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Clinical and microbiological characteristics of abscesses in patients with malignancy and factors associated with 90-day mortality

Year: 2026

Type: article

Abstract: Introduction: Cancer-specific evidence on the outcomes and microbiology of abscesses is limited. We aimed to characterize these infections and evaluate factors associated with 90-day all-cause mortality. Methods: We conducted a single-center retrospective cohort study of adults with histologically confirmed malignancy and a first imaging-confirmed abscess; culture positivity was not required. All isolates came from percutaneous aspirates, were tested by an automated system, and were classified for extended-spectrum beta-lactamase (ESBL) production and multidrug resistance; culture reports were adjudicated for contamination by two clinicians. Survival was measured from the index date (aspiration in 177 and first documentation in seven), with first imaging and admission as alternative origins, and follow-up extended to 1 year. Results: Among 184 patients (median age, 62 years; 58.2% men; 53.8% stage IV), an organism was recorded in 124 (67.4%) and a probable pathogen in 108 (58.7%), of which 85 (78.7%) were gram-negative, mainly Escherichia coli (43) and Klebsiella pneumoniae (27). Phenotypic ESBL was recorded in 38 of 80 (47.5%) Enterobacterales isolates, 69 of 85 (81.2%) gram-negative isolates were multidrug- or extensively drug-resistant, and resistance to third-generation cephalosporins exceeded 80%, to piperacillin-tazobactam 65.7%, and to ertapenem 37.3%. A total of 42 patients died within 90 days; the 90-day survival was 76.6% (95% CI 69.7%-82.2%) from the index date and 77.7% from first imaging, both among patients who survived to the index date. In a Cox model stratified by abscess multiplicity and adjusted for age and stage, higher albumin at the index date was associated with a lower 90-day mortality (HR 0.37 per 0.5 g/dL, 95% CI 0.26-0.53; model-based risk 39.4% at 2.5 g/dL versus 6.8% at 3.5 g/dL). The association persisted after adjustment for intensive-care admission, organ support, corticosteroids, C-reactive protein, and procalcitonin but weakened after day 90 (HR 0.48 per 1 g/dL), whereas stage IV disease, unrelated to 90-day mortality, was associated with mortality thereafter (HR 2.65, 95% CI 1.45-4.84). Discussion: Ninety-day mortality was substantial, gram-negative organisms predominated, and resistance to these agents was frequent. Low albumin at the index date is a marker of early mortality that most likely reflects acute illness severity as well as nutritional and tumor-related factors, whereas cancer stage is associated with later mortality.

Source: Frontiers in Cellular and Infection Microbiology

DOI: 10.3389/fcimb.2026.1969735