Medical Therapy for Leiomyomas

General Considerations

Most women with leiomyomas are asymptomatic and require no intervention. However, it has been estimated that approximately 30% will experience abnormal uterine bleeding (AUB), while others will present with infertility, recurrent pregnancy loss, or bulk or pressure-related symptoms that may include  abdominal distension, urinary frequency, dyspareunia, or gastrointestinal symptoms such as dyschezia or constipation.  Women with these symptoms may benefit from appropriate medical intervention (Giuliani, 2020). It is important to realize that the symptoms associated with leiomyomas may not be caused by the leiomyomas – for example, an individual with a 2.5 cm FIGO Type 6 fibroid and irregular onset of menses likely has AUB-O, something not caused by the presence of a fibroid. Or she might have ovulatory cycles and actually have a coagulopathy (AUB-C) or a primary disorder of endometrial hemostasis (AUB-E).

There are some important issues to consider when counseling patients regarding medical therapy for leiomyoma-associated symptoms, regardless of whether or not the fibroids themselves are the cause of the symptoms. First, medical therapy, while preserving the uterus, is not known to improve fertility or pregnancy outcomes. Second, and particularly with AUB, is that some medical interventions may be aimed at the tissue that is bleeding – the endometrium – and not the fibroid itself, so one is not “treating” leiomyomas per se.  Third, only a subset of medical interventions, such as selective progesterone receptor modulators (SERMs) and gonadotropin releasing hormone (GnRH) agonists and antagonists, have independent effects on the endometrium and the leiomyoma, so they can be used to stop bleeding as well as reduce leiomyoma volume. Finally, no known medical therapy results in a sustained reduction of leiomyoma volume once the treatment is stopped. This means that medical therapy designed to have a sustained impact on symptoms caused by leiomyomas must be given continuously or according to some appropriate intermittent dosing schedule. 

Medical treatments are generally considered to be first-line treatment, especially when preservation of the uterus is a goal (Angioni, 2021). However, selection of a medical intervention depends on the symptoms experienced, the immediate and longer-term fertility objectives of the patient, and the anticipated morbidity and efficacy associated with procedural interventions. For example, in the context of the symptom of heavy menstrual bleeding (HMB) associated with a 2.5 cm Type 1 leiomyoma (AUB-L_SM) in a patient desiring pregnancy, hysteroscopic myomectomy would usually be the preferred choice. However, if the leiomyoma were a 5 cm Type 2-5 lesion (also AUB-L_SM), and there was uncertainty regarding future fertility, medical therapy could be a compelling option.  Consequently, each medical option has its own advantages and disadvantages, making the selection dependent on the patient’s individual goals for therapy, whether volumetric reduction or treatment of HMB and associated iron deficiency (Sohn, 2018). Regardless of the treatment for HMB, it is important that the clinician also assess the patient for iron status, including anemia, and, if found treat iron deficiency appropriately (Internal Link).