Study of PIK3CA, BRAF, and KRAS mutations in breast carcinomas among Chinese women in Qinghai

Wang, Y.L.; Dai, Xiaotian; Li, Y.D.; Cheng, Runtan; Deng, Bingbing; Geng, Xuexia; Zhang, H.J.

doi:10.4238/2015.november.18.49

Cited by 9 publications

(2 citation statements)

References 28 publications

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“…Both missense mutations E545K and Q546K were equally prevalent in exon 9 (50% each), while the H1047R missense mutation was more prevalent (83.3%) in exon 20 compared to the H1047L mutation (16.7%). These mutations were clustered within the mutational hotspot regions covering nucleotides 1633–1636 (n = 4) and 3140 (n = 6), in agreement with what has been reported by others ( Nosho et al, 2008 ; Wang et al, 2015 ; Ahmad et al, 2016 ).…”

Section: Discussionsupporting

confidence: 91%

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal – U-PIK Project

Peixoto

Cirnes

Carvalho

et al. 2023

Front. Mol. Biosci.

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Background: Around 40% of ER+/HER2-breast carcinomas (BC) present mutations in the PIK3CA gene. Assessment of PIK3CA mutational status is required to identify patients eligible for treatment with PI3Kα inhibitors, with alpelisib currently the only approved tyrosine kinase inhibitor in this setting. U-PIK project aimed to conduct a ring trial to validate and implement the PIK3CA mutation testing in several Portuguese centers, decentralizing it and optimizing its quality at national level.Methods: Eight Tester centers selected two samples of patients with advanced ER+/HER2- BC and generated eight replicates of each (n = 16). PIK3CA mutational status was assessed in two rounds. Six centers used the cobas®PIK3CA mutation test, and two used PCR and Sanger sequencing. In parallel, two reference centers (IPATIMUP and the Portuguese Institute of Oncology [IPO]-Porto) performed PIK3CA mutation testing by NGS in the two rounds. The quality of molecular reports describing the results was also assessed. Testing results and molecular reports were received and analyzed by U-PIK coordinators: IPATIMUP, IPO-Porto, and IPO-Lisboa.Results: Overall, five centers achieved a concordance rate with NGS results (allele frequency [AF] ≥5%) of 100%, one of 94%, one of 93%, and one of 87.5%, considering the overall performance in the two testing rounds. NGS reassessment of discrepancies in the results of the methods used by the Tester centers and the reference centers identified one probable false positive and two mutations with low AF (1–3%, at the analytical sensitivity threshold), interpreted as subclonal variants with heterogeneous representation in the tissue sections processed by the respective centers. The analysis of molecular reports revealed the need to implement the use of appropriate sequence variant nomenclature with the identification of reference sequences (HGVS-nomenclature) and to state the tumor cell content in each sample.Conclusion: The concordance rates between the method used by each tester center and NGS validate the use of the PIK3CA mutational status test performed at these centers in clinical practice in patients with advanced ER+/HER2- BC.

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Section: Discussionsupporting

confidence: 91%

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal – U-PIK Project

Peixoto

Cirnes

Carvalho

et al. 2023

Front. Mol. Biosci.

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“…Another hypothesis of the uncontrolled activation mechanism is the increase in exposure of the activation segment when a small hydrophobic amino acid (valine) is replaced by a hydrophilic residue (glutamic acid), [3]. The BRAF gene is mutated in the majority of patients with melanoma and a minority of patients with breast, colon and lung cancer [4]. In this study, the hypothesis of the existence of nucleotide mutations involved in breast tumors in Senegalese women has been put forward.…”

Section: Introductionmentioning

confidence: 99%

Genetic Diversity and Structuring of the BRAF gene in Breast Tumors

2019

European Journal of Medical Research and Clinical Trials

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The International Agency for Research on Cancer (IARC) estimates an increase in breast cancer worldwide. In Senegal, the most common malignant tumour in women is breast cancer. But also in Senegal as in most African countries, benign tumours occupy an important place in mammary pathologies. To better understand the impact of nucleotide variability and genetic instability of benign and malignant breast tumours, we used the BRAF gene, which is a nuclear gene.This work allowed us to compare the polymorphism, diversity, structure and genetic evolution of exon 15 of the BRAF gene between patients with benign tumours, malignant breast tumours and control subjects. The analysis at the identification of mutation of exon 15 of the BRAF gene led us to conclude that BRAF was mutated in (1.5%) of cases. We observed a synonymous mutation A598A in malignant tumours. Our results showed that somatic mutations of this BRAF gene were common in Senegalese patients with both benign and malignant breast tumours. So our results allowed us to conclude that the BRAF gene is involved in breast tumours.

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Molecular evaluation of PIK3CA gene mutation in breast cancer: determination of frequency, distribution pattern and its association with clinicopathological findings in Indian patients

Ahmad¹,

Badwe²,

Verma³

et al. 2016

Med Oncol

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Somatic mutations in the PIK3CA gene are common in breast cancer and represent a clinically useful marker for prognosis and therapeutic target. Activating mutations in the PI3K p110 catalytic subunit (PIK3CA) have been identified in 18-40 % of breast carcinomas. In this study, we evaluated PIK3CA mutation in 185 Indian breast cancer patients by direct DNA sequencing. PIK3CA mutations were observed in 23.2 % (43/185) of breast tumor samples. PIK3CA mutations were more frequent exon 30 (76.8 %) than in exon 9 (23.2 %). Mutations were mostly clustered within two hotspot region between nucleotides 1624 and 1636 or between 3129 and 3140. Sequencing analysis revealed four different missense mutations at codon 542 and 545 (E542K, E545K, E545A and E545G) in the helical domain and two different amino acid substitutions at codon 1047 (H1047R and H1047L) in the kinase domain. None of the cases harbored concomitant mutations at multiple codons. PIK3CA mutations were more frequent in older patients, smaller size tumors, ductal carcinomas, grade II tumors, lymph node-positive tumors and non-DCIS tumors; however, none of the differences were significant. In addition, PIK3CA mutations were common in ER+, PR+ and HER2+ cases (30 %), and a comparatively low frequency were noted in triple-negative tumors (13.6 %). In conclusion, to our knowledge, this is the largest study to evaluate the PIK3CA mutation in Indian breast cancer patients. The frequency and distribution pattern of PIK3CA mutations is similar to global reports. Furthermore, identification of molecular markers has unique strengths and can provide insights into the pathogenic process of breast carcinomas.

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Study of PIK3CA, BRAF, and KRAS mutations in breast carcinomas among Chinese women in Qinghai

Cited by 9 publications

References 28 publications

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal – U-PIK Project

Evaluation of PIK3CA mutations in advanced ER+/HER2-breast cancer in Portugal – U-PIK Project

Genetic Diversity and Structuring of the BRAF gene in Breast Tumors

Molecular evaluation of PIK3CA gene mutation in breast cancer: determination of frequency, distribution pattern and its association with clinicopathological findings in Indian patients

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