Análisis de la expresión nuclear de pSer727-STAT3 como factor pronóstico en pacientes con carcinoma renal de células claras

INTRODUCTION: Currently, clear cell renal carcinoma (CCRCC) has no prognostic markers. STAT3 protein (Signal Transducer and Activator of Transcription 3) is involved in the carcinogenesis of CCRCC. Its activation is produced by phosphorylation of the serine 727 residue, translocating to the nucleus where it is involved in carcinogenesis and tumor progression. The primary objective of the study was to evaluate cancer-specific survival rates in a series of 166 patients with CCRCC, and its subsequent correlation with the expression of pSer727-STAT3 as a prognostic marker of CCRCC. MATERIAL AND METHODS: We conducted a retrospective study on 166 patients with CCRCC undergoing partial or radical nephrectomy between 2000 and 2010. A tumor tissue microarray was constructed for immunohistochemical analysis of pSer727-STAT3 expression. The main variable of the study was cancer-specific survival. RESULTS: Patients were classified according to the UICC risk groups as follows: low in 78 patients (47%), intermediate in 52 (31.3%) and high 36 (21.7%); 11 patients (6.7%) were diagnosed with metastatic disease. During a mean follow-up of 97.2 months (1-208), 37 patients (22.3%) developed local and/or distant recurrence. Cancer-specific and overall mortality rates were 28.3% and 67.5%, respectively. The mean expression of pSer727-STAT3 was 92.9 (95% CI: 84.6-101.1) without showing any relationship with risk groups or other prognostic factors. In a Cox logistic regression analysis, pSer727-STAT3 did not behave as an independent predictor of cancer-specific mortality. However, in high-risk and metastatic patients, cancer-specific survival was significantly higher when the expression of pSer727-STAT3 was lower than 110, HR: 5.4 (96% CI: 1.8-16.4) and HR: 2.3 (95% CI: 1.1-4.6) respectively, P<.001. CONCLUSIONS: pSer727-STAT3 is not a survival marker in patients with CCRCC. However, it is a cancer-specific survival marker in high-risk patients, even in metastatic patients undergoing treatment with antiangiogenic agents.