Abstract
Background: Breast cancer (BC) is a global health concern with significant mortality rates, necessitating a deep understanding of its molecular landscape. Objective: This study focuses on the prevalence of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations in Luminal A and B BC within the Indonesian population. Luminal A and B BC, characterized by estrogen receptor (ER) and/or progesterone receptor (PR) positivity, face challenges in endocrine therapy due to acquired resistance, often mediated by PI3K/Akt/mTOR pathway activation.
Methods: The study, conducted from 2019 to 2022, collected samples from diverse Indonesian regions, representing various islands. Histopathological analysis and immunohistochemistry classified samples into molecular subtypes.
Results: Genetic analysis using PIK3CA mutation detection kits revealed a mutation frequency of 36.2%, with Luminal A BC exhibiting the highest mutation rate (46.1%). Notably, Luminal B HER-2 (positive) BC demonstrated a lower mutation frequency (19%). Statistical analyses highlighted correlations between PIK3CA mutations and molecular subtypes (p=0.01), with Luminal A and Luminal B HER-2 (negative) BC showing higher mutation frequencies. No significant associations were observed with age, tumor location, or histopathology diagnosis. Luminal A BC demonstrated a higher prevalence of PIK3CA mutations in patients over 50 years old (68.1%). Comparisons with existing literature and inconsistencies in PIK3CA mutation prevalence across different BC subtypes underline the need for population-specific research.
Conclusion: The study emphasizes the importance of assessing PIK3CA mutations in BC management, offering insights for personalized therapies and potential advancements in understanding this complex disease within the Indonesian context.