Can Patterns Of Conversion From A Negative Initial Urine Cytology To A Positive Finding On Either

Subsequent Cytology Or Biopsy Be Used As A Benchmark For Surveillance In The Diagnosis Of

Urothelial Carcinoma?Karen Chau, CT(ASCP)1; Lisa Rosen, ScM2; Constantinos Coutsouvelis, CT(ASCP)1; Ryan Brenkert, CT(ASCP)1;

Farah Slim, CT(ASCP)1; Ryan Glass, MD; Stephen Raab, MD3; Rubina Cocker, MD1

1Department of Cytopathology, NSLIJ, Lake Success, NY; 2Department of Biostatistics Unit, NSLIJ, Manhasset, NY;

3Department of Cytopathology, Eastern Health Laboratories, Newfoundland and Labrador.

Background

Methodology

Results

Conclusions

30-70% of patients treated for urothelial carcinoma experience disease recurrence, with 10-30% of these progressing to higher grade or invasive disease. Urine cytology has been shown to be highly specific in the detection of recurrent bladder carcinoma and highly sensitive for detecting high-grade lesions. As part of a greater study on the accuracy of urine cytology, we explored patterns of conversion from negative cytology to positive findings on either cytology of biopsy.

A laboratory information system based search was conducted for two tertiary hospitals and one community hospital for the period from January 2008 to December 2010. The search identified 587 subjects (694 biopsy and cytology pairs) with histological follow-up that occurred within six months of urine cytology. Only subjects with cytological and histological follow-up were included in the study. We examined a subset of 176 positive biopsies that occurred within two years of an initial negative cytology to determine the amount of cytology specimens needed prior to a positive result, and the time needed for a positive result to occur following the initial negative cytology.

66.5% of patients who eventually had a positive biopsy had no prior positive cytology result. Of the patients that did convert, 66.10% did so on the second cytology, 20.34% on the third, and 6.78% on the fourth, with fewer patients converting after each subsequent specimen. A median of 2 cytology specimens were required before a positive specimen was encountered. The median time from the initial negative to the first observed positive cytology was 1.4 months (IQR: 5.0 months). The median time from the first negative cytology until positive biopsy was 5.5 months (IQR: 11.0 months).

Our study suggests that malignancies are most likely to be found within two or three cytology samples, after which likelihood is greatly diminished. Furthermore, the median time for conversion of negative cytology to positive cytology is much shorter than that from negative cytology to positive biopsy. This shorter time interval is helpful in identification of earlier recurrences of urothelialcarcinoma and underscores the importance of cytology as a more sensitive and efficient test. While cytology may not be the sole determinant in the triage of management, our study substantiates the currently accepted three monthly follow up with cytology as a post treatment urothelial carcinoma surveillance regimen.

*Data in the above graph is for the subgroup of specimens that converted to a positive cytology (n = 59)

Number of Cytology Specimens observed until the

Initial Negative Cytology Converts to a Positive One*

Total Number of Cytology Specimens Observed

Prior to Receiving a Positive Biopsy