[Research progress in non-small cell lung cancer with concomitant EML4-ALK fusion gene and EGFR gene mutation]

Mutation status analysis of 58 patients with advanced ALK fusion gene positive non small cell lung cancer

PURPOSE

To analyze the characteristics and prognostic values of Anaplastic Lymphoma Kinase (ALK) fusion gene partner, gene subtype and abundance in tumor tissues of advanced Non Small Cell Lung Cancer (NSCLC) patients with positive ALK fusion gene and to explore the best treatment mode of ALK-Tyrosine Kinase Inhibitors(TKIs).

METHODS

Cases of advanced NSCLC patients with ALK positive confirmed by both Next Generation Sequencing (NGS) and immunohistochemistry were retrospectively collected. The relationships of Overall Survival (OS)/Progression Free Survival (PFS) between different mutation subtypes, mutation abundance, clinicopathological features were analyzed. OS/PFS between different treatment mode of ALK inhibitors were compared.

RESULTS

Fifty-eight patients were enrolled. There were diverse fusion partners. Five subtypes of Echinoderm Microtubule-associated protein-Like 4 gene (EML4)-ALK fusion mutation were detected: V1,V2,V3,V5 and V7. The mutation abundance ranged from 0.13 to 27.77%, with a median of 5.34%. The abundance of V2 and V5 was higher than V1 and V3 respectively. There was no difference in OS between the low abundance group(≤ 5.34%) and the high abundance group(>5.34%) (P = 0.434). PFS of second-generation ALK inhibitors as first-line treatment was longer than that of Crizotinib as first-line (P<0.001). Never smokers had longer OS than current smokers(P = 0.001).

CONCLUSIONS

There are differences in abundance between different fusion partners and subtypes in advanced NSCLC with positive ALK. OS is not associated with subtypes, mutation abundance and first line treatment option of either generation of ALK inhibitors. Smoking is a poor prognostic factor.

Concomitant EML4-ALK rearrangement and EGFR mutation in non-small cell lung cancer patients: a literature review of 100 cases

The discovery of EGFR mutations and EML4-ALK gene rearrangements has radically changed the therapeutic scenario for patients with advanced non-small cell lung cancer. ALK and EGFR tyrosine-kinase inhibitors showed better activity and efficacy than standard chemotherapy in the first and second line treatment settings, leading to a clear advantage in overall survival of advanced non-small cell lung cancer patients harboring these genetic alterations.

Historically the coexistence of EGFR mutations and EML4-ALK rearrangements in the same tumor has been described as virtually impossible. Nevertheless many recent observations seem to show that it is not true in all cases.

In this review we will discuss the available literature data regarding this rare group of patients in order to give some suggestions useful for their clinical management. Furthermore we report here two cases of concomitant presence of both alterations that will help us in the development of discussion.

[Gene Expression and Clinical Characteristics of Molecular Targeted Therapy in Non-small Cell Lung Cancer Patients in Shandong]

BACKGROUND

Molecular targeted therapy has gradually become an important treatment for lung cancer, the aim of this research is to analyze the clinicopathologic features associated with the gene mutation status of epidermal growth factor receptor (EGFR), echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK), ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) and Kirsten rat sarcoma viral oncogene (KRAS) in non-small cell lung cancer (NSCLC) patients and determine the most likely populations to benefit from molecular target therapy treatment.

METHODS

The mutation status of EGFR, EML4-ALK fusion gene, ROS1 and KARS gene were determined by Real-time PCR, the relationship between clinical pathologic features and concomitant gene were analyzed with χ2 test by SPSS software 19.0.

RESULTS

A total of 514 specimens from Shandong tumor hospital were collected from NSCLC patients between January 2014 and May 2016. The total mutation rate of EGFR gene was 36.70%, major occurred in exon 19 (36.61%) and exon 21 (51.36%), respectively, and EGFR mutations usually occurred in female, non-smoking and adenocarcinoma patients (P<0.05). The total rearrangements rate of EML4-ALK fusion gene was 9.37%, EML4-ALK fusion gene usually occurred in younger age (≤60 yr) and non-smoking patients (P<0.05). Mutations were not related to gender and pathological type (P>0.05). ROS1 fusion gene was detected in 136 cases, the positive rate was 3.67%, all patients were 60 years old, and the difference was statistically significant (P<0.05). Only 23 samples were tested KARS gene mutations, two of them were positive and the positive rate was 8.70%. They all occurred in non-smoker and adenocarcinoma patients. No mutation was detected to coexist in EGFR, EML4-ALK and KARS gene mutation.

CONCLUSIONS

EGFR, EML4-ALK, ROS1 and KRAS defines different molecular subset of NSCLC with distinct characteristic, which provides a new option for the clinical treatment of patients with NSCLC.

Detection of EML4-ALK fusion gene and features associated with EGFR mutations in Chinese patients with non-small-cell lung cancer

PURPOSE

Echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) and epidermal growth factor receptor (EGFR) define specific molecular subsets of lung cancer with distinct clinical features. We aimed at revealing the clinical features of EML4-ALK fusion gene and EGFR mutation in non-small-cell lung cancer (NSCLC).

METHODS

We enrolled 694 Chinese patients with NSCLC for analysis. EML4-ALK fusion gene was analyzed by real-time polymerase chain reaction, and EGFR mutations were analyzed by amplified refractory mutation system.

RESULTS

Among the 694 patients, 60 (8.65%) patients had EML4-ALK fusions. In continuity correction χ (2) test analysis, EML4-ALK fusion gene was correlated with sex, age, smoking status, and histology, but no significant association was observed between EML4-ALK fusion gene and clinical stage. A total of 147 (21.18%) patients had EGFR mutations. In concordance with previous reports, EGFR mutation was correlated with age, smoking status, histology, and clinical stage, whereas patient age was not significantly associated with EGFR mutation. Meanwhile, to our surprise, six (0.86%) patients had coexisting EML4-ALK fusions and EGFR mutations.

CONCLUSION

EML4-ALK fusion gene defines a new molecular subset in patients with NSCLC. Six patients who harbored both EML4-ALK fusion genes and EGFR mutations were identified in our study. The EGFR mutations and the EML4-ALK fusion genes are coexistent.

[The research of clinical pathological features of ALK positive lung cancer in 525 patients and the discussion of detection methods]

BACKGROUND

The fusion (rearrangement) of anaplastic lymphoma kinase (ALK) gene has been identified as an import factor to the tumorigenesis and development of lung cancer. ALK tyrosine kinase inhibitors (ALK-TKIs) have been proved to have good effects to ALK positive lung cancers. The increasement of the relevance ratio of ALK will be very important to patients. The aim of this study is to investigate the clinical pathological features of ALK positive lung cancer, and the roles of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in screening and confirming the ALK positive cases in the testing flow of ALK.

METHODS

IHC analysis of ALK in tumor specimens was performed on 525 lung cancer patients. 34 cases among them were confirmed by FISH.

RESULTS

The positive incidence of ALK by IHC was 5.14% (27/525). The ALK positive patients were significantly younger than ALK negative patients (P<0.05), and femal was predominant (P<0.05). The proportion of solid predominant adenocarcinoma was significantly higher in ALK positive patients (P<0.05). While acinar and lepidic predominant adenocarcinoma were significantly lower in ALK positive patients (P<0.05). FISH was applied in 34 cases. The coincidence rate was increased with the increasement of positive intensity of IHC staining. All the IHC positive cases with or without EGFR mutation must be confirmed by FISH.

CONCLUSIONS

IHC is a reliable detection method to screening the ALK in lung cancer, and then enhance the relevance ration. To make a definite diagnosis of ALK positive lung cancer, FISH is a significant detection method.