One-fourth of patients who undergo breast conservation surgery required additional surgery

Approximately a quarter of patients with breast cancer who underwent breast conservation surgery went on to receive subsequent surgery, according to study results.

The rate of repeat surgeries — which declined slightly from 2004 to 2010 — varied significantly according to patient and tumor characteristics, as well as treatment facility type, results showed.

Lee G. Wilke, MD, director of the Breast Center at the University of Wisconsin School of Medicine and Public Health, and colleagues evaluated data from 316,114 patients diagnosed with stage 0 to II breast cancer between 2004 and 2010. All patients underwent breast conservation surgery.

More than three-quarters of patients (76.4%; n=241,597) underwent lumpectomy alone, whereas 23.6% (n=74,517) underwent additional surgery. Most patients who received additional surgery underwent completion lumpectomy (62.1%; n=46,250), and 37.9% (n=28,267) underwent mastectomy.

Overall, the rate for additional surgery declined from 25.4% in 2004 to 22.7% in 2010 (P˂.001).The proportion of patients who underwent additional surgery with completion lumpectomy increased during this time (60.4% vs. 63.7%), whereas the rate for mastectomy decreased (39.6% vs. 36.3%).

Age, race, insurance status, histologic subtype, ER status, tumor size and grade, and node status all were independent predictors of additional surgery (P˂.001 for all).

A significantly greater proportion of patients aged 18 to 29 years than those aged ≥80 years underwent repeat surgery (38.5% vs. 16.5%; P˂.001). The percentage of patients with node-positive disease also was significantly higher in the repeat surgery cohort (26.2% vs. 17%; P˂.001).

Multivariate analyses indicated patients were more likely to undergo a repeat surgery if they had invasive lobular carcinoma (OR=1.35; 95% CI, 1.29-1.4) or mixed histologic subtype (OR=1.23; 95% CI, 1.18-1.29), but they were less likely to undergo repeat surgery if they had invasive ductal carcinoma (OR=0.82; 95% CI, 0.8-0.85).

Patients with tumors >5 cm (OR=3.4; 95% CI, 3.14-3.68), as well as those with tumors 2 cm to 5 cm (OR=1.23; 95% CI, 1.21-1.26), were significantly more likely to undergo repeat surgery compared with patients with tumors <2 cm.

Researchers also found the occurrence of repeat surgery was associated with facility location and type. Repeat surgery was more common at facilities in the Northeast compared with the Mountain region (26.5% vs. 18.4%), and it was more common at academic or research facilities compared with community facilities (26% vs. 22.4%; P˂.001 for both).

“These findings can be used by surgeons to better inform their patients regarding repeat surgery rates and how patients or tumor characteristics influence these rates,” Wilke and colleagues wrote. “More important, these data can be used to further support the vitally important adoption of guidelines regarding re-excision after initial breast conservation surgery.”

The fact that more than 92% of patients in the analysis had negative margins indicates many of these patients may have been undergoing unnecessary additional surgery, Julie A. Margenthaler, MD, of Washington University School of Medicine in St. Louis, and Aislinn Vaughan, MD, of Sisters of St. Mary’s Breast Care in St. Charles, Mo., wrote in an accompanying editorial.

“We have robust evidence that additional operations for close, but negative, margins do not result in better outcomes,” Margenthaler and Vaughan wrote. “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.”

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Disclosure: The researchers report no relevant financial disclosures.