ORLANDO, Fla.-Providing prophylactic antibiotics to prevent infections in women undergoing breast cancer needle-directed lumpectomy procedures may be wasted efforts, researchers suggested here at the American Society of Breast Surgeons (ASBrS) Annual Meeting.

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"Our analysis showed no difference in infection rate, leading to the conclusion that it is safe to omit the use of antibiotics prior to needle-localized lumpectomy and avoid the cost of the medication, patient adverse reactions, and the increased risk of resistant organisms," said Lindsay Petersen, MD, Senior Resident in General Surgery at Rush University in Chicago and scheduled to start in July as a Fellow in Breast Surgery at the University of Michigan.

Of the 140 patients in the study who were not given prophylactic antibiotics, only three developed infections-a rate of two percent, compared with one percent (one infection) in the 80 patients given antibiotics, she noted in an interview at her poster presentation.

"We are being much too cautious in ordering antibiotics in patients undergoing these procedures," she said. "We are not violating anything other than the skin and soft tissue so there should not be a great risk for infection."

Karen Kostroff, MD, Chief of Breast Surgery at North Shore-LIJ Cancer Institute in Lake Success, N.Y., concurred with the findings: "I have not routinely given antibiotics to patients undergoing uncomplicated breast cancer surgery unless they are undergoing reconstruction," she said.

"If surgeons have been using antibiotics when a wire localization has been done, this study certainly would support their discontinuing that practice. We do tend to over-utilize antibiotics, which expose patients to allergic reactions, resistance to antibiotics in the future, and increased costs."

Contrary to ASBrS Position Statement

The findings appear contrary to the American Society of Breast Surgeons position statement on antibiotics and surgical site infections (http://bit.ly/1AsS2ES), which were released in 2012. "Those guidelines recommend a preoperative prophylactic dose of an antibiotic prior to needle-localized lumpectomy for cancer or prior to any excisional biopsy if risk factors are present, but it is unclear if this practice reduces the rate of infection," Petersen said.

For the study, she and her colleagues conducted a retrospective chart review of patients who underwent needle-localized lumpectomy from 2010 to 2012, collecting data on patient demographics, comorbid conditions, medical history, operative details, and pathology. Surgical infections requiring opening of the wound or treatment with antibiotics were documented if they occurred during the first three months following surgery.

During the study period, a total of 220 patients underwent needle-localized lumpectomy at one Chicago institution. Their mean age was 57, and average body mass index was 32 kg/m². About 14 percent of the patients were smokers. The mean duration of surgery was 92 minutes. The mean duration of time the needle was in place was 233 minutes. Thirty eight percent of patients had malignant pathology.

A greater percentage of patients undergoing re-excision procedures were given antibiotics-15 of 80 patients (19 percent) compared with 13 of 140 patients (9%) not given antibiotics.

All other differences between the groups-diabetes status, radiation, neoadjuvant chemotherapy, and malignant pathology-were not significantly different, Petersen said. Most of the 80 patients who received antibiotics were treated with cefazolin (79%); another 19 percent received clindamycin, one patient received ertapenem, and another received levofloxacin.

Petersen said that after examining the patient characteristics of the four individuals who developed an infection and the 216 patients who did not, she was unable to find any significant correlations. Although three of the four patients with infections (75%) were older than 65, 71 percent of the women who did not have infections were also over 65; four patients with an infection had received antibiotics (24%) and 37% of the patients who did not have an infection received antibiotics. Two of the four women undergoing lumpectomy who had infections had a malignancy diagnosis compared with 38 percent of the women without infection.

LINDSAY PETERSEN, MD. LINDSAY PETERSEN, MD: "Our analysis showed no difference in infection rate, leading to the conclusion that it is safe to omit the use of antibiotics prior to needle-localized lumpectomy and avoid the cost of the medication, patient adverse reactions, and increase in resistant organisms."

"The fears that longer wait times for surgery and more exposure to the needle lead to higher infection rates have not been justified by data we reviewed," Petersen summed up. She said there have been no studies that addressed the question of whether long-term needle exposure in the breast is linked to infection.

In the study, 215 of 216 patients who did not have infection had the needle in place for at least 90 minutes, but none of the women with infections had the needle in place for longer than that. Length of surgery also did not appear to make a difference: About 98 percent of the patients who did not have infections were in surgery for more than 45 minutes compared with none of the women who did have infections.