Deoxyribonucleic acid ploidy enhances the cytological prediction of recurrent transitional cell carcinoma of the bladder.

Abstract

We determined whether deoxyribonucleic acid (DNA) ploidy analysis by image analysis cytometry enhances the cytological diagnosis of recurrent transitional cell carcinoma of the bladder. A retrospective study was performed during a 5-year period to evaluate the cytological diagnosis and DNA ploidy analysis of 469 patients with previously diagnosed superficial transitional cell carcinoma. Cytological and DNA ploidy analysis was performed on 1,034 urine and bladder wash specimens, and the patients were monitored with cystoscopy and biopsies as clinically indicated. Cytology results were classified as normal, atypical, dysplastic or cancerous, and DNA ploidy was defined as normal if the diploid index was 1.2 or less, the S phase+G2M fraction was less than 21% or if there were 3% or less hyperploid cells, or abnormal if there was an increased S phase+G2M fraction, an aneuploid peak on the histogram or tetraploidy or hyperploidy was present. The majority of patients (85 of 88, 97%) with a cytological diagnosis of cancer had an abnormal DNA ploidy, and in 60 of 85 of these patients (71%) recurrence was diagnosed within 6 months. Only 5 of 284 specimens (2%) with normal cytology had abnormal DNA ploidy and 1 of these 5 (20%) heralded transitional cell carcinoma recurrence. However, in 145 patients with atypical cytological findings 29 (20%) with abnormal DNA ploidy had a recurrence, compared to 20 of 391 (5%) with normal DNA ploidy (p < 0.0001). Similarly, in 101 patients with dysplastic cytological findings 39 (39%) with abnormal DNA ploidy had transitional cell carcinoma recurrence compared to 4 of 25 with normal ploidy (p = 0.033). Abnormal DNA ploidy determined by image analysis significantly enhances the detection of bladder tumor recurrence in patients with atypical or dysplastic cytology but not in those with normal cytology or frank carcinoma on cytological findings.