Clinical significance of EGF and EGFR expression changes in cryptorchid boys

To explore the changes of epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) expressions in cryptorchid children and their clinical significance.

The level of serum EGF was measured by radioimmunoassay (RIA) and the expression of EGFR by immunohistochemistry.

(1) The level of serum EGF was significantly lower in cryptorchid children than in normal subjects at age group of 5-9 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 approximately 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).

The EGF and EGFR expressions may correlate with the age and the position of testes; orchiopexy improves the EGF and EGFR expressions in cryptorchid boys.