Clinical importance of intratumoral and normal renal parenchymal inflammatory cell infiltration in renal cell carcinoma

Abstract

To assess the relationship between inflammatory cell infiltration and tumor type, stage and grade, the presence of multifocality and survival in tumors and in tumor-free normal parenchyma. A total of 99 patients who underwent radical nephrectomy for renal cell carcinoma (RCC) between 1995 and 2001 and were subsequently followed up were included in the study. Formalin-fixed, paraffin-embedded tissues from the patients were reassessed by a pathologist and inflammation in both tumor and normal renal tissue was scored using a five-point scale. We evaluated the relationship between these scores and tumor type, stage, grade, the presence of multifocality and survival. There were positive correlations between tumor grade and both the intratumoral inflammation score (IIS) and the extratumoral inflammation score (EIS) (p=0.001 and 0.01, respectively). There were no relations between pathological stage and either the IIS or EIS. We found higher multifocality rates in patients who died because of metastasis than those who survived (p=0.002). The EIS was 1.76+/-1.54 in the non-multifocality group and 2.64+/-1.15 in the multifocality group and this difference was statistically significant (p=0.03). There was no statistically significant relationship between the IIS and multifocality. Oncocytomas and chromophobe carcinomas did not show inflammatory infiltrates in either tumors or normal renal tissue. Higher EIS and IIS are associated with increasing tumor grade and a higher EIS is associated with multifocality in RCC. We propose to evaluate tumor tissue and normal renal parenchyma for the presence of inflammatory infiltration in RCC.