Urinary cytology has a poor performance for predicting invasive or high‐grade upper‐tract urothelial carcinoma

Abstract

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? Accurate preoperative staging for upper‐tract urothelial carcinoma (UTUC) lesions is presently limited. Urinary cytology has shown promise for characterizing pathological features of bladder cancer. The role of cytology for UTUC is at present poorly defined. In this large multi‐institutional cohort of patients, urinary cytology was limited in its ability to accurately predict the grade and stage of upper‐tract lesions. Selective ureteral sampling improved the diagnostic accuracy of cytology when compared to bladder specimens. Improved preoperative surrogate markers for staging UTUC remain necessary. OBJECTIVE: • To evaluate the diagnostic accuracy of urine cytology for detecting aggressive disease in a multi‐institutional cohort of patients undergoing extirpative surgery for upper‐tract urothelial carcinoma (UTUC). METHODS: • We reviewed the records of 326 patients with urinary cytology data who underwent a radical nephroureterectomy or distal ureterectomy without concurrent or previous bladder cancer. • We assessed the association of cytology (positive, negative and atypical) with final pathology. Sensitivity and positive predictive value (PPV) of a positive (± atypical) cytology for high‐grade and muscle‐invasive UTUC was calculated. RESULTS: • On final pathology, 53% of patients had non‐muscle invasive disease (pTa, pTis, pT1) and 47% had invasive disease (≥pT2). Low‐grade and high‐grade cancers were present in 33% and 67% of patients, respectively. • Positive, atypical and negative urine cytology was noted in 40%, 40% and 20% of cases. Positive urinary cytology had sensitivity and PPV of 56% and 54% for high‐grade and 62% and 44% for muscle‐invasive UTUC. • Inclusion of atypical cytology with positive cytology improved the sensitivity and PPV for high‐grade (74% and 63%) and muscle‐invasive (77% and 45%) UTUC. Restricting analysis to patients with selective ureteral cytologies further improved the diagnostic accuracy when compared with bladder specimens (PPV > 85% for high‐grade and muscle‐invasive UTUC). CONCLUSIONS: • In this cohort of patients with UTUC treated with radical surgery, urine cytology in isolation lacked performance characteristics to accurately predict muscle‐invasive or high‐grade disease. • Improved surrogate markers for pathological grade and stage are necessary, particularly when considering endoscopic modalities for UTUC.