Is there a role for epidermal growth factor receptor tyrosine kinase inhibitors in epidermal growth factor receptor wild-type non-small cell lung cancer?

[Second- or third-line treatment with erlotinib in EGFR wild-type non-small cell lung cancer: Real-life data]

INTRODUCTION

The benefit of tyrosine kinase inhibitors for patients with an EGFR wild-type non-small cell lung cancer (NSCLC) remains controversial.

METHODS

The survival of patients with an EGFR wild-type NSCLC who received second- or third-line erlotinib treatment was assessed using real-life data that had been collected in a prospective, national, multicenter, non-interventional cohort study.

RESULTS

Data from 274 patients were analysed, 185 (68%) treated with erlotinib and 89 (32%) treated with supportive care only. The median overall survival was 4.2months (95% CI [3.5; 5.4]) with erlotinib, and 1.3months (95% CI [1.0; 1.8]) with supportive care. Survival rate at 3, 6, and 12months was 62%, 37%, and 17%, respectively, with erlotinib, versus 20%, 8%, et 3%, with exclusive supportive care. Significant predictive factors for longer overall survival were the presence of adenocarcinoma, and use of 1st line chemotherapy including either taxanes, pemetrexed or vinorelbine (P<0.05).

CONCLUSION

Erlotinib remains a valuable therapeutic option to treat inoperable locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen in fragile patients who are not eligible for chemotherapy.

Early Change in FDG-PET Signal and Plasma Cell-Free DNA Level Predicts Erlotinib Response in EGFR Wild-Type NSCLC Patients

INTRODUCTION: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are a treatment option in the second- or third-line palliative setting in EGFR wild-type (wt) non–small cell lung cancer (NSCLC) patients. However, response rates are low, and only approximately 25% will achieve disease control. Early prediction of treatment resistance could accelerate discontinuation of ineffective treatment and reduce unnecessary toxicity. In this study, we evaluated early changes on 18F-fluoro-D-glucose (F-18-FDG) positron emission tomography/computed tomography (PET/CT) and in total plasma cell-free DNA (cfDNA) as markers of erlotinib response in EGFR-wt patients. METHODS: F-18-FDG-PET/CT scans and blood samples were obtained prior to erlotinib initiation and were repeated after 1 week (PET/CT) and 1 to 4 weeks (blood sample) of treatment. Level of cfDNA was measured by droplet digital polymerase chain reaction. Percentage change (%∆) in SUL_peak and total lesion glycolysis (TLG) on FDG-PET/CT and in plasma cfDNA was correlated to radiological response, progression-free survival (PFS), and overall survival (OS). RESULTS: Fifty patients were prospectively enrolled. A significant correlation was found between CT response and %∆TLG (P = .003). All patients with early metabolic progression showed radiological progression. Increased %∆TLG and %∆cfDNA were significantly correlated with shorter PFS (P = .002 and P = .004, respectively) and OS (P = .009 and P = .009, respectively). Multivariate analysis indicated %∆cfDNA to be the strongest predictor of OS. CONCLUSION: Early increase in TLG on F-18-FDG-PET/CT correlates with radiological progression, and shorter PFS and OS. Early increase in cfDNA predicts shorter PFS and OS. Both assessments are promising tools for early detection of nonresponders and reduced OS in TKI-treated EGFR-wt NSCLC patients.

Metabolic tumor burden as marker of outcome in advanced EGFR wild-type NSCLC patients treated with erlotinib

OBJECTIVES

Accurate estimation of the prognosis of advanced non-small cell lung cancer (NSCLC) patients is essential before initiation of palliative treatment; especially in the second and third-line setting. This study was conducted in order to evaluate tumor burden measured on an 2'-deoxy-2'-[18F] fluoro-D-glucose (F-18-FDG) positron emission tomography/computed tomography (PET/CT) scan as a marker of outcome in advanced epidermal growth factor receptor (EGFR) wild-type patients treated with second or third-line erlotinib.

MATERIAL AND METHODS

Fifty-one patients were included from a prospectively collected cohort. An F-18-FDG-PET/CT scan was conducted prior to erlotinib treatment and tumor burden was measured in terms of metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Median values of MTV and TLG were used for dichotomization of patients. Survival outcome was compared between groups.

RESULTS

MTV and TLG could be measured in 49 patients. High values of MTV and TLG were significantly correlated with shorter PFS (p<0.001 and p=0.027, respectively) and OS (p<0.001 and p=0.002, respectively). In multivariate analyses, including both clinical and imaging data, high MTV and TLG remained strong independent markers of both shorter PFS (MTV, hazard ratio (HR)=5.44 (95% confidence interval (CI) 2.46-12.02); TLG, HR=2.17 (95% CI 1.11-4.26)) and OS (MTV, HR=4.80 (95% CI 2.08-11.06); TLG, HR=2.76 (95% CI 1.33-5.71)).

CONCLUSION

High MTV and TLG are independently correlated with shorter PFS and OS in advanced EGFR wild-type NSCLC patients treated with second or third-line erlotinib. Metabolic tumor burden is a highly promising clinical tool that may allow better patient selection for palliative treatment in the future.