Prognostic value of hormone receptor expression in patients with HR+/HER2− advanced BC treated with first-line ET+CDK4/6i: results from the multicentre observational, real-world PALMARES-2 study
Effectiveness of first-line ET plus CDK4/6i in patients with HR+/HER2− aBC worsens progressively with decreasing ERα expression, and PgR expression adds further prognostic discrimination, with low ERα and PgR expression identifying a subgroup of patients with particularly poor outcomes.