Beyond the Incision: Incidence and Risk Factors of Hypertrophic Scarring Following Gender-Affirming Mastectomy.

Abstract

Gender-affirming mastectomy (GAM) is the most common gender-affirming surgery. However, the double-incision technique involves long horizontal chest incisions which may be prone to hypertrophic scarring (HS). Despite the potential functional and psychosocial morbidity of HS, limited research has investigated their occurrence in this patient population. This study evaluated the incidence and risk factors of HS following GAM. A retrospective study was conducted of double-incision GAM patients from 2020 to 2024. Data included demographics, comorbidities, androgen therapy, postoperative complications including HS, corticosteroid injections, and scar revision. Multivariable regression was performed. 241 patients were included. HS developed in 16.6%, of which 50% underwent corticosteroid injections and 5% scar revision. Non-White race was significantly associated with higher rates of HS (26.5% vs. 14.1%, OR 2.7, 95%CI 1.2-6.0, p=0.018), as well as HS requiring corticosteroid injections (16.3% vs. 6.3%, p=0.023) and scar revision (4.1% vs. 0.0%, p=0.041). Perioperative androgen use (68.5% of patients) was significantly associated with higher rates of HS (20.0% vs. 9.2%, OR 2.6, 95%CI 1.0-6.4, p=0.028). Age, BMI, comorbidities, nicotine use, previous breast surgery and mastectomy weight were not significant risk factors. Average follow-up was 5.2±4.5 months. HS is a common postoperative complication following GAM, with non-White race and androgen therapy identified as significant risk factors. Patients should be counseled regarding their individual risk profile. High-risk patients should benefit from early preventive and therapeutic interventions. Future research should investigate perioperative androgen management that balance optimal scarring outcomes and patients' broader gender-affirming goals.