ProEx C as an adjunct marker to improve cytological detection of urothelial carcinoma in urinary specimens

MCM2 in human cancer: functions, mechanisms, and clinical significance

Background

Aberrant DNA replication is the main source of genomic instability that leads to tumorigenesis and progression. MCM2, a core subunit of eukaryotic helicase, plays a vital role in DNA replication. The dysfunction of MCM2 results in the occurrence and progression of multiple cancers through impairing DNA replication and cell proliferation.

Conclusions

MCM2 is a vital regulator in DNA replication. The overexpression of MCM2 was detected in multiple types of cancers, and the dysfunction of MCM2 was correlated with the progression and poor prognoses of malignant tumors. According to the altered expression of MCM2 and its correlation with clinicopathological features of cancer patients, MCM2 was thought to be a sensitive biomarker for cancer diagnosis, prognosis, and chemotherapy response. The anti-tumor effect induced by MCM2 inhibition implies the potential of MCM2 to be a novel therapeutic target for cancer treatment. Since DNA replication stress, which may stimulate anti-tumor immunity, frequently occurs in MCM2 deficient cells, it also proposes the possibility that MCM2 targeting improves the effect of tumor immunotherapy.

p16 is superior to Stathmin-1 and HSP27 in identifying cervical dysplasia

Background

The aim of this study was to determine how Stathmin-1 and Heat Shock Protein 27 (HSP27) can be used as adjunctive biomarkers to differentiate high-grade dysplasia from benign/reactive lesions in cervical tissues. In addition, we aimed to see if any of these markers can differentiate endometrial from endocervical adenocarcinomas.

Methods

Fifty cases including benign cervical tissue, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ of the endocervix, invasive endocervical adenocarcinoma, and endometrial adenocarcinoma were selected. Stathmin-1 and HSP27 immunohistochemistry (IHC) were performed for each case and the results were compared to the previously available p16 IHC stains.

Results

p16 stained positively in 100% of HSIL, endocervical adenocarcinoma in situ, and invasive endocervical cases. Stathmin-1 stained positively in 43% of HSIL and 90% of endocervical adenocarcinoma in situ and all invasive endocervical cases. Stathmin-1 and p16 were negative in all benign cervical samples. Stathmin-1, HSP27, and p16 stained 100% of LSIL cases. HSP27 stained indiscriminately, including 100% of benign cervical tissue. 87% of the endometrial adenocarcinomas stained positively for p16, Stathmin-1, and HSP27.

Conclusion

p16 remains superior to both Stathmin-1 and HSP27 in differentiating dysplasia from benign, reactive changes of the cervix.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01144-w.

Immunocytochemical expression of Ki-67/p16 in normal, atypical, and neoplastic cells in urine cytology using BD SurePath™ as preparation method

Objective:

The objective of this study was to investigate the expression of Ki-67/p16 in urothelial cells in cytological material.

Materials and Methods:

There were 142 urines including normal controls, anonymous rest urine, controls after treatment for urothelial carcinoma (UC) and newly diagnosed UC. Immunocytochemistry for ki-67/p16 dual staining kit was performed on all specimens.

Results:

Eight high-grade UC and six anonymous specimens showed dual positivity. None of the low-grade UC or the control specimens after treated UC showed dual staining. Fifteen of 84 (17.8%) symptomatic cases were negative for both markers, and 59/84 (70.2%) showed positivity for both but not dual staining. Twenty-seven of 84 cases were positive for either Ki-67 (n = 22) or p16 (n = 5). Normal controls and benign specimens were negative for p16.

Conclusions:

Co-expression of p16/Ki-67 in the same cells was found in 16.6% of the cases. All were high grade, and co-expression seems to have limited practical impact as an additional marker in urine cytology. Any positivity for p16 alone strongly indicates malignancy. Negative p16 accompanied by a positive Ki-67 rate at 5% or more could be considered as an additional marker for further clinical follow-up. Both markers, co-expressed and separate, can give additional information in follow-up patients after treatment for UC.

[A new terminology for urinary cytopathology: The Paris System for Reporting Urinary Cytology (2015)]

As for the Bethesda system for cervical and thyroid cytopathology, a terminology for reporting urinary cytology has been published in 2015. The new "Paris System" provides a consensus terminology for urinary cytology which underlines the criteria for the recognition of high-grade urothelial carcinoma (HGUC) and of those excluding HGUC, or suspicious for HGUC. It also focuses on new rules to recognize and report the subgroup of "atypical urothelial cells". Here we describe and illustrate the various categories as in the reference book. We analyse the main diagnostic criteria, including microscopic features as well as the risk of malignancy associated to every diagnostic category.

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.

ProEx C as Diagnostic Marker for Detection of Urothelial Carcinoma in Urinary Samples: A Review

The gold standard for the detection of urothelial carcinoma is represented by urethro-cystoscopy and biopsy. Both procedures are invasive and expensive and therefore cytology is often used as first approach to investigate on a possible neoplasia, being a safe and cost-effective diagnostic modality of evaluation. Because cytology alone is not highly sensitive for detection of low grade urothelial carcinoma and recurrence of the disease, several adjunct markers and urine based tests for urothelial carcinoma have been developed, which can help in the final diagnosis. In particular, ProEx C is an immunohistochemical cocktail containing antibodies direct against topoisomerase IIα (TOP2A) and minichromosome maintenance 2 (MCM2) proteins. It proved to be a valid biomarker especially in detecting squamous intraepithelial lesions in cervical liquid-based samples and in discerning these lesions from their mimickers, as well as in ovarian, endometrial, vulvar, primary and metastatic melanomas, breast, pancreatic and renal cell carcinomas. This brief review covers the effective utility of ProEx C as adjunct tool in assessing the urothelial lesions in urine cytology, also providing prognostic and therapeutic information to help in clinical decisions.

Ubiquilin2 as a novel marker for detection of urothelial carcinoma cells in urine

BACKGROUND

Ubiquilin 2 (UBQLN2), an ubiquitin-related protein, is strongly expressed in urothelial carcinoma cells, in contrast to no or less expression in non-neoplastic cells; it protects cancer cells from reactive oxygen species (ROS)-induced cytotoxicity. In this study, we investigated whether UBQLN2 immunostaining, using liquid-based cytology sample could improve the accuracy of cytological urine diagnosis.

METHODS

Two-hundred and forty-five urinary samples, including 143 negative controls and 102 urothelial carcinomas, consisting of 42 low-grade and 60 high-grade urothelial carcinomas, were used for immunocytochemical analysis of UBQLN2.

RESULTS

Urothelial carcinoma cells were positive for UBQLN2-staining, while non-neoplastic cells, including renal tubular cells and degenerative atypical cells, were negative. Interestingly, percentage of nuclear stain immunopositive for UBQLN2 was significantly higher in carcinoma cells with high grade/invasive phenotype than in those with low grade/noninvasive phenotype. UBQLN2 immunostaining had an overall sensitivity of 87.6%, specificity of 98.6%, positive predictive value of 97.8% and negative predictive value of 92.8% for the detection of urothelial carcinoma.

CONCLUSIONS

UBQLN2 immunostaining is a practical test for urine cytology, even in samples with few cells, with slight atypia or severe degenerative changes. In addition, it allows prediction of tumor grade and stage by examining the cellular localization of UBQLN2.

Comparative study of ProEx C immunocytochemistry and UroVysion fluorescent in-situ hybridization assays on urine cytology specimens

Background:

Detection of urothelial carcinoma (UC) by urine cytology can be challenging. Recently, ProEx C has been studied as a marker to improve detection of UC. ProEx C is an assay targeting expression of topoisomerase IIa and minichromosome maintenance protein-2 and is currently utilized to assist in diagnoses of the gynecological specimens. In this study, we compared the utility of ProEx C and UroVysion in urine specimens.

Materials and Methods:

Twenty-seven urine specimens with UroVysion assay analysis and surgical biopsy follow-up were selected. The smears were stained with ProEx C. ProEx C and UroVysion assay results were separated into two categories based on surgical biopsy follow-up (benign or neoplastic). Surgical biopsy diagnoses were used as the gold standard for comparative evaluation of the two assays. The surgical follow-up was 9 benign, 2 low grade, and 16 high grade UCs.

Results:

The sensitivity was 88.9% for ProEx C and 55.6% for UroVysion, while the specificity was 77.8% for ProEx C and 44.4% for UroVysion. Positive predictive value was 88.9% for ProEx C and 66.7% for UroVysion. Negative predictive value was 77.8% and 33.3% for ProEx C and UroVysion, respectively. Using the two-tailed paired t-test, P value of 0.033 was obtained when ProEx C stain was compared with the UroVysion assay.

Conclusion:

ProEx C immunocytochemistry has a more favorable performance than fluorescent in-situ hybridization with a significant difference between the two assays using paired two-tail t-test (P = 0.0033).

Comparative evaluation of ProEx C and ImmunoCyt/uCyt assays in atypical urine cytology

CONTEXT

Detection of urothelial carcinoma by urine cytology can be challenging. Recently, ProEx C has been studied as a marker to improve detection of urothelial carcinoma. ProEx C is an assay targeting expression of topoisomerase II-α and the minichromosome maintenance protein-2 and is used to assist in diagnoses of gynecologic specimens.

OBJECTIVE

To evaluate the utility of ProEx C and uCyt in atypical urine cytology.

DESIGN

Sixty-eight specimens with a diagnosis of atypical urine cytology, concurrent uCyt testing, and surgical biopsy follow-up were included. Slides were restained with ProEx C. ProEx C was recorded as positive when nuclear staining was seen in at least one morphologically atypical urothelial cell. The uCyt was scored as positive if at least one morphologically atypical urothelial cell showed positive fluorescence staining. Thirteen cases (19%) had benign histologic diagnoses, 18 (26%) had low-grade papillary urothelial carcinoma, and 37 (54%) had high-grade urothelial carcinoma.

RESULTS

The overall sensitivity was 85% for ProEx C, 85% for uCyt, and 93% for the combination of the 2 assays. The overall specificity was 69% for ProEx C, 31% for uCyt, and 23% for the combination of the 2 tests. In predicting high-grade urothelial carcinoma, sensitivity was 92% for ProEx C, 86% for uCyt, and 92% for both tests. In predicting low-grade papillary urothelial carcinoma, sensitivity was best with the combination of the 2 tests at 94%.

CONCLUSION

ProEx C has superior specificity to uCyt. The combination of the 2 tests yielded high sensitivity not only for high-grade urothelial carcinoma but also for low-grade papillary urothelial carcinoma.

Expression of ProEx C in primary and metastatic urothelial carcinoma

BACKGROUND

ProEx C is an antibody cocktail targeting the expression of topoisomerase IIα and minichromosome maintenance protein-2. Both these proteins are over-expressed in the cell nucleus during aberrant S-phase induction of neoplastic cells, which leads to cell proliferation. The aim of this study was to determine whether ProEx C expression can detect primary and metastatic urothelial carcinoma (UC).

METHODS

Thirty one fine needle aspiration cell blocks (CB) with metastatic UC were identified. Immunohistochemical staining for ProEx C and thrombomodulin was performed. Additionally, staining for Pro Ex C was also performed in tissue microarrays (TMA) of 46 cases of primary UC and carcinomas from colon (80), stomach (31), pancreas (33), liver (92), ovary (24), endometrium (25), breast (60), lung (27), kidney (32), and prostate (44), as well as melanoma (22). Nuclear staining of ProEx C and membrane staining of thrombomodulin in at least 10% tumor cells was considered a positive result.

RESULTS

Both ProEx C and thrombomodulin have similar sensitivity for metastatic UC (84% vs. 77%, p=0.75; whereas ProEx C yielded a higher sensitivity of 93% for primary UC than thrombomodulin (72%, p=0.01). In addition to UC, ProEx C is also expressed in most of the malignant neoplasms tested in our TMA study, and has the highest sensitivity in colon and stomach carcinomas (94%).

CONCLUSION

ProEx C has high sensitivity for UC. However, it is also expressed in carcinomas of colon, stomach, breast, and lung carcinomas and may not be a useful marker for workup of metastatic UC.

Utility of ProEx C in the histologic evaluation of the neoplastic and nonneoplastic urothelial lesions

ProEx C is an antibody cocktail targeting the expression of topoisomerase IIα and minichromosome maintenance protein 2. ProEx C staining is being used mainly to assist in diagnoses of dysplasia in gynecological specimens. This study was designed to determine the utility of ProEx C in assessing the urothelial lesions. Sixty-four patient specimens were divided into 5 groups: group I, 22 benign; group II, 13 low-grade noninvasive papillary urothelial carcinoma; group III, 10 high-grade urothelial carcinoma in situ (flat lesion); and group IV, 19 high-grade noninvasive papillary and invasive urothelial carcinomas. ProEx C reactions were scored in basal, parabasal, intermediate, and superficial cell layers. A sample was recorded as positive when nuclear staining was seen in the cells of the intermediate and/or superficial layers. Of 22 cases in group I, 21 were negative for ProEx C with a specificity of 95%. Of 13 cases in group II, 11 had positive results with sensitivity of 85%. All cases in groups III and IV had positive staining pattern with ProEx C with a sensitivity of 100%. In this study, ProEx C stain had an overall 95% sensitivity and specificity with positive and negative predictive values of 98% and 91%, respectively, for detection of urothelial carcinoma. We conclude that ProEx C is effective in differentiating carcinoma in situ and benign urothelial lesions. It also resolves issues in low- versus high-grade papillary urothelial carcinomas. To our knowledge, this is the first publication on the diagnostic application of ProEx C in histopathology of the urothelial lesions.