Effect of testosterone therapy on breast tissue composition and mammographic breast density in trans masculine individuals
Year: 2024
Type: article
Study design: Observational Study
Abstract: 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.
Source: Breast Cancer Research
Authors: Yujing J. Heng, Gabrielle M. Baker, Valerie J. Fein-Zachary, Yaileen D. Guzman-Arocho, Vanessa C. Bret-Mounet, Erica S. Massicott, Vanda F. Torous, Stuart J. Schnitt, Sy Gitin, Paul Russo, Adam M. Tobias, Richard A. Bartlett, Gopal Varma, Despina Kontos, Lusine Yaghjyan, Michael S. Irwig, Jennifer E. Potter, Gerburg M. Wulf
Institutions: Beth Israel Deaconess Medical Center, Harvard University, Massachusetts General Hospital, Brigham and Women's Hospital, Dana-Farber Cancer Institute, Dana-Farber Brigham Cancer Center, Fenway Health, Columbia University Irving Medical Center, University of Florida Health, University of Florida
Language: English
Subfield: Pulmonary and Respiratory Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,990
Awards: G1986498167, The role of breast stem cells in breast cancer etiology and risk prediction, Gender-affirming estrogen therapy and breast cancer treatment outcome, Gender-Affirming Testosterone Therapy on Breast Cancer Risk and Treatment Outcomes, Dana Farber/Harvard Cancer Center Specialized Program of Research Excellence in Breast Cancer
OpenAlex ID: W4400242776