The importance of IL-6 protein expression in primary human renal cell carcinoma: an immunohistochemical study
- 1Service d'Urologie, Hopital Henri Mondor, 51 Avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France
- 2Service d'Anatomo-pathologie, Hopital Henri Mondor
- 3UFR Biomédicale UPR 37, Régulation de l'expression des Génes, CNRS, 45 Rue des Saint- Péres, 75006 Paris, France
- Accepted 5 October 1999
Aims—Interleukin 6 (IL-6) is produced by some renal carcinoma cell lines in vitro. This might be biologically important because IL-6 is a cytokine of particular interest, owing to its involvement in the growth of renal cell carcinoma. In this study, the expression of IL-6 protein in tissue samples from primary renal cell carcinoma was analysed, and then its clinical importance was examined.
Methods—The distribution of IL-6 in renal cell carcinoma was examined by means of an immunohistochemical method in 47 untreated primary renal cell carcinoma samples. The search for a significant difference between histological patterns, Furhman's grading system, TNM classification, and IL-6 protein expression was carried out.
Results—Immunohistochemistry demonstrated that IL-6 is expressed in 70% of primary tumours. There was no significant difference in the tumour size and grade between renal cell carcinomas with or without IL-6 expression. However, a relatively large number of high grade tumours expressed IL-6.
Conclusion—The importance of IL-6 expression with regard to tumour size/local growth is questionable because IL-6 has been correlated with the development of metastatic disease. These data suggest that the production of IL-6 could exert a growth inhibitory effect on primary renal cell carcinoma.