Risk Factors for Fluoroquinolone Resistance on Pre-Prostate Biopsy Rectal Swab

Prostate cancer (PCa) is usually diagnosed through transrectal prostate needle biopsy (PNB). Targeted prophylaxis with pre-PNB rectal swab and tailored antibiotics, often fluoroquinolones, can decrease post-PNB urosepsis risk, but fluoroquinolone resistance (FQR) is rising. The 2016 AUA white paper discusses risk factors for post-PNB sepsis, but more contemporary evidence is needed. Here, we evaluated FQR rate across a multihospital system and identify FQR risk factors.

We report a retrospective cohort study of patients who underwent pre-PNB rectal swab between 2013 and 2024 across a multihospital health system. The Northwestern Enterprise Data Warehouse was used to identify patients who underwent pre-PNB rectal swab and to capture demographic, comorbidity, and encounter data. The primary outcome was FQR trend over time, and the secondary outcome was to identify FQR risk factors.

In total, 10,372 patients underwent pre-PNB rectal swabs from 2013 to 2024, and 1952 (18.8%) had FQR with Escherichia coli as 95.5% of the resistant bacteria. FQR rates remained stable between 2013 and 2024. On multivariable regression, age, uninsured status, Hispanic ethnicity, Asian race, Black race, prior diverticulitis, and any prior fluoroquinolone exposure were associated with increased risk of rectal FQR. Former smoking status and prior colonoscopy were associated with a decreased risk of rectal FQR. County-level analysis revealed no county-level factors associated with rectal FQR.

We identified novel patient-level FQR risk factors including any fluoroquinolone exposure, age, uninsured status, Hispanic ethnicity, non-White race, and prior diverticulitis. The current AUA guidance regarding FQR may not provide sufficient detail for comprehensive pre-PNB counseling, suggesting need for further refinement.