Efficacy of Second-line Tyrosine Kinase Inhibitors in the Treatment of Metastatic Advanced Non-small-cell Lung Cancer Harboring Exon 19 and 21 EGFR Mutations

Differential clinicopathological features, treatments and outcomes in patients with Exon 19 deletion and Exon 21 L858R EGFR mutation-positive adenocarcinoma non-small-cell lung cancer

The most common oncogenic driver in non-small-cell lung cancer (NSCLC) is the epidermal growth factor receptor (EGFR) gene mutations that occur more frequently among Asians (30%-50%) as opposed to Caucasians (10%-15%). Lung cancer is one of the most prevalent cancers in India, with a reported adenocarcinoma positivity ranging between 26.1% and 86.9% in NSCLC patients. The prevalence of EGFR mutations in adenocarcinoma patients (36.9%) in India is higher than that of Caucasian patients and lower than that of East Asian patients. The exon 19 deletion (Ex19del) is more common than exon 21 L858R mutations in Indian patients with NSCLC. Studies have shown that the clinical behaviour of patients with advanced NSCLC differs between EGFR Ex19del and exon 21 L858R mutation status. In this study, we investigated the differences in clinicopathological features and survival outcomes after first line and second-line treatment with EGFR tyrosine kinase inhibitors (EGFR TKIs) in NSCLC patients with Ex19del and exon 21 L858R EGFR mutation status. This study also focuses on the role and potential benefits of dacomitinib, a second-generation irreversible EGFR TKI, in patients with Ex19del and exon 21 L858R EGFR mutation-positive advanced NSCLC in Indian settings.

Development and Validation of a Novel Survival Prediction Model in Patients With Spinal Metastasis From Non-small Cell Lung Cancer

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to develop a model for predicting survival of patients with non-small cell lung cancer (NSCLC) spinal metastasis and compare its accuracy with the existing scoring systems.

SUMMARY OF BACKGROUND DATA

Spinal metastasis is commonly seen in advanced NSCLC and usually associated with poor survival prognosis.

METHODS

A total of 376 patients with NSCLC spinal metastases admitted to our institution from January 2010 to October 2016 were enrolled. They were randomly assigned at a 3:1 ratio to a training cohort (n = 282) and a validation cohort (n = 94). A nomogram for survival prediction was established by identifying and integrating significant prognostic factors, and then subjected to bootstrap validation in both training and validation cohorts. The discrimination was measured by concordance index (C-index). Predictive accuracy was compared with three existing models by the receiver-operating characteristic curve (ROC) and area under ROC in both training and validation cohorts.

RESULTS

Six independent prognostic factors including sex (P = 0.008), the presence of visceral metastasis (P = 0.008), the number of metastases in the vertebral body (P = 0.011), Frankel score (P < 0.001), D-dimer (P = 0.002), and sensitive epidermal growth factor receptor mutation (p < 0.001) were identified and entered into the nomogram. The calibration curves for probability of 3-, 6-, 12- and, 24-month overall survival showed good agreement between the predictive risk and the actual risk. The C-index of the nomogram was 0.708 (95% confidence interval [CI], 0.674-0.742) in the training cohort and 0.683 (95% CI, 0.619-0.747) in the validation cohort. Model comparison showed that this nomogram had better predictive accuracy than the Tomita et al, Tokuhashi et al, and Schwab et al scoring systems (P < 0.05 in the training cohort).

CONCLUSION

We established and validated a novel nomogram that could be used to predict the survival outcome of patients with NSCLC spinal metastasis, thus helping clinicians in decision making and individualized care planning of such patients.

LEVEL OF EVIDENCE

4.

The impact of EGFR mutations on the incidence and survival of stages I to III NSCLC patients with subsequent brain metastasis

Previous studies have demonstrated the association between EGFR mutations and distant metastasis. However, the association for subsequent brain metastasis (BM) in stages I-III non-small cell lung cancer (NSCLC) patients remains inconclusive. We conducted a retrospective analysis to clarify the impact of EGFR mutations on the incidence of BM and associated survival in patients with stage I-III NSCLC. A total of 491 patients screened for EGFR mutations were retrospectively enrolled. Brain MRI or CT was used to detect the BM. Cumulative incidence of subsequent BM and overall survival (OS) after diagnosis of BM were estimated by the Kaplan-Meier method and compared using log-rank test. We performed Cox proportional hazard regression for predictors of subsequent BM and determinants of OS after BM. The cumulative incidence of BM seemed higher in patients harboring EGFR mutations than those without EGFR mutations although it did not reach statistical significance (hazard ratio [HR] = 1.75, 95% confidence interval [CI] = 0.73~1.81). After adjusting possible confounders, including age, smoking, stage, and tumor size, EGFR mutation became one of the predictors for subsequent BM (HR = 1.89, 95% CI = 1.12~3.17, p = 0.017). Though there was no statistical difference in survival after BM between patients with EGFR mutations and wild-type EGFR (median survival: 17.8 vs. 12.2 months, HR = 0.79, 95% CI = 0.45–1.40), patients with EGFR 19 deletion (Del) tended to have a longer survival after BM than the non-EGFR 19 Del group (median survival: 29.4 vs. 14.3 months, HR 0.58, 95% CI = 0.32–1.09, p = 0.089). In conclusion, our data suggested EGFR mutation to be one of the predictors for subsequent BM in stage I-III patients. Given the small sample size, more studies are warranted to corroborate our results.

Transformation to small-cell lung cancer following treatment with icotinib in a patient with lung adenocarcinoma

The present study describes the case of a 48-year-old man who was diagnosed with lung adenocarcinoma with an epidermal growth factor receptor (EGFR) 21 L858R mutation. The patient received surgery and adjuvant chemotherapy. When multiple lung metastases appeared, icotinib was administered. Following resistance to icotinib, biopsy by endobroncheal ultrasonography for a right lung hilar lymph node revealed transformation to a neuroendocrine morphology. Neuron-specific enolase (NSE) levels were elevated, accompanied with disease progression following transformation to the neuroendocrine morphology. The post-operative and biopsy specimens were analyzed for 416 genes using next-generation sequencing, and phosphatidylinositol-3-kinase catalytic α mutation and retinoblastoma loss were evident. Five cycles of etoposide combined with cisplatin were administered and a partial response was achieved. The disease progressed again accompanied with an elevated NSE level, and bronchoscopy examination revealed small cell lung cancer (SCLC) after 3 months. The patient received chemotherapy consisting of irinotecan combined with carboplatin for two cycles and achieved stable disease. Overall, a secondary biopsy is important for the evaluation of genetic and histological changes and the selection of an appropriate treatment following tyrosine kinase inhibitor (TKI) resistance, and NSE may be useful for the early detection of SCLC transformation in cases that are resistant to EGFR-TKI therapy.

Validation of the graded prognostic assessment for lung cancer with brain metastases using molecular markers (lung-molGPA)

Background

Many patients with brain metastases from non-small cell lung cancer have limited survival, while others survive for several years, depending on patterns of spread, EGFR and ALK alterations, among others. The purpose of this study was to validate a new prognostic model (Lung-molGPA) originally derived from a North American database.

Patients and methods

This retrospective study included 269 German and Norwegian patients treated with individualized approaches, always including brain radiotherapy. Information about age, extracranial spread, number of brain metastases, performance status, histology, EGFR and ALK alterations was collected. The Lung-molGPA score was calculated as described by Sperduto et al.

Results

Median survival was 5.4 months. The score predicted survival in patients with adenocarcinoma histology and those with other types. For example, median survival was 3.0, 6.2, 14.7 and 25.0 months in the 4 different prognostic strata for adenocarcinoma. The corresponding figures were 2.4, 5.5 and 12.5 months in the 3 different prognostic strata for non-adenocarcinoma.

Conclusions

These results confirm the validity of the Lung-molGPA in an independent dataset from a different geographical region. However, median survival was shorter in 6 of 7 prognostic strata. Potential explanations include lead time bias and differences in treatment selection, both brain metastases-directed and systemically.

Survival difference between EGFR Del19 and L858R mutant advanced non-small cell lung cancer patients receiving gefitinib: a propensity score matching analysis

Objective

Although superior clinical benefits of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in the treatment of advanced non-small-cell lung cancer (NSCLC) had been reported, the survival difference between exon 19 deletion (Del19) and exon 21 Leu858Arg substitution (L858R) remains controversial. The purpose of this study is to investigate the differences in progression-free survival (PFS) and overall survival (OS) between different EGFR mutant subtypes among advanced NSCLC patients receiving gefitinib.

Methods

There were 204 advanced NSCLC patients with EGFR mutations treated with gefitinib were enrolled in this retrospective cohort study. Patients were divided into the EGFR Del19 group and the L858R mutated group according to their mutant subtype. Propensity score matching (PSM) was conducted by using a nearest-neighbor algorithm (1:1) to adjust for demographical and clinical covariates. Survival curves were constructed with the Kaplan-Meier method and compared by using the log-rank test.

Results

The PFS in Del19 group was similar to that in the L858R group [before PSM 8.6 vs. 7.2 months, P=0.072; after PSM 7.3 vs. 7.2 months, P=0.155]. No differences were detected in OS between the L858R and the Del19 group (before PSM 17.8 vs. 13.1 months, P=0.253; after PSM 16.9 vs. 13.1 months, P=0.339). The Del19 group was significantly younger compared with the L858R mutation group in age (P=0.015).

Conclusions

No significant difference was found in the PFS or OS between the Del19 and L858R mutant NSCLC patients receiving gefitinib. The age gap might contribute to the survival differences between Del19 and L858R groups. PSM is of important value to the elimination of potential bias.