Adénocarcinome bronchique avec mutation de l’ EGFR et réarrangement ALK concomitants

Two different patterns of lung adenocarcinoma with concomitant EGFR mutation and ALK rearrangement

Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements are considered mutually exclusive in non-small cell lung cancer (NSCLC), especially in lung adenocarcinoma (LUAC). However, sporadic cases harboring concomitant EGFR and ALK alterations have been increasingly reported. There is no consensus opinion regarding the treatment of patients positive for both molecular alterations. NSCLC with EGFR/ALK coalterations should be separated into two subtypes: unifocal and multifocal LUAC. Here, we present an overview of the available literature regarding this rare group of patients to provide useful suggestions for therapeutic strategies.

Concomitant EGFR Mutation and EML4-ALK Rearrangement in Lung Adenocarcinoma Is More Frequent in Multifocal Lesions

BACKGROUND

The coexistence of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement in patients with multifocal lung adenocarcinomas (LUAC) constitutes a rare molecular subtype of lung cancer. We aimed to investigate the intertumoral heterogeneity of pathologic and genetic characteristics of multifocal LUAC with EGFR/ALK co-alterations.

PATIENTS AND METHODS

A total of 1059 LUAC patients who underwent resection were investigated to screen for EGFR or ALK alterations using amplification refractory mutation system polymerase chain reaction and immunohistochemistry/fluorescence in situ hybridization. Molecular testing was extensively performed in patients with synchronous multifocal LUAC. Clonal evolution analysis was implemented using next-generation sequencing.

RESULTS

A total of 97 multiple synchronous lesions were observed among 1059 LUAC patients. Patients with at least 1 sample harboring EGFR mutation or ALK rearrangement were 62.89% (61/97) and 14.43% (14/97), respectively. Patients with concomitant EGFR and ALK alterations were 4.71% (4/97). Comparatively, patients with unifocal LUAC harboring EGFR mutation, ALK rearrangement, and EGFR/ALK co-alterations were 58.25% (570/962), 6.44% (62/962), and 0.83% (8/962), respectively. The prevalence of EGFR/ALK co-alterations in the multifocal LUAC was significantly higher than that in the unifocal LUAC (4.71% (4/97) vs. 0.83% (8/962)). Furthermore, we present 4 cases of EGFR/ALK co-altered multifocal LUAC with different morphological and molecular patterns. In addition to radiographic, pathological, and molecular testing results, clonal evolutional analysis could also be used to distinguish intertumoral heterogeneity.

CONCLUSION

The results highlight the importance of distinguishing synchronous primary tumors from intrapulmonary metastases, and of assessing the relative abundance of EGFR mutation and ALK rearrangement in patients with multifocal adenocarcinomas with EGFR/ALK co-alterations.

Comparison of Clinicopathological Features and Prognosis between ALK Rearrangements and EGFR Mutations in Surgically Resected Early-stage Lung Adenocarcinoma

Background: A number of mutations in key oncogenes have been identified as important for the initiation and maintenance of lung adenocarcinoma (LAC). This study elucidated the prevalence and prognostic significance of mutations in the epidermal growth factor receptor gene (EGFR) and rearrangements in the anaplastic lymphoma kinase gene (ALK) in patients with surgically resected primary LAC.

Patients and Methods: We retrospectively analyzed 675 consecutive patients who underwent radical resection at a single institution. We concurrently analyzed mutations in EGFR and the Kirsten rat sarcoma viral oncogene homolog gene (KRAS) by reverse transcription (RT)-PCR, and investigated ALK rearrangements by immunohistochemistry. LAC with or without various oncogenic mutations was studied for clinicopathological features and their association with disease-free survival (DFS) and overall survival (OS).

Result: ALK rearrangements and EGFR mutations were detected in 75 and 312 patients, respectively, with coexistence in 5 cases. ALK rearrangements and mutations in EGFR and KRAS were mutually exclusive. Compared with patients with EGFR mutations, ALK rearrangements were more common in younger patients, and those with advanced tumors, lymph node metastases, and higher rates of postoperative adjuvant therapy. Histologically, EGFR mutations were more common than ALK rearrangements in patients with the acinar predominant subtype and the lepidic predominant subtype of LAC, whereas ALK rearrangements were more frequent in the solid predominant subtype with mucin production and invasive mucinous adenocarcinomas. ALK-positive patients had a significantly worse DFS than those with EGFR mutations and wild-type (WT) patients. The mean OS after surgical procedures was significantly longer in EGFR-mutated versus WT patients. No significant differences were found in patients with ALK-positive tumors compared with EGFR-mutated and WT patients.

Conclusion: Clinicopathological features of LAC with ALK rearrangements differ from those of LAC with EGFR mutations. Patients with ALK rearrangements had a significantly worse DFS than those harboring EGFR mutations. Thus, ALK rearrangements are an adverse prognostic factor in surgically-resected LAC patients, while EGFR mutations are associated with a better prognosis.

[Advances in Double Mutations of EGFR and ALK Gene in Non-small Cell Lung Cancer]

Molecular target therapy is one of the most popular field of non-small cell lung cancer (NSCLC) treatmnet. Epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearragement are the most important two oncogenic drivers in NSCLC, early studies suggested that EGFR mutations and ALK rearrangements are mutually exclusive, but isolated cases or small sample research with concomitant EGFR and ALK alterations have been constantly reported. The co-occurrence of EGFR mutations and anaplastic lymphoma kinase (ALK) rearrangements constitutes a rare molecular, the frequency of EGFR/ALK co-alterations was about 1%, however, little has been known about clinicopathologic feature and treatment. This review summarized published case report, EGFR and ALK alterations are common in female, Asian origin, never smoker, IV stage, and denocarcinomas. First-line treatment can choose EGFR or ALK tyrosine kinase inhibitors (TKIs). However, studies about the origin and resistance mechanism in EGFR/ALK co-alterations are little, require more experimental and clinical research.
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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.