The following is a summary of “MED12 mutations in uterine leiomyomas: prediction of volume reduction by gonadotropin-releasing hormone agonists,” published in the FEBRUARY 2023 issue of Obstetrics and Gynecology by Nagai, et al.

Premenopausal uterine leiomyomas were treated with gonadotropin-releasing hormone agonists, but leiomyoma volume reduction was not always achieved. Even in the same patient, the decrease rate following the therapy differed depending on the leiomyoma. Consequently, a reliable strategy for anticipating uterine leiomyoma volume reduction was necessary to lessen the negative hypoestrogenic effects and the financial burden of gonadotropin-releasing hormone agonist use. For a study, researchers sought to evaluate the predictive value of MED12 mutations for assessing the effect of gonadotropin-releasing hormone agonist treatment for reducing uterine leiomyoma volume and to predict the MED12 mutation status based on the results of magnetic resonance imaging performed before treatment.

The effect of the MED12 exon 2 mutation and erythropoietin expression on the volume decrease of uterine leiomyomas was assessed using magnetic resonance imaging. To noninvasively predict the presence or absence of MED12 mutations in leiomyomas, we created a system for categorizing leiomyomas based on T2-weighted magnetic resonance imaging data. Between 2005 and 2021, 168 patients who underwent hysterectomy or myomectomy surgery at Yokohama City University Hospital provided leiomyoma samples (>5 cm). Leuprorelin acetate 3.75 mg, given monthly subcutaneously for three months, was preoperatively delivered to 41 patients to study the rate of leiomyoma volume reduction. Magnetic resonance imaging was done before and after therapy without a  contrast agent.

In comparison to patients with leiomyomas expressing the wild-type MED12 exon 2, those with MED12 exon 2 mutations had smaller volume reduction after treatment with the gonadotropin-releasing hormone agonist (P< .001, Mann-Whitney U test). They also exhibited lower signal intensity on T2-weighted images. A nearly equal distribution of mutated and wild-type MED12 exon 2 leiomyomas was seen in the intermediate group, according to the newly proposed magnetic resonance imaging-based classification system, which revealed that MED12 exon 2 mutations were more common in the low-signal group than in the high-signal group. The expression levels of erythropoietin were lower in the low-signal group than in the high-signal group (P< .001, Kruskal-Wallis test with the Dunn posthoc analysis).

A measure for predicting the impact of gonadotropin-releasing hormone agonists on uterine leiomyoma reduction is the MED12 mutation status. As a noninvasive method of choosing patients who will most likely benefit from gonadotropin-releasing hormone agonist treatment, magnetic resonance imaging findings can be used to evaluate the status of the MED12 mutation.

Reference: ajog.org/article/S0002-9378(22)00748-7/fulltext