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Updated: Jul 18, 2026
Next Generation Sequencing for the Detection of Actionable Mutations in Solid and Liquid Tumors
Published on: September 20, 2016
Subtype-specific prognostic implications of plasma-detected PIK3CA mutations in Vietnamese breast cancer patients
Dinh Thi Thao1,2, Dong Van Quyen2,3, Le Huu Song4
1Center for Genetic Consultation and Cancer Screening, 108 Military Center Hospital, Hanoi, Vietnam.
Background:
PIK3CA mutations are among the most frequent genomic alterations in breast cancer (BC), contributing to disease progression and therapeutic resistance. Non-invasive blood assays can reveal tumor-specific DNA alterations, enhancing personalized oncology.
Aim:
This study aims to investigate the clinical relevance of plasma-detected PIK3CA mutations in Vietnamese breast cancer patients, with a focus on subtype-specific outcomes.
Methods:
PIK3CA hotspot mutations (H1047R and E545K) were detected in plasma from 196 BC patients. Associations with clinicopathological features and progression-free survival (PFS) were assessed.
Results:
PIK3CA mutations were identified in 42.9% of patients with H1047R (31.6%) more prevalent than E545K (15.3%). Mutation rates were highest in HR+ subtypes and elevated in advanced or irradiated patients (p = 0.009). E545K was enriched in HR+ cases, while H1047R was more frequent in HER2+ tumors following radiotherapy. Among metastatic BC patients, those with PIK3CA mutations had shorter PFS (median, 7.0 vs. 15.0 months; p = 0.022), and univariate Cox regression showed increased progression risk (HR = 2.16), although not significant after multivariate adjustment. E545K was associated with lung (p = 0.047) and bone metastases (p = 0.012) and H1047R was enriched in brain metastases (p = 0.028).
Conclusion:
Plasma-detected PIK3CA mutations, particularly E545K and H1047R, exhibited subtype-specific associations with clinical outcomes, indicating that plasma analysis may provide complementary information for prognostic assessment in metastatic BC.
