Automated image analysis for bladder cancer

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.

Variability among observers utilizing the CellSolutions BestCyte Cell Sorter imaging system for the assessment of urinary tract cytology specimens

INTRODUCTION

Image analysis systems are not currently commonly used for evaluating urinary cytology specimens. We evaluated whether the BestCyte Cell Sorter (CellSolutions, Greensboro, NC) imaging system can reliably identify atypical cells in urinary cytology specimens.

METHODS

Fifty-three consecutive urine cytology specimens underwent 2 preparations: one slide using SurePath (SP; BD Diagnostics, Sparks, MD)^™ for routine clinical evaluation, and a second slide using the CellSolutions F50 system for analysis by the BestCyte Cell Sorter (BCCS) scanning system. Eight observers reviewed atypical cells flagged by BCCS and assigned a BCCS diagnosis to each of the 53 specimens. The observers also blindly reviewed the SP preparation (when available) and assigned an SP diagnosis. The SP diagnoses given by one "expert" observer was considered as a reference diagnosis.

RESULTS

There was fair-to-moderate agreement among observers for identifying any atypia and high-grade atypia (Fleiss kappa: 0.417 and 0.338, respectively) using BCCS. Review of SP preparations had slightly better agreement (Fleiss kappa: 0.558 and 0.564, respectively). Intraobserver agreement between the two methods varied greatly between individuals (Cohen's kappa range: 0.260 to 0.647). When a consensus diagnosis could be reached among the observers for cases with surgical follow-up, the consensus diagnosis was concordant in 11 of 12 instances, with one instance being a one-step discrepancy.

CONCLUSIONS

Specimen review by BCCS resulted in slightly greater interobserver variability than review of routine SP preparations. This may have been due to variations in observer experience and comfort with the use of a digital imaging system, which is further suggested by the wide range of intraobserver agreement among individuals.

Presence of carcinoma in situ and high 2C-deviation index are the best predictors of invasive transitional cell carcinoma of the bladder in patients with high-risk Quanticyt

OBJECTIVES

Karyometric analysis (Quanticyt) has proved of value as a cytologic marker for bladder cancer. This study was conducted to identify diagnostic and prognostic factors in a high-risk Quanticyt population to predict the prognosis of transitional cell carcinoma (TCC) of the bladder.

METHODS

Quanticyt is a karyometric system for quantitative bladder wash cytologic findings based on two nuclear features: the 2c-deviation index (2cDI) and the mean of nuclear shape. Samples are scored as low, intermediate, or high risk. Before 1995, 109 patients with high-risk quantitative bladder wash cytologic findings were identified at our clinic. Four patients with previous invasive tumors were excluded.

RESULTS

Histologically proven malignancy was found in 54 of 105 patients at first high-risk quantitative bladder wash cytologic findings. Invasive TCC was found in 16 patients, and another 10 patients had progression during a median follow-up of 3.7 years. In univariate analysis, the presence of carcinoma in situ (CIS), highest tumor grade, 2cDI, and highest tumor stage were significant predictors of progression. The presence of CIS proved to be the only predictor of progression in the multivariate analysis. A 2cDI of 2.00 c(2) or higher was a significant predictor of CIS, invasive TCC, and progression. At follow-up analysis after negative cystoscopy, 2cDI showed a tendency toward predicting progression.

CONCLUSIONS

These data confirm earlier findings that CIS is an important marker of progression. 2cDI as assessed by quantitative cytology is a practical tool to predict CIS, invasive TCC, and subsequent progression. A 2cDI of 2. 00 c(2) can be used to further stratify high-risk quantitative bladder wash cytologic findings.