Prevalence of reported penicillin allergy and associations with perioperative complications, length of stay, and cost in patients undergoing elective cancer surgery

Objective: Up to 10% of patients report penicillin allergy (PA), although only 1% are truly affected by Ig-E-mediated allergies. PA has been associated with worse postoperative outcomes, but studies on the impact of reported PA in cancer patients are lacking, and especially in these multimorbid patients, a non-complicated course is of utmost importance. Methods: Retrospective analysis of patients undergoing elective oncological surgery at a tertiary reference center. Data on surgical site infections (SSI), postoperative complications (measured by Clavien-Dindo classification and Comprehensive Complication Index (CCI)), hospitalization duration, and treatment costs were collected. Results: Between 09/2019 and 03/2020, 152 patients were identified. 16/152 patients (11%) reported PA, while 136/152 (89%) did not. There were no differences in age, BMI, Charlson Comorbidity Index, and smoking status between groups (p > 0.4). Perioperative beta-lactam antibiotics were used in 122 (89.7%) and 15 (93.8%) patients without and with reported PA, respectively. SSI and mean numbers of infections occurred non-significantly more often in patients with PA (p = 0.2 and p = 0.47). The median CCI was significantly higher in PA group (26 vs. 51; p = 0.035). The median hospitalization duration and treatment costs were similar between non-PA and PA groups (4 vs 3 days, p = 0.8; 16'818 vs 17'444 CHF, p = 0.4). Conclusions: In patients undergoing cancer surgery, reported PA is common. Failure to question the unproven PA may impair perioperative outcomes. For this reason, patient and provider education on which reactions constitute a true allergy would also assist in allergy de-labeling. In addition, skin testing and oral antibiotic challenges can be performed to identify the safe antibiotics and to de-label appropriate patients.