The role of STAT3 protein as a prognostic factor in the clear cell renal carcinoma. Systematic review

Abstract Context and objective There have been significant advances in the knowledge of renal carcinogenesis in the last years. Nowadays, renal tumours are classified according to their genetic profile and specific treatments based on the identification of therapeutic targets have also been developed. However, no prognostic markers have yet been identified. The aim of this review is to analyze literature that has evaluated the expression of the STAT3 protein as a molecular marker in clear cell renal carcinoma (ccRCC). Evidence acquisition In January 2018 a systematic review was conducted in Pubmed, Cochrane library and Sciencedirect databases, from papers published from 1990. Search terms were “renal cell carcinoma” and “STAT3” or “STAT-3” and prognostic factor. Following the principles of the PRISMA declaration and the PICO selection strategy, original articles with series of patients diagnosed with localized or metastatic ccRCC, and where the activity of STAT3 is analyzed as a prognostic marker, were selected. A total of 132 publications were identified, of which 10 were finally revised, for they met the inclusion criteria. Evidence synthesis STAT3 activation (phosphorylation) through Ser727 is important during ccRCC development and progression. PSTAT3 expression seems to be a prognostic marker and an antiangiogenic-resistance marker in metastatic patients. There is little evidence as prognostic marker in patients with localized disease. Conclusions STAT3 (Ser 727) expression in the nucleus of the ccRCC cells can be a prognostic marker and an antiangiogenic-resistance marker. Current scientific evidence is limited and more studies are needed to demonstrate its usefulness.