Lung cancer is the leading cause of cancer-related death, with non-small cell lung cancer (NSCLC) being the predominant form of the disease. Most lung cancer is caused by the accumulation of genomic alterations due to tobacco exposure. To uncover its mutational landscape, we performed whole-exome sequencing in 31 NSCLCs and their matched normal tissue samples. We identified both common and unique mutation spectra and pathway activation in lung adenocarcinomas and squamous cell carcinomas, two major histologies in NSCLC. In addition to identifying previously known lung cancer genes (TP53, KRAS, EGFR, CDKN2A and RB1), the analysis revealed many genes not previously implicated in this malignancy. Notably, a novel gene CSMD3 was identified as the second most frequently mutated gene (next to TP53) in lung cancer. We further demonstrated that loss of CSMD3 results in increased proliferation of airway epithelial cells. The study provides unprecedented insights into mutational processes, cellular pathways and gene networks associated with lung cancer. Of potential immediate clinical relevance, several highly mutated genes identified in our study are promising druggable targets in cancer therapy including ALK, CTNNA3, DCC, MLL3, PCDHIIX, PIK3C2B, PIK3CG and ROCK2.
Calcification score based on the location and degree of calcifications can predict the increased likelihood of video-assisted thoracoscopic surgery conversion. This scoring system could be one element used to choose the approach for a lobectomy, especially during a surgeon's learning curve.
Background
Low-dose CT (LDCT) screening reduces lung cancer mortality by at least 20%. The COVID-19 pandemic required an unprecedented shutdown in our institutional LDCT program. The purpose of this study was to examine the impact of COVID-19 on lung cancer screening and subsequent cancer diagnosis.
Study Design
We analyzed our prospective institutional LDCT screening database, which began in 2012. In all, 2,153 patients have participated. Monthly mean number of LDCTs were compared between baseline (January 2017 to February 2020) and COVID-19 periods (March 2020 to July 2020).
Results
LDCT was suspended on March 13, 2020 and 818 screening visits were cancelled. Phased reopening began on May 5, 2020 and full opening on June 1, 2020. Total monthly mean ± SD LDCTs (146 ± 31 vs 39 ± 40; p < 0.01) and new patient monthly LDCTs (56 ± 14 vs 15 ± 17; p < 0.01) were significantly decreased during the COVID-19 period. New patient monthly LDCTs have remained low despite resuming full operations. Three- and 6-month interval follow-up LDCTs were prioritized and were significantly increased compared with baseline (11 ± 4 vs 30 ± 4; p < 0.01). The “no-show” rate was significantly increased from baseline (15% vs 40%; p < 0.04). Most concerning, the percentage of patients with lung nodules suspicious for malignancy (Lung-RADS 4) were significantly increased after screenings resumed (8% vs 29%; p < 0.01).
Conclusions
COVID-19 caused significant disruption in lung cancer screening, leading to a decrease in new patients screened and an increased proportion of nodules suspicious for malignancy once screening resumed. Using lung cancer and the LDCT screening program as a model, this early analysis showed the unrecognized consequences related to the pandemic for screening programs and cancer care.
Chronic obstructive pulmonary disease (COPD) is a lethal progressive lung disease culminating in permanent airway obstruction and alveolar enlargement. Previous studies suggest CTL involvement in COPD progression; however, their precise role remains unknown. Here, we investigated whether the CTL activation receptor NK cell group 2D (NKG2D) contributes to the development of COPD. Using primary murine lung epithelium isolated from mice chronically exposed to cigarette smoke and cultured epithelial cells exposed to cigarette smoke extract in vitro, we demonstrated induced expression of the NKG2D ligand retinoic acid early transcript 1 (RAET1) as well as NKG2D-mediated cytotoxicity. Furthermore, a genetic model of inducible RAET1 expression on mouse pulmonary epithelial cells yielded a severe emphysematous phenotype characterized by epithelial apoptosis and increased CTL activation, which was reversed by blocking NKG2D activation. We also assessed whether NKG2D ligand expression corresponded with pulmonary disease in human patients by staining airway and peripheral lung tissues from never smokers, smokers with normal lung function, and current and former smokers with COPD. NKG2D ligand expression was independent of NKG2D receptor expression in COPD patients, demonstrating that ligand expression is the limiting factor in CTL activation. These results demonstrate that aberrant, persistent NKG2D ligand expression in the pulmonary epithelium contributes to the development of COPD pathologies.
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