ABSTRACT
The novel coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Severely symptomatic COVID-19 is associated with lung inflammation, pneumonia, and respiratory failure, thereby raising concerns of elevated risk of COVID-19-associated mortality among lung cancer patients. Angiotensin-converting enzyme 2 (ACE2) is the major receptor for SARS-CoV-2 entry into lung cells. The single-cell expression landscape of ACE2 and other SARS-CoV-2-related genes in pulmonary tissues of lung cancer patients remains unknown. We sought to delineate single-cell expression profiles of ACE2 and other SARS-CoV-2-related genes in pulmonary tissues of lung adenocarcinoma (LUAD) patients. We examined the expression levels and cellular distribution of ACE2 and SARS-CoV-2-priming proteases TMPRSS2 and TMPRSS4 in 5 LUADs and 14 matched normal tissues by single-cell RNA-sequencing (scRNA-seq) analysis. scRNA-seq of 186,916 cells revealed epithelial-specific expression of ACE2, TMPRSS2, and TMPRSS4. Analysis of 70,030 LUAD- and normal-derived epithelial cells showed that ACE2 levels were highest in normal alveolar type 2 (AT2) cells and that TMPRSS2 was expressed in 65% of normal AT2 cells. Conversely, the expression of TMPRSS4 was highest and most frequently detected (75%) in lung cells with malignant features. ACE2-positive cells co-expressed genes implicated in lung pathobiology, including COPD-associated HHIP, and the scavengers CD36 and DMBT1. Notably, the viral scavenger DMBT1 was significantly positively correlated with ACE2 expression in AT2 cells. We describe normal and tumor lung epithelial populations that express SARS-CoV-2 receptor and proteases, as well as major host defense genes, thus comprising potential treatment targets for COVID-19 particularly among lung cancer patients.
ABSTRACT
BACKGROUND: For patients with bilateral pulmonary metastases, staged resections have historically been the preferred surgical intervention. During the spring of 2020, the COVID-19 pandemic made patient travel to the hospital challenging and necessitated reduction in operative volume so that resources could be conserved. We report our experience with synchronous bilateral metastasectomies for the treatment of disease in both lungs. METHODS: Patients with bilateral pulmonary metastases who underwent simultaneous bilateral resections were compared with a cohort of patients who underwent staged resections. We used nearest-neighbor propensity score (1:1) matching to adjust for confounders. Perioperative outcomes were compared between groups using paired statistical analysis techniques. RESULTS: Between 1998 and 2020, 36 patients underwent bilateral simultaneous metastasectomies. We matched 31 pairs of patients. The length of stay was significantly shorter in patients undergoing simultaneous resection (median 3 vs. 8 days, p < .001) and operative time was shorter (156 vs. 235.5 min, p < .001) when compared to the sum of both procedures in the staged group. The groups did not significantly differ with regard to postoperative complications. CONCLUSION: In a carefully selected patient population, simultaneous bilateral metastasectomy is a safe option. A single procedure confers benefits for both the patient as well as the hospital resource system.