Prescribing extended antibiotic prophylaxis may not reduce the risk of infections in patients with breast cancer undergoing breast reconstruction following mastectomy, according to a new study published by Sisco et al in Plastic and Reconstructive Surgery.
"Our experience suggests that discontinuing routine oral antibiotic treatment after implant-based breast reconstruction does not lead to an increase in surgical site infections and will eliminate a small but significant risk of allergy and other antibiotic-related complications," explained first study author Mark Sisco, MD, Clinical Associate Professor of Surgery at the University of Chicago Pritzker School of Medicine and Chief of the Division of Plastic and Reconstructive Surgery at NorthShore University HealthSystem.
A growing number of patients with breast cancer are undergoing breast reconstruction after mastectomy, particularly immediate reconstruction using implants. Surgical site infections—occurring in 10% to 25% of patients undergoing this procedure—may lead to increased rates of hospital readmissions, repeat surgeries, and reconstructive failure.
Historically, plastic surgeons have prescribed extended antibiotic prophylaxis to reduce the risk of surgical site infections, despite a lack of evidence for its effectiveness. However, the use of postoperative oral antibiotics has continued amid rising concerns about antibiotic resistance.
Study Methods and Results
In the new study, researchers compared the outcomes between 654 patients who received extended antibiotic prophylaxis and 423 patients who did not receive extended antibiotic prophylaxis. Both groups received a single dose of intravenous antibiotic prior to mastectomy.
The researchers discovered that the overall infection rate was similar between groups: 7.9% of patients who received extended antibiotic prophylaxis and 9.1% of patients who did not receive the antibiotics experienced infections. After adjusting for differences in patient characteristics, the researchers reported no statistically significant differences in the risk of surgical site infections between the two groups. This was true despite the fact that patients who did not receive extended antibiotic prophylaxis were more likely to undergo newer techniques—including nipple-sparing mastectomy and prepectoral implant placement—thought to carry an increased risk of complications.
Further, the researchers revealed that the patients receiving extended antibiotic prophylaxis consequently experienced infrequent but not insignificant adverse events such as moderate to severe allergic reactions among 2% of the patients in this group. At least four other patients developed antibiotic-resistant Clostridium difficile bacterial infections. Neither of these complications occurred in patients who forwent extended antibiotic prophylaxis.
Evidence also suggested that extended antibiotic prophylaxis led to higher rates of infections from microbes such as gram-negative bacteria and was associated with a broader range of pathogens and a greater need for second-line intravenous antibiotics.
"Although the use of [extended antibiotic prophylaxis] does not appear to worsen clinical outcomes, marked differences in the microbiology of associated infections may make them more difficult to treat, [especially at a time when breast reconstruction rates are rapidly increasing]," Dr. Sisco stressed. "Our findings suggest that thousands of [patients] are having adverse reactions to [extended antibiotic prophylaxis] nationwide, and some of these are likely to be serious," he added.
The researchers underscored, however, that a definitive randomized trial designed to end routine extended antibiotic prophylaxis may be unlikely to be performed.
"We hope that our experience will give surgeons additional evidence and courage to change their practice," Dr. Sisco concluded.
Disclosure: For full disclosures of the study authors, visit journals.lww.com.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.