Antibiotic prophylaxis in breast cancer surgery (PAUS trial): randomised clinical double-blind parallel-group multicentre superiority trial

This is a randomized clinical trial of a single dose of prophylactic antibiotic in breast cancer surgery. The trial shows no benefit for the antibiotic. There is little research about antibiotics in breast cancer surgery. Surgeons are not certain whether or not to use antibiotics for their patients. The aim of the Prophylactic Antibiotic Use in Surgery (PAUS) trial was to ask a question, 'Do preoperative antibiotics have any benefit for patients having surgery for breast cancer?' In the PAUS trial patients were given information to decide whether they wished to take part in the trial or not. Participants were randomly placed in one of two groups. Half were given one dose of the amoxicillin-clavulanic acid antibiotic at the time of their operation. The other half had no antibiotic. Neither the patient nor the surgeon knew which group the patient was in. Patients were carefully checked until 30 days after their operation for signs of wound infection. Altogether, 871 patients agreed to take part in the PAUS trial. Of these, 438 patients had the antibiotic and 433 had no antibiotic. The PAUS trial showed that there was no difference in the number of wound infections when comparing the two groups. Seventy-one patients (16.2 per cent) who had been given the antibiotic developed a wound infection by 30 days versus 83 (19.2 per cent) in the group who had not been given the antibiotic. This trial shows that antibiotics may not be needed for breast cancer surgery. PAUS may help to cut down on unnecessary antibiotic use. Background Participants were patients with invasive breast cancer undergoing primary surgery. The aim was to test whether a single dose of amoxicillin-clavulanic acid would reduce wound infection at 30 days postoperatively, and to identify risk factors for infection. Methods Participants were randomised to either a single bolus of 1.2 g intravenous amoxicillin-clavulanic acid after the induction of anaesthesia (intervention) or no antibiotic (control). The primary outcome was the incidence of wound infection at 30 days postoperatively. Results There were 871 evaluable patients. Of these, 438 received prophylactic antibiotic and 433 served as controls. Seventy-one (16.2 per cent) patients in the intervention group developed a wound infection by 30 days, while there were 83 (19.2 per cent) infections in the control group. This was not statistically significant (odds ratio (OR) 0.82, 95 per cent c.i. 0.58 to 1.15; P = 0.250). The risk of infection increased for every 5 kg/m(2) of BMI (OR 1.29, 95 per cent c.i. 1.10 to 1.52; P = 0.003). Patients who were preoperative carriers of Staphylococcus aureus had an increased risk of postoperative wound infection; however, there was no benefit of preoperative antibiotics for patients with either a high BMI or who were carriers of S. aureus. Conclusion There was no statistically significant or clinically meaningful reduction in wound infection at 30 days following breast cancer surgery in patients who received a single dose of amoxicillin-clavulanic acid preoperatively. Registration number N0399145605 (National Research Register).