Comparison of grading systems for estimating the prognosis of renal cell carcinoma.

In this study histologic slides of 165 patients who were diagnosed as RCC between 1983 and 1993 were re-evaluated and each tumour was graded according to Thoenes, Fuhrman, Arner and Skinner's grading systems. According to Thoenes' system, patients with grade (G) 2 and 3 tumours had significantly shorter survival compared to patients with G 1 tumours. The survival difference between the subgroups of Fuhrman and Skinner's grading systems did not reach statistical significance. When the histologic differentiation was grouped as low grade (G 1&2) and high grade (G 3&4) tumours in Fuhrman and Skinner's systems, a statistically significant difference was noted between the groups in terms of survival.