Brain metastases in resected non-small cell lung cancer: The impact of different tyrosine kinase inhibitors

Clinicopathologic and genomic features associated with brain metastasis after resection of lung adenocarcinoma

Objective

To identify clinicopathologic and genomic features associated with brain metastasis after resection of lung adenocarcinoma (LUAD) and to evaluate survival after brain metastasis.

Methods

Patients who underwent complete resection of stage I-IIIA LUAD between 2011 and 2020 were included. A subset of patients had broad-based panel next-generation sequencing performed on their tumors. Fine-Gray models for the development of brain metastasis were constructed, with death without brain metastasis as a competing risk.

Results

A total of 2660 patients were included. The median duration of follow-up was 71 months (95% confidence interval [CI], 69-73 months). The cumulative incidence of brain metastasis at 10 years was 9.8%. Among patients who developed a brain metastasis, the median time from surgery to brain metastasis was 21 months (interquartile range, 10-42 months). Higher maximum standardized uptake value of the primary tumor, neoadjuvant therapy, lymphovascular invasion, and stage III disease were associated with the development of brain metastasis. Among patients who underwent next-generation sequencing, a multivariable analysis identified neoadjuvant therapy, pathologic stage, and TP53 mutations as associated with development of brain metastasis. The median survival after brain metastasis was 18 months (95% CI, 13-24 months). Better performance status, lack of extracranial metastasis, stereotactic radiosurgery, and targeted therapy were associated with better survival after brain metastasis.

Conclusions

Brain metastasis is common after complete resection of LUAD and often occurs within 2 years. Markers of aggressive tumor biology, including higher maximum standardized uptake value, lymphovascular invasion, and TP53 mutations, and neoadjuvant therapy are associated with brain metastasis.

First- versus Third-Generation EGFR Tyrosine Kinase Inhibitors in EGFR-Mutated Non-Small Cell Lung Cancer Patients with Brain Metastases

Introduction: Up to 50% of non-small cell lung cancer (NSCLC) harbor EGFR alterations, the most common etiology behind brain metastases (BMs). First-generation EGFR-directed tyrosine kinase inhibitors (EGFR-TKI) are limited by blood-brain barrier penetration and T790M tumor mutations, wherein third-generation EGFR-TKIs, like Osimertinib, have shown greater activity. However, their efficacy has not been well-studied in later therapy lines in NSCLC patients with BMs (NSCLC-BM). We sought to compare outcomes of NSCLC-BM treated with either first- or third-generation EGFR-TKIs in first-line and 2nd-to-5th-line settings. Methods: A retrospective review of NSCLC-BM patients diagnosed during 2010-2019 at Cleveland Clinic, Ohio, US, a quaternary-care center, was performed and reported following 'strengthening the reporting of observational studies in epidemiology' (STROBE) guidelines. Data regarding socio-demographic, histopathological, molecular characteristics, and clinical outcomes were collected. Primary outcomes were median overall survival (mOS) and progression-free survival (mPFS). Multivariable Cox proportional hazards modeling and propensity score matching were utilized to adjust for confounders. Results: 239 NSCLC-BM patients with EGFR alterations were identified, of which 107 received EGFR-TKIs after diagnosis of BMs. 77.6% (83/107) received it as first-line treatment, and 30.8% (33/107) received it in later (2nd-5th) lines of therapy, with nine patients receiving it in both settings. 64 of 107 patients received first-generation (erlotinib/gefitinib) TKIs, with 53 receiving them in the first line setting and 13 receiving it in the 2nd-5th lines of therapy. 50 patients received Osimertinib as third-generation EGFR-TKI, 30 in first-line, and 20 in the 2nd-5th lines of therapy. Univariable analysis in first-line therapy demonstrated mOS of first- and third-generation EGFR-TKIs as 18.2 and 19.4 months, respectively (p = 0.57), while unadjusted mPFS of first- and third-generation EGFR-TKIs was 9.3 and 13.8 months, respectively (p = 0.14). In 2nd-5th line therapy, for first- and third-generation EGFR-TKIs, mOS was 17.3 and 11.9 months, (p = 0.19), while mPFS was 10.4 and 6.08 months, respectively (p = 0.41). After adjusting for age, performance status, presence of extracranial metastases, whole-brain radiotherapy, and presence of leptomeningeal metastases, hazard ratio (HR) for OS was 1.25 (95% CI 0.63-2.49, p = 0.52) for first-line therapy. Adjusted HR for mOS in 2nd-to-5th line therapy was 1.60 (95% CI 0.55-4.69, p = 0.39). Conclusions: No difference in survival was detected between first- and third-generation EGFR-TKIs in either first or 2nd-to-5th lines of therapy. Larger prospective studies are warranted reporting intracranial lesion size, EGFR alteration and expression levels in primary tumor and brain metastases, and response rates.

Simultaneous analysis of ALK, RET, and ROS1 gene fusions by NanoString in Brazilian lung adenocarcinoma patients

Background

Gene fusions have been successfully employed as therapeutic targets for lung adenocarcinoma. However, tissue availability for molecular testing of multiples alterations is frequently unfeasible. We aimed to detect the presence of ALK, RET, and ROS1 rearrangements by a RNA-based single assay in Brazilian lung adenocarcinomas and to associate with clinicopathological features and genetic ancestry.

Methods

From a FFPE series of 444 molecularly characterized lung adenocarcinomas, 253 EGFR/KRAS wild-type cases were eligible for gene rearrangement analysis. Following RNA isolation, ALK, RET, and ROS1 rearrangements were simultaneously analyzed employing the ElementsXT Custom panel (NanoString Technologies). Rearrangements were further associated with clinicopathological features and genetic ancestry of the patients.

Results

The NanoString platform was performed in subset of 142 cases. Gene fusion results were conclusive for 94.4% (n=134) cases (failure rate =5.6%). ALK rearrangements were observed in 21 out of 134 cases, and associated with younger, never smokers, metastatic disease, and metastases in the central nervous system. RET and ROS1 fusions were detected in two and one out of 134 cases, respectively. Genetic ancestry was not associated with gene fusions. Overall, considering all cases for which a molecular analysis was conclusive (EGFR/KRAS/ALK/RET/ROS1), ALK fusions frequency was observed in 6.5% (21/325), RET in 0.6% (2/325), and ROS1 in 0.3% (1/325).

Conclusions

This study successfully used a RNA-based single assay for the simultaneous analysis of ALK, RET, and ROS1 fusions employing routine biopsies from Brazilian patients lung adenocarcinoma allowing an extensive molecular testing for actionable rearrangements contributing to guide clinical strategies.