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

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.

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.

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.