Risk of brain metastasis reduced after erlotinib treatment in advanced pulmonary adenocarcinoma patients with sensitive EGFR mutation

Computed tomography-based radiomics and clinical-genetic features for brain metastasis prediction in patients with stage III/IV epidermal growth factor receptor-mutant non-small-cell lung cancer

PURPOSE

To evaluate the value of computed tomography (CT)-based radiomics combined with clinical-genetic features in predicting brain metastasis in patients with stage III/IV epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC).

METHODS

The study included 147 eligible patients treated at our institution between January 2018 and May 2021. Patients were randomly divided into two cohorts for model training (n = 102) and validation (n = 45). Radiomics features were extracted from the chest CT images before treatment, and a radiomics signature was constructed using the Least Absolute Shrinkage and Selection Operator regression. Kaplan-Meier survival analysis was used to describe the differences in brain metastasis-free survival (BM-FS) risk. A clinical-genetic model was developed using Cox regression analysis. Radiomics, genetic, and combined prediction models were constructed, and their predictive performances were evaluated by the concordance index (C-index).

RESULTS

Patients with a low radiomics score had significantly longer BM-FS than those with a high radiomics score in both the training (p < 0.0001) and the validation (p = 0.0016) cohorts. The C-indices of the nomogram, which combined the radiomics signature and N stage, overall stage, third-generation tyrosine kinase inhibitor treatment, and EGFR mutation status, were 0.886 (95% confidence interval [CI] 0.823-0.949) and 0.811 (95% CI 0.719-0.903) in the training and validation cohorts, respectively. The combined model achieved a higher discrimination and clinical utility than the single prediction models.

CONCLUSIONS

The combined radiomics-genetic model could be used to predict BM-FS in stage III/IV NSCLC patients with EGFR mutations.

Efficacy and safety of WBRT+EGFR-TKI versus WBRT only in the treatment of NSCLC patients with brain metastasis: An updated meta-analysis

BACKGROUND

To investigate the efficacy and safety of whole brain radiotherapy (WBRT) combined with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) versus WBRT only in the treatment of brain metastasis in non-small cell lung cancer (NSCLC) patients by pooling open published data.

METHODS

Prospective clinical studies relevant to WBRT+EGFR-TKI versus WBRT only in the treatment of NSCLC brain metastasis were electronically searched in the Pubmed, EMbase, Cochrane, Wangfang, CNKI and Google scholar databases. The treatment response, 1-year survival and treatment-associated toxicity were pooled and expressed by odds ratio (OR) under a fixed or random effect model. The publication bias was evaluated by Begg's funnel plot and Egger's line regression test.

RESULTS

Eighteen prospective clinical studies were included in the study. The combined results indicated that the objective response rate (ORR) in the WBRT+TKI group was superior to WBRT only with a statistical difference (OR = 2.67, 95% CI: 2.10-3.38, p < 0.05) under a fixed effect model. Ten studies reported the 1-year survival rate between the WBRT+TKI and WBRT only groups. The combined results showed that 1-year survival rate in the WBRT+TKI group was higher than that of the WBRT only group with a statistical difference (OR = 2.70, 95% CI: 1.95-3.74, p < 0.05). For treatment-associated toxicity, the combined data indicated that the treatment-related rash in the WBRT+TKI group was significantly higher than that of the WBRT only group with a statistical difference (OR = 2.72, 95% CI: 1.53-4.84, p < 0.05). However, the incidence of nausea/vomiting (OR = 0.84, 95% CI: 0.60-1.17, p > 0.05), diarrhea (OR = 1.31, 95% CI: 0.83-2.07, p > 0.05), fatigue (OR = 1.40, 95% CI: 0.70-2.81, p > 0.05) and myelosuppression (OR = 0.86, 95% CI: 0.56-1.32, p > 0.05) were not statistically different between the two groups.

CONCLUSIONS

Based on the current publications, WBRT+EGFR-TKI can improve the treatment response and 1-year survival rate but not increase the toxicity except for rash compared to WBRT alone in the treatment of brain metastasis in NSCLC patients.

Advances in Lung Cancer Driver Genes Associated With Brain Metastasis

Brain metastasis, one of the common complications of lung cancer, is an important cause of death in patients with advanced cancer, despite progress in treatment strategies. Lung cancers with positive driver genes have higher incidence and risk of brain metastases, suggesting that driver events associated with these genes might be biomarkers to detect and prevent disease progression. Common lung cancer driver genes mainly encode receptor tyrosine kinases (RTKs), which are important internal signal molecules that interact with external signals. RTKs and their downstream signal pathways are crucial for tumor cell survival, invasion, and colonization in the brain. In addition, new tumor driver genes, which also encode important molecules closely related to the RTK signaling pathway, have been found to be closely related to the brain metastases of lung cancer. In this article, we reviewed the relationship between lung cancer driver genes and brain metastasis, and summarized the mechanism of driver gene-associated pathways in brain metastasis. By understanding the molecular characteristics during brain metastasis, we can better stratify lung cancer patients and alert those at high risk of brain metastasis, which helps to promote individual therapy for lung cancer.

Tyrosine Kinase Inhibitors Could Be Effective Against Non-small Cell Lung Cancer Brain Metastases Harboring Uncommon EGFR Mutations

Background: The significance of uncommon epidermal growth factor receptor (EGFR) mutations in patients with non-small cell lung cancer (NSCLC) and brain metastasis (BM) remains unclear. Cerebrospinal fluid (CSF) liquid biopsy is a novel tool for assessing EGFR mutations in BM. This study aimed to evaluate the EGFR mutations in patients with NSCLC and newly diagnosed BM and to examine the effect of EGFR tyrosine kinase inhibitors (TKI) on BM harboring CSF-tested uncommon EGFR mutations.

Methods: This was a prospective study of 21 patients with NSCLC and BM diagnosed between 04/2018 and 01/2019. CSF was obtained to detect the BM EGFR mutations by next-generation sequencing. BM characteristics at magnetic resonance imaging (MRI) and EGFR-TKI response were examined.

Results: Of 21 patients with NSCLC, 10 (47.6%) had leptomeningeal metastasis (LM), while 11 (52.4%) had brain parenchymal metastasis (BPM); 13 (61.9%) had confirmed EGFR mutation-positive primary tumors. The uncommon mutation rate in CSF ctDNA was 33.3% (7/21). Among those with EGFR mutation-positive primary tumors, the rate of uncommon EGFR mutations in CSF was 53.8% (7/13). Uncommon EGFR mutations were more common in patients with LM than in patients with PBM (6/11, 54.5% vs. 1/10, 10%), and included G719A, L861Q, L703P, and G575R. TKI was effective for four patients with BMs harboring uncommon EGFR mutations.

Conclusion: In patients with NSCLC and LM, the rate of uncommon EGFR mutation was high. The BMs with uncommon EGFR mutations seem to respond to EGFR-TKI treatment. CSF liquid biopsy could reveal the EGFR genetic profile of the BM and help guide treatment using small-molecule TKI.