Palbociclib and letrozole for hormone receptor-positive HER2-negative breast cancer with residual disease after neoadjuvant chemotherapy.

ABSTRACT: With the incorporation of cyclin-dependent kinase inhibitors in early breast cancer (BC), a better identification of biomarkers is needed. The PROMETEO II trial aimed to evaluate the antitumor activity of palbociclib plus letrozole and to identify response biomarkers in patients with operable HR+/HER2- BC and residual disease after neoadjuvant chemotherapy (NAC). The primary endpoint was the rate of complete cell cycle arrest (CCCA), centrally determined by Ki67 ≤ 2.7% at surgery. A comprehensive translational analysis was conducted. At surgery, the CCCA rate was 59.1%, with a 44.2% decrease in Ki67 from the end of NAC. Changes in intrinsic subtypes occurred in 48% of patients, with proliferation genes suppressed, and immune genes more upregulated in tumors with CCCA. Overall, 14% of tumor

SUBMITTER: Pernas S 

PROVIDER: S-EPMC11599376 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature