Summary
This review gathered 39 studies on breast removal surgery for young people with gender distress and rated how trustworthy the evidence was. Nearly all only followed operated patients, with no comparison group. Only short-term surgical complications were rated high-quality evidence, and they were uncommon: no deaths, about 2% to 3% loss of the nipple or skin graft through tissue death, and about 5% thick scarring. For the results that matter most, such as gender distress, mental health, suicide attempts, quality of life and regret, the evidence was weak or very weak. One study did suggest people were about half as likely to self-harm after surgery. The authors call for better studies. The review shows the evidence is weak; it does not show that surgery fails to help. It was funded by SEGM, a group that urges caution, and surgeons have challenged its framing in published letters.
Key findings
- De review vond 39 studies, gezocht tot juni 2023: slechts 3 vergeleken groepen en 2 maten mensen voor en na de operatie; de andere 34 beschreven alleen geopereerde patiënten.
- Bewijs van hoge kwaliteit kwam alleen van studies naar chirurgische complicaties: geen sterfgevallen (5 studies), ongeveer 20 op 1.000 verloren de tepel of het huidtransplantaat door weefselsterfte (13 studies), ongeveer 10 op 1.000 verloren een huidflap (3 studies), en ongeveer 50 op 1.000 kregen dikke littekens (12 studies).
- Twee studies die operatie vergeleken met borstbinden gaven zeer zwak bewijs over borstgerelateerde genderklachten en over tevredenheid met lichaam en borst.
- Eén studie die operatie vergeleek met geen operatie gaf zeer zwak bewijs over nood en suïcidepogingen, en zwak bewijs dat mensen na de operatie ongeveer half zo vaak zichzelf beschadigden (zonder suïcidale bedoeling).
- Kwaliteit van leven, depressie, overlijden door suïcide, tevredenheid met de borst en spijt werden allemaal als zeer zwak bewijs beoordeeld, vooral omdat er geen vergelijkingsgroep was.
- Geplande controles op de vraag of resultaten verschilden naar andere psychische aandoeningen, leeftijd waarop de nood begon of seksuele oriëntatie konden niet worden uitgevoerd, en suïcidale gedachten, seksuele functie en latere operaties werden niet beoordeeld.
- De auteurs pleiten voor studies die patiënten in de tijd vooruit volgen en, indien ethisch, gerandomiseerde onderzoeken, om patiënten, chirurgen, richtlijnopstellers en beleidsmakers te informeren.
Abstract
BACKGROUND: Gender dysphoria (GD) refers to psychological distress associated with the incongruence between one's sex and one's gender. In response to GD, birth-registered female patients may choose to undergo mastectomy. In this systematic review, the authors summarize and assess the certainty of the evidence about the effects of mastectomy. METHODS: We searched MEDLINE, Embase, PsycINFO, Social Sciences Abstracts, LGBTQ+ Source, and Sociological Abstracts through June 20, 2023. We included studies comparing mastectomy to no mastectomy in birth-registered patients younger than 26 years with GD. Outcomes of interest included psychological and psychiatric outcomes, and physical complications. Pairs of reviewers independently screened articles, abstracted data, and assessed risk of bias of the included studies. We performed meta-analysis and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. RESULTS: We included 39 studies. Observational studies (n = 2) comparing mastectomy to chest binding provided very low-certainty evidence for the outcome of GD. One observational study comparing mastectomy to no mastectomy provided very low-certainty evidence for the outcomes of global functioning and suicide attempts, and low-certainty evidence for the outcome nonsuicidal self-injury (adjusted OR, 0.47; 95% CI, 0.22 to 0.97). Before-and-after (n = 2) studies provided very low-certainty evidence for all outcomes. Evidence from case series (n = 34) studies ranged from high to very low certainty. CONCLUSIONS: Case series studies demonstrated high-certainty evidence for the outcomes of death, necrosis, and excessive scarring; however, these are limited in methodologic quality. In comparative and before-and-after studies, the evidence ranged from low to very low certainty.
Conclusion
The best available evidence reporting the effects of mastectomy in individuals with GD ranged from high to very low certainty. High certainty evidence in this SR was derived from case series studies only. High-certainty evidence from prospective cohort studies and, if ethical, randomized controlled trials, are needed to describe the short- and long-term effects of mastectomy in individuals with GD on mental health outcomes. Higher certainty evidence would be useful to individuals with GD considering chest masculinization; clinicians and surgeons involved in their care; guideline developers; and policy makers and stakeholders who make decisions about treatment related to GD.