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Next-generation sequencing methodologies to identify patients for targeted therapy: focus on HR+/HER2- metastatic
Umberto Malapelle1, Simonetta Buglioni2, Isabella Castellano3
1Department of Public Health, University Federico II of Naples, Naples, Italy.
Abstract:
Alterations in the phosphoinositide 3-kinase (PI3K)/AKT/PTEN signaling pathway are a well-recognized mechanism of resistance in hormone receptor-positive, HER2-negative metastatic breast cancer (HR+/HER2- mBC). These alterations are present in approximately half of patients with HR+/HER2- mBC. The major alterations in the pathway are somatic mutations in the PIK3CA (40-45%) and AKT1 (5%) genes, and loss-of-function alterations in PTEN (5-10%). New targeted agents that act against these alterations have been developed. Therefore, it is important to determine the mutational status of genes in this pathway to potentially offer a therapeutic alternative for these patients. In this review, we discuss the clinical and biological significance of PI3K pathway alterations in HR+/HER2- mBC, focusing on tumors that progress following endocrine therapy and CDK4/6 inhibitor treatment. We then highlight how different diagnostic strategies, including sample type, testing methodology, and timing, can improve the identification of patients who are eligible for targeted therapies and promote the effective integration of molecular diagnostics into routine clinical care.
Insights
Alterations in the PI3K/AKT/PTEN pathway drive resistance in metastatic breast cancer. Identifying these genetic changes offers new targeted therapy options for patients progressing on standard treatments.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- The phosphoinositide 3-kinase (PI3K)/AKT/PTEN pathway is frequently altered in hormone receptor-positive, HER2-negative metastatic breast cancer (HR+/HER2- mBC), contributing to therapeutic resistance.
- Somatic mutations in PIK3CA (40-45%) and AKT1 (5%), along with PTEN loss-of-function (5-10%), are the primary alterations observed in approximately half of these patients.
Purpose of the Study:
- To review the clinical and biological significance of PI3K pathway alterations in HR+/HER2- mBC, particularly in tumors resistant to endocrine therapy and CDK4/6 inhibitors.
- To emphasize the importance of determining the mutational status of PI3K pathway genes for guiding targeted therapy selection.
Main Methods:
- This review synthesizes current literature on PI3K pathway alterations in HR+/HER2- mBC.
- It discusses the clinical implications of these alterations and the role of targeted agents.
- Diagnostic strategies for identifying eligible patients are also examined.
Main Results:
- PI3K pathway alterations are a key mechanism of resistance in HR+/HER2- mBC, impacting treatment outcomes.
- New targeted therapies are emerging for patients with specific PI3K pathway alterations.
- Effective molecular diagnostics are crucial for patient stratification.
Conclusions:
- Understanding PI3K pathway alterations is vital for managing HR+/HER2- mBC.
- Accurate and timely molecular testing can identify patients who may benefit from targeted therapies.
- Integrating molecular diagnostics into clinical care is essential for advancing treatment strategies.
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