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. 2021 Oct 13;156(5):926-933.
doi: 10.1093/ajcp/aqab050.

Keratin 17 Is a Novel Cytologic Biomarker for Urothelial Carcinoma Diagnosis

Sruthi Babu  1   2 , Nam W Kim  3 , Maoxin Wu  1 , Ina Chan  1 , Luisa F Escobar-Hoyos  1   4   5   6 , Kenneth R Shroyer  1
Affiliations

Keratin 17 Is a Novel Cytologic Biomarker for Urothelial Carcinoma Diagnosis

Sruthi Babu et al. Am J Clin Pathol. .

Abstract

Objectives: The microscopic features of urine cytology specimens are subjective and may not reliably distinguish between benign urothelial cells and low-grade urothelial carcinoma (UC). Prior studies demonstrated that keratin 17 (K17) detection in biopsies is highly sensitive for UC. The current study aimed to define K17 diagnostic test performance for initial screening and detect recurrent UC in urine specimens.

Methods: K17 was detected by immunocytochemistry (ICC) in consecutively collected urine specimens (2018-2019). A qualitative score for the K17 test was determined in 81 samples (discovery cohort) and validated in 98 samples (validation cohort). K17 sensitivity and specificity were analyzed in both cohorts across all grades of UC.

Results: Based on the discovery cohort, the presence of 5 or more K17 immunoreactive urothelial cells (area under the curve = 0.90; P < .001) was the optimal threshold to define a K17-positive test. The sensitivity of the K17 ICC test for biopsy-confirmed UC was 35 of 36 (97%) and 18 of 21 (86%) in the discovery and validation cohorts, respectively. K17 was positive in 16 of 19 (84%) specimens with biopsy-confirmed low-grade UC and in 34 of 34 (100%) of specimens with high-grade UC.

Conclusions: K17 ICC is a highly sensitive diagnostic test for initial screening and detection of recurrence across all grades of UC.

Keywords: Diagnostic biomarker; Keratin 17; Urine cytology; Urothelial carcinoma.

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Figures

Figure 1
Figure 1
Detection of Keratin 17 in 5 or more strong positive urothelial cells defines a positive test. A, Benign urothelial cells. B, Keratin 17 (K17)–positive urothelial cell (arrow) adjacent to benign squamous cell (arrowhead). C, Urothelial cells (arrows) showing strong K17 staining. D, The optimal cutoff value from receiver operating characteristic (ROC) curves was determined using the Youden index (area under the curve = 0.9013; P < .0001). The optimal cutoff value in the resulting ROC curve corresponded to 5 or more positive urothelial cells for determining a K17 immunocytochemistry (ICC)–positive test (C) or K17 ICC–negative test (A and B).
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References

    1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2019. CA Cancer J Clin. 2019;69:7-34. - PubMed
    1. Aldousari S, Kassouf W. Update on the management of non-muscle invasive bladder cancer. Can Urol Assoc J. 2010;4:56-64. - PMC - PubMed
    1. DeGeorge KC, Holt HR, Hodges SC. Bladder cancer: diagnosis and treatment. Am Fam Physician. 2017;96:507-514. - PubMed
    1. Witjes JA, Compérat E, Cowan NC, et al. ; European Association of Urology . EAU guidelines on muscle-invasive and metastatic bladder cancer: summary of the 2013 guidelines. Eur Urol. 2014;65:778-792. - PubMed
    1. Babjuk M, Böhle A, Burger M, et al. . EAU guidelines on non-muscle-invasive urothelial carcinoma of the bladder: update 2016. Eur Urol. 2017;71:447-461. - PubMed