Materials and Methods: In this experimental study, 30 adult Balb/c female mice (5-8 weeks old, weighing 24-28 g) were divided into three groups (n=10/ each group) (Control group, T. group, and C. group). T. group received 2.5 mg/kg of thiotepa for four consecutive days. The C. group received cetrorelix (0.25 mg/kg) before and at the same time as thiotepa administration and a week after the end of thiotepa administration. Ovaries were used for quantitative and immunohistochemical studies at the end of the investigation.

Results: The mean numbers of follicles such as primordial, primary, secondary, and tertiary significantly decreased in the T. group than control group (P = 0.02). Cetrorelix treatment exerted a protective effect against thiotepa-induced damage by increasing the mean numbers of follicles in the ovarian cortex (P = 0.04).

Conclusions: As a GnRH antagonist, cetrorelix can be considered as one of the effective drugs to protect the granulosa cells against chemotherapy-induced damages in cancer disease.