Multicenter retrospective study of HER2-positivity as a prognostic biomarker and therapeutic target in advanced biliary tract cancer

A retrospective study of advanced biliary tract cancer (aBTC) patients of Yonsei University (Seoul, South Korea) and MD Anderson Cancer Center (Houston, TX) evaluated the prognostic relevance of HER2-positivity and clinical impact of anti-HER2 therapy in aBTC. The study included 388 patients with aBTC and known HER2 status between 2009 and 2023. HER2-positivity was observed in 25.2% of the cohort. HER2-positive aBTCs were associated with shorter overall survival (13.7 versus 17.1 months; HR 1.25; 95% CI 0.97-1.60) and shorter first-line progression-free survival (5.1 versus 7.4 months; 1.91; 1.46-2.48) compared with HER2-negative aBTCs. Anti-HER2 therapy significantly improved OS among HER2-positive patients (18.2 versus 8.1 months; HT 0.39; 95% CI 0,21-0.62). The authors conclude that HER2 status is a clinical meaningful biomarker with prognostic and predictive relevance in aBTC.