Initial breast conservation surgery can lead to further operations, including mastectomies.
In their study, published by JAMA Surgery, the authors suggest that a lack of consensus on sufficient margin width - the distance between the tumor and the edge of the surrounding tissue that is removed during surgery - leads to variable rates of re-excision and the possibility of repeat or additional operations.
"Until recently, no nationally or internationally accepted guidelines for an adequate margin width for invasive or noninvasive breast cancer have been available," write the authors. "This lack of a consensus has led to variable rates of re-excision and ranges in rates of 0% to 60%."
Experts regard the complete removal of breast cancer through conservation surgery as the best way to reduce the recurrence of cancer and improve survival.
According to the American Cancer Society (ACS), breast cancer is the second leading cause of cancer death in women. The ACS have estimated that in 2014, around 232,670 new cases of invasive breast cancer will be diagnosed, with around 40,000 women dying from the disease.
Assessing the rate of repeat surgery
Dr. Lee G. Wilke, of the University of Wisconsin School of Medicine and Public Health, and colleagues set out to analyze the repeat surgery rates for patients undergoing breast conservation surgery (BCS) in the US.
Using the National Cancer Data Base, the researchers assessed the data for 316,114 patients with breast cancer who underwent BCS from 2004-2010, excluding patients initially treated with chemotherapy or those diagnosed by excision biopsy.
Of these patients, 241,597 (76.4%) were found to have only a single lumpectomy, compared with 74,517 (23.6%) having at least one additional operation after their BCS. Of the repeat surgery, 46,250 (62.1%) patients had a completion lumpectomy and 28,267 (37.9%) patients required mastectomy.
During the study period, the researchers found that the number of patients undergoing additional procedures decreased over time, from 25.4% to 22.7%.
Rates of repeat surgery varied between different institutions; academic centers were 19% more likely to perform further operations than community centers. Additionally, facilities in the Mountain region were significantly less likely to perform repeat surgery compared with those in the Northeast, with respective rates of 18.4% and 26.5%.
Could new guidelines reduce repeat surgery rates?
The authors write that their findings can be used to both inform patients about repeat surgery rates and support calls for the adoption of guidelines regarding re-excision after initial BCS. They consider standardization as a "vitally important" step in breast cancer treatment:
"At the root of the variability in repeat surgery rates for BCS is the lack of standardization of an acceptable margin width. The tumor margin width that will provide the lowest local recurrence rate has not been established in a randomized clinical trial setting."
They acknowledge that their findings are limited by the fact that several factors that influence the rates of repeat surgery - preoperative imaging and localization techniques, for example - were not recorded by the National Cancer Data Base, along with the exact margin width in each procedure.
Standard definitions of adequate margins have been set forth by the Society of Surgical Oncology and the American Society for Radiation Oncology. Special ink is applied to tumors and surrounding tissue to allow pathologists to examine margins, and it is their suggestion of a definition of "no tumor on ink" that the authors recommend.
Dr. Julie A. Margenthaler and Dr. Aislinn Vaughan are supportive of this proposed change, writing in a related commentary:
"[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."
In recognition of Breast Cancer Awareness Month this past October, Medical News Today ran a feature on breast cancer in men. Although the disease is rarer in men than women, previous research indicates that men with breast cancer are less likely to survive the disease than women.