Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Open Access

Peer-reviewed

Research Article

High frequency of the PIK3CA H1047L mutation in Indonesian breast cancer across molecular subtypes

  • Yan Wisnu Prajoko,

    Roles Conceptualization, Data curation, Funding acquisition, Supervision, Writing – original draft, Writing – review & editing

    Affiliation Department of Surgical Oncology, Faculty of Medicine, Universitas Diponegoro, Semarang, Indonesia

    ⨯
  • Didik Setyo Heriyanto ,

    Roles Conceptualization, Data curation, Funding acquisition, Project administration, Supervision, Writing – original draft, Writing – review & editing

    didik_setyoheriyanto@mail.ugm.ac.id

    Affiliations Department of Anatomical Pathology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr. Sardjito General Hospital, Yogyakarta, Indonesia, Department of Surgery, Division of Cardiac, Thoracic, and Vascular Surgery, Faculty of Medicine, Public Health, and Nursing/Dr. Sardjito General Hospital, Yogyakarta, Indonesia, Collaboration Research Center for Precision Oncology based Omics- PKR PrOmics, Yogyakarta, Indonesia

    ⨯
  • Bayu Tirta Dirja,

    Roles Formal analysis, Investigation, Resources, Validation

    Affiliation Department of Microbiology, Faculty of Medicine, Mataram University, Mataram, Indonesia

    ⨯
  • Susanto Susanto,

    Roles Formal analysis, Investigation, Resources, Validation

    Affiliation Semarang Medical Center (SMC) Telogorejo Hospital, Semarang, Indonesia

    ⨯
  • Vincent Lau,

    Roles Data curation, Formal analysis, Methodology, Software, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Anatomical Pathology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr. Sardjito General Hospital, Yogyakarta, Indonesia

    ⨯
  • Andrew Nobiantoro Gunawan,

    Roles Data curation, Formal analysis, Methodology, Software, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Anatomical Pathology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr. Sardjito General Hospital, Yogyakarta, Indonesia

    ⨯
  • Brigitta Natasya Halim,

    Roles Software, Visualization, Writing – original draft, Writing – review & editing

    Affiliation Department of Anatomical Pathology, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr. Sardjito General Hospital, Yogyakarta, Indonesia

    ⨯
  • Nur Dina Amalina

    Roles Conceptualization, Investigation, Methodology, Project administration, Resources, Software, Validation, Writing – original draft, Writing – review & editing

    Affiliation Department of Pharmaceutical Sciences, Faculty of Medicine, Universitas Negeri Semarang, Semarang, Indonesia

    ⨯

Abstract

Breast cancer (BC) is a global health concern with significant mortality rates, necessitating a deep understanding of its molecular landscape. 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, frequently driven by PI3K/AKT/mTOR pathway activation. This study focuses on the frequency of PIK3CA mutations across molecular subtypes BC within the Indonesian population. The study analyzed collected samples from diverse Indonesian regions, representing various islands. Histopathological analysis and immunohistochemistry classified samples into molecular subtypes. Genetic analysis using PIK3CA mutation detection kits revealed a mutation frequency of 32.9%, with 30 (14.5%) samples located in exon 9 and 38 (18.4%) samples in exon 20. Statistical analyses highlighted associations between PIK3CA mutations and molecular subtypes (p = 0.029), with luminal B HER2-negative (40.5%) and luminal A (40.2%) exhibiting the highest mutation rate. A significant association was also observed between the exon location of only mutated PIK3CA samples and age group (p < 0.001), with most of the PIK3CA exon 9 being ≤ 50 years old (72.4%) and PIK3CA exon 20 being > 50 years old. No statistically significant association was observed between the location of PIK3CA mutation (exons 9 and 20) and the breast site, histopathological diagnosis, and molecular subtypes. Comparisons with existing literature and inconsistencies in PIK3CA mutation frequencies across different BC subtypes underline the need for population-specific research. 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.

Citation: Prajoko YW, Heriyanto DS, Dirja BT, Susanto S, Lau V, Gunawan AN, et al. (2025) High frequency of the PIK3CA H1047L mutation in Indonesian breast cancer across molecular subtypes. PLoS One 20(5): e0322154. https://doi.org/10.1371/journal.pone.0322154

Editor: Rashi Kalra, University of Alabama at Birmingham, UNITED STATES OF AMERICA

Received: December 5, 2024; Accepted: March 17, 2025; Published: May 5, 2025

Copyright: © 2025 Prajoko et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the manuscript and are available from OSF database doi:10.17605/OSF.IO/SRCD2.

Funding: This research was supported by grants from the Ministry of Education, Culture, Research, and Technology, Indonesia, under the National Collaborative Research Scheme 2023 No. 449A-43/UN7.D2/PP/VI/2023. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Breast cancer (BC) is a significant global public health issue with a high mortality rate among women [1,2]. It is the second most diagnosed cancer after lung cancer, with over two million new cases and the fourth leading cause of cancer-related deaths for both sexes in 2022 [3]. Statistically, 5–10% of BCs are caused primarily by genetic factors caused by the accumulation of acquired somatic changes [4,5] The diagnosis, prognosis, predictive usefulness, therapy, and prevention of BC depend on molecular biomarkers and their association with pathological features [6].

Research has underscored the significance of analyzing phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene mutations due to their association with the onset and progression of BCs. These mutations are observed in 20–40% of BC patients [7–10]. Positioned on chromosome 3q26.32, the PIK3CA gene encodes the alpha isoform (p110α), the principal isoform of the catalytic subunit within the class 1A PI3K, a lipid phosphokinase [7,9,11]. Functionally, the PI3K family mediates signals crucial for various cellular activities, encompassing proliferation, metabolism, migration, translation, apoptosis evasion, and angiogenesis. Four common ‘hotspot’ PIK3CA mutations (E542K, E545K, H1047R, and H1047L) constitute 80–90% of all PIK3CA mutations in human cancers and serve as predictive biomarkers [7,11,12].

Previous research has indicated that endocrine-resistant PIK3CA-mutant cases may potentially benefit from treatment with PI3K inhibitors, underscoring the significance of elucidating the prevalence of PIK3CA mutations among populations to inform potential future avenues in hormone receptor-positive BC treatment [13–15]. Research also suggests that the presence of PIK3CA mutations can adversely affect the disease-free survival (DFS) and pathological complete response (pCR) to targeted therapy and chemotherapy in patients with human epidermal growth factor receptor 2 (HER2)-enriched and triple negative breast cancer (TNBC) [7–9,11,16]. This suggests that it might be beneficial to assess PIK3CA mutations in all BCs molecular subtypes including the non-hormonal subtypes. However, there is a noticeable lack of data on this subject, particularly in the Indonesian population. So far, many studies have been conducted on BC PIK3CA mutations in various countries and regions, and the results of studies related to the clinical pathological characteristics of PIK3CA mutation have inconsistencies between one study and another [17–24]. Small sample sizes, different detection methods, and different inclusion criteria are likely to be contributing factors to this inconsistent outcome.

This study aims to determine the frequency of PIK3CA mutations among Indonesian BC patients–an underrepresented group in current research–and to examine the association of those mutations with clinicopathological features. Given the limited national data on PIK3CA mutations, our findings may contribute to improved BC management in Indonesia and provide a foundation for future research and targeted therapeutic strategies

Methods

Study design

This study employed a cross-sectional approach to analyze samples obtained from the archive of Cito Clinical Laboratory, Indonesia, spanning the period from 2019 to 2022. The samples were collected from various islands across the Indonesian archipelago, including Java, Kalimantan, Sumatera, Mataram, and Papua. Histopathological examination and grading of BC samples were conducted, as necessary. Subsequently, the samples underwent immunohistochemistry (IHC) analysis to determine their molecular subtypes. Finally, genetic analysis was performed on each viable sample to identify the presence of any PIK3CA mutations. The archival samples for this study were accessed and analyzed from 06/02/2023–06/11/2023.

Ethics approval

Ethical approval for this study was granted by the Medical and Health Research Ethics Committee (MHREC) under Ethical Approval Number 32/EC/KEPK/FK-UNDIP/II/2023.

Samples collection

Paraffin blocks obtained from patients histopathologically diagnosed with primary BC, including Invasive of No Special Type (NST), Invasive Lobular Carcinoma, Invasive Papillary Carcinoma, and Mucinous Carcinoma, were included in this study. Samples were collected from multiple centers situated in various provinces across the diverse islands of Indonesia. Initial diagnoses and tumor grading for each sample were obtained from the referring hospitals across Indonesia. Upon receipt at Cito Clinical Laboratory, Yogyakarta, two pathologists, at the institution verified and confirmed the histopathological diagnoses and grades, also assess the quality of paraffin blocks before proceeding with any additional examinations. Exclusion criteria comprised formalin-fixed paraffin embedded (FFPE) samples of inadequate quality and incomplete medical records data. Patient data regarding clinicopathological characteristics, including sociodemographic (age), tumor pathology (location/site, histopathology, histologic grade), were acquired from medical records obtained from referring hospitals.

IHC staining

Confirmed samples then underwent IHC analysis at Cito Clinical Laboratory and the Department of Anatomical Pathology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, located in Yogyakarta. IHC was utilized to examine the samples, by using anti-estrogen receptor (anti-ER), anti-progesterone receptor (anti-PR), anti-human epidermal growth factor receptor 2 (anti-HER2), and anti-Ki67 antibodies from Ventana™ (Roche Diagnostics, AZ, USA). Staining procedures were conducted utilizing the Ventana BenchMark XT and Discovery XT™ Tissue Diagnostic and IHC Autostainer (Roche Diagnostics, AZ, USA). All protocols strictly adhered to the manufacturer’s instructions and protocols to ensure the attainment of consistent and reliable results. Our institution adheres to the 2013 St. Gallen International Expert Consensus guidelines. According to these guidelines, luminal A BC is defined by the presence of ER and PR, with PR expression at 20% or higher, absence of HER2 expression, and low Ki-67 expression levels (less than 14%). In contrast, luminal B (HER2-negative) BC is characterized by the presence of ER, absence of HER2 expression, PR expression below 20%, or high Ki-67 expression levels. Overexpression or amplification of HER2 (3+; strong reactivity in ≥ 10% of tumor cells in the sample) are defined as HER2-enriched. Meanwhile, lacking ER, PR, and HER2 expressions are defined as TNBC subtypes.

DNA extraction

Paraffin blocks from various BC subtypes were cut into 10 pieces with 5 μm thickness. Ten pieces in one slide continued with DNA extraction. Genomic DNA was extracted using the GeneAll® Exgene™ FFPE Tissue DNA (GeneAll Clinic SV mini, Seoul, Korea) according to the manufacturer’s protocol. DNA samples were then quantified using a NanoDrop™ spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). Samples of sufficient concentration and quality were adjusted to a concentration of 20 ng/ µL for Polymerase Chain Reaction (PCR) applications.

Detection of PIK3CA mutation

The samples were further analyzed for PIK3CA mutation at both Cito Clinical Laboratory and the Department of Anatomical Pathology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada. Specimens originating from islands other than Java were meticulously transported to Yogyakarta, ensuring strict adherence to established standards. The detection of PIK3CA mutation biomarkers was conducted using the BioColomelt-Dx™ in vitro diagnostics kit, developed by Biofarma Ltd, Indonesia. This molecular diagnostic kit utilizes PCR and High-Resolution Melting (HRM) techniques. Subsequently, the findings were validated using the Qiagen Therascreen® PIK3CA RGQ PCR kit (QIAGEN, Hilden, Germany). The Qiagen Therascreen® PIK3CA RGQ PCR kit (QIAGEN, Hilden, Germany) was designed to detect 11 mutations in exons 7, 9, and 20 of the PIK3CA gene. The specific mutations detectable by this kit include C420R in exon 7; E542K, E545A, E545D (1635G > T only), E545G, E545K, Q546E and Q546R in exon 9; and H1047L, H1047R, and H1047Y in exon 20.

Statistical analysis

The statistical analysis was conducted using Microsoft Excel (Microsoft 365, Washington, USA) and IBM SPSS version 27.0 (IBM, New York, USA). The association between variables was calculated using Fisher’s Exact Test with a significance level of p-values < 0.05.

Results

Clinicopathologic characteristics of the BC samples

This study included 207 cases of diverse BC types, with 63.8% of patients aged over age 50 (Table 1). Tumor location, histopathological types, and molecular subtypes are detailed in Table 1, along with their respective frequencies and percentages.

thumbnail
Download:
Table 1. Clinicopathology characteristics of the study samples.

https://doi.org/10.1371/journal.pone.0322154.t001

PIK3CA mutations landscape in BC samples

A total of 68 (32.9%) of 207 samples showed positive PIK3CA mutation; 30 (14.5%) samples are located in exon 9 and 38 (18.4%) samples are in exon 20 (Fig 1A). The specific mutation spectrum among BC samples is presented in Fig 1B. The 7 (9.3%) samples that are identified for positive PIK3CA mutation using BioColomelt-Dx™ in vitro diagnostics kit (Biofarma Ltd, Jakarta, Indonesia) yet negative in Qiagen Therascreen® PIK3CA RGQ PCR kit (QIAGEN, Hilden, Germany) (Fig 1B) are subsequently excluded from the association analysis. The most common variants in our samples are H1047L (24, 35.3%) for exon 20 and E542K (9, 13.2%) for exon 9 (Fig 1C).

thumbnail
Download:
Fig 1. PIK3CA mutation.

(A) PIK3CA mutation frequency based on the exon location. (B) PIK3CA specific mutation spectrum. (C) Proportion of PIK3CA variants of all positive PIK3CA mutations divided according to exon location.

https://doi.org/10.1371/journal.pone.0322154.g001

The association of PIK3CA mutation status and exon location with clinicopathological characteristics is summarized in Table 2. Overall, no significant differences were noted in PIK3CA mutation frequency by age group (≤ 50 vs. > 50 years) or tumor location (OR 0.665, 95% CI 0.366–1.208, p = 0.218; and OR 1.209, 95% CI 0.676–2.160, p = 0.556, respectively). However, among tumors already harboring a PIK3CA mutation, patients aged ≤ 50 years were markedly more likely to have an exon 9 mutation than exon 20 (OR 8.750, 95% CI 2.902–26.382, p < 0.001). In terms of molecular subtype, PIK3CA mutations were significantly associated with luminal B HER2-negative tumors (p = 0.029), which demonstrated the highest mutation rate (40.5%), followed by luminal A (40.2%), HER2-enriched (20%), TNBC (18.5%), and luminal B HER2-positive (14.3%).

thumbnail
Download:
Table 2. Association between PIK3CA mutation and mutation exon locations with clinicopathological characteristics of BC.

https://doi.org/10.1371/journal.pone.0322154.t002

Further exploration on the specific PIK3CA mutation location with clinicopathological characteristics are presented in Table 3. A significant association between PIK3CA specific mutation location and age group is observed (p < 0.001), consistent with previous PIK3CA mutation exon location (p < 0.001, Table 2). Patients >50 years old have higher frequency of H1047L and H1047R mutations.

thumbnail
Download:
Table 3. Association between specific PIK3CA mutation location and clinicopathological characteristics.

https://doi.org/10.1371/journal.pone.0322154.t003

Discussion

The PI3K pathway plays a pivotal role in the proliferation and viability of malignant cells and is frequently dysregulated in various types of cancer, including BC. This deregulation can occur through several mechanisms, such as mutations or amplifications in PI3K itself, the inactivation of the tumor suppressor PTEN, or the activation of upstream oncogenes and tyrosine kinase growth factor receptors [25]. PIK3CA mutations have been extensively studied in newly diagnosed BC, often linked to favorable characteristics like positive ER expression, smaller tumor size, and low histological grade [26,27]. Studies also found that PIK3CA mutations were associated with older age and lower tumor grade at diagnosis [26,28,29]. However, these mutations show variable frequencies and implications across different studies and populations. Recent studies from different populations have also presented conflicting results regarding the relationship between PIK3CA mutations and tumor grading, adding the layer of complexity [30]. PIK3CA wild-type tumors had lower tumor grade, higher ER expression, and lower androgen receptor (AR) expression compared to mutant tumors, contradictory with recent findings that there was no significant correlation between histological Scarff-Bloom-Richardson (SBR) tumor grading and PIK3CA mutation status [31,32]. In contrast, our study is in accordance with the study by Cizkova that showed that PIK3CA mutations are predominantly found in higher-grade tumors [7]. Due to the inconclusive findings, additional investigation is warranted, ideally encompassing a larger sample size and more comprehensive population representation.

Our findings indicate a varying frequency of PIK3CA mutation across different molecular subtypes, with the highest proportion frequency observed in luminal B HER2-negative, followed by luminal A, HER2-enriched, TNBC, and luminal B HER2-positive subtypes. The results are partially consistent with the research conducted by Wu et al. (2019) [17]. Nonetheless, the study did not further categorize luminal B into luminal B HER2-negative or luminal B HER2-positive [17]. Within the luminal subtypes, mutation rates can reach up to 46.6% in luminal A [33] and approximately 27% in luminal B [34]. In HER2-positive disease, especially the HER2-enriched subtype—which is linked to aggressive behavior and poorer outcomes—about 21% of tumors harbor PIK3CA mutations [35]. By contrast, TNBC generally exhibits a lower frequency, varying from 12.5% to as high as 28.6% [22,36]. These distributions reinforce the stronger association of PIK3CA mutations with hormone receptor–positive tumors—often tied to more favorable outcomes [37,38]—whereas TNBC cases may experience poorer prognosis [39].

Recent studies have highlighted the frequency of PIK3CA mutations in various cancer types within the Indonesian population. For instance, a study by Heriyanto reported a mutation frequency of 43.85% in colorectal cancer patients, which is notably lower than other regions in Indonesia that reported frequencies as high as 70.9% [40]. This discrepancy may be attributed to differences in sample sizes and population genetics, suggesting that the H1047L mutation could be more prevalent in certain demographic groups or cancer subtypes. The implications of these findings are profound, as they suggest that the high frequency of PIK3CA mutations, particularly H1047L, could serve as a potential biomarker for targeted therapies in the Indonesian population. Understanding the mutational landscape of PIK3CA in this context not only aids in the development of personalized treatment approaches but also enhances our comprehension of the molecular mechanisms underlying cancer in diverse populations [41,42].

Research has shown that PIK3CA mutations, including H1047L, can influence treatment responses. For instance, patients with ER + BC harboring PIK3CA mutations have shown favorable response to PI3K inhibitors such as alpelisib [15,43]. The prognostic implications of PIK3CA mutations, particularly H1047L, appear to be multifaceted. While some studies suggest that these mutations correlate with poorer responses to chemotherapy and targeted therapies, others indicate that they may be associated with favorable outcomes in specific contexts, such as in early-stage, hormone receptor-positive BC [44]. For example, a meta-analysis indicated that PIK3CA mutations could serve as favorable prognostic biomarkers in operable BC, suggesting that the clinical significance of these mutations may vary depending on the tumor’s molecular subtype and the treatment regimen [45].

On the other hand, a study highlighted that PIK3CA mutations were identified in 24.2% of HER2-enriched breast tumors, with a significant association with poor prognosis in certain contexts [46]. Moreover, the H1047L mutation, along with other hotspot mutations like H1047R, has been linked to the activation of the PI3K signaling pathway, which plays a crucial role in cell proliferation and survival [47,48]. This activation can lead to resistance against various therapies, including trastuzumab and other anti-HER2 agents, thereby complicating treatment outcomes [36,39,49]. Since our results showed a 35.3% frequency of the H1047L mutation, the therapeutic strategy should be discussed by a multidisciplinary team to consider potential drug resistance and guideline implementation.

Therapeutically, the presence of PIK3CA mutations has been linked to reduced rates of achieving pCR in neoadjuvant chemotherapy, indicating potential chemoresistance [39,50]. Moreover, these mutations have been associated with resistance to anti-HER2 treatment in HER2-enriched patients and endocrine treatment in ER-positive patients [14,36,51] A previous study reported that ER-positive, HER2-negative, PIK3CA mutant BCs, despite apparent PI3K/AKT pathway activation, downstream mTOR1 signaling was not greatly elevated at the transcriptional and biological levels. One of their hypotheses for underlying the mechanism is that PIK3CA mutations are associated with weak pathway activation, and that other PI3K pathway alterations produce stronger pathway activation. The study suggests that, in ER-positive/HER2-negative BC with PIK3CA mutations, pathway activation surprisingly does not result in greatly elevated downstream signaling and their functional output differs substantially compared with that of PTEN loss [50,52].

Notably, the C420R mutation is not identified in any of our samples. The mutation, while less common than the major hotspots such as H1047R and E545K, has been shown to possess oncogenic properties comparable to these more prevalent mutations [53]. This suggests that even less frequent mutations like C420R, representing 1–1.9% of all PIK3CA mutations, can impact tumor biology and patient outcomes [10,54].

Approximately 30–40% of BC cases that are HER2-enriched exhibit a mutation in the PIK3CA gene [55,56]. Some studies have shown that the PIK3CA mutation in circulating tumor DNA (ctDNA) was observed in patients who tested negative for the mutation in the tissue samples [57,58]. As a result, the implementation of liquid biopsy as a valuable method to more effectively capture temporal heterogeneity and detect metastatic disease has been proposed in various other studies [58–61]. This approach has the potential to increase the number of patients who may derive therapeutic benefits from targeted treatments, since such mutations have been associated with trastuzumab resistance in HER2-enriched patients [36,62].

The presence of PIK3CA gene mutations has been observed in approximately 9% of TNBC, including cases that recur as metastatic tumors after initial HR-positive BC [63]. In such cases, the PIK3CA mutation has been found to persist [63]. TNBC can be classified into six subtypes according to gene expression, as proposed by Lehman [32]. Among these subtypes, the luminal androgen receptor (LAR) and mesenchymal stem-like (MSL) subtypes exhibit a greater frequency of PIK3CA mutations [32]. The role of PIK3CA mutations and alterations in the PI3K/AKT pathway is significant in BC biology. However, their significance is more comprehensively understood in HR-positive/HER2-negative BC in comparison to TNBC and HER2-enriched BC, which necessitate additional research endeavors [8].

In the clinical setting of TNBC and HER2-enriched subtypes, it is important to highlight their aggressive features. These types of BC demonstrate wild-type status in relation to PIK3CA mutations. The presence of other complex pathways that have substantial roles in the development of BC across different molecular subtypes may explain this phenomenon. In order to advance future research, it is crucial to conduct further investigation into the PIK3/AKT/PTEN and mTOR pathways, as they are closely associated with PIK3CA. Moreover, it is imperative to conduct protein expression level analysis to obtain a comprehensive understanding of the involvement of these pathways in TNBC and HER2-enriched subtypes.

Our study also has limitations. We lacked certain clinical variables such as staging, metastasis status, and tumor-infiltrating lymphocytes, mainly because we relied on archival data. This limitation prevented us from analyzing how PIK3CA mutations correlate with these factors and from following patients for long-term prognoses. Prior research shows that AR-positive TNBC cell lines respond significantly to PI3K inhibitors combined with AR antagonists, suggesting a biomarker-driven approach for selecting TNBC patients [32]. Regrettably, our study focuses on the fundamental molecular subtypes of TNBC, not the additional six types proposed by Lehman [32]. Future work should incorporate these refined subtyping methods to better discern the role of PIK3CA mutations in TNBC and explore novel therapy combinations.

Conclusion

Our research underscores a high frequency of the PIK3CA H1047L mutation in Indonesian BC, with luminal B HER2-negative and luminal A subtypes showing the highest rates. Furthermore, the location of the mutated PIK3CA samples were associated with age groups, with the majority of PIK3CA exon 9 mutations identified in individuals aged ≤ 50 years and PIK3CA exon 20 mutations in older patients. These findings prompt further exploration of the role of PIK3CA mutations as biomarkers for personalized therapy, particularly in hormone receptor-positive disease.

Acknowledgments

We extend our sincere gratitude to all those who contributed to the completion of this manuscript.

References

  1. 1. Giaquinto AN, Sung H, Miller KD, Kramer JL, Newman LA, Minihan A, et al. Breast Cancer Statistics, 2022. CA Cancer J Clin. 2022;72(6):524–41. pmid:36190501
  2. 2. Wilkinson L, Gathani T. Understanding breast cancer as a global health concern. Br J Radiol. 2022;95(1130):20211033. pmid:34905391
  3. 3. Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, et al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2024;74(3):229–63. pmid:38572751
  4. 4. Smolarz B, Nowak AZ, Romanowicz H. Breast Cancer-Epidemiology, Classification, Pathogenesis and Treatment (Review of Literature). Cancers (Basel). 2022;14(10):2569. pmid:35626173
  5. 5. Feng Y, Spezia M, Huang S, Yuan C, Zeng Z, Zhang L, et al. Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis. Genes Dis. 2018;5(2):77–106. pmid:30258937
  6. 6. Alowiri NH, Hanafy SM, Haleem RA, Abdellatif A. PIK3CA and PTEN Genes Expressions in Breast Cancer. Asian Pac J Cancer Prev. 2019;20(9):2841–6. pmid:31554385
  7. 7. Cizkova M, Susini A, Vacher S, Cizeron-Clairac G, Andrieu C, Driouch K, et al. PIK3CA mutation impact on survival in breast cancer patients and in ERα, PR and ERBB2-based subgroups. Breast Cancer Res. 2012;14(1):R28. pmid:22330809
  8. 8. Hu H, Zhu J, Zhong Y, Geng R, Ji Y, Guan Q, et al. PIK3CA mutation confers resistance to chemotherapy in triple-negative breast cancer by inhibiting apoptosis and activating the PI3K/AKT/mTOR signaling pathway. Ann Transl Med. 2021;9(5):410. pmid:33842631
  9. 9. Miricescu D, Totan A, Stanescu-Spinu I-I, Badoiu SC, Stefani C, Greabu M. PI3K/AKT/mTOR Signaling Pathway in Breast Cancer: From Molecular Landscape to Clinical Aspects. Int J Mol Sci. 2020;22(1):173. pmid:33375317
  10. 10. Martínez-Sáez O, Chic N, Pascual T, Adamo B, Vidal M, González-Farré B, et al. Frequency and spectrum of PIK3CA somatic mutations in breast cancer. Breast Cancer Res. 2020;22(1):45. pmid:32404150
  11. 11. Vatte C, Al Amri AM, Cyrus C, Chathoth S, Alsayyah A, Ahmad A, et al. Helical and kinase domain mutations of PIK3CA, and their association with hormone receptor expression in breast cancer. Oncol Lett. 2019;18(3):2427–33. pmid:31404155
  12. 12. Keraite I, Alvarez-Garcia V, Garcia-Murillas I, Beaney M, Turner NC, Bartos C, et al. PIK3CA mutation enrichment and quantitation from blood and tissue. Sci Rep. 2020;10(1):17082. pmid:33051521
  13. 13. Schagerholm C, Robertson S, Toosi H, Sifakis EG, Hartman J. PIK3CA mutations in endocrine-resistant breast cancer. Sci Rep. 2024;14(1):12542. pmid:38822093
  14. 14. Verret B, Cortes J, Bachelot T, Andre F, Arnedos M. Efficacy of PI3K inhibitors in advanced breast cancer. Ann Oncol. 2019;30 Suppl 10:x12–20. pmid:31928690
  15. 15. Wang M, Li J, Huang J, Luo M. The Predictive Role of PIK3CA Mutation Status on PI3K Inhibitors in HR+ Breast Cancer Therapy: A Systematic Review and Meta-Analysis. Biomed Res Int. 2020;2020:1598037. pmid:32461963
  16. 16. Kim JW, Lim AR, You JY, Lee JH, Song SE, Lee NK, et al. PIK3CA Mutation is Associated with Poor Response to HER2-Targeted Therapy in Breast Cancer Patients. Cancer Res Treat. 2023;55(2):531–41. pmid:36097803
  17. 17. Wu H, Wang W, Du J, Li H, Wang H, Huang L, et al. The distinct clinicopathological and prognostic implications of PIK3CA mutations in breast cancer patients from Central China. Cancer Manag Res. 2019;11:1473–92. pmid:30863158
  18. 18. Al-Shamsi HO, Abu-Gheida I, Abdulsamad AS, AlAwadhi A, Alrawi S, Musallam KM, et al. Molecular Spectra and Frequency Patterns of Somatic Mutations in Arab Women with Breast Cancer. Oncologist. 2021;26(11):e2086–9. pmid:34327780
  19. 19. Hamadeh LN, Farhat L, Hilal L, Assi H, Nasr F, Chahine G, et al. Frequency and mutational spectrum of PIK3CA gene mutations in breast cancer patients: Largest and first report from Lebanon. Gene. 2023;871:147433. pmid:37068694
  20. 20. Ben Rekaya M, Sassi F, Saied E, Bel Haj Kacem L, Mansouri N, Zarrouk S, et al. PIK3CA mutations in breast cancer: A Tunisian series. PLoS One. 2023;18(5):e0285413. pmid:37195967
  21. 21. Lian J, Xu E-W, Xi Y-F, Wang H-W, Bu P, Wang J-F, et al. Clinical-Pathologic Analysis of Breast Cancer With PIK3CA Mutations in Chinese Women. Technol Cancer Res Treat. 2020;19:1533033820950832. pmid:33047659
  22. 22. Deng L, Zhu X, Sun Y, Wang J, Zhong X, Li J, et al. Prevalence and Prognostic Role of PIK3CA/AKT1 Mutations in Chinese Breast Cancer Patients. Cancer Res Treat. 2019;51(1):128–40. pmid:29540052
  23. 23. Lee M-H, Cho J-H, Kwon S-Y, Jung S-J, Lee J-H. Clinicopathological Characteristics of PIK3CA Mutation and Amplification in Korean Patients with Breast Cancers. Int J Med Sci. 2020;17(8):1131–5. pmid:32410843
  24. 24. Elwy F, Helwa R, El Leithy AA, Shehab El din Z, Assem MM, Hassan NHA. PIK3CA mutations in HER2-positive Breast Cancer Patients; Frequency and Clinicopathological Perspective in Egyptian Patients. Asian Pac J Cancer Prev. 2017;18(1):57–64. pmid:28240010
  25. 25. De Mattos-Arruda L. PIK3CA mutation inhibition in hormone receptor-positive breast cancer: time has come. ESMO Open. 2020;5(4):e000890. pmid:32817061
  26. 26. Kalinsky K, Jacks LM, Heguy A, Patil S, Drobnjak M, Bhanot UK, et al. PIK3CA mutation associates with improved outcome in breast cancer. Clin Cancer Res. 2009;15(16):5049–59. pmid:19671852
  27. 27. Zardavas D, Fumagalli D, Loi S. Phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin pathway inhibition: a breakthrough in the management of luminal (ER+/HER2-) breast cancers? Curr Opin Oncol. 2012;24(6):623–34. pmid:22960556
  28. 28. Mosele F, Stefanovska B, Lusque A, Tran Dien A, Garberis I, Droin N, et al. Outcome and molecular landscape of patients with PIK3CA-mutated metastatic breast cancer. Ann Oncol. 2020;31(3):377–86. pmid:32067679
  29. 29. Lv W, Du C, Zhang Y, Wu F, Jin Y, Chen X, et al. Clinicopathological characteristics and prognostic analysis of PIK3CA mutation in breast cancer patients in Northwest China. Pathol Res Pract. 2022;238:154063. pmid:35994807
  30. 30. Ishida N, Baba M, Hatanaka Y, Hagio K, Okada H, Hatanaka KC, et al. PIK3CA mutation, reduced AKT serine 473 phosphorylation, and increased ERα serine 167 phosphorylation are positive prognostic indicators in postmenopausal estrogen receptor-positive early breast cancer. Oncotarget. 2018;9(25):17711–24. pmid:29707142
  31. 31. Tharin Z, Richard C, Derangère V, Ilie A, Arnould L, Ghiringhelli F, et al. PIK3CA and PIK3R1 tumor mutational landscape in a pan-cancer patient cohort and its association with pathway activation and treatment efficacy. Sci Rep. 2023;13(1):4467. pmid:36934165
  32. 32. Lehmann BD, Bauer JA, Schafer JM, Pendleton CS, Tang L, Johnson KC, et al. PIK3CA mutations in androgen receptor-positive triple negative breast cancer confer sensitivity to the combination of PI3K and androgen receptor inhibitors. Breast Cancer Res. 2014;16(4):406. pmid:25103565
  33. 33. McGee SR, Tibiche C, Trifiro M, Wang E. Network Analysis Reveals A Signaling Regulatory Loop in the PIK3CA-mutated Breast Cancer Predicting Survival Outcome. Genomics Proteomics Bioinformatics. 2017;15(2):121–9. pmid:28392480
  34. 34. Ramirez-Ardila D, Timmermans AM, Helmijr JA, Martens JWM, Berns EMJJ, Jansen MPHM. Increased MAPK1/3 Phosphorylation in Luminal Breast Cancer Related with PIK3CA Hotspot Mutations and Prognosis. Transl Oncol. 2017;10(5):854–66. pmid:28886403
  35. 35. Garay JP, Smith R, Devlin K, Hollern DP, Liby T, Liu M, et al. Sensitivity to targeted therapy differs between HER2-amplified breast cancer cells harboring kinase and helical domain mutations in PIK3CA. Breast Cancer Res. 2021;23(1):81. pmid:34344439
  36. 36. Cizkova M, Dujaric M-E, Lehmann-Che J, Scott V, Tembo O, Asselain B, et al. Outcome impact of PIK3CA mutations in HER2-positive breast cancer patients treated with trastuzumab. Br J Cancer. 2013;108(9):1807–9. pmid:23612454
  37. 37. Pang B, Cheng S, Sun S-P, An C, Liu Z-Y, Feng X, et al. Prognostic role of PIK3CA mutations and their association with hormone receptor expression in breast cancer: a meta-analysis. Sci Rep. 2014;4:6255. pmid:25176561
  38. 38. Cizkova M, Cizeron-Clairac G, Vacher S, Susini A, Andrieu C, Lidereau R, et al. Gene expression profiling reveals new aspects of PIK3CA mutation in ERalpha-positive breast cancer: major implication of the Wnt signaling pathway. PLoS One. 2010;5(12):e15647. pmid:21209903
  39. 39. Guo S, Loibl S, von Minckwitz G, Darb-Esfahani S, Lederer B, Denkert C. PIK3CA H1047R Mutation Associated with a Lower Pathological Complete Response Rate in Triple-Negative Breast Cancer Patients Treated with Anthracycline-Taxane-Based Neoadjuvant Chemotherapy. Cancer Res Treat. 2020;52(3):689–96. pmid:32019278
  40. 40. Heriyanto DS, Yoshuantari N, Akbariani G, Lau V, Hanini H, Hidayati Z, et al. High Probability of Lynch Syndrome Among Colorectal Cancer Patients Is Associated With Higher Occurrence of KRAS and PIK3CA Mutations. World J Oncol. 2024;15(4):612–24. pmid:38993255
  41. 41. Khoury K, Tan AR, Elliott A, Xiu J, Gatalica Z, Heeke AL, et al. Prevalence of Phosphatidylinositol-3-Kinase (PI3K) Pathway Alterations and Co-alteration of Other Molecular Markers in Breast Cancer. Front Oncol. 2020;10:1475. pmid:32983983
  42. 42. Rahmawati Y, Setyawati Y, Widodo I, Ghozali A, Purnomosari D. Molecular Subtypes of Indonesian Breast Carcinomas - Lack of Association with Patient Age and Tumor Size. Asian Pac J Cancer Prev. 2018;19(1):161–6. pmid:29373908
  43. 43. Tau S, Miller TW. Alpelisib Efficacy without Cherry-PI3King Mutations. Clin Cancer Res. 2023;29(6):989–90. pmid:36626159
  44. 44. Fujimoto Y, Morita TY, Ohashi A, Haeno H, Hakozaki Y, Fujii M, et al. Combination treatment with a PI3K/Akt/mTOR pathway inhibitor overcomes resistance to anti-HER2 therapy in PIK3CA-mutant HER2-positive breast cancer cells. Sci Rep. 2020;10(1):21762. pmid:33303839
  45. 45. Hayama S, Nakamura R, Ishige T, Sangai T, Sakakibara M, Fujimoto H, et al. The impact fpostmenopausal luminal breast cancer patients. BMC Cancer. 2023;23: 1–10.
  46. 46. Saikia KK, Panigrahi MK, Mehta A, Kumar D. Clinico-pathological Features of PIK3CA Mutation in HER2-Positive Breast Cancer of Indian Population. Indian J Surg Oncol. 2018;9(3):381–6. pmid:30288002
  47. 47. Abba MC, Zhong Y, Lee J, Kil H, Lu Y, Takata Y, et al. DMBA induced mouse mammary tumors display high incidence of activating Pik3caH1047 and loss of function Pten mutations. Oncotarget. 2016;7(39):64289–99. pmid:27588403
  48. 48. Xiao W, Zhang G, Chen B, Chen X, Wen L, Lai J, et al. Mutational Landscape of PI3K-AKT-mTOR Pathway in Breast Cancer: Implications for Targeted Therapeutics. J Cancer. 2021;12(14):4408–17. pmid:34093841
  49. 49. Zhao Y, Tang W, Sun L, Xiong D, Sheng M, Luo Y. The effects of PIK3CA and TP53 on prognosis in patients with Triple-negative breast cancer (TNBC): a single institution’s long-term follow-up (6 years). European Journal of Gynaecological Oncology. 2021;42(6):1320.
  50. 50. Loi S, Haibe-Kains B, Majjaj S, Lallemand F, Durbecq V, Larsimont D, et al. PIK3CA mutations associated with gene signature of low mTORC1 signaling and better outcomes in estrogen receptor-positive breast cancer. Proc Natl Acad Sci U S A. 2010;107(22):10208–13. pmid:20479250
  51. 51. Bertucci A, Bertucci F, Gonçalves A. Phosphoinositide 3-Kinase (PI3K) Inhibitors and Breast Cancer: An Overview of Current Achievements. Cancers (Basel). 2023;15(5):1416. pmid:36900211
  52. 52. Yip PY. Phosphatidylinositol 3-kinase-AKT-mammalian target of rapamycin (PI3K-Akt-mTOR) signaling pathway in non-small cell lung cancer. Transl Lung Cancer Res. 2015;4(2):165–76. pmid:25870799
  53. 53. Spangle JM, Von T, Pavlick DC, Khotimsky A, Zhao JJ, Roberts TM. PIK3CA C-terminal frameshift mutations are novel oncogenic events that sensitize tumors to PI3K-α inhibition. Proc Natl Acad Sci U S A. 2020;117(39):24427–33. pmid:32929011
  54. 54. Peixoto A, Cirnes L, Carvalho AL, Andrade MJ, Brito MJ, Borralho P, et al. Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal - U-PIK Project. Front Mol Biosci. 2023;10:1082915. pmid:36825198
  55. 55. Cancer Genome Atlas Network. Comprehensive molecular portraits of human breast tumours. Nature. 2012;490(7418):61–70. pmid:23000897
  56. 56. Berns K, Horlings HM, Hennessy BT, Madiredjo M, Hijmans EM, Beelen K, et al. A functional genetic approach identifies the PI3K pathway as a major determinant of trastuzumab resistance in breast cancer. Cancer Cell. 2007;12(4):395–402. pmid:17936563
  57. 57. Keegan NM, Furney SJ, Walshe JM, Gullo G, Kennedy MJ, Smith D, et al. Phase Ib Trial of Copanlisib, A Phosphoinositide-3 Kinase (PI3K) Inhibitor, with Trastuzumab in Advanced Pre-Treated HER2-Positive Breast Cancer “PantHER”. Cancers (Basel). 2021;13(6):1225. pmid:33799597
  58. 58. Nakai M, Yamada T, Sekiya K, Sato A, Hankyo M, Kuriyama S, et al. Use of Liquid Biopsy to Detect PIK3CA Mutation in Metastatic Breast Cancer. J Nippon Med Sch. 2022;89(1):66–71. pmid:33692304
  59. 59. Wu H-J, Chu P-Y. Current and Developing Liquid Biopsy Techniques for Breast Cancer. Cancers (Basel). 2022;14(9):2052. pmid:35565189
  60. 60. Galvano A, Castellana L, Gristina V, La Mantia M, Insalaco L, Barraco N, et al. The diagnostic accuracy of PIK3CA mutations by circulating tumor DNA in breast cancer: an individual patient data meta-analysis. Ther Adv Med Oncol. 2022;14:17588359221110162. pmid:36188485
  61. 61. Dumbrava EE, Call SG, Huang HJ, Stuckett AL, Madwani K, Adat A, et al. PIK3CA mutations in plasma circulating tumor DNA predict survival and treatment outcomes in patients with advanced cancers. ESMO Open. 2021;6(5):100230. pmid:34479035
  62. 62. Rugo HS, Raskina K, Schrock AB, Madison RW, Graf RP, Sokol ES, et al. Biology and Targetability of the Extended Spectrum of PIK3CA Mutations Detected in Breast Carcinoma. Clin Cancer Res. 2023;29(6):1056–67. pmid:36321996
  63. 63. Pascual J, Turner NC. Targeting the PI3-kinase pathway in triple-negative breast cancer. Ann Oncol. 2019;30(7):1051–60. pmid:31050709