Clinicopathological characteristics and survival of ALK, ROS1 and RET rearrangements in non-adenocarcinoma non-small cell lung cancer patients

EML4-ALK fusions drive lung adeno-to-squamous transition through JAK-STAT activation

Human lung adenosquamous cell carcinoma (LUAS), containing both adenomatous and squamous pathologies, exhibits strong cancer plasticity. We find that ALK rearrangement is detectable in 5.1-7.5% of human LUAS, and transgenic expression of EML4-ALK drives lung adenocarcinoma (LUAD) formation initially and squamous transition at late stage. We identify club cells as the main cell-of-origin for squamous transition. Through recapitulating lineage transition in organoid system, we identify JAK-STAT signaling, activated by EML4-ALK phase separation, significantly promotes squamous transition. Integrative study with scRNA-seq and immunostaining identify a plastic cell subpopulation in ALK-rearranged human LUAD showing squamous biomarker expression. Moreover, those relapsed ALK-rearranged LUAD show notable upregulation of squamous biomarkers. Consistently, mouse squamous tumors or LUAD with squamous signature display certain resistance to ALK inhibitor, which can be overcome by combined JAK1/2 inhibitor treatment. This study uncovers strong plasticity of ALK-rearranged tumors in orchestrating phenotypic transition and drug resistance and proposes a potentially effective therapeutic strategy.

Clinical characteristics and progression of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET rearrangements: a retrospective cohort study

Background

Patients harboring anaplastic lymphoma kinase (ALK) or rearranged during transfection (RET) rearrangements are usually diagnosed at a relatively late stage with nodal and distant metastasis, and rapid progression course of ALK/RET fusion-positive lung cancer were well-known. However, clinical characteristics and course of pre-/minimally invasive lung adenocarcinoma harboring ALK or RET fusions are poorly described. Identifying patients with gene fusions at early stage may offer surgical options that could cure those patients.

Methods

We retrospectively included patients with surgically resected pre-/minimally invasive lung adenocarcinomas harboring epidermal growth factor receptor (EGFR) mutations or ALK/RET rearrangements, and further compared the patient clinical characteristics, nodule natural course, and survival outcomes. Radiological characteristics including ground-glass component, cystic airspace, pleural attachment, etc. were specially assessed for this study. EGFR (exons 18-22) was detected by Sanger sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the ALK/RET rearrangements. Lung cancer-specific survival (LCSS), relapse-free survival (RFS), and overall survival (OS) were all evaluated.

Results

Of 238 patients with pre-/minimally invasive lung adenocarcinomas, 226 patients had EGFR mutations, 7 patients had ALK fusions, and 5 patients had RET fusions. Average age at surgery was 45.3 years for ALK/RET-positive group and 52.6 years for EGFR-positive group (P=0.049). Radiologically, among the 12 patients with ALK/RET fusions, the majority of lesions (10/12) manifested as mixed ground-glass opacities (mGGOs), which was significantly more prevalent when compared with patients with EGFR mutations (83.4% vs. 24.3%, P<0.001). Moreover, a substantial proportion of cystic airspace was found in ALK/RET-positive group but not in EGFR-positive group (66.7% vs. 14.2%, P<0.001). Among four patients with ALK/RET fusions undergoing surveillance over 1 year before surgery, two of them developed rapid radiologic progression. The 5-year LCSS and RFS were 100%, 100% for ALK/RET-positive group, and 100%, 100% for EGFR-positive group, respectively.

Conclusions

ALK/RET-positive pre-/minimally invasive lung adenocarcinomas were mostly characterized as mGGOs with cystic airspace developing rapid nodule progression, and no recurrence occurred during long-term follow-up after resection. This provides insights into proper curative surgery timing in the management of patients with gene fusions. However, these findings must be treated with caution and validated in future multi-center studies with larger sample size.

Clinicopathological characteristics and prognosis of resectable lung adenosquamous carcinoma: a population-based study of the SEER database

OBJECTIVE

Adenosquamous carcinoma is a rare subtype of non-small cell lung cancer characterized by aggressive behavior, with combination of adenocarcinoma and squamous cell carcinoma components. The clinicopathological characteristics and prognosis of resectable adenosquamous carcinoma are incompletely understood and this study aimed to depict those in a large population.

METHODS

A total of 805 adenosquamous carcinoma, 7875 squamous cell carcinoma and 23 957 adenocarcinoma patients who underwent lobectomy or sublobectomy were queried from the Surveillance, Epidemiology, and End Results database (2010-17). Clinicopathological characteristics of adenosquamous carcinoma patients were compared with those of squamous cell carcinoma and adenocarcinoma patients. Prognostic factors were identified by univariable and multivariable Cox regression analyses. Propensity score matching was applied to reduce confounding effects.

RESULTS

Adenosquamous carcinoma was associated with higher pleural invasion incidence and poorer differentiation compared with squamous cell carcinoma or adenocarcinoma (P values < 0.001). The independent risk factors of cancer-specific survival of adenosquamous carcinoma patients were increasing age, male sex, invading through visceral pleura, poor differentiation and higher stage. Stage IB adenosquamous carcinoma patients whose tumor invaded through visceral pleura had significantly worse survival than those not (P = 0.003). Adenosquamous carcinoma patients had worse survival compared with squamous cell carcinoma (5-year-survival: 64.55 vs. 69.09%, P = 0.003) and adenocarcinoma (5-year-survival: 64.55 vs. 76.79%, P < 0.001) patients before match. And this difference persisted after match.

CONCLUSIONS

Resectable adenosquamous carcinoma patients had higher pleural invasion incidence, poorer differentiation and worse survival compared with squamous cell carcinoma and adenocarcinoma patients. Visceral pleural invasion status and differentiation grade were vital prognostic factors of adenosquamous carcinoma patients on the basis of stage.

Fusion-positive non-small cell lung carcinoma: Biological principles, clinical practice, and diagnostic implications

Based on superior efficacy and tolerability, targeted therapy is currently preferred over chemotherapy and/or immunotherapy for actionable gene fusions that occur in late-stage non-small cell lung carcinoma (NSCLC). Consequently, current clinical practice guidelines mandate testing for ALK, ROS1, NTRK, and RET gene fusions in all patients with newly diagnosed advanced non-squamous NSCLC (NS-NSCLC). Gene fusions can be detected using different approaches, but today RNA next-generation sequencing (NGS) or combined DNA/RNA NGS is the method of choice. The discovery of other gene fusions (involving, eg, NRG1, NUT, FGFR1, FGFR2, MET, BRAF, EGFR, SMARC fusions) and their partners has increased progressively in recent years, leading to the development of new and promising therapies and mandating the development and implementation of comprehensive detection methods. The purpose of this review is to focus on recent data concerning the main gene fusions identified in NSCLC, followed by the discussion of major challenges in this domain.

Brigatinib treated ALK positive lung squamous cell carcinoma after failed chemotherapy: A case report

The definitive efficacy of anaplastic lymphoma kinase (ALK) inhibitors in ALK positive lung squamous cell carcinoma (sqCC) patients remain unclear. Here, we report a case in which brigatinib had a therapeutic effect on ALK‐positive lung squamous cell carcinoma. The patient in this report was diagnosed with ALK‐positive lung squamous cell carcinoma with brain metastases, and received brigatinib after failure of first‐line chemotherapy. Response duration was approximately 11 months, with tolerable side effects. In conclusion, a good clinical effect was achieved in a patient with ALK positive lung squamous cell carcinoma who received treatment with an ALK inhibitor.

Practical Considerations Relating to Routine Clinical Biomarker Testing for Non-small Cell Lung Cancer: Focus on Testing for RET Fusions

For patients with advanced non–small cell lung cancer, genomic profiling of tumors to identify potentially targetable alterations and thereby inform treatment selection is now part of standard care. While molecular analyses are primarily focused on actionable biomarkers associated with regulatory agency-approved therapies, there are a number of emerging biomarkers linked to investigational agents in advanced stages of clinical development will become approved agents. A particularly timely example is the reported data and US Food and Drug Administration approval of highly specific small molecule inhibitors of the proto-oncogene tyrosine-protein kinase receptor RET indicate that testing for tumor RET gene fusions in patients with NSCLC has become clinically important. As the number of biomarkers to be tested in NSCLC grows, it becomes increasingly important to optimize and prioritize the use of biopsy tissue, in order to both continue to allow accurate histopathological diagnosis and also to support concurrent genomic profiling to identify perhaps relatively uncommon genetic events. In order to provide practical expert consensus guidance to optimize processes facilitating genomic testing in NSCLC and to overcome barriers to access and implementation, a multidisciplinary advisory board was held in New York, on January 30, 2019. The panel comprised physicians involved in sample procurement (interventional radiologists and a thoracic surgeon), surgical pathologists specializing in the lung, molecular pathologists, and thoracic oncologists. Particular consideration was given to the key barriers faced by these experts in establishing institutional genomic screening programs for NSCLC. Potential solutions have been devised in the form of consensus opinions that might be used to help resolve such issues.

Molecular Epidemiology of the Main Druggable Genetic Alterations in Non-Small Cell Lung Cancer

Lung cancer is the leading cause of death for malignancy worldwide. Its molecular profiling has enriched our understanding of cancer initiation and progression and has become fundamental to provide guidance on treatment with targeted therapies. Testing the presence of driver mutations in specific genes in lung tumors has thus radically changed the clinical management and outcomes of the disease. Numerous studies performed with traditional sequencing methods have investigated the occurrence of such mutations in lung cancer, and new insights regarding their frequency and clinical significance are continuously provided with the use of last generation sequencing technologies. In this review, we discuss the molecular epidemiology of the main druggable genetic alterations in non-small cell lung cancer, namely EGFR, KRAS, BRAF, MET, and HER2 mutations or amplification, as well as ALK and ROS1 fusions. Furthermore, we investigated the predictive impact of these alterations on the outcomes of modern targeted therapies, their global prognostic significance, and their mutual interaction in cases of co-occurrence.

A comprehensive study on the oncogenic mutation and molecular pathology in Chinese lung adenocarcinoma patients

BACKGROUND

Several genetic driver alterations have been identified in micropapillary lung adenocarcinoma (MPA). However, the frequency of co-alteration of ROS1, EGFR, and EML4-ALK is yet unclear. Herein, we investigated the relationship between clinicopathologic characteristics and well-identified driver mutations of MPA compared with non-micropapillary lung adenocarcinoma (LA).

METHODS

Formalin-fixed paraffin-embedded (FFPE) sections derived from lung adenocarcinoma patients who never received adjuvant chemotherapy or radiation therapy prior to surgical resection were collected from October 2016 to June 2019. EGFR mutations, ROS1 rearrangements, and EML4-ALK fusion were identified in a set of 131 MPA and LA cases by using the amplification refractory mutation system (ARMS). The response rate and duration of response were assessed using Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1).

RESULTS

EGFR mutations had occurred in 42 (76.4%) MPA patients and 42 (55.3%) LA patients. Interestingly, ROS1 rearrangements were highly enriched only in the MPA cases (6/55, 10.9%) but rarely in the LA cases (1/76, 1.3%). Furthermore, 7.3% (4/55) MPA samples had double gene mutations, while only 1.3% (1/76) LA cases had double gene alterations. Of 5 patients with harboring two driver oncogene mutations, four patients (80%) obtained partial response, and one patient (20%) suffered recurrence.

CONCLUSIONS

A higher prevalence of ROS1 rearrangement or combined mutations of ROS1, EGFR, and EML4-ALK may play a critical role in the tumorigenesis of MPA. These findings provide a novel therapeutic strategy for patients with malignant MPA through combining TKIs than one TKI.

Clinical characteristics of patients with ROS1 gene rearrangement in non-small cell lung cancer: a meta-analysis

BACKGROUND

ROS1 gene rearrangement has been reported in several types of cancers, including non-small cell lung cancer (NSCLC). It is reported that tyrosine kinase inhibitors are effective in the treatment of ROS1-rearranged NSCLC. Therefore, the identification of ROS1 rearrangement can be used as potential therapeutic target in lung cancer. Epidemiological data indicates that ROS1 gene rearrangement occurs in approximately 1-2% of NSCLC patients. The small sample sizes of the existing associated studies only represent the characteristics of patients in specific regions or countries, and there is still no latest statistical analysis on ROS1 gene rearrangement anywhere in the world.

METHODS

We conducted a systematic search of the PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), CBM, CNKI, Wanfang, and VIP databases to identify studies on ROS1 gene rearrangement in NSCLC patients from January 1, 2015 to October 27, 2019. We conducted a meta-analysis to investigate the relationship between ROS1 gene rearrangement and clinical characteristics of NSCLC patients. The four clinical features are as follows: gender, smoking status, pathological type, and lung cancer stage.

RESULTS

Thirty-nine studies constituting of 25,055 NSCLC patients were eligible for inclusion in this meta-analysis. A prominently higher rate of ROS1 gene rearrangement was observed in female NSCLC patients (OR =1.94, 95% CI: 1.62-2.32%, P<0.05), patients with no smoking history (OR =2.82, 95% CI: 2.24-3.55%, P<0.05), patients with adenocarcinoma (OR =1.55, 95% CI: 1.14-2.11%, P<0.05), and patients with stage III-IV disease (OR =1.50, 95% CI: 1.15-1.94%, P<0.05). Our meta-analysis also showed that the prevalence of ROS1 rearrangement in adenocarcinoma was 2.49% (95% CI: 1.92-3.11%), while it was lower in non-adenocarcinoma patients (1.37%).

CONCLUSIONS

ROS1 gene rearrangement was more predominant in female patients, patients without smoking history, patients with adenocarcinoma and patients with advanced-stage disease (stages III to IV).

Characteristics and Response to Crizotinib in ALK-Rearranged, Advanced Non-Adenocarcinoma, Non-Small Cell Lung Cancer (NA-NSCLC) Patients: a Retrospective Study and Literature Review

BACKGROUND

Oncogenic fusion genes consisting of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) can be detected in 5-7% of lung adenocarcinoma cases. The prevalence of ALK rearrangement in non-adenocarcinoma, non-small cell lung cancers (NA-NSCLC) is currently unknown. In addition, the efficacy of crizotinib in these patients has not been well established.

OBJECTIVES

The aim of this study was to investigate the prevalence of ALK rearrangement in NA-NSCLC patients and the therapeutic efficacy of crizotinib in these patients.

METHODS

We included NA-NSCLC patients who were tested for the presence of ALK rearrangement in our institution from January 2013 to May 2018. The effectiveness of crizotinib in ALK-positive patients was retrospectively analyzed. A literature review was performed and eligible previously published cases were analyzed in combination with our data.

RESULTS

A total of 4662 patients were screened and 1696 NA-NSCLC patients were tested for the presence of ALK rearrangement during the study period. Thirty-two positive patients were identified (1.9%, 95% CI, 1.2-2.5%). A statistically higher percentage of younger (58.0 vs. 63.0, p = 0.01), female patients (53.1% vs. 10.8%, p < 0.01) who were non-smokers (71.9% vs. 40.6%, p < 0.01) and whose tumors contained adenocarcinoma components (34.4% vs. 6.1%, p < 0.01) were observed in the ALK-positive group. Eighteen patients were excluded from the study and 14 eligible patients were included for survival analysis. The median duration of crizotinib treatment (MDT) as a proxy for progression-free survival of the 14 eligible patients in our institution was 6.0 months (95% CI, 1.2-10.8 months). We combined our data with sporadic cases from 16 previous publications (total n = 37) and found that the MDT was 7.0 months (95% CI, 6.0-8.0 months).

CONCLUSIONS

Our study suggests the opportunity to test ALK rearrangement in NA-NSCLC patients, especially in younger, female, non-smoking patients containing adenocarcinoma components. Crizotinib provides an option for the treatment of NA-NSCLC patients who have an ALK rearrangement.

Discovery Stories of RET Fusions in Lung Cancer: A Mini-Review

In 2004, a chemical inhibitor of the kinase activity of EGFR was reported to be effective in a subset of lung cancer patients with activating somatic mutations of EGFR. It remained unclear, however, whether kinase fusion genes also play a major role in the pathogenesis of lung cancers. The discovery of the EML4-ALK fusion kinase in 2007 was a breakthrough for this situation, and kinase fusion genes now form a group of relevant targetable oncogenes in lung cancer. In this mini-review article, the discovery of REarrangement during Transfection fusions, the third kinase fusion gene in lung cancer, is briefly described.

ALK and ROS1 concurrent with EGFR mutation in patients with lung adenocarcinoma

PURPOSE

The purpose of this study was to explore the frequencies of ALK and ROS1 fusion genes in EGFR-mutant lung adenocarcinoma patients and examine the therapeutic efficacies of EGFR-tyrosine kinase inhibitors (TKIs).

MATERIALS AND METHODS

A total of 421 EGFR-mutated patients taking EGFR-TKIs were examined for ALK and ROS1 fusion genes based on reverse transcription-polymerase chain reaction (RT-PCR). Progression-free survival (PFS) and overall survival (OS) were evaluated by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

The mutations of ALK rearrangement (n=10) and ROS1 rearrangement (n=3) were detected. All the patients received EGFR-TKIs, and eight took subsequent ALK/ROS1 inhibitor. PFS was longer in single EGFR mutants (n=408) than in EGFR/ALK or EGFR/ROS1 counterparts (n=13; 10.7 vs 6.6 months, P=0.004). No difference in OS existed between single EGFR and EGFR/ALK or EGFR/ROS1 mutants (21.0 vs 23.0 months, P=0.196). The median PFS of eight patients treated with ALK/ROS1 inhibitor was 6.0 months.

CONCLUSION

Concomitant ALK/ROS1 fusion genes occurred in 3.1% EGFR-mutated lung adenocarcinoma patients. Concomitant ALK/ROS1-EGFR mutations may influence the therapeutic efficacy of EGFR-TKIs.

Clinicopathological characteristics of ROS1- and RET-rearranged NSCLC in caucasian patients: Data from a cohort of 713 non-squamous NSCLC lacking KRAS/EGFR/HER2/BRAF/PIK3CA/ALK alterations

Targeted therapies have substantially changed the management of non-small cell lung cancer (NSCLC) patients with driver oncogenes. Given the high frequency, EGFR and ALK aberrations were the first to be detected and paved the way for tyrosine kinase inhibitor (TKI) treatments. Other kinases such as ROS1 and more recently RET have emerged as promising targets, and ROS1 and RET TKIs are already available for precision medicine. We screened a large cohort of 713 Caucasian non-squamous NSCLC patients lacking EGFR/KRAS/BRAF/HER2/PI3KCA/ALK aberrations for ROS1 and RET rearrangements using fluorescence in situ hybridization to determine the frequency and clinicopathological characteristics of ROS1- and RET-positive patients. Frequencies of ROS1 and RET rearrangements were 2.1% and 2.52%, respectively. Contrary to common belief, both ROS1 and RET rearrangements were detected in patients with a history of smoking, and the RET-positive patients were not younger than the negative patients. Moreover, RET but not ROS1 rearrangement was associated with the female gender. Nearly half of the ROS1-rearranged patients were successfully treated with ROS1 TKIs. In contrast, only 5/18 RET-positive patients received off-label RET TKIs. Two patients had stable disease, and three experienced disease progression. In addition to the 18 RET-positive cases, 10 showed isolated 5' signals. The clinical relevance is unknown but if the frequency is confirmed by other groups, the question whether these patients are eligible to TKIs will arise. More potent RET TKIs are under development and may improve the response rate in RET-positive patients. Therefore, we recommend the routine implementation of RET testing in non-squamous NSCLC patients, including those with a history of smoking.