Aim: The STAT 3 (Signal Transducer and Activator of Transcription) gene is a member of a family known as the Stat genes. These genes enable the production of proteins that are part of the basic chemical signaling pathways within the cell. This protein acts in many cellular functions by regulating genes including cell growth, cell division and cell motions. In addition to these functions, it also regulates self-destruction of the cell, called apoptosis. The effects of nuclear grading (Fuhrman) and its subtypes on survival in RCC (Renal Cell Carcinoma) are known. In this study, the relationship between STAT 3 and RCC will be evaluated. Material and Methods: 41 RCC cases were included in this study. The cases were 26 clear cell RCC (CCRCC), 7 chromophobe cell RCC (ChRCC), 8 papillary RCC (PRCC). Twelve of the CCRCC lesions were Fuhrman grade 1. Five of the CCRCC lesions were Fuhrman grade 2. Nine of the CCRCC lesions were Fuhrman grade 3. STAT 3 was administered immunohistochemically to paraffin blocks of these cases. Results: When the distribution of staining intensity was evaluated with respect to the groups, the frequency of those with staining intensity "3" was found as 19.2% in the CCRCC group, 28.6% in the chromophobe group and 50% in the papillary group. However, these differences are not statistically significant. When the relationship between the Fuhrman grade and the degree of staining was examined in the CCRCC group (n = 26), it was determined that the degree of staining increased significantly as the Fuhrman grade increased. The correlation was r = 0.456 and there was a positive correlation (p = 0.019) Conclusion: In this study, STAT 3 expression was found to be in positive corelation with Fuhrman grading.
