Looking at HRT in perspective

Addition of progesterone to feminizing gender-affirming hormone therapy in transgender individuals for breast development: a randomized controlled trial

BACKGROUND

Feminizing gender-affirming hormone therapy (GAHT) for transgender individuals traditionally includes estradiol and androgen deprivation. Research has demonstrated that breast size as a result of GAHT in transgender women is often limited. Therefore, transgender women often choose to undergo breast augmentation surgery. Progesterone is important for breast development in cisgender women during puberty. A potential role for progesterone in breast development in transgender women has not been investigated in a randomized controlled experimental set-up. The primary objective of this study is to explore the effects on breast volume of addition of oral progesterone to GAHT with estradiol in transgender women after vaginoplasty or orchiectomy. Secondary objectives include assessment of safety, satisfaction, mood, sleep and sexual pleasure.

METHODS

This is a non-blinded, non-placebo, randomized controlled trial using a factorial design in adult transgender individuals assigned male sex at birth who have undergone GAHT for at least one year and underwent vaginoplasty or orchiectomy. The study design allows for rapid assessment of potential synergistic effects of various dose combinations of estradiol and progesterone on breast volume change: Ninety participants will be randomized into six groups of 15 subjects each, receiving either the baseline dose of estradiol, the baseline dose of estradiol and progesterone 200 mg daily, the baseline dose of estradiol and progesterone 400 mg daily, twice the baseline dose of estradiol, twice the baseline dose of estradiol and progesterone 200 mg daily or twice the baseline dose of estradiol and progesterone 400 mg daily, all for a duration of 12 months. The main study parameters include changes in breast volume as determined by 3D measurements. Participants will be followed-up with laboratory testing including serum progesterone concentrations as well as surveys for satisfaction, mood, sleep quality and sexual pleasure.

DISCUSSION

This study will indicate whether progesterone is safe and of additional value with regard to breast volume change in transgender individuals receiving feminizing GAHT. The results of this study will be useful for innovation of feminizing GAHT.

TRIAL REGISTRATION

WHO International Clinical Trials Registry Platform: EUCTR2020-001952-16-NL; date of registration: 12 December 2020 https://trialsearch.who.int/Trial2.aspx?TrialID=EUCTR2020-001952-16-NL .

Association of hormone replacement therapy with risk of gastric cancer: a systematic review and meta-analysis

Hormone replacement therapy (HRT) is widely used to relieve menopausal symptoms; however, it remains unclear whether the use of HRT was associated with gastric cancer. We conducted a systematic review and meta-analysis to synthesize available evidence. This study followed the PRISMA guideline to report meta-analysis. PubMed, Embase, and Cochrane library were searched from conception through 23 February 2022. Eligible studies reporting risk of gastric cancer after HRT were screened and accessed by two independent reviewers. Random-effects meta-analysis was used to calculate pooled risk estimate as relative risk (RR, 95% CI). Pre-established review protocol was registered in PROSPERO (CRD42021281260). Among the 1095 articles identified, we included 11 studies with 1,919,089 women in this meta-analysis. The combined risk estimate (RR, 0.72; 95% CI 0.64–0.81; I² = 2%) indicated that the use of HRT was associated with a 28% reduction in risk of gastric cancer compared with those who had no HRT exposure. The narrow prediction interval (0.62–0.84) for gastric cancer risk suggested a low between-study variance. In subgroup analysis defined by HRT formulation, there were reduction in risks of gastric cancer after the use of estrogen-only therapy (Pooled RR, 0.63; 95% CI 0.51–0.77, I² = 0%) and estrogen-progestin therapy (Pooled RR, 0.70; 95% CI 0.57–0.87; I² = 0%), as compared with non-users. In this systematic review and meta-analysis, the use of HRT was associated with a reduced gastric cancer risk regardless of HRT formulation. Further investigations are warranted to confirm underlying mechanisms.