Clinical significance of EGF and EGFR expression changes in cryptorchid boys

Aim: To explore the changes of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) expressions in cryptorchid children and their clinical significance. Methods: The level of serum EGF was measured by radioimmunoassay (RIA) and the expression of EGFR by immunohistochemistry. Results: (1) The level of serum EGF was significantly lower in cryptorchid children than in normal subjects at age group of 59 years (P<0.01) and 10-14 years (P<0.01), (2) The level of EGF was significantly lower in boys with impalpable testis than in those with extracanalicular and intracanalicular testes (P<0.01), (3) The serum EGF level increased significantly 6 months after orchiopexy (P<0.05), (4) The EGFR expression in testicular Leydig's cells was lower in 2-4 year-old boys than in those over 5 years (P<0.05) and (5) the EGFR expression was less positive in the impalpable group and the intracanalicular group than that of the extracanalicular group (P<0.01). Conclusion: The EGF and EGFR expr essions may correlate with the age and the position of testes; orchiopexy improves the EGF and EGFR expressions in cryptorchid boys. (Asian J Androl 2002 Dec; 4: 255-258)