PIK3CA Gene Research Articles

Two genes related to apoptosis in the hepatopancreas of juvenile prawn, Macrobrachium nipponense: Molecular characterization and transcriptional response to nanoplastic exposure

Nanoplastics have been widely found in the global water environment, causing plastic pollution and affecting human beings and numerous organisms. Studies involving freshwater crustacean exposure to nanoplastics, however, are limited. In this study, juvenile prawns (Macrobrachium nipponense) were exposed to 75 nm polystyrene nanoplastics at different concentrations (0, 5, 10, 20, or 40 mg/L) for a 28-d chronic exposure experiment. To study the effects of exposure to nanoplastics on hepatopancreas cell apoptosis, C-Jun N-terminal kinase (JNK) and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) genes were selected, and hepatotoxic enzyme activities and Toll pathway- and apoptosis-related gene expression were determined. For the first time, full-length Mn-JNK and Mn-PIK3CA cDNAs were cloned from M. nipponense. Homologous comparisons showed that JNK and PIK3CA had conserved functional sequences. The apoptosis rate in the high-concentration nanoplastic group (40 mg/L) was significantly higher than in the low-concentration nanoplastic (5 mg/L) and control groups (0 mg/L). The alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamyl transpeptidase (GGT) and xanthine oxidase (XOD) enzyme activities in the hepatopancreas increased with exposure to higher concentrations of nanoplastics. In addition, the levels of apoptosis- and Toll pathway-related gene expression and JNK and PIK3CA gene expression were initially increased, then decreased with exposure to higher concentrations of nanoplastics. This study showed that polystyrene nanoplastics activate toll-related pathways leading to apoptosis and hepatopancreas damage, which provides theoretical support for future aquatic toxicological research.

KRAS, NRAS, BRAF, and PIK3CA mutation rates, clinicopathological association, and their prognostic value in Iranian colorectal cancer patients

Mutations in KRAS, NRAS, BRAF, and PIK3CA genes are critical factors in clinical evaluation of colorectal cancer (CRC) development and progression. In Iran, however, the data regarding genetic profile of CRC patients is limited except for KRAS exon2 and BRAF V600F mutations. This study aimed to investigate the mutational spectrum and prognostic effects of these genes and explore the relationship between these mutations and clinicopathological features of CRC. To achieve these objectives, mutations in KRAS (exons 2, 3, and 4), NRAS (exons 2, 3, and 4), PIK3CA (exons 9 and 20), and BRAF (exon 15) was determined using PCR and pyrosequencing in a total of 151 patients with colorectal cancer. KRAS, BRAF, NRAS, and PIK3CA mutations were identified in 41%, 5.96%, 3.97%, and 13.24% of the cases, respectively. There were some significant correlations between clinicopathological features and KRAS, PIK3CA, BRAF, and NRAS mutations. Mutations in KRAS and PIK3CA were shown to be independent risk factors for poor survival of the patients at stage I-IV (p <0.0001 and p =0.001, respectively). No significant impact on prognosis was observed in patients with BRAF mutations. Our study revealed the prevalence of CRC biomarkers mutations in Iranian patients and emphasized the role of KRAS and PIK3CA on shorter overall survival rates in this population.

Abstract P5-03-05: Distinct molecular differences between African American/Black and White women with Triple Negative Breast Cancer

Abstract Introduction: Triple-negative breast cancer (TNBC) is an aggressive disease that lacks well-defined molecular targets. It accounts for 15-20% of all breast cancers and disproportionately affects women of color due to both limited access to treatment and genetic variation. Recent studies identified BRCA1(or 2) and the PIK3CA/AKT1/PTEN axis as targets for treatment, but these studies neglected to account for genetic variations between race. Here, we present molecular differences between African American/Black (AA) and White (W) women with TNBC to highlight the importance of accounting for race to develop effective therapy and improve long-term outcomes. Methods: This study utilized the TCGA Firehose Legacy Breast Carcinoma dataset on cBioPortal. Subjects with breast cancer and negative ER, PR, and HER2 scores were stratified into AA (n=32) and W (n=69) subgroups. Data was analyzed to compare the most altered genes, copy number variation (CNV), and survival rates between the subgroups. The logrank test was used to obtain the hazard rate. The GISTIC2 model was used to assess CNV and G-scores (G; amplitude of aberration x frequency of occurrence). Results: The main genetic differences were in PIK3CA and BRCA1(or 2) genes. PIK3CA was detected as one of the ten most altered genes in TNBC, but this alteration was found in less than 10% of the TNBC cases. Of the 10%, PIK3CA was altered in 19% of W and 9% of AA subgroup. BRCA1(2) were altered in 10%(7%) of W but 0%(3%) of AA. Additionally, structural differences in chromosomes contributed to different survival outcomes. Both groups had co-amplification in 8q, but a significant hazard rate difference (z = 5.32, p &amp;lt; 0.001) was found for the W compared to the AA for the MYC gene. Further, the W had significantly higher amplification at 3q (G = 0.8 in W; 0.45 in AA). It is important to note that the PIK3CA gene lies in the 3q.26 region, meaning this gene is amplified significantly in the W subgroup. The AA group had a significant deletion at 8p.23 (G=0.5 in W; 0.8 in AA). Deletion of 8p causes MYC amplification, a targetable alteration. Conclusion: Our analysis reveals critical differences between AA and W subgroups with TNBC. Thus, it is clear that targeting the PIK3CA or BRCA1(2) gene benefits the W more than the AA population. To alleviate the disproportionate burden that AA women with TNBC face, more effort must be geared to find solutions specific to the AA subgroup. A greater sample size will help determine whether MYC amplification is unique to the AA subgroup, and if so, it could be targeted to improve outcomes of AA women with TNBC. Nevertheless, more data and research is needed to understand causes and decrease the rate of disparate outcomes in patients with TNBC. Citation Format: So Hyeon Park, Roy Khalife, Evan White, Anthony Magliocco. Distinct molecular differences between African American/Black and White women with Triple Negative Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-03-05.

Abstract OT3-31-01: The Amelia-1 Study: A phase 1b/2 trial of evexomostat (SDX-7320) plus fulvestrant (Faslodex®) and alpelisib (Piqray®) in patients with advanced breast cancer at risk for alpelisib (Piqray)-induced hyperglycemia

Abstract Background: Breast cancer patients with mutation(s) in the PIK3CA gene have more aggressive disease and worse outcomes relative to patients without PIK3CA mutations. Alpelisib (Piqray), an inhibitor of PIK3CA, was approved for breast cancer patients with PIK3CA mutations. An on-target toxicity of alpelisib is hyperglycemia leading to hyperinsulinemia which may limit effectiveness of this drug. Patients with baseline metabolic dysfunction, insulin resistance, and/or elevated HbA1c are at greater risk of developing grade 3,4 hyperglycemia after receiving alpelisib (Piqray) than patients without metabolic dysfunction. Restoring insulin sensitivity and reducing systemic insulin levels improved the efficacy of alpelisib in preclinical models of breast cancer. Evexomostat is a polymer-drug conjugate of a novel small molecule methionine aminopeptidase 2 (MetAP2) inhibitor that in normal mice reduced alpelisib-induced hyperglycemia/hyperinsulinemia and in the MCF-7 model of HR+/PIK3CA-mutant breast cancer showed synergistic anti-tumor activity with alpelisib (Piqray). Evexomostat was well-tolerated in a phase 1 monotherapy safety study in late-stage cancer patients and improved insulin resistance in patients with elevated insulin at baseline, among other metabolic and angiogenic markers. Methods: This is a phase 1b/2, open-label, single-arm pilot study (NCT05455619) in postmenopausal women with PIK3CA-mutated, HR+, HER2- metastatic breast cancer with disease progression following treatment with endocrine therapy plus a CDK4/6 inhibitor who are at risk for hyperglycemia, with risk factors defined as HbA1c between 5.7 and 6.4% and/or HOMA-IR ≥1.8. The primary objective is to determine the safety of evexomostat plus standard of care treatment alpelisib (Piqray) and fulvestrant (combined, the ‘triplet therapy’), to measure the severity and number of hyperglycemic events, and to assess clinical, anti-tumor benefit of the triplet therapy. The trial will begin with a dose-escalation cohort (n=6) at an evexomostat dose of 36 mg/m2 (one dose below the monotherapy MTD of 49 mg/m2) in combination with alpelisib and fulvestrant given in accordance with their respective labels. Based on safety data from the first 6 patients (two cycles), the safety review committee may increase the evexomostat dose for the next cohort of six patients to 49 mg/m2 or may decrease the evexomostat dose to 27 mg/m2 and may adjust the dose of alpelisib if warranted. Once the MTD of the triplet therapy has been defined, additional enrollment will occur until a total of up to 20 patients have completed at least two cycles of triplet therapy at that dose. If warranted, an additional 20 patients may be enrolled to further characterize the safety profile and/or anti-tumor effect of the triplet therapy (total of up to 52 patients). This trial will open to accrual in August, 2022. Primary safety analysis consists of the type, frequency, and severity of treatment-emergent adverse events (TEAEs) per the NCI CTCAE, v5.0, the number of patients with grade 3 or 4 hyperglycemia during the first 2 cycles of therapy plus an estimate of the proportion and its exact upper one-sided 97.5% confidence bound will be analyzed. Efficacy analyses include calculation of the ORR, consisting of complete response (CR) and partial response (PR). The number of patients alive without disease progression six months from the start of the triplet therapy will be assessed. The CBR of CRs, PRs plus stable disease ≥24 weeks from C1D1 will be calculated. Overall survival data will be summarized as available or appropriate. QoL will be analyzed according to functional scores and recommendations in the EORTC scoring manual. ECOG performance status and change from baseline will be summarized. Citation Format: Peter Cornelius, Neal Salomon, David Browning, Sakirat Gill, Ben Mayes, Pierre Dufour, James Shanahan, Bradley Carver, Hope Rugo. The Amelia-1 Study: A phase 1b/2 trial of evexomostat (SDX-7320) plus fulvestrant (Faslodex®) and alpelisib (Piqray®) in patients with advanced breast cancer at risk for alpelisib (Piqray)-induced hyperglycemia [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT3-31-01.

Abstract P5-03-04: PIK3CA mutation prevalence in hormone receptor positive breast cancer patients in United Arab Emirates

Abstract Background: The Phosphatidylinositol-4,5-bisphosphonate 3-kinase catalytic subunit alpha (PIK3CA) gene is mutated in about 30-40% of hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2−) breast cancer (BC) patients. For HR+/HER2- advanced breast cancer patients with disease progression following endocrine-based therapy, the NCCN guideline recommends testing for PIK3CA mutations with tumour or liquid biopsy to identify suitable patients for targeted therapy with alpelisib, an oral α-specific PI3K inhibitor in combination with fulvestrant. The primary objective of this study was to evaluate the proportion and distribution of PIK3CA mutational landscape of HR+ve BC patients at the largest cancer centre in the United Arab Emirates (UAE). Material and methods: Retrospective review of consecutive HR+ve BC patients at Tawam Hospital for whom PIK3CA testing was requested. DNA was extracted from the samples and a targeted resequencing assay was used for mutation detection in exons 7, 9 and 20 of the PIK3CA gene. Sequencing was carried out using the Next Generation Sequencing platform Ion GeneStudio S5 Prime System with a detection limit of 2-5% of the mutant allelic content. Results: 124 patients with HR+ve BC were enrolled in the present study. The pathology samples were considered unsuitable/unsatisfactory in 18 cases. The median age was 51.5 years (range 31-90). All patients were female, 54% were post-menopausal and 49% presented with de-novo metastatic disease. Of the 106 eligible patients, PIK3CA mutations were detected in 33 (31%) patients, the most common being H1047R (45%) and E545K (30%) mutations in exons 20 and 9, respectively. Other less common mutations included C420R mutations (6%) in exon 7, E542 (6%) in exon 9 and H1047Y (3%) in exon 20. 9% of patients had more than one hotspot mutations, primarily in exons 9 and 20. Of the 12 HER2 +ve patients tested, 3 had PIK3CA mutations, most commonly the H1047R mutation in exon 20. Conclusion: The prevalence of PIK3CA mutations and the presence of most common hotspot mutations in exons 20 and 9 was consistent with prior published studies. The clinical relevance of PIK3CA mutations in HER2 +ve BC patients needs further assessment. Citation Format: Fathi Azribi, Mohammad Hourani, Sulaman Magdub, Aydah Alawadhi, Ali Yousif, Emad Dawoud, Khaled Al Qawasmeh, Mouza Al Ameri, Diaeddine Trad, Nouri Bennini, Mohamed Ahmed, Jawaher Ansari. PIK3CA mutation prevalence in hormone receptor positive breast cancer patients in United Arab Emirates [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-03-04.

Cytotoxic Effect of Prunus Divaricata Ledeb. Extract on Lung Cancer Cells and Determination of Expression Profiles of Genes in the MAP-Kinase Pathway

Cherry plum (Prunus divaricata Ledeb.) is a diploid fruit tree that belongs to the Rosaceae family. Anticarcinogenic activity of Prunus divaricata Ledeb. methanol extract was examined in lung cancer cell lines A549 and H1299 as well as in healthy cell line Beas-2b in this study. The changes in the expression levels of the most frequently mutated oncogenes in lung cancer, KRAS, EGFR, BRAF, and PIK3CA were investigated as well. In vitro cytotoxicity assays of P. divaricata Ledeb. fruit methanol extract was conducted by measuring the percentage of viable cells spectrophotometrically using the cell viability identification kit (CVDK) based on the colorimetric method. The AB 7500 Fast RT-PCR device with Sybr Green Master Mix was used to create gene expression profiles, and the Ct values of all genes were assessed by normalizing the Ct value of the housekeeping gene. The methanol extract of P. divaricata Ledeb. fruit was found to have a cytotoxic effect on A549 and H1299 cancer cell lines at 20 mg/ml, but not on the Beas-2b cell line at these concentrations. By reducing proliferation, low KRAS and PIK3CA gene expression caused the cells to undergo apoptosis. The methanol extract of P. divaricata Ledeb. fruit has been found to inhibit the development of cancerous cells while promoting the proliferation of healthy cells. We believe it does this through the apoptotic pathway by regulating gene expression levels in oncogenes via the MAP-Kinase pathway.

The prognostic value of tumor mutation burden (TMB) and its relationship with immune infiltration in breast cancer patients

ObjectiveAlthough the tumor mutation burden (TMB) was reported as a biomarker for immunotherapy of various cancers, whether it can effectively predict the survival prognosis in breast cancer patients remains unclear. In this study, the prognostic value of TMB and its correlation with immune infiltration were explored by using multigroup studies.MethodsThe somatic mutation data of 986 breast cancer patients were obtained from TCGA database. Breast cancer patients were divided into a low-TMB group and a high-TMB group according to the quartile of TMB scores. The differentially expressed genes (DEGs) were identified by the “limma” R program. The CIBERSORT algorithm was utilized to estimate the immune cell fraction of each sample. The TIMER database was utilized to evaluate the association between CNVs of immune genes and tumor immune cell infiltration and the prognostic value of the immune cells in breast cancer.ResultsIn breast cancer, TP53, PIK3CA, TTN, CDH1 and other genes were the most important mutated genes. Higher survival rate of patients was found in the low-TMB group. Among the top 10 DEGs, three of them belong to the KRT gene family. GSEA enrichment analysis showed that MAPK, Hedgehog, mTOR, TGF-bate and GnRH signaling pathways were enriched in the low-TMB group. The infiltration levels of the most of immune cells were higher in the low-TMB group (P < 0.01). Higher expression of CCL18 and TRGC1 was correlated with poor prognosis. Breast cancer patients with CCL18 copy number variations, especially arm-level gains, showed significantly decreased immune cell infiltration. In the low B cell infiltration group, the survival prognosis of breast cancer patients was poor.ConclusionsTMB is a potential prognosis marker in breast cancer. Immune-related gene CCL18 and TRGC1 are biomarkers of poor prognosis while immune (B cell) infiltration is a biomarker of good prognosis.

Exploring the mechanism of anti-fatigue of resveratrol based on network pharmacology and molecular docking, and in vitro studies

To investigate the potential mechanism of resveratrol in anti-fatigue by network pharmacology and molecular docking, and to investigate the anti-fatigue efficacy of resveratrol through in vitro animal experiments. Resveratrol action targets and fatigue-related targets were obtained using various databases. The anti-fatigue targets of resveratrol were obtained using the Venn diagram, uploaded to the String database, imported into Cytoscape 3.7.1, and constructed into a Protein-protein interaction network. The target genes were then subjected to Gene ontology and Kyoto encyclopedia of gene and genome enrichment analysis. Molecular docking verification was performed on the binding ability of the core target to resveratrol. Using swimming-trained mice as exercise models, exhaustive swimming time and fatigue-related biochemical parameters were used as indicators to investigate the effects of resveratrol on exercise endurance and energy metabolism. 104 anti-fatigue targets and 10 core target genes of resveratrol were obtained. KEGG analysis enrichment included AGE-RAGE signaling pathway in diabetic complications, Human cytomegalovirus infection, and Pathways in cancer. Molecular docking showed that the core target genes TP53, PIK3R1, AKT1, PIK3CA, and MAPK1 had good binding activity to resveratrol. Animal experiments showed that resveratrol could prolong the exhaustive swimming time of endurance-trained mice (P < 0.01), decrease aspartate aminotransferase, alanine aminotransferase, uric acid, blood lactate (P < 0.01), decrease blood urea nitrogen (P < 0.05), increase the liver glycogen, muscle glycogen (P < 0.01). Conclusion: Resveratrol has the characteristics of multiple targets and multiple pathways in anti-fatigue; resveratrol can enhance exercise endurance in mice.

Recurrent PIK3CA H1047R-Mutated Congenital Infiltrative Facial Lipomatosis: A Case Report and Review of Literature

Congenital infiltrating lipomatosis of the face (CILF) is a rare, congenital, nonhereditary facial overgrowth due to post-zygomatic activating mutations in PIK3CA gene. It is unilateral and involves hypertrophy of both the soft and hard tissue structures on the affected side of the face. This commonly results in early eruption of the teeth, hypertrophy of the facial bones, macroglossia, and proliferation of the parotid gland. Less than 80 cases of CILF have been reported in the literature so far. Treatment modalities include liposuction and surgical excision. However, since the hallmark of CILF is mutation in the PIK3CA gene, PI3K inhibitors may play a therapeutic role in CILF. We report a case of an 8-year-old boy with recurrent CILF of the scalp and nose, with PIK3CA H1047R mutation. We discuss the differential diagnoses, clinical outcomes, and management of this rare entity.

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

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.

Triple-Negative Apocrine Carcinomas: Toward a Unified Group With Shared Molecular Features and Clinical Behavior

Triple-negative apocrine carcinomas (TNACs) are rare breast tumors with limited studies evaluating their molecular characteristics and clinical behavior. We performed a histologic, immunohistochemical, genetic, and clinicopathologic assessment of 42 invasive TNACs (1 with a focal spindle cell component) from 41 patients, 2 pure apocrine ductal carcinomas in situ (A-DCIS), and 1 A-DCIS associated with spindle cell metaplastic carcinoma (SCMBC). All TNACs had characteristic apocrine morphology and expressed androgen receptor (42/42), gross cystic disease fluid protein 15 (24/24), and CK5/6 (16/16). GATA3 was positive in most cases (16/18, 89%), and SOX10 was negative (0/22). TRPS1 was weakly expressed in a minority of tumors (3/14, 21%). Most TNACs had low Ki67 proliferation (≤10% in 67%, 26/39), with a median index of 10%. Levels of tumor infiltrating lymphocytes were low (≤10% in 93%, 39/42, and 15% in 7%, 3/42). Eighteen percent of TNACs presented with axillary nodal metastasis (7/38). No patients treated with neoadjuvant chemotherapy achieved pathologic complete response (0%, 0/10). Nearly all patients with TNAC (97%, n = 32) were without evidence of disease at the time of study (mean follow-up of 62 months). Seventeen invasive TNACs and 10 A-DCIS (7 with paired invasive TNAC) were profiled by targeted capture-based next-generation DNA sequencing. Pathogenic mutations in phosphatidylinositol 3-kinase pathway genes PIK3CA (53%) and/or PIK3R1 (53%) were identified in all TNACs (100%), including 4 (24%) with comutated PTEN. Ras-MAPK pathway genes, including NF1 (24%), and TP53 were mutated in 6 tumors each (35%). All A-DCIS shared mutations, such as phosphatidylinositol 3-kinase aberrations and copy number alterations with paired invasive TNACs or SCMBC, and a subset of invasive carcinomas showed additional mutations in tumor suppressors (NF1, TP53, ARID2, and CDKN2A). Divergent genetic profiles between A-DCIS and invasive carcinoma were identified in 1 case. In summary, our findings support TNAC as a morphologically, immunohistochemically, and genetically homogeneous subgroup of triple-negative breast carcinomas and suggest overall favorable clinical behavior.

Mammary mucinous cystadenocarcinoma with long-term follow-up: molecular information and literature review

BackgroundMucinous cystadenocarcinoma (MCA) is a very rare form of breast cancer that was first described in 1998. Only 33 cases of primary MCA, including our present case, have been reported thus far. As a consequence, its molecular features, prognosis and treatment regimen are poorly known. Here, we describe a less common presentation of MCA, detail its molecular features, discuss the major differential diagnosis, and provide a brief review of the literature.Case presentationA 59-year-old woman presented with a breast lump in which mammography showed a well-defined nodule. Core needle biopsy (CNB) revealed several lesions lined by tall columnar cells with stratification and abundant mucinous secretion; excision was recommended for final diagnosis. The resected specimens showed cavities of different sizes without surrounding myoepithelial cells. The cavities were rich in mucus, and the nuclei were located at the base of the cells, containing intracellular mucus. Immunohistochemical analysis revealed that it was triple-negative breast cancer (TNBC). Next-generation sequencing (NGS) revealed pathogenic mutations in the PIK3CA, KRAS, MAP2K4, RB1, KDR, PKHD1, TERT, and TP53 genes. A diagnosis of MCA was rendered. The patient has been followed up for 108 months to date and showed no signs of recurrence or metastasis.ConclusionOur study presents the gene profile of an MCA case with no recurrence or metastatic tendency after 108 months of follow-up, and a review of the literature helps us better understand the clinical, pathologic, and molecular features of this tumor.

Low-grade oncocytic tumour (LOT) of the kidney is characterised by GATA3 positivity, FOXI1 negativity and mTOR pathway mutations.

Aims: We present a 5-case series of low-grade oncocytic tumour of the kidney to further discuss their clinicopathological characteristics. Methods and results: Five patients were included in this study. There were three females and two males aged 45-66years, with a median age of 65years. Four tumours were located in the right kidney, and one was located in the left kidney. Most of the tumour sections were yellow-brown in colour. Tumour sizes ranged from 2.5 to 4.5cm, with a median size of 3cm. Microscopically, the tumours were well-circumscribed but lacked a fibrous capsule; the tumours consisted of monomorphous oncocytic cells arranged mainly in solid and nested architectural patterns. The tumour cells had uniformly round to oval nuclei and often had perinuclear halos but lacked significant irregularities. Immunohistochemically, the tumour cells showed a diffuse and strong positivity for CK7 and were negative for CD117. The tumour cells were also positive for GATA3, E-cadherin, Pax-8, Succinate dehydrogenase B (SDHB) and Fumarate hydratase (FH), and negative for vimentin, Carbonic anhydrase 9 (CA9), CD10, P504s, CK20, TFE3, TFEB, HMB45, ALK and Forkhead box protein I1 (FOXI1). Next-generation sequencing identified genetic variations in these tumours, including MTOR gene mutations (4/5) and PIK3CA gene mutation (1/5). All patients were alive without disease progression at a median follow-up of 32months (range 10-57months). Conclusion: LOT is an emerging renal entity of indolent behaviour that has morphologic overlap with some renal tumours with eosinophilic cytoplasm, primarily with oncocytoma and eosinophilic variant of chromophobe renal cell carcinoma. Familiarity with the distinctive morphological features, immunophenotype and molecular genetics of LOT helps avoid misdiagnosis.

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.

Abstract B027: PIK3CA hotspot mutations as biomarkers for prognosis and treatment prediction in low-risk postmenopausal breast cancer patients

Abstract The PIK3CA gene, encoding the p110α catalytic subunit of PI 3-kinase (PI3K), is mutated in more than 30% of breast cancers. Most mutations concentrate to the hotspots E542K and E545K and H1047R and are associated with hyperactivation of the phosphatidylinositol 3′-kinase/Akt pathway in vitro. The estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) (ER+/HER2-) breast cancers stand for more than 40% of the PIK3CA mutations where these constitute a new therapeutic target for endocrine-treatment resistant advanced breast cancers. Although PIK3CA is an oncogene, its mutations are associated with good prognosis. Here, we explored the prognostic and predictive role of PIK3CA hotspot mutations for low-risk postmenopausal breast cancer patients randomized to receive tamoxifen vs. no systemic treatment, followed for over 25 years and with extensive clinical records. Mutation analysis was performed using formalin-fixed paraffin-embedded tumors with digital droplet PCR (ddPCR). PIK3CA mutations were present in 35,6% of patients, predominantly within the ER+/HER2- subtype (49,8%) compared with the HER2+ and TNBC subtypes. The most frequent mutation found in all patients was H1047R (18%) followed by E545K (14%) and E542K (6%). Significant associations were found between all hotspot mutations and low grade, positive progesterone receptor (PR) expression, HER2 negative status, low Ki-67 (proliferation marker), and high expression score of a PIK3CA-mutation-associated gene module. Moreover, PIK3CA mutations were often found in patients with ultralow risk to develop distant recurrences according to the 70-gene signature. All PIK3CA mutations were coupled with longer distant recurrence-free interval (DRFI) in all patients in univariate and multivariable analysis after adjusting for tumor size, receptor status (ER, PR, HER2), tumor grade, Ki-67 and tamoxifen: HR multivariable (95% CI)=0.53 (0.28-0.98). In agreement with our previous results, PIK3CA mutations indicated good prognosis for patients with highly proliferative tumors (Ki-67&amp;gt;15%): H.R multivariable (95% CI)=0.15 (0.03-0.69) and high risk by the 70-gene signature: HR multivariable (95% CI)=0.14 (0.03-0.61) but not for low proliferative tumors (Ki-67&amp;lt;15%). In fact, PIK3CA mutations indicated adverse prognosis within those patients with ultralow risk where the registered survival was 100% in presence of the PIK3CA wild type genotype. PIK3CA mutations did not have predictive value for tamoxifen. In conclusion, PIK3CA mutations predominate within the ER+/HER2- subtype, are coupled with good clinical markers and longer DRFI in all patients and especially among aggressive tumors but not in ultralow risk patients. Further investigation will be needed to decipher the role of PIK3CA in patients with ultralow risk or indolent tumors who may present long-term relapses and specially benefit from PI3K inhibition. Citation Format: Carolin Jönsson, Zeinab Alkashaf, Josefine Sandström, Annelie Johansson, Tommy Fornander, Linda S. Lindström, Gizeh Perez Tenorio. PIK3CA hotspot mutations as biomarkers for prognosis and treatment prediction in low-risk postmenopausal breast cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr B027.

Single-Cell Analysis of Circulating Tumor Cells from Patients with Colorectal Cancer Captured with a Dielectrophoresis-Based Micropore System.

This study aimed to analyze circulating tumor cells (CTCs) from patients with colorectal cancer (CRC). We designed a dielectrophoresis-based micropore system and tested its cell capture with HT29 colon cancer cells. Then, blood samples were drawn from 24 patients with stages II-IV CRC. Mononuclear cells were isolated and loaded into the micropore system. Single cells were positioned into small pores with dielectrophoresis. After labeling the cells with the appropriate antibodies, tumor-like cells were collected with an automated micromanipulator. We collected 43 CTCs from 15 out of 24 patient samples. The presence of CTC was significantly associated with ling metastasis. We performed whole genome amplification, followed by PCR and Sanger sequencing, to examine the point mutations in the KRAS, BRAF, and PIK3CA genes. This mutation analysis was successfully performed in 35 cells. Among the 14 cytokeratin (CK)-positive cells, we found PIK3CA mutations in three cells (21%) from two patients. Among the 21 CK-negative cells, we found a KRAS mutation in one cell (5%) from one patient and a PIK3CA mutation in one cell (5%) from one patient. It is noteworthy that these mutations were not detected in the corresponding primary tumors. In conclusion, dielectrophoresis-based capture in a micropore system was useful for detecting both CK-positive and CK-negative CTCs. This simple method could be applied to various tumor types.

PIK3CA is recurrently mutated in canine mammary tumors, similarly to in human mammary neoplasia

Biological features of neoplastic disease affecting mammary gland tissue are shared between canines and humans. Research performed in either species has translational value and early phase clinical trials performed in canines with spontaneous disease could be informative for human trials. The purpose of this study was to investigate the somatic genetic aberrations occurring in canine mammary neoplasia by exome capture and next generation sequencing. Based on 55 tumor-normal pairs we identified the PIK3CA gene as the most commonly mutated gene in canine mammary tumors, with 25% of samples carrying mutations in this gene. A recurrent missense mutation was identified, p.H1047R, which is homologous to the human PIK3CA hotspot mutation found in different types of breast neoplasia. Mutations homologous to other known human mutation hotspots such as the PIK3CA p.E545K and the KRAS p.G12V/D were also identified. We identified copy number aberrations affecting important tumor suppressor and oncogenic pathways including deletions affecting the PTEN tumor suppressor gene. We suggest that activation of the KRAS or PIK3CA oncogenes or loss of the PTEN suppressor gene may be important for mammary tumor development in dogs. This data endorses the conservation of cancer across species and the validity of studying cancer in non-human species.

Pharmacotherapy regimens for patients with hormone-receptor positive (HR+), human epidermal growth factor 2 negative (HER2–) metastatic breast cancer in routine clinical practice (results of non-interventional retrospective study)

Background . Analysis of the sequence of HR+ HER2– mBC therapy in routine practice is important for the assessment and optimization of approaches to the treatment of breast cancer. Automatic analysis of electronic medical records (EMR) using artificial intelligence technology makes it possible to collect and analyze a large array of patient data. Purpose . Study of drug therapy regimens and schemes in female patients with HR+ HER2– mBC in routine clinical practice in the Russian Federation. Methods . The retrospective data of patients who received mBC therapy in routine clinical practice in eight healthcare facilities of the Russian Federation was extracted using machine learning methods. The data were obtained from the EMRs of patients who received drug therapy from February 1, 2018 to May 31, 2021. Main study objectives: to determine the proportion of patients who received various types of pharmacotherapies (chemotherapy [CT], hormone therapy [HT], targeted therapy [TT]); the number of pharmacotherapy lines, the proportion of patients with resistance and sensitivity to HT. Additional objectives included the determination of demographic characteristics, TNM stages. Ki‑67 proliferative activity index, mutations in the PIK3CA gene, and the presence of a visceral crisis. Results. The analysis included data from 932 patients diagnosed with HR+ HER2– mBC. The average patient age was 58.9 ± 11.3 years. Primary metastatic breast cancer was diagnosed in 172 (18.4%) patients. The bones were the most common localization of the first metastases (32.6%). Visceral crisis was reported in 29 (3.1%) patients. 21% of patients were sensitive to HT, 11.1% were primarily resistant, and 31.9% of patients had secondary resistance. The 353 (37.9%) patients received one therapy line, 269 (28.9%) patients received two lines, 139 (14.9%) patients received three lines, and 81 (8.7%) patients received four therapy lines. The first-line treatment included mono-regimens of HT (antiestrogens – 22.8%, aromatase inhibitors [AI] – 20.9%), chemotherapy mono-regimens (taxanes – 11.7%, pyrimidine analogs – 4.4%). Among the combined regimens, the most common were combined chemotherapy with cyclophosphamide + anthracyclines (14.3%) and HT + TT: aromatase inhibitors + targeted therapy (5.2%). In subsequent lines, the HT monotherapy remained the most frequently prescribed, and the specific gravity of CT increased with each line. The CDK4/6 inhibitors with Fulvestrant (8.6%) and aromatase inhibitors (5.1%) were most often prescribed as part of the combined regimens. Conclusions. The study was the first experience of using AI technology for the retrospective analysis of data of patients with breast cancer in routine practice. The study shows that in routine clinical practice in Russia there are still high frequency of hormone therapy in mono-regime and chemotherapy in the early lines. iCDK4/6 were used in 9.0%, 14.8%, and 10.8% in the first three therapy lines, respectively. The methodology limitations may be associated with the retrospective study design and possible errors when extracting data from the EMR using artificial intelligence.

Early Triple-Negative Breast Cancers in a Singapore Cohort Exhibit High PIK3CA Mutation Rates Associated With Low PD-L1 Expression

Mutations in the PI3K pathway, particularly PIK3CA, were reported to be intimately associated with triple-negative breast cancer (TNBC) progression and the development of treatment resistance. We profiled PIK3CA and other genes on 166 early-stage TNBC tumors from Singapore for comparison to publicly available TNBC cohorts. These tumors were profiled transcriptionally using a NanoString panel of immune genes and multiplex immunohistochemistry, then manually scored for PD-L1-positivity using 2 clinically relevant clones, SP142 and 22C3. We discovered a higher rate of PIK3CA mutations in our TNBC cohort than in non-Asian cohorts, along with TP53, BRCA1, PTPN11, and MAP3K1 alterations. PIK3CA mutations did not affect overall or recurrence-free survival, and when compared with PIK3CAWT tumors, there were no differences in immune infiltration. Using 2 clinically approved antibodies, PIK3CAmut tumors were associated with PD-L1 negativity. Analysis of comutation frequencies further revealed that PIK3CA mutations tended to be accompanied by MAP kinase pathway mutation. The mechanism and impact of PIK3CA alterations on the TNBC tumor immune microenvironment and PD-L1 positivity warrant further study.

Occult lipomatosis of the nerve as part of macrodystrophia lipomatosa: illustrative case.

Macrodystrophia lipomatosa (MDL) is characterized by progressive overgrowth affecting soft tissues and bony structures and is part of lipomatous overgrowth syndromes. MDL has been associated with lipomatosis of the nerve (LN), an adipose lesion of nerve that has a pathognomonic magnetic resonance imaging (MRI) appearance as well as a mutation in the PIK3CA gene. The authors present a case of occult LN in the setting of MDL. A 2-year-old boy with progressive soft tissue overgrowth of his proximal right lower extremity was initially diagnosed with neurofibromatosis type 1 (NF1). At our institution, NF1 as well as other overgrowth syndromes including PTEN hamartoma tumor syndrome were excluded. He was diagnosed as having so-called MDL. Upon reinterpretation of the patient's MRI studies, short-segment LN involving the proximal sciatic nerve and part of lumbosacral plexus was identified. He underwent 2 debulking/liposuction procedures for soft tissue overgrowth. Genetic testing of tissue revealed a mutation in PIK3CA. Thorough clinical examination (for signs of overgrowth) as well as an MRI study of the entire neural pathway is a critical part of the diagnostic workup to evaluate for LN. The authors believe that an increasing association of LN, even when occult, will emerge that will explain many cases with marked nerve-territory overgrowth.