ABSTRACT
The insulin-like growth factor-I receptor (IGF-IR), a tyrosine kinase receptor over expressed in many tumor cell lines and in some human tumors, plays a critical role in transformation, tumorigenicity and metastasis. The aim of the present study is to investigate the role of IGF-IR expression as a prognostic factor in RCC. This study was conducted in a historical cohort of 82 patients who had RCC treated with radical nephrectomy from 1994 to 2005. Specimens were reevaluated with regard to histological subtype, nuclear grade, stage and IGF-IR expression. The IGF-IR stain was semi-quantitatively evaluated using the Allred score system. Kaplan-Meier analysis demonstrated a significant positive correlation between Fuhrman nuclear grade and IGF-IR Allred score (P< 0.0001). Survival in patients with score IGF-I < or = 4 was 90.21 month and in patients with score IGF-1R> 4 was 33.39 month (P Value < 0.0001). Cox regression analysis indicated that expression of IGF-IR is a prognostic factor in patients with RCC (P Value < 0.0001, odds Ratio = 2.38). In conclusion, a statistically significant correlation was demonstrated between IGF-IR expression and Fuhrman nuclear grading and survival in patients with RCC. In stage-by-stage and grade-by-grade analysis; however, it seems that we cannot consider IGF-IR as an independent prognostic factor.
