Heterogeneity of tumour necrosis factor production in renal cell carcinoma

Endogenous tumour necrosis factor (TNF) production was investigated by in situ hybridisation and immunohistochemistry in 8 renal cell carcinoma (RCC) patients at different stages of disease. Analysis of frozen sections of tumour biopsy specimens revealed variable degrees of macrophage infiltration and great heterogeneity in TNF gene expression. Two metastatic tumours investigated showed abundant TNF protein production and marked macrophage infiltration. Based on morphological criteria, these TNF-positive cells most likely belong to the macrophage lineage. Two years after nephrectomy the individual survival time was recorded; however, the small numbers did not yet allow any correlation of TNF production to the clinical course of disease. Further studies will be required to eventually reveal the role of TNF in renal cell carcinoma development.