Characteristics of Massive Weight Loss Patients Having Implant-Based Breast Reconstruction After Mastectomy - A Case-Control Study.

BACKGROUND: Massive weight loss (MWL) is becoming more common, yet there is limited knowledge about the sociodemographic and clinical features of women undergoing post-mastectomy breast reconstruction following MWL. This study compared women with and without prior MWL who are undergoing breast reconstruction. METHODS: This nationwide, population-based case-control study used prospectively collected Swedish national registry data. Women who underwent bariatric surgery between 2007 and 2022 and subsequently received implant-based breast reconstruction after mastectomy were identified and matched by age and body mass index to controls without previous bariatric surgery, with at least 3 controls per patient. Sociodemographic characteristics, specialist-care diagnoses, and dispensed drugs were compared between groups. RESULTS: Eighty-one women with MWL were matched with 993 controls. Women with MWL had lost an average of 30.6 kg before reconstruction. They were more frequently separated or divorced and had lower educational attainment, although the educational difference did not remain significant after Bonferroni correction. Employment and income levels were similar between groups. Diagnoses from specialist care were generally more common among women with MWL: diabetes, cardiovascular, gastrointestinal, rheumatic, and psychiatric diseases occurred at more than twice the frequency compared to controls, although most differences were not significant after correction. Women with MWL also had higher usage of several types of drugs. Differences in dispensed vitamins and minerals and anemia drugs remained significant after Bonferroni correction. CONCLUSIONS: Women undergoing breast reconstruction after MWL form a distinct subgroup with higher medical and psychosocial complexity than women without MWL. Recognising these differences can aid patient assessment and perioperative planning.