Urine cytology discrepancies: frequency, causes, and outcomes

Evaluation of a triple combination of cytokeratin 20, p53 and CD44 for improving detection of urothelial carcinoma in urine cytology specimens

Background:

Atypical urine cytology results trigger cystoscopy or molecular tests, both of which are costly, complex and difficult to perform tests. Several immunostains are being investigated to improve cancer detection; however, cytology material is limited and restricts the use of multiple immunostains. This study was designed to determine the utility of a cocktail of three stains, cytokeratin (CK20), p53 and CD44 in urine cytology samples for improving the detection of urothelial carcinoma.

Materials and Methods:

Urine cytology specimens with cell blocks containing adequate cytologic material between 2005 and 2010 and subsequent follow-up biopsy and/or Urovysion test (102 cases including 29 negative, 56 atypical and 17 malignant) were included in the study and evaluated with the triple stain. Results were first validated on the positive and negative cases and then applied to the atypical cases to determine the utility in the diagnosis of urothelial carcinoma.

Results:

Based on the validation and published literature, two distinct immunoprofiles were defined – malignant, characterized by at least five CK20 and/or p53 positive atypical cells and reactive, all other staining patterns. The malignant immunoprofile showed 88% sensitivity, 78% specificity, 74% positive predictive value (PPV) and 90% negative predictive value (NPV) for detecting urothelial carcinoma. These values improved to 95% sensitivity and 96% NPV when low-grade urothelial carcinoma cases were excluded.

Summary:

Our results indicate that the triple stain is an inexpensive, easy to perform test most useful for differentiating high-grade urothelial carcinoma from its mimics. However Inclusion of CD44 in the cocktail did not provide additional value and is best excluded.

Decreased expression of RNA-binding motif protein 3 correlates with tumour progression and poor prognosis in urothelial bladder cancer

Background

Low nuclear expression of the RNA-binding motif protein 3 (RBM3) has previously been found to be associated with poor prognosis in several cancer forms e.g. breast, ovarian, colorectal, prostate cancer and malignant melanoma. The aim of this study was to examine the prognostic impact of RBM3 expression in urinary bladder cancer.

Methods

Immunohistochemical RBM3 expression was examined in tumours from 343 patients with urothelial bladder cancer. Chi-square and Spearman’s correlation tests were applied to explore associations between RBM3 expression and clinicopathological characteristics. The impact of RBM3 expression on disease-specific survival (DSS), 5-year overall survival (OS) and progression-free survival (PFS) was assessed by Kaplan-Meier analysis and Cox proportional hazards modelling.

Results

Reduced nuclear RBM3 expression was significantly associated with more advanced tumour (T) stage (p <0.001) and high grade tumours (p=0.004). Negative RBM3 expression was associated with a significantly shorter DSS (HR=2.55; 95% CI 1.68-3.86)) and 5-year OS (HR=2.10; 95% CI 1.56-2.82), also in multivariable analysis (HR=1.65; 95% CI 1.07-2.53 for DSS and HR=1.54; 95% CI 1.13-2.10 for 5-year OS). In patients with Ta and T1 tumours expressing reduced RBM3 levels, Kaplan-Meier analysis revealed a significantly shorter PFS (p=0.048) and 5-year OS (p=0.006).

Conclusion

Loss of RBM3 expression is associated with clinically more aggressive tumours and an independent factor of poor prognosis in patients with urothelial bladder cancer and a potentially useful biomarker for treatment stratification and surveillance of disease progression.

Evaluation of atypical urine cytology progression to malignancy

BACKGROUND

In urine cytology, the diagnosis of atypia is subjective and clinical management based on these results can be difficult to determine. In this study, the authors determined the percentage of atypical urine diagnoses that progressed to positive cytology or surgical pathology results over an 11-year period.

METHODS

In a retrospective review of the authors' institution, 1320 atypical urine cytology diagnoses were identified in specimens from 851 patients obtained from January 2000 through December 2010. All subsequent pathology reports were reviewed to determine which patients developed positive cytology/surgical pathology diagnoses. In total, 4106 cytology and surgical pathology specimen reports were reviewed.

RESULTS

At the authors' institution, 1320 of 16,299 of urine cytology specimens (8.1%) were diagnosed as atypical during the 11-year period. Overall, 271 of 1320 initial atypical urine specimens (21%) progressed to positive cytology or surgical pathology results with a mean time to progression of 155 days. Of the cases that progressed to malignancy, 118 were high-grade urothelial carcinoma and 92 were low-grade urothelial carcinoma.

CONCLUSIONS

The rate of atypia in urine specimens at this institution was 8.1%. Of the specimen types, atypia was the most common in urinary diversion specimens (16%) and the least common in upper tract cytology (3.8%). When diagnosed as atypical, upper tract specimens had the highest percentage of progression to high-grade carcinoma. Therefore, the authors concluded that the diagnosis of atypia in this specimen group has higher clinical significance and should be managed more aggressively. Cancer (Cancer Cytopathol) 2013;121:387-391. © 2013 American Cancer Society.

UroVysion® multiprobe FISH in the triage of equivocal urinary cytology cases

The search for biological and clinical significance of equivocal urinary cytology has emerged as the most promising application of fluorescence in situ hybridization (FISH). Using the multiprobe UroVysion(®) assay, a negative FISH result in the presence of atypical urothelial cells favors the presence of reactive, benign alterations and helps to avoid unnecessary invasive procedures. However, a negative FISH result in case of a negative or equivocal cytology does not exclude low-grade urothelial neoplasia. Equivocal findings are a notorious problem after conservative treatment, particularly after BCG immunotherapy of carcinoma in situ, where even benign reactive changes can appear worrisome. In this situation, a positive FISH result in spite of non-high grade cytology independently indicates persistent or recurrent urothelial carcinoma. However, chromosomal abnormalities are not restricted to malignancy but may also occur in benign cells. Tetraploidy with a balanced duplication of the whole genome, or polyploidy can occur in non-neoplastic conditions of the bladder such as Decoy cells, radiotherapy-induced changes and urolithiasis. Thus, a positive FISH result in a patient with a history of pelvic irradiation does not prove cancer unless there is unequivocal 9p21 deletion. Recent studies show that an aggressive workup of patients with a suspicious cytology+positive UroVysion(®) result and negative cystoscopy is not currently justified. However, multi-target UroVysion(®) FISH remains an excellent tool to improve diagnosis in urinary cytopathology, provided that FISH results are interpreted in the light of the clinical situation, and that one reminds that FISH adds no diagnostic value in case of clearly positive, high-grade cytology.

Reflex ImmunoCyt testing for the diagnosis of bladder cancer in patients with atypical urine cytology

BACKGROUND

ImmunoCyt/uCyt (Scimedx, Denville, NJ, USA) is a well-established urinary marker assay with high sensitivity for the diagnosis of urothelial carcinoma (UC) and can function as a second-level test to arbitrate atypical reads of urine cytology.

OBJECTIVE

To determine the utility of uCyt as a reflex test for atypical cytology in patients undergoing a hematuria evaluation or surveillance with a history of UC.

DESIGN, SETTING, AND PARTICIPANTS

The uCyt assay was performed as a second-level reflex test on all voided urine cytology tests read as atypical between January 2007 and June 2010 in an academic medical center. Records were retrospectively reviewed. Three hundred twenty-four patients underwent a total of 506 uCyt assays.

INTERVENTION

Reflex uCyt assay on atypical urine cytology.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The uCyt test characteristics include sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV).

RESULTS AND LIMITATIONS

Reflex uCyt was performed on 506 atypical voided urine samples that were followed by cystoscopy within 90 d. Reflex uCyt with a history of UC showed a sensitivity of 73%, a specificity of 49%, and an NPV of 80%. In those with a history of low-grade UC, reflex uCyt had a sensitivity of 75%, a specificity of 50%, and an NPV of 82%, while in those with a history of high-grade UC, it had a sensitivity of 74%, a specificity of 44%, and an NPV of 79%. Without prior history of UC, reflex uCyt had a sensitivity of 85%, a specificity of 59%, and an NPV of 94%. This study's limitations include its retrospective design and interobserver variability inherent to cystoscopy, which was used as the reference test.

CONCLUSIONS

When used as a reflex test on atypical urine cytology, negative uCyt may predict a negative cystoscopy in select patients and modulate the urgency and further work-up in those with no prior history or low-grade disease.

Diagnostic significance of atypical category in the voided urine samples: A retrospective study in a tertiary care center

Background:

Voided urine samples continue to play an important role in the surveillance of urothelial malignancy and also as a screening mode for high risk patients. In some cases, it is difficult to reliably distinguish changes induced by inflammation, stone or other reactive condition from neoplasm, and these cases are categorized as atypical. The aim of our study is to evaluate the prevalence and the significance of atypical diagnosis in the voided urine samples and also to identify the cytomorphologic features that are seen more frequently in the atypical malignant urine samples.

Materials and Methods:

All voided urine cytology samples with a diagnosis of atypical urothelial cells, between the period of 2000 and 2009, were obtained from the cytology database. Only those cases with histologic follow-up were included in the study. The cytology and the histology slides were retrieved and reviewed. The following parameters were evaluated: cellularity, cell clusters, nuclear membrane irregularities, hyperchromasia and India-ink type nuclei, the presence of spindle cells and the cytoplasmic characteristics.

Results:

Out of 72 voided urine samples included in the study, 49 cases (68%) had a positive histologic diagnosis of urothelial malignancy in the follow-up histology; of these (55%) were high-grade urothelial carcinoma. Increased cellularity, papillary cell clusters, nuclear membrane irregularity, hyperchromasia and India-ink type nuclei were observed more frequently in the atypical malignant urine samples, while cytoplasmic vacuolization were seen more in the negative reactive urine samples.

Conclusion:

The atypical category diagnosis is associated with a significant proportion of urothelial carcinoma. It should be used by the pathologist to convey concern to the clinician in difficult cases that may require close follow-up.

Accuracy of urine cytology and the significance of an atypical category

The "atypical urothelial cell" cytologic category is nonstandardized. We subclassify atypical cases to "atypical, favor a reactive process" or "atypical, unclear if reactive or neoplastic." We evaluated the predictive significance of atypical cases by looking at their histologic follow-up. Among the 1,114 patients and 3,261 specimens included, 282 specimens had histologic follow-up. An atypical diagnosis did not carry a significant increased risk of urothelial neoplasia compared with the benign category. Although an "atypical unclear" diagnosis carried a higher rate of detection of high-grade cancer on follow-up biopsy in comparison with "atypical reactive" or "negative" diagnoses (26/58 [45%] vs 15/52 [29%] and 16/103 [15.5%], respectively), this difference was not statistically significant. These results suggest that dividing atypical cases into 2 categories based on the level of cytologic suspicion of cancer does not add clinically relevant information within the atypical category. They also raise the question of the significance of the atypical category altogether.

[Usefulness of urine cytology for bladder carcinoma diagnosis: comparative study with biopsy]

OBJECTIVES

Traditionally, urine cytology has been considered as the gold standard for bladder cancer screening. However, new methods are playing new roles in these cases. In order to assess the value of cytology of voided urine we performed one comparative study between cytology and biopsy.

METHODS

We retrospectively analyzed the results of urine cytology and biopsy follow-up in 109 patients. All cytologies were from voided urine. They were cytocentrifuged and stained with Papanicolaou stain.

RESULTS

We found 70 true positive cases and 24 true negative cases. Sensitivity was calculated to be 97% and specifity 96-100%. 12 cases had the first cystoscopy test and biopsy negative, as the cancer was diagnosed in the second biopsy.

CONCLUSIONS

Patients with clearly positive urine cytology, which was not confirmed in a first cystoscopic study, should be carefully followed up to identify a possible bladder or upper urinary tract cancer. The urine cytology still has a significant role as the gold standard for bladder cancer screening.

Assessing the value of reflex fluorescence in situ hybridization testing in the diagnosis of bladder cancer when routine urine cytological examination is equivocal

PURPOSE

We evaluated the usefulness of fluorescence in situ hybridization in the treatment of patients with equivocal cytology.

MATERIALS AND METHODS

Fluorescence in situ hybridization was performed in residual urine from 124 patients with a cytological diagnosis of cell clusters (22), atypical findings (46) and suspicious findings (56) who had a same day cystoscopy result and bladder biopsy within 6 months of the cytology diagnosis. Urologists and fluorescence in situ hybridization technologists were blinded to the matching fluorescence in situ hybridization and cystoscopy results, respectively.

RESULTS

In conjunction with cystoscopy fluorescence in situ hybridization was significantly more sensitive than cystoscopy alone for detecting cancer (87% vs 67%, p <0.001) and muscle invasive cancer (94% vs 56%, p = 0.031). Of the 124 equivocal cytology specimens 58 (47%) were positive by fluorescence in situ hybridization. Of these patients 53 (91%) had subsequent evidence of carcinoma, including Ta tumors in 17, Tis in 13, T1 in 8 and T2 or greater in 15, on the first followup biopsy. Three of the 5 remaining patients with a positive fluorescence in situ hybridization result and negative first followup biopsy had evidence of cancer at a later date, including TxN+ disease in 2 and Tis in 1. A total of 66 specimens were diagnosed as negative by fluorescence in situ hybridization. Of these patients 34 (52%) had negative biopsy results, whereas the remaining 32 (48%) demonstrated bladder cancer, including Ta disease in 20, Tis in 8, T1 in 2 and T2+ in 2. Cystoscopy detected 21 of the 32 tumors (66%) not detected by fluorescence in situ hybridization, while fluorescence in situ hybridization detected 17 of the 28 (61%) not detected by cystoscopy.

CONCLUSIONS

Our data suggest that fluorescence in situ hybridization with cystoscopy can aid clinicians in the diagnosis of bladder cancer in patients with equivocal cytology.