Age and Ethnic Disparities in Postmastectomy Immediate Breast Reconstruction: A cohort study from a Korean single center and National Cancer Database

Purpose Postmastectomy immediate breast reconstruction (PMIBR) rates in breast cancer patients have increased over recent decades but remain less frequently performed and understudied in elderly patients. We aim to evaluate postmastectomy breast reconstruction trends by age in Korea and the United States, highlighting potential disparities related to age, geography and ethnicity. Methods This is a multi-cohort retrospective study analyzing three databases. The Asan Medical Center-Breast Cancer Registry (AMC-BCR) included 13,654 total mastectomy patients from 2001–2021. A subset of patients, separately collected as AMC-plastic surgery registry (AMC-PSR) was used to analyze age-related differences in comorbidities and complications. The National Cancer Database (NCDB) included 966,354 total mastectomy patients with stage 0–3 breast cancer from 2004–2020. Results PMIBR rates in AMC-BCR increased from 13–78% in younger patients (< 60 years) and from 0–28% in older patients (≥ 60 years). Patients living in a metropolitan area (49.4% vs. 46.6%, p = 0.001), with higher education (93.2% vs. 66.3%, p < 0.001), unmarried (12.5% vs. 5.1%, p < 0.001), and with no childbirth history (10.5% vs. 6.3%, p < 0.001) were more likely to undergo reconstruction. In the NCDB, the rates were 37% for young (< 60) Asian-Americans, 48% for young non-Asians, 14% for older (≥ 60) Asian-Americans, and 24% for older non-Asians in 2020. Asian-Americans had the lowest reconstruction rates across ethnicities. AMC-PSR data showed no significant difference in major complications by age. Conclusions Older patients exhibited lower reconstruction rates than the younger patients and demographic factors differed between age groups, suggesting disparities by age, ethnicity and cultural factors.