Clinicopathogenomic analysis of PI3K/AKT/PTEN-altered luminal metastatic breast cancer in Japan

Breast Cancer. 2025 Jan;32(1):208-216. doi: 10.1007/s12282-024-01639-6. Epub 2024 Oct 28.

Abstract

This rapid communication highlights the correlation between protein kinase B alpha (AKT1)-phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)- phosphatase and tensin homolog (PTEN) alterations and clinicopathological factors in Japanese patients with metastatic recurrent breast cancer (mBC). This study analyzed 1967 patients with luminal-type breast cancer who underwent cancer gene panel testing. The results demonstrated that AKT pathway alterations, including PI3K/AKT/PTEN, occurred in 1038 (52.8%) cases. Patients with AKT pathway mutations were older (p = 0.002) and had a higher rate of invasive lobular carcinoma (ILC) histology (p = 0.001), progesterone receptor (PgR) positivity (p = 0.006), and bone metastases (p = 0.001), and a lower rate of germline BRCA2 (p < 0.001). Comprehensive genomic profile results demonstrated a higher tumor mutational burden (TMB) (< 0.001) and lower tumor BRCA1/2 expression (< 0.001) in patients with mutations in the AKT pathway. These results are crucial for characterizing candidates for AKT pathway-targeted molecular therapies and conceptualizing optimal treatment strategies. Clinical trial registration: This study is an observational study and is therefore not registered with the clinical trials registration.

Keywords: PI3K/AKT/PTEN alterations; AKT inhibitors; AKT pathway mutations; Comprehensive genomic profiling; Metastatic recurrent breast cancer.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • BRCA1 Protein / genetics
  • BRCA2 Protein / genetics
  • Biomarkers, Tumor / genetics
  • Bone Neoplasms / genetics
  • Bone Neoplasms / secondary
  • Breast Neoplasms* / genetics
  • Breast Neoplasms* / pathology
  • Carcinoma, Lobular / genetics
  • Carcinoma, Lobular / pathology
  • Carcinoma, Lobular / secondary
  • Class I Phosphatidylinositol 3-Kinases / genetics
  • Female
  • Humans
  • Japan / epidemiology
  • Middle Aged
  • Mutation
  • PTEN Phosphohydrolase* / genetics
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt* / genetics
  • Proto-Oncogene Proteins c-akt* / metabolism
  • Receptors, Progesterone / metabolism
  • Signal Transduction

Substances

  • Proto-Oncogene Proteins c-akt
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • AKT1 protein, human
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • BRCA1 Protein
  • BRCA2 Protein
  • Receptors, Progesterone
  • BRCA2 protein, human
  • BRCA1 protein, human
  • Phosphatidylinositol 3-Kinases
  • Biomarkers, Tumor