Comparison of the effects of raloxifene and anastrozole on experimental endometriosis.

Objective: To compare the efficacies of anastrozole and raloxifene on endometriosis.

Study Design: A randomized, placebo-controlled, single-blind, experimental study was performed on 45 adult Wistar female rats in the Experimental Surgery Laboratory at Ondokuz Mayis University in Turkey. Endometrial tissues were implanted on the abdominal peritoneum in 45 rats. Six weeks later, the implant volumes were measured (volume-1) by performing a second laparotomy. Rats were randomized to one of three equal study groups. Saline solution (0.1 cc/rat/week, subcutaneously) was administered to group 1 (control group), anastrozole (0.004 mg/rat/day, orally) to group 2 (anastrozole group), and raloxifene (0.24 mg/rat/day, orally) to group 3 (raloxifene group) for 8 weeks. At the end of administration, a third laparotomy was performed to remeasure implant volumes (volume-2), and implants were totally excised for histopathologic examination. Volume-1 and volume-2 within the groups, as well as stromal and glandular tissues between the groups, were compared.

Result(s): In the anastrozole and raloxifene groups, volume-2 values were significantly lower than those of volume-1. When compared to the control group, in both anastrozole and raloxifene groups, while glandular tissue scores were found significantly lower, stromal tissue scores were not different than that of the control group. There was no significant difference between both the GT and ST scores of the anastrozole and raloxifene groups.

Conclusion(s): Anastrozole and raloxifene were seen to have caused equally the regression of the experimental endometriosis statistically significantly.