Results showed a comparable decrease in uterine volumes (20.1, 15.4 and 13 cm3 in letrozole group vs. 21.7, 15.1 and 11.7 cm3 in goserelin group, at 4, 8 and 12 weeks respectively), and adenomyoma volumes across both groups suggesting that aromatase inhibitors are as effective as GnRH agonists in reducing progression and improving symptoms of adenomyosis [38]. This evidence concerns the gene CYP19A1 and adenomyoma.