Epidermal growth factor receptor (EGFR) is frequently overexpressed in triple-negative breast cancer and is emerging as a therapeutic target. EGFR gene copy number alteration and mutation are highly variable and scientists have been challenged to define their prognostic significance in triple-negative breast cancer. We examined EGFR protein expression, EGFR gene copy number alteration and mutation of exon 18 to 21 in 151 cases of triple-negative breast cancer and correlated these findings with clinical outcomes. In addition, intratumoral agreement of EGFR protein overexpression and gene copy number alteration was evaluated. EGFR overexpression was found in 97 of 151 cases (64%) and high EGFR gene copy number was detected in 50 cases (33%), including 3 gene amplification (2%) and 47 high polysomy (31%). Five EGFR mutations were detected in 4 of 151 cases (3%) and included G719A in exon 18 (n ¼ 1), V786M in exon 20 (n ¼ 1), and L858R in exon 21 (n ¼ 3). One case had two mutations (G719A and L858R). High EGFR copy number, but not EGFR mutation, correlated with EGFR protein overexpression. Intratumoral heterogeneity of EGFR protein overexpression and EGFR copy number alteration was not significant. In survival analyses, high EGFR copy number was found to be an independent prognostic factor for poor disease-free survival in patients with triple-negative breast cancer. Our findings showed that EGFR mutation was a rare event, but high EGFR copy number was relatively frequent and correlated with EGFR overexpression in triple-negative breast cancer. Moreover, high EGFR copy number was associated with poor clinical outcome in triple-negative breast cancer, suggesting that evaluation of EGFR copy number may be useful for predicting outcomes in patients with triple-negative breast cancer and for selecting patients for anti-EGFR-targeted therapy.

We found a significant correlation between the size of the solid component on thin-section CT and the invasive component on pathology.

Background & Aims-Intestinal metaplasia (IM) and spasmolytic polypeptide-expressing metaplasia (SPEM) are precursors to gastric carcinogenesis. We sought to identify molecular biomarkers of gastric metaplasias and gastric cancer by gene expression profiling of metaplastic lesions from patients.

Compound EGFR mutations, defined as double or multiple mutations in the EGFR tyrosine kinase domain, are frequently detected with advances in sequencing technology but its clinical significance is unclear. This study analyzed 61 cases of EGFR mutation positive lung adenocarcinoma using next-generation sequencing (NGS) based repeated deep sequencing panel of 16 genes that contain actionable mutations and investigated clinical implication of compound EGFR mutations. Compound EGFR mutation was detected in 15 (24.6%) of 61 cases of EGFR mutation-positive lung adenocarcinoma. The majority (12/15) of compound mutations are combination of the atypical mutation and typical mutations such as exon19 deletion, L858R or G719X substitutions, or exon 20 insertion whereas 3 were combinations of rare atypical mutations. The patients with compound mutation showed shorter overall survival than those with simple mutations (83.7 vs. 72.8 mo; P = 0.020, Breslow test). Among the 115 missense mutations discovered in the tested genes, a few number of actionable mutations were detected irrelevant to the subtype of EGFR mutations, including ALK rearrangement, BCL2L11 intron 2 deletion, KRAS c.35G>A, PIK3CA c.1633G>A which are possible target of crizotinib, BH3 mimetics, MEK inhibitors, and PI3K-tyrosine kinase inhibitors, respectively. 31 missense mutations were detected in the cases with simple mutations whereas 84 in those with compound mutation, showing that the cases with compound missense mutation have higher burden of missense mutations (P = 0.001, independent sample t-test). Compound EGFR mutations are detected at a high frequency using NGS-based repeated deep sequencing. Because patients with compound EGFR mutations showed poor clinical outcomes, they should be closely monitored during follow-up.

No abstract