HER2-low prevalence among Hispanic/Latino women with breast cancer: A systematic review and meta-analysis

HER2-low has garnered significant attention for the treatment of HER2-negative breast cancer. We aimed to determine the prevalence of HER2-low expression in Hispanic/Latino women with breast cancer (BC). We searched in Embase, LILACS, and Medline databases for articles reporting the expression of HER2 immunohistochemistry with scores reported as 0, 1+, 2+, or 3+, with equivocal cases (2+) confirmed through in situ hybridization (ISH). A total of 12 articles were finally included, comprising 73,467 individuals. The prevalence of HER2-zero, HER2-low and HER2 positive cases among all BC (0, 1+, 2+/ISH-, 2+/ISH+ and 3+), was 45.0%, 32.0%, and 23.0%, respectively. The prevalence of HER2-zero and HER2-low expression among negative cases (0, 1+ and 2+/ISH-), was 53.0% and 47.0%, respectively. There is an important percentage of Hispanic/Latino individuals who would benefit from HER2-targeted therapies, even in HER2 negative cases. Additional research on the prevalence of HER2-low tumors across a wider range of Latin American countries is required to better understand the molecular epidemiology of this biomarker within the Hispanic/Latino population.