Contenu en ADN par cytométrie en flux et cytologie dans le diagnostic et le pronostic des tumeurs vésicales : résultats préliminaires d'une étude comparative sur lavage de la vessie

Abstract

Objective : To compare flow cytometric data (ploidy and proliferative activity or percentage SG2M-phase cells) to cytologic and histologic data of the bladder carcinomas. Materials and methods : Cytologic and flow cytometric analysis of DNA content were performed on 48 bladder washings: 28 bladder washings from patients being followed for urothelial carcinomas and 20 control washings from individuals undergoing cytoscopy for other reasons. Results : Cytological sensitivity and specificity of bladder washing were 75% and 91% respectively. Specificity was increased to 94% using flow cytometric DNA analysis whereas sensibility was moderately decreased to 68%. Combination of flow cytometry and cytology increased the diagnostic yield to 100%. The study of the patient group showed an increased abnormalities (aneuploidy and/or proliferate activity SG2M > 10%) according to the tumor grading and tumor staging. A cytometric test was positive in 80% for G3 tumours and in 68% for G2 tumours. The staging tumor was positive in 46%, 89% and 100% of the pTa-pT1, pT2 and pT4 tumours respectively. Otherwise the comparison of control group with patients showed a statistical correlation between cytometric test, staging tumour and tumoral grading as showed in the following groups: control/G1-G2 ( p<0.05), control/G3 ( p<0.001), control/pTa-pT ( p<0.05), control/pT2-pT4 ( p<0.001). Conclusion : We confirmed through this study the interest of the flow cytometric DNA analysis in the diagnosis and prognosis of bladder carcinomas, and we showed the importance of the histogram classification in order to facilitate their interpretation and to avoid the trap of false aneuploidy.