Mastectomy rates decrease with adoption of breast tumor margin guidelines

Liz Meszaros, MDLinx | August 08, 2017

Between 2013 and 2015, after clinical guidelines were issued endorsing a minimal negative margin, lumpectomy rates increased significantly while more aggressive surgical options—such as mastectomies—decreased significantly. Researchers concluded that surgeon-led initiatives addressing overtreatment may reduce the burden of surgical management in patients with cancer, and published their results in JAMA Oncology.


Breast Service Chief Monica Morrow discusses the surgical treatment options available for women diagnosed with breast cancer. Video courtesy: MSK.

“The shift away from more-aggressive treatment and the adoption of these guidelines is a positive step in the effort to help women choose the best breast surgery options for them,” said lead author Monica Morrow, MD, FACS, chief, Breast Surgery Service, Memorial Sloan Kettering Cancer Center (MSK), New York, NY. “We want women to be confident in their cancer surgery and avoid a mastectomy or additional surgery when medically appropriate. This rapid change, observed within two years of the guidelines’ dissemination, illustrates the willingness of the surgical community to adopt evidence-based practices that improve outcomes for their patients.”

Dr. Morrow and colleagues conducted this study to assess the impact of a 2014 consensus statement that endorsed a minimal negative margin for invasive breast cancer in post-lumpectomy surgery and final surgical treatment (“no ink on tumor”).

Researchers included a population-based sample of 3,729 women (aged 20 to 79 years) with stage I and II breast cancer diagnosed in 2013 to 2015 from the Georgia and Los Angeles County, California, Surveillance, Epidemiology, and End Results (SEER) registries who had undergone initial lumpectomy between 2013 and 2015.

They then surveyed 488 surgeons between April 2015 and May 2016 regarding lumpectomy margins, of whom 70% responded. Researchers reviewed pathology reports from all patients undergoing a second surgery, and reviewed a 30% sample of patients with only one surgery. Using multinomial regression models, they analyzed time trends.

During the study, the 67% rate of initial lumpectomy did not change, the rate of final lumpectomy increased by 13% from 2013 to 2015, and rates of unilateral and bilateral mastectomy decreased (P=0.002). Researchers also observed a decline of 16% in the rate of surgery after initial lumpectomy (P < 0.001).

Upon pathology review, they found no significant associations between date of treatment and positive margins.

Of the 342 surgeons who responded to the survey, 69% endorsed a margin of no ink on tumor to avoid re-excision in patients with estrogen receptor-positive progesterone receptor-positive cancer, and 63% for estrogen-receptor-negative progesterone receptor-negative cancer.

Dr. Morrow and colleagues also found that most of the 105 surgeons who treated more than 50 breast cancers annually were significantly more likely to report this margin as adequate, compared with the 131 who treated 20 cases or fewer annually (85% vs 55%, respectively; P < 0.001).

“Our goal in issuing these guidelines was to save patients from unnecessary surgery while still minimizing the risk of the cancer returning. It is heartening to see that this primary aim has been met. With more time and further adoption of these guidelines, we anticipate seeing a greater decline in the use of additional surgery after a lumpectomy,” concluded Dr. Morrow.