Surgical Strategies for Metastatic Lung Cancer

Development of metastasis-associated seven gene signature for predicting lung adenocarcinoma prognosis using single-cell RNA sequencing data

Metastasis is the primary cause of lung adenocarcinoma (LUAD)-related death. This study evaluated the metastasis-associated genes (MAGs) in single-cell RNA sequencing (scRNA-seq) data from LUAD tissues and developed a MAG signature to predict overall survival (OS) of LUAD patients. The LUAD scRNA-seq data was downloaded from the Gene Expression Omnibus (GEO) Database and MAGs were identified from LUAD scRNA-seq data. The LUAD transcriptomic and clinical data were obtained from The Cancer Genome Atlas (TCGA). Cox and LASSO regression analyses were performed to identify differentially expressed MAGs (DEMAGs) with prognostic value that were then used to construct a MAG signature and MAG-nomogram model. Finally, a functional enrichment analysis was performed via Gene Set Enrichment Analysis (GSEA). 414 MAGs and 22 prognostic DEMAGs were revealed in the study. Multivariate Cox proportional hazards regression analysis was utilized to construct a 7-MAG signature for predicting the OS of LUAD patients. Patients with high risk scores had a significantly worse OS than those with low risk scores in the training group (n = 236), and the 7-MAG signature was successfully confirmed in the testing group (n = 232) and the entire TCGA-LUAD cohort (n = 468). Furthermore, univariate and multivariate Cox regression suggested that the 7-MAG signature was an independent prognostic indicator. Additionally, based on the 7-MAG signature, a nomogram was established that could more intuitively help to predict the OS of LUAD patients. The GSEA revealed the underlying molecular mechanisms of the 7-MAG signature in LUAD metastasis. In conclusion, a 7-MAG signature was developed based on LUAD scRNA-seq data that could effectively predict LUAD patient prognosis and provide novel insights for therapeutic targets and the potential molecular mechanism of metastatic LUAD.

Blood-brain barrier permeability of gefitinib in patients with brain metastases from non-small-cell lung cancer before and during whole brain radiation therapy

INTRODUCTION

To explore the ability of gefitinib to penetrate blood brain barrier (BBB) during whole brain radiation therapy (WBRT).

PATIENTS AND METHODS

Enrolled in this study were eligible patients who were diagnosed with BM from NSCLC. Gefitinib was given at 250 mg/day for 30 days, then concurrently with WBRT (40 Gy/20 F/4 w), followed by maintenance. Serial CSF and blood samples were collected on 30 day after gefitinib administration, and at the time of 10, 20, 30 and 40 Gy following WBRT. CSF and plasma samples of 13 patients without BM who were treated with gefitinib were collected as control. CSF and plasma gefitinib levels were measured by LC-MS/MS.

RESULTS

Fifteen BM patients completed gefitinib plus WBRT. The CSF-to-plasma ratio of gefitinib in patients with BM was higher than that in patients without BM (1.34% vs. 0.36%, P < 0.001). The CSF-to-plasma ratio of gefitinib increased with the increased dose of WBRT and reached the peak (1.87 ± 0.72%) at 30 Gy, which was significantly higher than that 1.34 ± 0.49% at 0 Gy (P = 0.01). The median time to progression of brain lesions and the median overall survival were 7.07 and 15.4 months, respectively.

CONCLUSION

The BBB permeability of gefitinib increased in accordance with escalated dose of WBRT.

Gefitinib alone or with concomitant whole brain radiotherapy for patients with brain metastasis from non-small-cell lung cancer: a retrospective study

BACKGROUND

Gefitinib, a tyrosine kinase inhibitor (TKI) of epidermal growth factor receptor (EGFR), is used both as a single drug and concurrently with whole brain radiotherapy (WBRT) the standard treatment for brain metastases (BM), and is reported to be effective in a few small studies of patients with BM from non-small-cell lung cancer (NSCLC). However, no study has compared the two treatment modalities. This retrospective analysis was conducted to compare the efficacy of gefitinib alone with gefitinib plus concomitant WBRT in treatment of BM from NSCLC.

METHODS

We retrospectively reviewed 90 patients with BM from NSCLC who received gefitinib alone (250 mg/day, gefitinib group) or with concomitant WBRT (40 Gy/20 f/4 w, gefitinib-WBRT group) between September 2005 and September 2009 at Sun Yat-Sen University Cancer Center. Forty-five patients were in each group.

RESULTS

The objective response rate of BM was significantly higher in gefitinib-WBRT group (64.4%) compared with gefitinib group (26.7%, P<0.001). The disease control rate of BM was 71.1% in gefitinib- WBRT group and 42.2% in gefitinib group (P=0.006). The median time to progression of BM was 10.6 months in gefitinib-WBRT group and 6.57 months in gefitinib group (P<0.001). The median overall survival (OS) of gefitinib-WBRT and gefitinib alone group was 23.40 months and 14.83 months, respectively (HR, 0.432, P=0.002).

CONCLUSION

Gefitinib plus concomitant WBRT had higher response rate of BM and significant improvement in OS compared with gefitinib alone in treatment of BM from NSCLC.

Application of conditional probability analysis to distant metastases from lung cancer

The aim of this study was to reveal whether there was non-randomness in the occurrence of metastasis and, if the non-randomness was denied, whether there were specific metastatic patterns in lung cancer patients. Patients who presented with pathologically diagnosed lung cancer between January 1986 and March 2009 at our hospitals were included. A statistical method and conditional probability analysis were used to analyze the data. Under the condition of one metastatic organ A (lung, bone, brain, liver or adrenal gland; the 5 most common metastatic organs), we determined the conditional probability of distant metastasis to a specific organ B, which was written as P(B | A), and compared it with the probability of distant metastasis P(B). The study group consisted of 1,994 patients. Of the 1,994 patients, 839 (42.1%) had distant metastases at the time of the initial diagnosis of lung cancer. With the exception of the comparisons between P(lung) and P(lung | adrenal gland) and between P(adrenal gland) and P(adrenal gland | lung), there were statistically significant differences between P(B | A) and P(B) in the 5 metastatic organs. In addition, P(B | A) and P(C | B | A) varied according to each organ and P(confined to A), P(confined to A and B) and P(confined to A, B and C) were different in each metastatic organ. In lung cancer patients, distant metastasis occurred non-randomly and there may be certain specific patterns of distant metastasis. The accumulation of knowledge of specific patterns of metastasis may aid the approach to individualized treatments.