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Breast development modest with cross-sex hormonal treatment in transgender women

ORLANDO, Fla. — Breast development in transgender women treated with cross-sex hormonal therapy occurs primarily in the first 6 months of administration and stabilizes with no increase during the last 6 months, according to research presented here.

Christel JM de Blok, MD, of VU University Medical Center in Amsterdam, Netherlands, and colleagues evaluated 288 transgender women (median age, 28 years) from the European Network for the Investigation of Gender Incongruence to determine the effect of 1 year of cross-sex hormonal treatment on breast development.

After 1 year of therapy, mean breast-chest difference increased from 4 cm at baseline to 7.5 cm. Development occurred primarily during the first 6 months of therapy and then stabilized, with a growth of only 0.4 cm over the remaining 6 months. Breast development was not modified by age, weight change, serum estradiol levels or estrogen administration route.

Guy T'Sjoen
Guy T'Sjoen

“Breast development after 1 year of estrogen treatment is often suboptimal, regardless of serum estradiol levels, and little change is to be expected beyond 1 year of treatment,” researcher Guy T’Sjoen, MD, PhD, head of the department of endocrinology and Center for Sexology and Gender at Ghent University Hospital in Belgium, told Endocrine Today.

“Increasing estrogen dosage will most likely not enhance feminization, but will increase the risk of side-effects. There are transwomen who report an anecdotal improved breast development, mood or sexual desire with the use of progesterones, but there have been no well-designed studies of the role of progesterones in feminizing hormone regimens, so the question is still open. Many transwomen are eager to start with a maximal dosage of estrogens, but a step-up dose regimen could improve results,” he said – by Amber Cox

Reference:

De Blok CJM, et al. OR36-2. Presented at: The Endocrine Society Annual Meeting; April 1-4, 2017; Orlando, Fla.

Disclosures: DeBlok reports no relevant financial disclosures. T’Sjoen reports various financial ties with Bayer Shering, Ferring, Ipsen, Novartis and Sandoz.

ORLANDO, Fla. — Breast development in transgender women treated with cross-sex hormonal therapy occurs primarily in the first 6 months of administration and stabilizes with no increase during the last 6 months, according to research presented here.

Christel JM de Blok, MD, of VU University Medical Center in Amsterdam, Netherlands, and colleagues evaluated 288 transgender women (median age, 28 years) from the European Network for the Investigation of Gender Incongruence to determine the effect of 1 year of cross-sex hormonal treatment on breast development.

After 1 year of therapy, mean breast-chest difference increased from 4 cm at baseline to 7.5 cm. Development occurred primarily during the first 6 months of therapy and then stabilized, with a growth of only 0.4 cm over the remaining 6 months. Breast development was not modified by age, weight change, serum estradiol levels or estrogen administration route.

Guy T'Sjoen
Guy T'Sjoen

“Breast development after 1 year of estrogen treatment is often suboptimal, regardless of serum estradiol levels, and little change is to be expected beyond 1 year of treatment,” researcher Guy T’Sjoen, MD, PhD, head of the department of endocrinology and Center for Sexology and Gender at Ghent University Hospital in Belgium, told Endocrine Today.

“Increasing estrogen dosage will most likely not enhance feminization, but will increase the risk of side-effects. There are transwomen who report an anecdotal improved breast development, mood or sexual desire with the use of progesterones, but there have been no well-designed studies of the role of progesterones in feminizing hormone regimens, so the question is still open. Many transwomen are eager to start with a maximal dosage of estrogens, but a step-up dose regimen could improve results,” he said – by Amber Cox

Reference:

De Blok CJM, et al. OR36-2. Presented at: The Endocrine Society Annual Meeting; April 1-4, 2017; Orlando, Fla.

Disclosures: DeBlok reports no relevant financial disclosures. T’Sjoen reports various financial ties with Bayer Shering, Ferring, Ipsen, Novartis and Sandoz.

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