Clinical-Pathologic Analysis of Breast Cancer With PIK3CA Mutations in Chinese Women

Biomarkers in Breast Cancer: An Old Story with a New End

Breast cancer is the second most frequent cancer in the world. It is a heterogeneous disease and the leading cause of cancer mortality in women. Advances in molecular technologies allowed for the identification of new and more specifics biomarkers for breast cancer diagnosis, prognosis, and risk prediction, enabling personalized treatments, improving therapy, and preventing overtreatment, undertreatment, and incorrect treatment. Several breast cancer biomarkers have been identified and, along with traditional biomarkers, they can assist physicians throughout treatment plan and increase therapy success. Despite the need of more data to improve specificity and determine the real clinical utility of some biomarkers, others are already established and can be used as a guide to make treatment decisions. In this review, we summarize the available traditional, novel, and potential biomarkers while also including gene expression profiles, breast cancer single-cell and polyploid giant cancer cells. We hope to help physicians understand tumor specific characteristics and support decision-making in patient-personalized clinical management, consequently improving treatment outcome.

Frequency and Mutational Spectrum of PIK3CA gene mutations in Breast Cancer Patients: Largest and First Report from Lebanon

The PIK3CA pathway is one of the most frequently altered pathways in human cancers, especially in breast cancer with approximately 40% of HR+/HER2- advanced breast cancer cases exhibiting mutations in the PIK3CA gene. While the mutations can occur across the entire gene, the most common are observed in exon 9 corresponding to the helical domain, and in exon 20 encompassing the kinase domain. This study constitutes the first attempt at determining the frequency and mutational spectrum in Lebanese breast cancer patients. For this purpose, DNA samples from 280 breast cancer patients from across Lebanon were screened for PIK3CA mutations using the Therascreen® PIK3CA RGQ Real-time PCR assay. In line with previous reports, 38.57% of cases were positive for at least one PIK3CA mutation, among which approximately 59% were in exon 9 and 37% in exon 20. However, PIK3CA mutations are breast cancer are heterogeneous whereby 20% of known PIK3CA mutants might not be detected by compact PCR based assays. Thus, the adoption of comprehensive Next Generation Sequencing based panels to decipher the complete clinical, molecular and immunohistochemical profile of breast cancer tumor requires further investigation.

Identification and Validation of FGF-Related Prognostic Signatures in Prostate Cancer

Background

FGF signaling is critical to controlling various cancers. Nevertheless, the functions of FGF-related genes in PCa are still unknown.

Objective

The objective of this study is to build a FGF-related signature that was capable of accurately predicting PCa survival and prognosis for BCR.

Methods

The univariate and multivariate Cox regression, infiltrating immune cells, LASSO, and GSEA analyses were carried out to build a prognostic model.

Results

A FGF-related signature that consists of PIK3CA and SOS1 was developed for the purpose of predicting PCa prognosis, and all patients were categorized into low- and high-risk groups. In comparison to the low-risk group, high-risk score patients had poorer BCR survival. This signature's predictive power has been investigated utilizing the AUC of the ROC curves. The risk score has been shown to be an independent prognostic factor by multivariate analysis. The four enriched pathways of the high-risk group were obtained by gene set enrichment analysis (GSEA) and found to be associated with the tumorigenesis and development of PCa, including focal adhesion, TGF-β signaling pathway, adherens junction, and ECM receptor interaction. The high-risk groups had considerably higher levels of immune status and tumor immune cell infiltration, suggesting a more favorable response to immune checkpoint inhibitors. IHC found that the expression of the two FGF-related genes in the predictive signature was extremely different in PCa tissues.

Conclusion

To summarize, our FGF-related risk signature may effectively predict and diagnose PCa, indicating that in PCa patients, they are potential therapeutic targets and promising prognostic biomarkers.

Enzyme-Free Colorimetric Method for Fast Detection of PIK3CA Gene Mutation by Praseodymia Nanorods

The frequently mutated phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) gene is associated with multiple tumors and endocytosis of viruses. Identification of muted nucleotides at the hotspot can help in finding the susceptible people who are vulnerable to cancers and viruses. Herein, a simple enzyme-free colorimetric method is developed for the quick detection of PIK3CA gene mutations. The main mechanism lies in the dissimilar interactions between praseodymia nanorods and different nucleotides, as well as the underlying oxidase-mimicking characteristics of praseodymia. With rational designs of probes and processes, this method has great potential for expanded applications in the screening of mutations in other genes of interest.

PIK3CA mutations in breast cancer: A Tunisian series

BACKGROUND

The aim of this study was to analyze PIK3CA mutations in exons 9 and 20 in breast cancers (BCs) and their association with clinicopathological characteristics.

METHODS

Mutational analysis of PIK3CA exon 9 and 20 was performed by Sanger sequencing in 54 primary BCs of Tunisian women. The associations of PIK3CA mutations with clinicopathological characteristics were analyzed.

RESULTS

Fifteen exon 9 and exon 20 PIK3CA variants were identified in 33/54 cases (61%). PIK3CA mutations including pathogenic (class 5/Tier I) or likely pathogenic (class 4/Tier II) occurred in 24/54 cases (44%): 17/24 cases (71%) in exon 9, 5/24 cases (21%) in exon 20 and 2/24 cases (8%) in both exons. Of these 24 cases, 18 (75%) carried at least one of the three hot spot mutations: E545K (in 8 cases), H1047R (in 4 cases), E542K (in 3 cases), E545K/E542K (in one case), E545K/H1047R (in one case) and P539R/H1047R (in one case). Pathogenic PIK3CA mutations were associated with negative lymph node status (p = 0.027). Age distribution, histological SBR tumor grading, estrogen and progesterone receptors, human epidermal growth factor receptor 2, and molecular classification were not correlated with PIK3CA mutations (p > 0.05).

CONCLUSION

The frequency of somatic PIK3CA mutations in BCs of Tunisian women is slightly higher than that of BCs of Caucasian women and more observed in exon 9 than in exon 20. PIK3CA mutated status is associated with negative lymph node status. These data need to be confirmed in larger series.

Comparison of PIK3CA Mutation Prevalence in Breast Cancer Across Predicted Ancestry Populations

PURPOSE

Understanding the differences in biomarker prevalence that may exist among diverse populations is invaluable to accurately forecast biomarker-driven clinical trial enrollment metrics and to advance inclusive research and health equity. This study evaluated the frequency and types of PIK3CA mutations (PIK3CAmut) detected in predicted genetic ancestry subgroups across breast cancer (BC) subtypes.

METHODS

Analyses were conducted using real-world genomic data from adult patients with BC treated in an academic or community setting in the United States and whose tumor tissue was submitted for comprehensive genomic profiling.

RESULTS

Of 36,151 patients with BC (median age, 58 years; 99% female), the breakdown by predicted genetic ancestry was 75% European, 14% African, 6% Central/South American, 3% East Asian, and 1% South Asian. We demonstrated that patients of African ancestry are less likely to have tumors that harbor PIK3CAmut compared with patients of European ancestry with estrogen receptor-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) BC (37% [949/2,593] v 44% [7,706/17,637]; q = 4.39E-11) and triple-negative breast cancer (8% [179/2,199] v 14% [991/7,072]; q = 6.07E-13). Moreover, we found that PIK3CAmut were predominantly composed of hotspot mutations, of which mutations at H1047 were the most prevalent across BC subtypes (35%-41% ER+/HER2- BC; 43%-61% HER2+ BC; 40%-59% triple-negative breast cancer).

CONCLUSION

This analysis established that tumor PIK3CAmut prevalence can differ among predicted genetic ancestries across BC subtypes on the basis of the largest comprehensive genomic profiling data set of patients with cancer treated in the United States. This study highlights the need for equitable representation in research studies, which is imperative to ensuring better health outcomes for all.

Clinicopathological characteristics and prognostic analysis of PIK3CA mutation in breast cancer patients in Northwest China

PURPOSE

Multiple studies on PIK3CA mutations in breast cancer (BC) had been performed, which showed the controversial results among different countries and races even those from the same country. The present study aimed to explore the PIK3CA gene mutation status in BC patients in Northwest China and reveal the relationship between PIK3CA mutations and clinicopathological features along with prognosis.

MATERIALS AND METHODS

1002 BC patients from Northwest China were recruited in this study, genomic DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tumor tissues, and hotspot mutations in the exon 9 and 20 of PIK3CA gene were detected by ARMS-PCR.

RESULTS

PIK3CA mutations were found in 31.2% (313/1002) of BC patients, among them 66.1% were mutations in exon 20% and 32.6% were mutations in exon 9. H1047R was the most common mutation type, accounting for 56.5% of the total mutated samples. Significant correlations were observed between PIK3CA mutation status and age (P = 0.035), histopathologic types (P = 0.004), pathological grade (P = 0.013), ER positivity (P < 0.001), PR positivity (P < 0.001), molecular subtypes (P = 0.004) and family history (P = 0.007). Cox multivariate analysis showed that patients with mutations in exon 9 or 20 had shorter DFS and OS than wild-type patients. Those with exon 9 mutations subgroup had the worst prognosis. Interestingly, patients with H1047L mutation had the best prognosis than others.

CONCLUSION

PIK3CA mutations could be used as an indicator of clinical outcome or targeted therapy for multiple breast cancer subgroups in Northwest China.

PIK3CA Mutation as Potential Poor Prognostic Marker in Asian Female Breast Cancer Patients Who Received Adjuvant Chemotherapy

Background: The prognostic relevance of the PIK3CA mutation together with PD-L1, c-Met, and mismatch repair deficiency (dMMR) have not been fully investigated in Asian women with breast cancer (BC) who have undergone postoperative adjuvant chemotherapy. Methods: We analyzed PIK3CA mutations via peptide nucleic acid (PNA)-mediated real-time PCR assay, PD-L1/c-Met expression via immunohistochemistry (IHC), and microsatellite instability (MSI) status using PCR and IHC, in 191 resected BCs from 2008 to 2011. The Cancer Genome Atlas (TCGA) dataset for the involvement of the PIK3CA mutation with PD-L1/c-Met/MMR was explored. Results: The PNA clamp-mediated assay was able to detect the PIK3CA mutation in 1% of the mutant population in the cell line validation. Using this method, the PIK3CA mutation was found in 78 (49.4%) of 158 samples. c-Met and PD-L1 positivity were identified in 31.4 and 21.8% of samples, respectively, which commonly correlated with high histologic grade and triple-negative subtype. MSI/dMMR was observed in 8.4% of patients, with inconsistency between MMR IHC and the MSI PCR. The PIK3CA mutation exhibited a poor prognostic association regarding recurrence-free survival (RFS) in both overall and triple-negative BCs. In subgroup analyses, the PIK3CA-mutated tumors showed poorer RFS than the PIK3CA-wildtype within the c-Met-positive, MSS, triple-negative, or age onset <50 years subgroups, which showed a similar trend of association in TCGA data. Conclusions: PIK3CA mutation together with c-Met or dMMR/MSI status might be relevant to poor prognosis in BC subsets, especially in Asian women.