Real-World Biomarker Testing Patterns in Patients With Metastatic Non-Squamous Non-Small Cell Lung Cancer (NSCLC) in a US Community-Based Oncology Practice Setting.

INTRODUCTION/BACKGROUND: This study was designed to describe real-world changes in biomarker testing among patients with non-squamous, metastatic non-small cell lung cancer (mNSCLC) in a community oncology setting from 2015 to 2020. PATIENTS AND METHODS: This retrospective study randomly selected 500 adult patients diagnosed with nonsquamous mNSCLC to undergo chart review and data extraction. Data were extracted and validated by 2 independent abstractors. Biomarker testing rates were described before and after national guideline updates and FDA approval of targeted agents. RESULTS: At least 1 biomarker test was received by 89.4% of patients with mNSCLC. Of all patients, 46.6%, 34.6%, and 8.2% received both single-gene and next generation sequencing (NGS)-based testing, single-gene testing only, and NGS-based testing only, respectively. However, there were changes in testing rates at the time of drug approvals for targeted agents. Biomarker testing increased for ALK (45.0% before to 78.3% after ALK-targeted drug approval), BRAF (from 20.0% to 67.8%), EGFR (from 20.0% to 78.2%), NTRK (from 34.6% to 55.7%), and ROS1 (increased from 29.6% before approval to 74.2% after). Biomarker testing increased after changes were made to national guidelines for BRAF (from 18.8% before to 68.1% after inclusion in guidelines), NTRK (from 37.2% to 56.5%), and ROS1 (increased from 40.8% to 74.5% after guideline updates). Targeted therapy was received by 62.4% of patients with a positive biomarker. CONCLUSION: Increases in biomarker testing rates were observed relative to targeted agent approvals and national guideline updates. However, many patients with non-squamous mNSCLC did not receive full genotyping in accordance with national guidelines and represent an opportunity to identify reasons and solutions for barriers to care.

IL2RG, identified as overexpressed by RNA-seq profiling of pancreatic intraepithelial neoplasia, mediates pancreatic cancer growth.

Pancreatic ductal adenocarcinoma evolves from precursor lesions, the most common of which is pancreatic intraepithelial neoplasia (PanIN). We performed RNA-sequencing analysis of laser capture microdissected PanINs and normal pancreatic duct cells to identify differentially expressed genes between PanINs and normal pancreatic duct, and between low-grade and high-grade PanINs. One of the most highly overexpressed transcripts identified in PanIN is interleukin-2 receptor subunit gamma (IL2RG) encoding the common gamma chain, IL2Rγ. CRISPR-mediated knockout of IL2RG in orthotopically implanted pancreatic cancer cells resulted in attenuated tumor growth in mice and reduced JAK3 expression in orthotopic tumors. These results indicate that IL2Rγ/JAK3 signaling contributes to pancreatic cancer cell growth in vivo.

Susceptibility of ATM-deficient pancreatic cancer cells to radiation.

Ataxia telangiectasia mutated (ATM) is inactivated in a significant minority of pancreatic ductal adenocarcinomas and may be predictor of treatment response. We determined if ATM deficiency renders pancreatic cancer cells more sensitive to fractionated radiation or commonly used chemotherapeutics. ATM expression was knocked down in three pancreatic cancer cell lines using ATM-targeting shRNA. Isogenic cell lines were tested for sensitivity to several chemotherapeutic agents and radiation. DNA repair kinetics were analyzed in irradiated cells using the comet assay. We find that while rendering pancreatic cancer cells ATM-deficient did not significantly change their sensitivity to several chemotherapeutics, it did render them exquisitely sensitized to radiation. Pancreatic cancer ATM status may help predict response to radiotherapy.

Overexpression of ankyrin1 promotes pancreatic cancer cell growth.

The methylation status of a promoter influences gene expression and aberrant methylation during tumor development has important functional consequences for pancreatic and other cancers. Using methylated CpG island amplification and promoter microarrays, we identified ANK1 as hypomethylated in pancreatic cancers. Expression analysis determined ANK1 as commonly overexpressed in pancreatic cancers relative to normal pancreas. ANK1 was co-expressed with miR-486 in pancreatic cancer cells. Stable knockdown of ANK1 in the pancreatic cancer cell line AsPC1 led to changes in cell morphology, and decreases in colony formation. Stable knockdown of ANK1 also marked reduced the growth of tumors in athymic nude mice. Among patients undergoing pancreaticoduodenectomy, those with pancreatic cancers expressing ANK1 had a poorer prognosis than those without ANK1 expression. These findings indicate a role for ANK1 overexpression in mediating pancreatic cancer tumorigenicity.

Pancreatic cancer: Classifying pancreatic cancer using gene expression profiling.

Despite some advances in our understanding of the molecular characteristics of pancreatic cancer, much more progress is needed. In a new study, RNA profiling of pancreatic cancers was used to identify gene signatures of tumour cells and stromal cells to help predict patient outcomes.

Epigenetic silencing of EYA2 in pancreatic adenocarcinomas promotes tumor growth.

To identify potentially important genes dysregulated in pancreatic cancer, we analyzed genome-wide transcriptional analysis of pancreatic cancers and normal pancreatic duct samples and identified the transcriptional coactivator, EYA2 (Drosophila Eyes Absent Homologue-2) as silenced in the majority of pancreatic cancers. We investigated the role of epigenetic mechanisms of EYA2 gene silencing in pancreatic cancers, performed in vitro and in vivo proliferation and migration assays to assess the effect of EYA2 silencing on tumor cell growth and metastasis formation, and expression analysis to identify genes transcriptionally regulated by EYA2. We found loss of tumoral Eya2 expression in 63% of pancreatic cancers (120/189 cases). Silencing of EYA2 expression in pancreatic cancer cell lines correlated with promoter methylation and histone deacetylation and was reversible with DNA methyltransferase and HDAC inhibitors. EYA2 knockdown in pancreatic cancer cell lines increased cell proliferation. Compared to parental pancreatic cancer cells, pancreatic cancers stably-expressing EYA2 grew more slowly and had fewer metastases in orthotopic models. The transcriptional changes after stable expression of EYA2 in pancreatic cancer cells included induction of genes in the TGFbeta pathway. Epigenetic silencing of EYA2 is a common event in pancreatic cancers and stable expression EYA2 limits the growth and metastases of pancreatic adenocarcinoma.