Effects of hormonally active agents on steroid hormone receptor expression and cell proliferation in the myometrium of ovariectomized macaques

Depot Medroxyprogesterone Acetate Use and the Development and Progression of Uterine Leiomyoma

OBJECTIVE

Investigate the association between use of depot medroxyprogesterone acetate (DMPA) (an injectable progestin-only contraceptive) and leiomyoma development.

METHODS

We conducted a cohort study in the Detroit, Michigan, area that involved four clinic visits at 20-month intervals over 5 years (2010-2018) and used a standardized ultrasonography protocol to prospectively measure leiomyomas 0.5 cm or more in diameter. Participants were 1,693 self-identified Black women aged 23-35 years with no prior leiomyoma diagnosis and no hysterectomy. For this substudy, years since last use of DMPA was ascertained from questionnaire data at every visit. Leiomyoma incidence was defined as the first visit with an observed leiomyoma among women who were leiomyoma-free at enrollment. Depot medroxyprogesterone acetate associations were examined with Cox models. Leiomyoma growth was calculated as the change in log-volume for leiomyomas matched at successive visits and was modeled using linear mixed models accounting for clustered data. Leiomyoma loss, defined as a reduction in leiomyoma number in successive visits, was modeled using Poisson regression. All models used time-varying exposure and covariates.

RESULTS

Of participants with at least one follow-up visit (N=1,610), 42.9% had ever used DMPA. Participants exposed to DMPA within the previous 2 years experienced reduced leiomyoma development during the subsequent observation interval compared with never users, including lower leiomyoma incidence (5.2% vs 10.7%), adjusted hazard ratio 0.6 (95% CI 0.4-1.0), 42.0% lower leiomyoma growth (95% CI -51.4 to -30.7) and 60% greater leiomyoma loss (adjusted risk ratio 1.6, 95% CI 1.1-2.2). Excess leiomyoma loss was also seen for those who used DMPA 2-4 years before the visit compared with never users, 2.1-fold increase (95% CI 1.4-3.1).

CONCLUSION

Recent use of DMPA was associated with reduced leiomyoma development and increased leiomyoma loss. Such changes in early leiomyoma development in young women could delay symptom onset and reduce the need for invasive treatment.

Growth factors and myometrium: biological effects in uterine fibroid and possible clinical implications

BACKGROUND

Growth factors are proteins secreted by a number of cell types that are capable of modulating cellular growth, proliferation and cellular differentiation. It is well accepted that uterine cellular events such as proliferation and differentiation are regulated by sex steroids and their actions in target tissues are mediated by local production of growth factors acting through paracrine and/or autocrine mechanisms. Myometrial mass is ultimately modified in pregnancy as well as in tumour conditions such as leiomyoma and leiomyosarcoma. Leiomyomas, also known as fibroids, are benign tumours of the uterus, considered to be one of the most frequent causes of infertility in reproductive years in women.

METHODS

For this review, we searched the database MEDLINE and Google Scholar for articles with content related to growth factors acting on myometrium; the findings are hereby reviewed and discussed.

RESULTS

Different growth factors such as epidermal growth factor (EGF), transforming growth factor-α (TGF-α), heparin-binding EGF (HB-EGF), acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet-derived growth factor (PDGF) and TGF-β perform actions in myometrium and in leiomyomas. In addition to these growth factors, activin and myostatin have been recently identified in myometrium and leiomyoma.

CONCLUSIONS

Growth factors play an important role in the mechanisms involved in myometrial patho-physiology.