New Breast Cancer Surgical Guidelines Published

The consensus guidelines could reduce healthcare costs and improve treatment for women with breast cancer

The Society of Surgical Oncology (SSO) and the American Society for Radiation Oncology (ASTRO) have released a new set of consensus guidelines for breast cancer surgeons. The guideline panel says that the new comprehensive guidelines will reduce healthcare costs and improve treatment for women with breast cancer. The new guidelines provide evidence-based surgical approaches, on best practice margins in breast conservation surgery for stage I and stage II invasive disease, that could prevent unnecessary surgery for patients recently diagnosed with breast cancer.

The guidelines “can be used to decrease unnecessary margin re-excisions while maintaining excellent outcomes in breast conserving surgery and will serve as a definitive resource to the profession,” according to the SSO.

The guidelines are published in the Journal of Clinical Oncology, and have been endorsed by the American Society of Clinical Oncology (ASCO) and the American Society of Breast Surgeons (ASBS).

“The guidelines provides physicians with evidence that in the current environment of multidisciplinary treatment, bigger margins don’t improve outcomes,” said guideline committee co-chair Monica Morrow, MD, department of surgery at the Memorial Sloan-Kettering Cancer Center, New York.

“There has never been an evidence-based guideline on margin width before,” Morrow added. “We undertook this guideline because approximately 25% of patients having breast conservation were undergoing re-excision, and about half of those re-excisions were done for margins that were technically negative-tumor not touching ink.”

These current guidelines apply to patients with invasive breast cancer who subsequently received whole-breast radiation therapy. The results cannot be extrapolated for patients receiving neoadjuvant chemotherapy or accelerated partial-breast irradiation, or for patients diagnosed with ductal carcinoma in situ only.

The guideline committee, chaired by Dr. Morrow and Meena S. Moran, MD, of the department of therapeutic radiology at the Yale School of Medicine in New Haven, Conn., assessed the current evidence on the link between surgical margins and the rate of ipsilateral breast tumor recurrence (IBTR). Prior to these guidelines, there was no consensus on the optimal width of negative margins in breast-conserving surgery for invasive breast cancer.

The committee did not support the removal of large amounts of healthy breast tissue in most cases as long as no cancer cells are detected at the edge of the lumpectomy specimen. “Many treatment teams had rules that all margins had to be 2 mm, 5 mm, or even 1 cm in the belief that this would decrease local recurrence. The guideline says such rules are inappropriate and promote unnecessary surgery,” said Morrow. “This doesn’t mean that in selected patients a margin bigger than no ink on tumor will not be beneficial, but what it does mean is that bigger margins are not the standard.”

The panel’s review found that these recommendations can be applied to a patient of any age and for women with more aggressive disease, including those with triple-negative breast cancer. These recommendations, the panel believes, should prevent unnecessary surgery and result in fewer unnecessary mastectomies, which are not always necessary.

“Our hope is that this guideline will ultimately lead to significant reductions in the high re-excision rate for women with early-stage breast cancer undergoing breast conserving surgery. Based on the consensus panel’s extensive review of the literature, the vast majority of re-excisions are unnecessary because disease control in the breast is excellent for women with early-stage disease when radiation and hormonal therapy and/or chemotherapy are added to a woman’s treatment plan,” said Dr. Moran, in a released statement.

The panel reviewed 33 studies that included a total of 28,162 patients, and concluded that using negative margins (no ink on tumor) as the standard for adequate margins in invasive cancer is associated with a low rate of IBTR and can lower the rate of re-excision, improve cosmetic outcomes, and lower healthcare costs. At a median follow-up of 6.6 years, the median prevalence of IBTR was 5.2%. The median age of patients was 53.4 years of age. Fifty-five percent of patients had stage I disease and 44.4% had stage II disease. Patients had a median tumor size of 1.6 cm.

Positive margins were associated with a twofold increase in the risk of IBTR compared with negative margins and this increased risk is not lessened by the biology of the tumor, or endocrine or radiation therapy. Wider, clear margins did not significantly decrease the risk of IBTR compared with no ink on tumor. “There is no evidence that more widely clear margins reduce IBTR for young patients (40 years old or younger), unfavorable biology, lobular cancers, or cancers with an extensive intraductal component,” concluded the authors.

About one in four women need re-excision to obtain clear margins, according to the guidelines, which adds healthcare costs and increases the risk for surgical complications. The 10-year survival rate for both a mastectomy and a lumpectomy plus radiation therapy is similar, although a lumpectomy can result in a faster recovery time and better cosmetic outcomes.

“The controversy has been whether removing more normal breast tissue with a bigger margin reduces the risk of local recurrence in the breast,” said Morrow. “This was thought to be true many years ago when mammography and pathology were not as good as they are today and when systemic therapy was not routinely given. Today, most women with invasive cancer get systemic therapy, which has a dramatic effect on reducing local recurrence.”