Prognostic significance of nucleolar morphometry in clear cell renal cell carcinoma

Aim and hypothesis: Many parameters so far have been suggested in determining the prognosis of renal cell carcinomas (RCC), some of which were associated with survival. Fuhrman nuclear grading system is one of the parameters used in determining prognosis, but because it is a subjective method, new systems with more objective criteria are needed. The aim of this study is to determine the correlation of mean nucleolar volume with the prognostically significant parameters such as nuclear grade, stage and other clinical variables, and in addition to determine its ability to predict survival time and the risk of recurrence-metastasis.Method: Five µm thick slides were prepared from the tumour containing blocks of 64 clear cell RCC cases who had radical nefrectomy between 1990-2003 at our instutition. The images were viewed on a light microscope with X400 magnification and reflected on the monitor with a total of X2320 magnification. The estimation of mean nucleolar volume (MnV) is calculated according to the method described by Gundersen et al. For univariate analysis Mann-Whitney U test and Pearson chi-square tests were used. Kaplan-Meier method with log-rank test was used for survival analysis. For multivariate analysis Cox regression test was used.Results: Seventyfive percent of the cases are men, 25% are women and the mean age at diagnosis is 58.2 years. The mean follow-up time is 53.7 months. The five year survival is 54.8% and overall survival is 48.4%. Of the variables age at diagnosis, gender, Fuhrman grade, stage, MnV and tumour size; stage, MnV and tumour size were associated with recurrence-metastasis; gender, stage, MnV and tumour size were associated with survival. Significant relationship was found between MnV and Fuhrman grade. Considering the survival times; women, cases younger than 60 years of age, cases at low stages, cases with tumour size smaller than 5 cm, and cases with a MnV ? 18 µm3 are living longer than the other groups.Conclusion: There is a significant relationship between MnV and Fuhrman grade. The tumours of the group of patients with MnV ? 18 µm3 are at a lower stage and grade. The risk of recurrence is lower and survival time is longer for this group. Estimates of mean nucleolar volume can give important information on tumour prognosis, grading and staging. Only age and stage are independent prognostic parameters.