[Expression of Hemeoxygenase-1 and clear cell renal cell carcinoma aggressiveness.]

OBJECTIVE Hemoxigenase 1 (HO-1) is an enzyme that has anti-apoptotic and proliferative effects on tumor cells. However, there is little epidemiological and clinical evidence on the role of HO-1 in urologic tumors. OBJECTIVE To determine if there is correlation between the expression of HO-1 and the histological characteristics, evolution, Disease Free Survival (DFS) and cancer mortality in Clear Cell Renal Cell Carcinoma (cRCC). MATERIALS AND METHODS A retrospective study including 34 patients (9 women and 25 men) with cRCC from the "Servicio de Urologia del Policlinico Neuquen" (Argentina) throughout 2003-2008. The expression of HO-1 by Immunohistochemistry (IHC) was determined. The statistical analysis was performed using the Student'sT test and Pearson correlation coefficient (p≤0.05). RESULTS: HO-1 was expressed in the epithelial cells of the tubules from normal kidney tissue and in the cytoplasmof cRCC tumor cells. There were no differences in the HO-1 expression related to the gender, age, tumorsize, stage of disease and 5 years DFS. High FuhrmancRCC had a greater expression of HO-1 compared with low Fuhrman cRCC (p≤0.05). The score of immunostaining for HO-1 was greater in those tumors located in the mesorrenal area, which coincidentally presented a more advanced stage of the disease. CONCLUSIONS: Over expression of HO-1 in tumors located in the interpolar zone and with high Furhman grade suggest that HO-1 could be a good adjunctive marker for the aggressiveness of the cRCC.