Assessment of atypical cells in detecting bladder cancer in female patients.

Objectives: Atypical or malignant urothelial cells may be identified with a research parameter of atypical cells (Atyp.C) using a fully automated urine particle analyzer in routine urinalysis. This study aimed to determine whether Atyp.C can serve as an effective screening tool for female bladder cancer (BC) and to observe the impact of pyuria and bacteriuria on Atyp.C concentrations.

Methods: Patients were classified into six groups: primary BC, recurrent BC, post-treatment monitoring of BC, other urological tumors, pyuria and bacteriuria, and controls. Atyp.C concentrations were compared across these groups, and its diagnostic performance for BC or pyuria and bacteriuria was analyzed. Logistic regression determined whether Atyp.C was an independent risk factor for BC or pyuria and bacteriuria. Subsequently, key factors contributing to abnormal Atyp.C elevations were investigated.

Results: The median Atyp.C concentrations were significantly elevated in both primary (2.9/µL) and recurrent BC cases (4.0/µL) compared to patients with pyuria and bacteriuria (2.0/µL) and controls (1.7/µL) (p<0.01). Diagnostic performance of Atyp.C to detect primary female BC reached an area under curve of 0.818 when combined with age and urine conductivity. Multivariate analysis confirmed Atyp.C as an independent risk factor for BC in women. Falsely increased Atyp.C concentrations were caused by WBC clumps, clue cells covered by bacteria, and macrophages.

Conclusions: Atyp.C did not reach sufficient specificity for screening of BC in women with existing pyuria or bacteriuria. WBC clumps, macrophages and clue cells contributed to falsely positive Atyp.C counts.