Evaluation of Sienna Cancer Diagnostics hTERT Antibody on 500 Consecutive Urinary Tract Specimens

Clinical application of the anti-human telomerase reverse transcriptase (hTERT) antibody (SCD-A7) immunocytochemistry in liquid-based urine cytology: A prospective, single institute study

OBJECTIVES

Urine cytology is the most widely used noninvasive screening tool for urothelial carcinoma diagnosis and surveillance. Although highly specific, urine cytology exhibits suboptimal sensitivity. This study aimed to determine whether hTERT immunocytochemistry (ICC) could be applicable as an ancillary test in routine cytology practice.

METHODS

A total of 561 urinary tract samples were initially screened in this study. All of them were prepared using SurePath liquid-based cytology (LBC), while additional LBC slides were made and subsequently used for hTERT (SCD-A7) ICC.

RESULTS

From the 561 samples screened, 337 were finally analyzed, all having an adequate cellularity and available follow-up histology. The hTERT ICC-positive rate was 95.9% (n = 208/217), 96% (n = 24/25), and 100% (n = 4/4) in cytology samples with high-grade urothelial carcinoma, carcinoma in situ, and low-grade urothelial carcinoma subsequent histology. Among the 64 atypical cytology cases histologically confirmed as urothelial carcinomas, 92.2% (n = 59/64) were immunoreactive to hTERT, whereas the two histologically benign cases were ICC-negative. 87/90 (96.7%) of the cytology cases confirmed to be benign in follow-up were hTERT-negative. The overall sensitivity and specificity of hTERT ICC were 96.3% and 98.8%, respectively (AUROC = 0.963; 95% CI = 0.960-0.967).

CONCLUSIONS

The hTERT ICC test exhibited consistent and intense staining in malignant urothelial cells, suggesting its value as an ancillary test in liquid-based urine cytology.

Biological and clinical perspectives of TERT promoter mutation detection on bladder cancer diagnosis and management

The telomerase reverse transcriptase (TERT) promoter mutations are associated with increased TERT mRNA and TERT protein levels, telomerase activity, and shorter but stable telomere length. TERT promoter mutation is the most common mutation that occurs in approximately 60-80% of patients with bladder cancer. The TERT promoter mutations occur in a wide spectrum of urothelial lesions, including benign urothelial proliferation and tumor-like conditions, benign urothelial tumors, premalignant and putative precursor lesions, urothelial carcinoma and its variants, and nonurothelial malignancies. The prevalence and incidence of TERT promoter mutations in a total of 7259 cases from the urinary tract were systematically reviewed. Different platforms of TERT promoter mutation detection were presented. In this review, we also discussed the significance and clinical implications of TERT promoter mutation detection in urothelial tumorigenesis, surveillance and early detection, diagnosis, differential diagnosis, prognosis, prediction of treatment responses, and clinical outcome. Identification of TERT promoter mutations from urine or plasma cell-free DNA (liquid biopsy) will facilitate bladder cancer screening program and optimal clinical management. A better understanding of TERT promoter mutation and its pathway would open new therapeutic avenues for patients with bladder cancer.

Biomarkers for Precision Urothelial Carcinoma Diagnosis: Current Approaches and the Application of Single-Cell Technologies

Simple Summary

Urothelial carcinoma (UC) is the most frequently diagnosed cancer of the urinary tract and is ranked the sixth most diagnosed cancer in men worldwide. About 70–75% of newly diagnosed UCs are non-invasive or low grade. Different tests such as urine cytology and cystoscopy are used to detect UC. If abnormal tissue is found during cystoscopy, then a biopsy will be performed. Cytology has low sensitivity for low-grade cancer while cystoscopy is invasive and costly. Detecting UC early improves the chances of treatment success. Therefore, many researchers have painstakingly identified urine biological markers for non-invasive UC diagnosis. In this review, we summarize some of the latest and most promising biological markers (including FDA-approved and investigational markers). We also discuss some new technologies that can aid research efforts in biological marker discovery for early UC detection.

Abstract

Urothelial carcinoma (UC) is the most frequent malignancy of the urinary system and is ranked the sixth most diagnosed cancer in men worldwide. Around 70–75% of newly diagnosed UC manifests as the non-muscle invasive bladder cancer (NMIBC) subtype, which can be treated by a transurethral resection of the tumor. However, patients require life-long monitoring due to its high rate of recurrence. The current gold standard for UC diagnosis, prognosis, and disease surveillance relies on a combination of cytology and cystoscopy, which is invasive, costly, and associated with comorbidities. Hence, there is considerable interest in the development of highly specific and sensitive urinary biomarkers for the non-invasive early detection of UC. In this review, we assess the performance of current diagnostic assays for UC and highlight some of the most promising biomarkers investigated to date. We also highlight some of the recent advances in single-cell technologies that may offer a paradigm shift in the field of UC biomarker discovery and precision diagnostics.

An institutional experience evaluating hTERT immunostaining in 100 consecutive ThinPrep urine specimens

INTRODUCTION

Studies have shown that expression of human telomerase reverse transcriptase (hTERT) in mature urothelial cells indicates an increased risk of urothelial carcinoma. We evaluated the utility of immunocytochemistry with a commercially available anti-hTERT antibody (SCD-A7) in 100 consecutive urine cytology specimens using ThinPrep processing.

MATERIALS AND METHODS

ThinPrep slides prepared from 100 consecutive urine specimens were stained using anti-hTERT antibody (SCD-A7) after staining optimization had been successfully completed. Patient demographics, cytology diagnoses, histologic follow-up data, and anti-hTERT staining results were recorded.

RESULTS

The cytology diagnoses included 7 cases of high-grade urothelial carcinoma (HGUC), 2 cases suspicious for HGUC (SHGUC), 24 cases of atypical urothelial cells (AUCs), and 67 cases negative for HGUC (NHGUC). Of 92 samples, 68 (74%) were positive and 24 (26%) were negative for anti-hTERT staining. Although 31 of 32 specimens (97%) with a diagnosis of AUCs and greater showed positive staining, 37 of 60 NHGUC cases (62%) were also positive for anti-hTERT. Although the HGUC and suspicious for HGUC cases were more likely to show strong staining (6 of 9; 67%), 7 AUC (32%) and 8 NHGUC (22%) cases also demonstrated strong staining. Eight samples (8%) were unsatisfactory for interpretation. Anti-hTERT staining of nonurothelial cells was seen in 77 of 92 samples (84%).

CONCLUSIONS

Interpretation of anti-hTERT immunocytochemical staining of ThinPrep material is challenging owing to obscuring of nonurothelial cell staining and difficulty discerning individual urothelial cell cytomorphology when the cells are stained. The significance of the large number of anti-hTERT-positive but cytology-negative cases in our study is uncertain.

A Review of Urine Ancillary Tests in the Era of the Paris System

Aside from its diagnostic importance, urinary tract endoscopy is an uncomfortable, expensive, and time-consuming procedure. Patients with a history of urothelial carcinoma remain at an increased risk for recurrence and the development of de novo disease; most have had exposure to carcinogenic risk factors for decades prior to their first diagnosis that have bathed the entire urothelial tract. Consequently, monitoring these patients over their lifetime has made urothelial carcinoma one of the most expensive cancers for the US healthcare system. This expense has provided a financial incentive for academic and commercial groups to develop a test with a sufficient negative predictive value to reduce the frequency of surveillance procedures. Slide-based tests require a separate slide prepared from a split urine sample or from an additional urinary tract specimen. This process can place an additional burden on the laboratory due to changes in the workflow, especially if the split specimens need to be stored until a cytologic diagnosis is rendered (i.e., when used as a reflex test). Importantly, slide-based tests allow for the result to be directly correlated with cytomorphologic findings; however, these tests require the cells of interest to be present. Thus, slide-based tests suffer from the same sensitivity issues as urinary tract cytology. In contrast, slide-free tests do not require an additional slide to be prepared, and laboratory testing may be centralized to a core facility or performed on-site. Some tests detect the expression of altered or abnormally expressed subcellular material (proteins, DNA, etc.) in urothelial neoplasms, which are found in tumor cells and/or in the urine specimen when the proteins are either excreted or leaked from degenerating tumor cells. Slide-free tests may also be developed into point-of-care tests, meaning that the result may be available to the urologist but not to the cytopathologist. Since these proteins are often disassociated from the tumor cells that produce them, such tests may have a positive result even if tumor cells are absent in the tested specimen. Here we review critical concepts as well as several ancillary tests that have been developed for urinary tract specimens.

Cell block preparation in urine cytology: examination of utility and workflow in an academic practice

INTRODUCTION

Urine cytology is a common non-invasive test to screen for urothelial carcinoma. Urine cell blocks may sometimes be prepared as a diagnostic aid (eg, to characterize architecture or perform immunohistochemistry). The aim of this study was to determine whether routinely preparing cell blocks on urine specimens improves diagnostic sensitivity.

MATERIALS AND METHODS

Three time periods were compared: time period 1 (prior to November 2009; 1437 consecutive selected cases), when cell blocks were rarely prepared; period 2 (November 2009 to May 2010; 1230 selected cases), when cell blocks were prepared on all cases; and period 3 (after May 2010; 1499 consecutive selected cases), when cell blocks were made only when indicated (for samples with substantial cellular pellets or when requested by a pathologist).

RESULTS

Patient demographics and the type of specimens received were relatively similar during the 3 time periods. Increased preparation of cell blocks was not accompanied by a notable improvement in specimen adequacy rate, given that <1%, 2%, and 1% of samples were unsatisfactory for the 3 periods. Only the proportion of atypical cases differed during the time periods, being highest in period 1 (23%), but lower in periods 2 and 3. Turnaround time was fastest for period 1 (mean: 47 hours, median: 33 hours), and slower for period 2 and period 3.

CONCLUSION

These data show that routinely preparing cell blocks for urine samples did not improve our laboratory's specimen adequacy rate. Nonetheless, cell block preparation on urine samples did help lower the proportion of atypical diagnoses, when routinely or selectively prepared. Because preparation of cell blocks on all urine cases can be costly and only provides minimal added clinical benefit, our recommendation is to rather judiciously utilize cell blocks when screening urine cytology samples.