Decisional Conflict, Regret, Gender Congruence, and Quality of Life before and After Mastectomy in Transmasculine and Nonbinary Adolescents Compared to Young Adults

Purpose: This study aimed to assess whether transmasculine and nonbinary adolescents can make decisions about and benefit from mastectomy in a manner comparable to transmasculine and nonbinary adults. Methods: This cross-sectional matched (matched for surgery year and technique) control study was conducted between October 2023 and June 2024. It compared 16–17-year-old transmasculine and nonbinary adolescents with 18–20-year-old young adults on several aspects. Decisional conflict was assessed preoperatively, while decisional regret and treatment satisfaction were assessed postoperatively. Social support, gender appearance, chest/nipple satisfaction, mental health, and quality of life were assessed pre- and postoperatively. Results: Preoperatively, 20 adolescents and 25 young adults participated. Postoperatively, 37 adolescents and 35 young adults participated. The mean follow-up period was 2.6 (standard deviation, 0.60) years after mastectomy. No significant differences existed between age groups in any assessed aspect, either pre- or postoperatively, except that adolescents reported more social support than young adults postoperatively. Both age groups experienced low decisional conflict preoperatively, and low decisional regret and high treatment satisfaction postoperatively. Comparing preoperative (preop) and postoperative (postop) adolescents and young adults, both postop age groups reported greater gender appearance satisfaction, mental health, and quality of life compared to their preop age groups with large to medium effect sizes. Age of mastectomy was not associated with any of the postop outcomes in multivariate analyses. Conclusions: These findings support offering mastectomy to trans masculine and nonbinary adolescents from age 16 when clinically appropriate and carefully counseled.