Near-diploid transitional cell carcinoma: a preliminary report.

DNA ploidy analysis has been accepted as an important prognostic factor for patients with transitional cell carcinoma (TCC). However, there was few information dealing with the clinical relevance of slightly aberrant DNA content by flow cytometry (FCM). Here we present five cases of near-diploid (ND) tumours, with DNA index (DI) varying from 0.92 to 1.14, obtained from a prospective study of fifty-one cases (9.8%). The frequency of ND tumours showed a tendency to decrease with increasing tumour stage. Higher fraction of tumour proliferation, defined by Ki-67 index, showed a steady increment from 3.4 to 23.5% with occurrence of gross chromosomal changes. In contrast, the expression of epidermal growth factor receptor (EGFR) decreased from 48.3 to 35.3% for diploid (n = 29) through aneuploid (n = 17) tumours. All three ND bladder cancers had recurrence of one to three times with median follow-up of 36 months. The incidences of tumour recurrence (60%) and cancer death (20%) in ND tumours were intermediate between the aneuploid and diploid TCCs. But, flow DNA analysis of paraffin-embedded ND tumours revealed wide and symmetrical G0/G1 peak with DI varying from 5.6 to 13.0. Our limited experience suggests the necessity of special treatment for G0/G1 peaks having CV values greater than 5.5% from paraffin-embedded urothelial carcinomas.