Michael S Irwig’s research while affiliated with Beth Israel Deaconess Medical Center and other places

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Publications (57)


of the histological, radiological, and quantitative data used for each part of this study. a Breast histology image from a subject who had been using testosterone therapy for 4.2 years at the time of chest-contouring surgery. Pathologists assessed the breast tissue as demonstrating a moderate degree of lobular atrophy with mixed fatty and fibrous stroma. Our algorithm quantified this breast tissue as containing 2.8% epithelium, 53.1% fibrous stroma, and 44.1% fat. b Corresponding mammogram from the same subject taken two months prior to surgery. The radiologist classified this case as B-scattered fibroglandular density. The Laboratory for Individualized Breast Radiodensity Assessment (LIBRA) software estimated the breast percent density as 1.9%. Digital imaging and communications in medicine, DICOM
a Lobular atrophy was assessed by the pathologists using four categories. b The duration of testosterone therapy (TT) significantly correlated with increasing degrees of lobular atrophy (rho = 0.30, 95% Confidence Interval (CI) 0.21, 0.38, adj p < 0.001). c Stromal composition was assessed by the pathologists using three categories. d There was no correlation between duration of TT and stromal composition as assessed by the pathologists (rho = − 0.01, 95% CI − 0.11,0.08, adj p = 0.77)
a Breast tissue density was assessed by a radiologist using four categories with increasing amounts of fibroglandular tissue (epithelium and fibrous stroma). Mammograms were from transmasculine subjects. b There was no association between the duration of testosterone therapy (TT) and breast tissue density (rho = − 0.09, 95% Confidence Interval (CI) − 0.38, 0.22, p = 0.58)
Effect of testosterone therapy on breast tissue composition and mammographic breast density in trans masculine individuals
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  • Full-text available

July 2024

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38 Reads

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1 Citation

Breast Cancer Research

Yujing J. Heng

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Gabrielle M. Baker

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Valerie J. Fein-Zachary

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[...]

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Gerburg M. Wulf

Background The effect of gender-affirming testosterone therapy (TT) on breast cancer risk is unclear. This study investigated the association between TT and breast tissue composition and breast tissue density in trans masculine individuals (TMIs). Methods Of the 444 TMIs who underwent chest-contouring surgeries between 2013 and 2019, breast tissue composition was assessed in 425 TMIs by the pathologists (categories of lobular atrophy and stromal composition) and using our automated deep-learning algorithm (% epithelium, % fibrous stroma, and % fat). Forty-two out of 444 TMIs had mammography prior to surgery and their breast tissue density was read by a radiologist. Mammography digital files, available for 25/42 TMIs, were analyzed using the LIBRA software to obtain percent density, absolute dense area, and absolute non-dense area. Linear regression was used to describe the associations between duration of TT use and breast tissue composition or breast tissue density measures, while adjusting for potential confounders. Analyses stratified by body mass index were also conducted. Results Longer duration of TT use was associated with increasing degrees of lobular atrophy (p < 0.001) but not fibrous content (p = 0.82). Every 6 months of TT was associated with decreasing amounts of epithelium (exp(β) = 0.97, 95% CI 0.95,0.98, adj p = 0.005) and fibrous stroma (exp(β) = 0.99, 95% CI 0.98,1.00, adj p = 0.05), but not fat (exp(β) = 1.01, 95%CI 0.98,1.05, adj p = 0.39). The effect of TT on breast epithelium was attenuated in overweight/obese TMIs (exp(β) = 0.98, 95% CI 0.95,1.01, adj p = 0.14). When comparing TT users versus non-users, TT users had 28% less epithelium (exp(β) = 0.72, 95% CI 0.58,0.90, adj p = 0.003). There was no association between TT and radiologist’s breast density assessment (p = 0.58) or LIBRA measurements (p > 0.05). Conclusions TT decreases breast epithelium, but this effect is attenuated in overweight/obese TMIs. TT has the potential to affect the breast cancer risk of TMIs. Further studies are warranted to elucidate the effect of TT on breast density and breast cancer risk.

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Effect of testosterone therapy on breast tissue composition and mammographic breast density in trans masculine individuals

January 2024

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6 Reads

Objective: Determine the association between TT and breast tissue composition and breast tissue density in trans masculine individuals (TMIs). Design: This is a cross-sectional study. Setting: TMIs (n=444) underwent chest-contouring surgeries to treat their gender dysphoria between 2013 and 2019 at an urban medical center. Participants: Of the 444 TMIs, 425 had pathology images analyzed by our deep-learning algorithm to extract breast tissue composition. A subset of 42/444 TMIs had mammography prior to surgery; mammography files were available for 25/42 TMIs and analyzed using a breast density software, LIBRA. Main Outcome(s) and Measure(s): The first outcome was the association of duration of TT and breast tissue composition assessed by the pathologists (categories of lobular atrophy and stromal composition) or by our algorithm (% epithelium, % fibrous stroma, and % fat). The second outcome is the association of TT and breast density as assessed by a radiologist (categorical variable) or by LIBRA (percent density, absolute dense area, and absolute non-dense area). Results: Length of TT was associated with increasing degrees of lobular atrophy (p<0.001) but not fibrous content (p=0.821) when assessed by the pathologists. Every six months of TT was associated with decreased amounts of both epithelium (exp(β)=0.97, 95% CI 0.95-0.98, adj p=0.005) and stroma (exp(β)=0.99, 95% CI 0.98-1.00, adj p=0.051), but not fat (exp(β)=1.01, 95%CI 0.98-1.05, p=0.394) in fully adjusted models. There was no association between TT and radiologist breast density assessment (p=0.575) or LIBRA measurements (p>0.05). Conclusions. TT decreases breast epithelium and fibrous stroma, thus potentially reducing the breast cancer risk of TMIs. Further studies are warranted to elucidate the effect of TT on breast density and breast cancer risk.



Fig. 1. Timeline that summarizing the main clinical events.
Invasive Ductal Carcinoma of the Breast in a Transgender Man: A Case Report

September 2023

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28 Reads

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1 Citation

Case Reports in Oncology

There is limited literature about breast cancer in the transgender population. Very little is known about how gender-affirming hormone therapy affects their breast cancer risk. On the other end, for those diagnosed with breast cancer, there are no clinical guidelines to manage their breast cancer, specifically, how to manage their gender-affirming hormone therapy during breast cancer treatment. Here, we report a 52-year-old transman diagnosed with a grade 2 invasive ductal carcinoma (ER+/PR+/HER2−), and ductal carcinoma in situ (DCIS) of intermediate grade. We discussed his risk factors as well as treatment options.


Beliefs and counseling practices among dermatologists regarding sexual and other adverse effects of finasteride

August 2023

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62 Reads

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1 Citation

International Journal of Impotence Research

Finasteride may cause low libido and erectile dysfunction and the product label of finasteride also includes post-marketing reactions of sexual dysfunction that continued after discontinuation of treatment, as well as male infertility and depression. The aim of this study was to evaluate the beliefs and counseling practices among dermatologists regarding adverse effects of finasteride. Anonymous paper surveys were personally distributed to 122 attendees at two annual major dermatology meetings. The participation rate was 82% with 47% women and 77% residents of the United States. 51% of respondents believed that finasteride could cause sexual side effects and 18% believed that it could cause persistent sexual side effects. Fewer than a quarter believed that finasteride could cause depression or lower sperm counts. When initiating finasteride, 69% of respondents counseled at least half of their patients about potential sexual side effects with 52% for persistent sexual side effects and 30% for depression. This study identifies the need for greater awareness of the potential adverse effects of finasteride and identifies opportunities for improvement in counseling practices that reflect finasteride’s product labeling.


Lipid profiles and hypertriglyceridemia among transgender and gender diverse adults on gender-affirming hormone therapy

November 2022

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81 Reads

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15 Citations

Journal of Clinical Lipidology

Background The effects of gender-affirming hormone therapy on lipid profiles among transgender adults have been inconsistent and incompletely characterized. Objective To longitudinally assess changes to lipid profiles following hormone therapy and to establish prevalence rates of hyperlipidemia/low HDL-cholesterol. Methods This longitudinal study followed lipid profiles of 366 transgender and gender-diverse adult patients (170 transfeminine and 196 transmasculine; mean age, 28 years) in Washington DC USA. Lipid profiles were measured at baseline and at multiple follow-up clinical visits up to 57 months after the initiation of hormone therapy. Results Within 2-10 months of starting gender-affirming hormone therapy, mean levels of HDL-cholesterol decreased by 16% in transmasculine individuals and increased by 11% in transfeminine individuals. Over the study, mean triglyceride levels increased by 26-37% in the transmasculine group. Over the study, the prevalence of moderate hypertriglyceridemia (175-499 mg/dL) ranged from 11-32% in the transfeminine group and 6-19% in the transmasculine group. Severe hypertriglyceridemia (≥500 mg/dL) was only observed in one individual. On hormone therapy, 24-30% of the transfeminine group had a HDL-cholesterol < 50 mg/dL and 16-24% of the transmasculine group had a HDL-cholesterol < 40 mg/dL. LDL-cholesterol levels ≥160 mg/dL were rare among both groups. Conclusions In a gender-diverse population on hormone therapy, low HDL-cholesterol and moderate hypertriglyceridemia were relatively common. HDL-cholesterol decreased with testosterone therapy and increased with a combination of oral estrogen and spironolactone. Testosterone use was associated with an increase in triglycerides. Our data support the recommendation to routinely monitor lipid profiles in gender-diverse patients on GAHT.



Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

September 2022

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4,526 Reads

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1,288 Citations

International Journal of Transgender Health

Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person.


Citations (50)


... [5][6][7] Notably, gender-affirming therapies can influence the anatomical and histopathologic makeup of a person's fibroglandular breast tissue. 8,9 In this review article, we examine the current data on breast care considerations for TGD persons, highlight topics, and discuss opportunities for future work to guide evidence-based and equitable breast care for persons of all genders. ...

Reference:

Breast care considerations for transgender and gender-diverse patients
Effect of testosterone therapy on breast tissue composition and mammographic breast density in trans masculine individuals

Breast Cancer Research

... 1 That said, some authors have advocated for reducing starting doses of IM estradiol to 5 mg/wk, noting the prevalence of supraphysiologic levels of serum estradiol in users of IM estradiol at the currently recommended doses. 7 The route and dose of estrogen may be chosen based on factors like cost/availability, ease of administration, and concern for adverse events. ...

The Use of Injectable Estradiol in Transgender and Gender Diverse Adults: A Scoping Review of Dose and Serum Estradiol Levels
  • Citing Article
  • May 2024

Endocrine Practice

... In fact, recent reports and clinical observations have raised concerns that the dosing suggested in guidelines may result in supraphysiological estradiol levels and that higher doses and levels may put patients at elevated risk of thromboembolic events. [15][16][17][18] This scoping review examines the available data on levels achieved with various dosages of estradiol injections in TGD adults. We also report on testosterone suppression, route (ie, SC vs IM), and type of estradiol ester as well as timing of blood draw relative to dose, where available. ...

Revisiting Injectable Estrogen Dosing Recommendations for Gender-Affirming Hormone Therapy
  • Citing Article
  • February 2024

Transgender Health

... Second, a foundation of claims-based research involves identification of gender-affirming care by people without an explicitly associated diagnosis (e.g., endocrine disorder not otherwise specified) [9]. State-level anti-TGD legislation has escalated dramatically [40] including bills which criminalize gender-affirming care [41] [42] and compel the release of TGD patient records [43]. Claims-based algorithms could facilitate such criminalization of TGD people, their clinicians, and families. ...

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8
  • Citing Article
  • September 2023

Yearbook of Paediatric Endocrinology

... The copyright holder for this preprint this version posted August 22, 2024. ; https://doi.org/10.1101/2024.08.21.24312383 doi: medRxiv preprint suicide [40]. It was found that an increased risk of suicide may exist with finasteride in the treatment of men with a history of psychological disorders [41]. ...

Beliefs and counseling practices among dermatologists regarding sexual and other adverse effects of finasteride

International Journal of Impotence Research

... Thirty-Five (35/51, 69%) studies investigated lipid profile (Table 3). Some studies reported no difference in parameters of lipid profile in TGW, whilst the rest demonstrated a potential shift towards an anti-atherogenic profile through either a decrease in triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL) or increase in high-density lipoprotein (HDL) (9,14,19,20,22,25,36,38,39,44,45,49,51,53,56,58,59). In TGM, most studies indicated a pro-atherogenic change, i.e., increased TG, TC, LDL and decreased HDL, under at least one measurement (9, 11-14, 19, 22, 25-27, 36, 38, 39, 44, 47-51, 53, 54, 56, 58-61) ( (14,21,22,25,38,62) and 5 demonstrated increased glucose (13,25,45,57,62). ...

Lipid profiles and hypertriglyceridemia among transgender and gender diverse adults on gender-affirming hormone therapy

Journal of Clinical Lipidology

... Based on the symptomatic descriptions of each case report, we examined which of the theories proposed by Wattel [27] could explain them. The abbreviation AMAB was used to signify that the gender assigned at birth was male, and AFAB was used if the gender assigned at birth was female [57]. ...

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

International Journal of Transgender Health

... We are therefore pleased to incorporate a variety of topics into this special issue pertinent to hypertension pathophysiology such as sex-hormone mediated mechanisms [6], the impact of psychosocial gender [3], the effect of menopause [7], preclinical models [8] and hypertensive multi-organ damage [9][10][11][12]. Importantly, this special issue provides the scope to discuss underrepresented and underserved populations who may experience hypertension, including women [13,14], gender-diverse individuals [15], those with chromosomal aneuploidies [16], the young [17], and those living in low and middle income countries [18]. To translate findings into clinical practice we look at hypertension guidelines [13] and data from primary care [19]. ...

Hypertension in transgender individuals
  • Citing Article
  • July 2022

Journal of Human Hypertension

... This raises concerns when TRT services are promoting themselves en masse to young and older men alike, highlighting non-specific symptoms like fatigue and low libido as indicative of low testosterone. This advertising often suggests to these men that low testosterone is the root cause of their symptoms and can be reversed through testosterone therapy, yet leaves out negatives associated with testosterone use, and other possible causes for symptoms (Irwig, 2022). This may result in otherwise healthy men, or men with separate underlying issues, commencing testosterone use in the belief it will enhance their wellbeing. ...

Battling the Testosterone Clinics and Websites
  • Citing Article
  • July 2022

Journal of General Internal Medicine

... "Detransition" refers to stopping or reversing a transition and can involve social and legal changes, discontinuation of endocrine medications, surgical intervention to reverse the effects of transition, or varying combinations of the above(Irwig 2022;Jorgensen, 2023b). ...

Detransition Among Transgender and Gender-Diverse People—An Increasing and Increasingly Complex Phenomenon

The Journal of Clinical Endocrinology and Metabolism