UNASSIGNED: The 2021 World Health Organization Classification of Central Nervous System Tumors updates glioma subtyping and grading system, and incorporates EGFR amplification (Amp) as one of diagnostic markers for glioblastoma (GBM).
UNASSIGNED: This study aimed to describe the frequency, clinical value and molecular correlation of EGFR Amp in diffuse gliomas based on the latest classification.
UNASSIGNED: We reviewed glioma patients between 2011 and 2022 at our hospital, and included 187 adult glioma patients with available tumor tissue for detection of EGFR Amp and other 59 molecular markers of interest. Clinical, radiological and pathological data was analyzed based on the status of EGFR Amp in different glioma subtypes.
UNASSIGNED: 163 gliomas were classified as adult-type diffuse gliomas, and the number of astrocytoma, oligodendroglioma and GBM was 41, 46, and 76. EGFR Amp was more common in IDH-wildtype diffuse gliomas (66.0%) and GBM (85.5%) than IDH-mutant diffuse gliomas (32.2%) and its subtypes (astrocytoma, 29.3%; oligodendroglioma, 34.8%). EGFR Amp did not stratify overall survival (OS) in IDH-mutant diffuse gliomas and astrocytoma, while was significantly associated with poorer OS in IDH-wildtype diffuse gliomas, histologic grade 2 and 3 IDH-wildtype diffuse astrocytic gliomas and GBM.
UNASSIGNED: Our study validated EGFR Amp as a diagnostic marker for GBM and still a useful predictor for shortened OS in this group.

BACKGROUND: Epidermal growth factor receptor (EGFR) amplification refers to the copy number increase of EGFR gene, and is often identified as a \"bypass\" way of Epidermal growth factor receptor Tyrosine kinase inhibitors (EGFR-TKI) resistance. We aimed to explore the effect of EGFR amplification on EGFR mutation treatment-naive advanced non-squamous non-small cell lung cancer (NSCLC) patients.
METHODS: We conducted a prospective observational study in single center, enrolling advanced non-squamous NSCLC patients receiving Tyrosine kinase inhibitors (TKIs) between March 3, 2019, and February 1, 2022. Next-generation sequencing (NGS) was used to detect genetic alterations in tumor tissue samples. Progression-free survival (PFS) curves were performed using the Kaplan-Meier method. Univariate and multivariate analyses were used to evaluate factors affecting the efficacy of TKIs.
RESULTS: A total of 117 treatment-naive advanced NSCLC patients were identified in this study. EGFR amplification was found in 22 of 117 (18.8%) patients with EGFR mutations. Of 22 patients with EGFR amplification, 10 patients harbored EGFR 19 del, 11 patients with 21-L858R. The median follow-up time was 22.47 months. The median PFS of the patients with or without EGFR amplification was 8.25 months and 10.67 months, respectively (log-rank test, P = 0.63). In multivariate analysis, EGFR amplification was not an independent prognosis factor for the patients receiving first-line TKIs [HR = 1.38, 95%CI (0.73-2.58), P = 0.321]. Subgroup analysis revealed that EGFR amplification is a risk factor for progression in the brain metastasis population. [HR = 2.28, 95%CI (1.01, 5.14), P = 0.047].
CONCLUSIONS: EGFR amplification is not an independent prognosis factor for PFS in advanced non-squamous NSCLC patients receiving first-line TKIs. However, it is an independent risk factor for PFS in the brain metastasis population.

BACKGROUND: Larotinib is a new first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. This open-label, phase 1b study is aimed to evaluate the efficacy, safety of larotinib in patients with advanced esophageal squamous cell carcinoma (ESCC) with EGFR overexpression or amplification pretreated with one or more system regimens, and to recommend an appropriate dose for its further study.
METHODS: Patients received larotinib orally at 3 doses (250, 300, 350 mg), once daily. Clinical response was evaluated every 8 weeks according to RECIST v1.1 criteria by both investigators and independent radiology review (IRC).
RESULTS: 81 patients were enrolled. The investigator-assessed overall response rate (ORR) was 13.7% (10/73), all responses were observed in the 350 mg group of which ORR up to 20.0% (10/50), with 10 of them having EGFR overexpression and 4 having EGFR amplification. Per IRC assessment, ORR for all patients and 350 mg group were 13.9% (10/72) and 16.3% (8/50). In the 350 mg group, median overall survival (OS) and progression-free survival (PFS) were 8.0 (95% CI 4.9-10.2) months and 3.4 (95% CI 2.4-3.7) months, respectively. The most common treatment-related adverse events (TRAEs) were diarrhea, rash, and palmar-plantar erythrodysesthesia syndrome, elevated AST/ALT, vomiting, similarly with other EGFR TKIs.
CONCLUSIONS: Larotinib demonstrated promising antitumor activity and manageable safety profiles in patients with pre-treated advanced ESCC with EGFR overexpression or amplification, especially at the dose of 350 mg, which showed better efficacy and acceptable safety. A phase 3 study is underway on 350 mg larotinib in ESCC patients with EGFR overexpression.
BACKGROUND: This trial was retrospectively registered on 25/03/2019, NCT03888092. https://clinicaltrials.gov/ct2/show/NCT03888092 .

BACKGROUND: Resistance to third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) presents a major clinical challenge in advanced non-small cell lung cancer (NSCLC). Here, we report resistance mechanisms to abivertinib, a novel third-generation EGFR TKI, from a phase I dose-escalation/expansion study (NCT02330367).
METHODS: Patients with EGFR T790M-positive advanced NSCLC and progression on prior EGFR TKIs received abivertinib in dose escalation (50-350 mg twice daily [BID]) or expansion (300 mg BID) cohorts. Patients enrolled at Guangdong Lung Cancer Institute who underwent next-generation sequencing (NGS)-based genomic profiling upon abivertinib progression (prior to October 30, 2018) were enrolled in this exploratory analysis.
RESULTS: Thirty of 73 patients enrolled were eligible for resistance analysis. Upon abivertinib progression, 27 patients provided plasma samples (six patients also provided paired samples from the progression sites) and three patients only provided tissue samples from the progression sites for NGS. A heterogeneous landscape of resistance to abivertinib was observed: 15% (4/27) experienced EGFR T790M loss and 13% (4/30) developing EGFR tertiary mutations including C797S. EGFR amplification was observed in 11 patients (37%), and considered a putative resistance mechanism in seven (23%) patients. Other EGFR-independent resistance mechanisms involved CDKN2A, MET, PIK3CA, HER2, TP53, Rb1 and small-cell lung cancer transformation.
CONCLUSIONS: Our findings reveal a heterogenous pattern of resistance mechanisms to abivertinib which is distinct from that previously reported with osimertinib. EGFR amplification was the most common resistance mechanism in this cohort. FUND: The National Key R&D Program of China (Grant No. 2016YFC1303800), Key Lab System Project of Guangdong Science and Technology Department - Guangdong Provincial Key Lab of Translational Medicine in Lung Cancer (Grant No. 2012A061400006/2017B030314120).

Epithelioid glioblastoma (e-gbm) is a recently described variant of glioblastoma (GBM) which is associated with short survival and now added as a provisional entity to WHO 2016 classification of CNStumors. About half of these tumors show characteristic BRAF-V600E mutation. However, unlike conventional GBMs, e-gbm lack specific diagnostic and prognostic markers. Hence, we aimed to molecularly characterize these tumors. An extensive review of literature was performed.In a multi-institutional effort, all the cases of glioblastoma of year 2017 were reviewed. Cases with predominant epithelioid morphology were analysed. Seven cases of e-gbm (adults:4 and pediatric: 3) were identified. Duration of symptoms varied from 2 weeks to one month. Radiologically, all cases were supratentorial, contrast enhancing with solid and cystic appearance. Majority of the cases were immunopositive for GFAP (71%), EMA (71%), S100 (71%) and vimentin (85%). All the cases showed ATRX, INI-1 and H3K27me3 expression. BRAFV600Emutation was seen in 28% of cases. TERT mutation was seen in 40% cases, while one case showed EGFR amplification. H3F3A mutations and PTEN deletions were seen in none. Although e-gbms are rare, epithelioid morphology of a CNS tumor in a young adult or children with areas of necrosis needs thorough histomorphological and genetic workup.

Epidermal growth factor receptor (EGFR) has been reported to be overexpressed and amplified in a high percentage of patients with esophageal squamous cell carcinoma (ESCC). The activity of icotinib, an EGFR tyrosine kinase inhibitor, was assessed in previously treated ESCC with EGFR overexpression or amplification.
For this phase 2, single-arm, multicenter trial undertaken at six hospitals in China, we included Chinese patients with previously treated, histologically confirmed advanced ESCC and EGFR overexpression (immunohistochemical staining sore of 3+) or amplification (positive fluorescence in situ hybridization result). These patients received oral icotinib (250 mg, three times daily).The primary end point was the proportion of patients with objective responses as assessed by an independent radiology review committee.
Between December 5, 2013, and May 28, 2015, a total of 281 patients were screened. Fifty-four eligible patients were enrolled. Nine responses were observed, including one complete response and eight partial responses, and 16 patients had stable disease, resulting in a 16.7% objective response rate (95% confidence interval [CI]: 6.7-26.6) and 46.3% disease control rate (95% CI: 33.0-59.6). The median progression-free survival and overall survival times were 52 (95% CI: 40-95) days and 153 (95% CI: 139-218) days, respectively. A total of 43 patients experienced at least one adverse event, but most were only grade 1 to 2 in severity. The most frequent was rash (48.1%), followed by diarrhea (22.2%).
Icotinib showed favorable activity in patients with advanced, previously treated ESCC with EGFR overexpression or amplification. These findings suggest further research into EGFR overexpression or amplification for selecting responsive patients.

The targeted treatment of advanced non-small-cell lung cancer (NSCLC) depends on confirmation of activating somatic EGFR mutation. The aim of the study was to evaluate the incidence of EGFR mutations in NSCLC detected in cytological and histological material and present literature review on European EGFR mutation incidence. 273 patients with confirmed NSCLC were entered into the study: 189 histological, paraffin-embedded materials, 12 fresh and 72 fixed cytological specimens. DNA was extracted from both types of material and the EGFR mutation in exons 18-21 was analyzed by direct sequencing. In addition the EGFR gene copy number in cases with sufficient histological material (110 patients) was evaluated by fluorescent in situ hybridization (FISH) technique. The percentage of EGFR somatic mutations was 10.62%. FISH positive results (amplification or high polysomy of EGFR gene) were identified in 33 patients (30.0%). The strongest clinicopathological correlation with the EGFR mutation was found for histological type (adenocarcinoma; p < 0.01), gender (females; p < 0.01) and FISH positive result (p < 0.05). This is the first, single institution study that estimates the EGFR mutation incidence in the Polish population. Cytological material recovered from fixed preparations and stained with hematoxylin and eosin showed DNA quality comparable to fresh tumor cells and histological samples.

Sinonasal intestinal-type adenocarcinomas (ITACs) are uncommon tumors of poor prognosis defined by their similarities to colorectal adenocarcinomas. The involvement of the epidermal growth factor receptor (EGFR) pathway in colorectal adenocarcinoma oncogenesis is well established, and the same is expected to apply to ITACs. In a series of 39 ITACs, we investigated EGFR amplification and chromosome 7 polysomy by fluorescence in situ hybridization; EGFR, KRAS, and BRAF mutational status by polymerase chain reaction sequencing; EGFR variant messenger RNA expression by quantitative reverse transcriptase polymerase chain reaction; and EGFR protein expression by immunohistochemistry with antibodies targeting the extracellular domain, the intracellular domain, and the phosphorylated isoform. The findings were analyzed with respect to clinical data, histologic typing, and patient outcome. EGFR amplification was observed in 3 cases with a focal distribution. EGFR proteins were overexpressed in all these foci with both extracellular domain and intracellular domain antibodies, suggesting involvement of the whole receptor. Chromosome 7 polysomy was observed in 15 cases and was not associated with EGFR protein expression. EGFR, KRAS, or BRAF mutations were observed in 5 different cases. The EGFRvIII mutant was not detected. In all cases, EGFR variants were expressed. There was no association between these molecular features and patient survival. In conclusion, (1) our study revealed various EGFR expression patterns in ITACs, indicating tumor heterogeneity; (2) EGFR amplification should be distinguished from chromosome 7 polysomy; (3) fluorescence in situ hybridization analysis could be guided by immunohistochemistry; and (4) ITACs share common alterations of the EGFR pathway with colorectal adenocarcinomas, except for a lower frequency of KRAS and BRAF mutations.