ROLE OF DNA IMAGE CYTOMETRY IN THE FOLLOW-UP OF PATIENTS WITH URINARY-TRACT TRANSITIONAL CELL-CARCINOMA

Detection of recurrent urinary tract transitional cell carcinoma (TCC) is a frequent diagnostic challenge in exfoliative cytology because of the difficulty in distinguishing reactive changes from low grade tumo rs. This study evaluated the role of DNA analysis by image cytometry ( ICM) as a diagnostic aid to cytology. Eighty-seven urine samples from patients with a known history of transitional cell carcinoma were exam ined by both cytology and ICM, and the results were compared with conc urrent surgical biopsy specimens and patients' follow-up data. Twenty- seven patients were also examined by cystoscopy, and the results were compared to those of DNA analysis, cytology and biopsy. Urine samples were cytocentrifuged and stained with Papanicolaou stain for general c ytology and Feulgen stain for ICM. DNA ploidy and the proliferating ce ll fraction (SG2M) were measured using the CAS 200 image analyzer. Amo ng the 87 specimens included in the study, 59 were from patients consi dered to have recurrent disease when urine was obtained. Of the 59 rec urrences, 33 were detected by cytology, 50 by ICM and 50 by biopsy, re sulting in 55%, 85% and 85% sensitivity, respectively. When combined, cytology and ICM detected 53 recurrences and achieved 90% sensitivity. Nine cases originally undetected by biopsy had abnormal DNA histogram s and were found to have TCC on follow-up examination. All cases undet ected by ICM were low grade lesions with DNA diploidy and low prolifer ation. Among the 27 patients examined by cystoscopy, 14 had recurrent disease; 5,13 and 6 of those cases were detected by cystoscopy, DNA an alysis and cytology, respectively. The present data indicate that DNA analysis by ICM is a useful adjunct to cytopathology in the follow-up of patients with TCC of the urinary tract and that recurrence may go u ndetected if using cystoscopy, cytology or biopsy alone.