High performance of 5-aminolevulinic acid-induced fluorescent selective upper tract urinary cytology.

Objectives: To investigate the efficacy of selective upper tract urinary cytology using extracorporeal 5-aminolevulinic acid for the diagnosis of upper urinary tract urothelial carcinoma.

Methods: We evaluated 104 patients who underwent radical nephroureterectomy and were diagnosed pathologically as having upper urinary tract urothelial carcinoma between March 2013 and May 2019 in Osaka Rosai Hospital. Preoperatively, we collected upper tract urinary cytology from both sides, and compared the sensitivity and specificity between conventional urine cytology and 5-aminolevulinic acid-induced fluorescent urine cytology.

Results: The sensitivity of 5-aminolevulinic acid-induced fluorescent selective upper tract urinary cytology was significantly higher than conventional cytology (90.4% vs 66.3%, P < 0.001), whereas the specificity was equally high (100% vs 98.2%, P = 1.0). In more detailed analysis, the sensitivity of 5-aminolevulinic acid-induced fluorescent selective upper tract urinary cytology was significantly higher than that of conventional cytology unrelated to patients' age (<76 years: 90.2% vs 68.6%, P = 0.013; ≥76 years: 90.6% vs 64.2%, P = 0.021), sex (male: 89.2% vs 67.5%, P = 0.001; female: 95.2% vs 61.9%, P = 0.02) or pT stage (pT1 or less: 91.4% vs 69.0%, P = 0.005; pT2 or more: 89.1% vs 63.0%, P = 0.006), tumor grade (high grade: 91.0% vs 70.5%, P = 0.002; low grade: 88.5% vs 53.8%, P = 0.013), and tended to be more efficacious for tumors that could not be detected by imaging techniques (83.3% vs 50.0%, P = 0.075).

Conclusions: 5-Aminolevulinic acid-induced fluorescent selective upper tract urinary cytology is more sensitive than conventional cytology for the diagnosis of upper urinary tract urothelial carcinoma, regardless of pT stage and tumor grade.