Improving the prognostic value of histopathological grading and clinical staging in renal cell carcinomas by means of computer-assisted microscopy

The present work aims to refine prognosis in cases of renal cell carcinoma (RCC) by integrating a variety of parameters with the prognostic informatio n provided by histopathological grading and clinical staging, carried out o n a series of 97 RCCs, To this end, Feulgen-stained RCC cell nuclei mere ch aracterized by means of 38 variables describing nuclear DNA ploidy levels a nd morphology. All of these data were subjected to a principal components a nalysis, On the basis of this multivariate analysis, Fuhrman grade II was s ubdivided into grades II- and II+, and Fuhrman grade III into grade III- an d III+. The same kind of subcategorization was performed in the case of the T2 and T3 clinical stages. The results show that the classification into g rade II- and III- RCCs correspond to a more favourable prognosis than grade II+ and III+, to which shorter survival periods mere attributable. Similar results were obtained for the subcategorization of the T2 and T3 clinical stages, Very simple biological characterizations of these grade- or stage-r elated RCC groups mere obtained by means of a decision tree approach applie d to the cytometry-generated variables. The resulting classification rules mere validated on a new series of 18 patients and enabled very accurate pre dictions of survival. Copyright (C) 1999 John Wiley & Sons, Ltd.