López-García, M ÁngelesCarretero-Barrio, IrenePérez-Míes, BelénChiva, MiguelCastilla, CarolinaVieites, BegoñaPalacios, José2025-01-072025-01-072020-06-152072-6694https://hdl.handle.net/10668/27491Conflicting results have been reported regarding the prevalence of screen-detected human epidermal growth factor receptor 2 (HER2)-positive breast carcinomas and non-screen detected HER2-positive breast carcinomas. To address this issue, we evaluated the prevalence of HER2-positive breast carcinomas in two independent regional screening programs in Spain. The clinicopathologic and immunohistochemical characteristics of 479 (306 and 173) screen-detected breast carcinomas and 819 (479 and 340) non-screen-detected breast carcinomas diagnosed in women between 50 and 69-year-olds were compared. The prevalence of HER2-positive breast carcinomas was 8.8% and 6.4% in the two series of screen-detected tumors, compared with 16.4% and 13% in non-screen-detected carcinomas. These differences were statistically significant. This lower prevalence of HER2-positive in-screen-detected breast carcinomas was observed in both hormone receptor positive (luminal HER2) and hormone-receptor-negative (HER2 enriched) tumors. In addition, a lower prevalence of triple-negative and a higher prevalence of luminal-A breast carcinomas was observed in screen-detected tumors. Moreover, a literature review pointed out important differences in subrogate molecular types in screen-detected breast carcinomas among reported series, mainly due to study design, technical issues and racial differences.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/HER2breast cancerestrogen receptorluminalprogesterone receptorscreeningtriple negativeresearch article32549380open access10.3390/cancers12061578PMC7352518https://www.mdpi.com/2072-6694/12/6/1578/pdf?version=1592290876https://pmc.ncbi.nlm.nih.gov/articles/PMC7352518/pdf