And the reasons aren’t necessarily medical: repeat surgery rates are driven by factors such as demography and differences of opinion about how much cancer-free tissue make up an adequate surgical margin. The result is that some patients may needlessly have a second surgery.
“Past studies were too small and too regional to know the true national statistics,” says lead author Dr. Lee Wilke, who directs the UW Health Breast Center at the UW Carbone Cancer Center. “Now we have a baseline, and while it declined slightly during the study period (from 25.4 to 23.7 percent) it is still too high. We’ll never get to zero but 10 percent is a reasonable goal.”
The survey of 316,114 patients was published online today in JAMA Surgery, a journal of the American Medical Association, which also wrote an editorial.
“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,” says the editorial, urging surgeons to adopt new guidelines.
The study looked at women who had lumpectomy in the United States from 2004 through the end of 2010. Women have increasingly chosen lumpectomy rather than the former standard of mastectomy, which removed the entire breast and underlying tissue. Long-term survival rates for the two procedures are similar, but women with lumpectomy may have to go in for a second surgery if lab results show that there is cancer at or near the edge of the tissue removed.
It found that women who were younger, had larger tumors, had surgery at an academic medical center or lived in the Northeast faced higher odds of having a second surgery.
The biggest driver is suspected to be a lack of agreement over adequate tissue margins – some doctors felt that a margin of five millimeters is necessary while others believed one or two millimeters is the ideal, Wilke says. Different specialties – surgery, pathology and radiation oncology – had different standards. Earlier this year, three national cancer organizations cited study data saying that the standard should be a clear margin for early stage invasive cancer. The “no tumor on ink” rule refers to the fact that after the surgeon removes a tumor, it is coated with ink and sent to a pathologist to be examined. If no cancer cells are present in the outer, ink-coated edge, further surgery is likely unwarranted. Additional factors which may influence the rate of repeat surgery are associated with the hospital’s experience with breast cancer.
“Repeat surgeries take a financial, emotional and physical toll on patients, so we need to find a way to reduce them,” Wilke says. She says that all surgeons and their institutions should know their own rate of repeat surgeries and work to identify processes to reduce this rate of second surgery.
Wilke, a professor of surgery at the University of Wisconsin School of Medicine and Public Health, is leading a quality improvement effort at her institution to reduce repeat surgeries; she says her hospital has reduced its repeat rate to less than 20 percent and has a goal of 10 percent or less.
Her co-author on the study was Dr. Katharine Yao of NorthShore University Health System. The data came from the National Cancer Database, a nationwide oncology database of the Commission on Cancer.
The JAMA editorial urges 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,” it says, concluding, “Data from the study by Wilke et al will provide an excellent historical reference for future investigation of the success of this paradigm shift.”
University of Wisconsin School of Medicine and Public Health