries. Academic research facilities had a 26 percent repeat surgery rate compared with a 22.4 percent rate at community facilities. Facilities in the Mountain region of the U.S. were less likely to perform repeat surgery compared with facilities in the Northeast (18.4% and 26.5% respectively).

"These findings can be used by surgeons to better inform regarding repeat surgery rates and how patient or tumor characteristics influence these rates. More important, these data can be used to further support the vitally important adoption of guidelines regarding reexcision after initial BCS. Standard definitions of adequate margins as set forth in the consensus guidelines by the Society of Surgical Oncology and the American Society for Radiation Oncology and the indications for reexcision will decrease the wide variation in repeat surgery rates and decrease costs and patient anxiety surrounding tumor-positive margins," the authors conclude.

In a related commentary, Julie A. Margenthaler, M.D., Washington University School of Medicine, St. Louis, and Aislinn Vaughan, M.D., of the Sisters of St. Mary's Breast Care, St. Charles, Mo., write: "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 . 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 et al will provide an excellent historical reference for future investigation of the success of this paradigm shift," the authors conclude.

More information: JAMA Surgery. Published online November 12, 2014. DOI: 10.1001/jamasurg.2014.926
JAMA Surgery. Published online November 12, 2014. DOI: 10.1001/jamasurg.2014.950

Journal information: JAMA Surgery