Tiziana Vavalà

EGFR Fusions as Novel Therapeutic Targets in Lung Cancer

UNLABELLED Here, we report that novel epidermal growth factor receptor (EGFR) gene fusions comprising the N-terminal of EGFR linked to various fusion partners, most commonly RAD51, are recurrent in lung cancer. We describe five patients with metastatic lung cancer whose tumors harbored EGFR fusions, four of whom were treated with EGFR tyrosine kinase inhibitors (TKI) with documented antitumor responses. In vitro, EGFR-RAD51 fusions are oncogenic and can be therapeutically targeted with available EGFR TKIs and therapeutic antibodies. These results support the dependence of EGFR-rearranged tumors on EGFR-mediated signaling and suggest several therapeutic strategies for patients whose tumors harbor this novel alteration. SIGNIFICANCE We report for the first time the identification and therapeutic targeting of EGFR C-terminal fusions in patients with lung cancer and document responses to the EGFR inhibitor erlotinib in 4 patients whose tumors harbored EGFR fusions. Findings from these studies will be immediately translatable to the clinic, as there are already several approved EGFR inhibitors. Cancer Discov; 6(6); 601-11. ©2016 AACR.See related commentary by Paik, p. 574This article is highlighted in the In This Issue feature, p. 561.

Early Response to Chemotherapy in Patients With Non–Small-Cell Lung Cancer Assessed by [18F]-Fluoro-Deoxy-D-Glucose Positron Emission Tomography and Computed Tomography

BACKGROUND This study aimed to demonstrate that patients who exhibit a tumor metabolic response to first-line chemotherapy seen on FDG-PET and computed tomography (CT) would survive longer than those who did not show such a response, comparing this evaluation with the morphologic response seen on CT. PATIENTS AND METHODS Images were acquired in 22 consecutive patients with advanced non-small-cell lung cancer (NSCLC) randomized to receive carboplatin/paclitaxel/sorafenib or placebo. FDG-PET was performed within 4 weeks before (PET1) and 2 weeks after starting treatment (PET2). Similarly, CT (CT1) was performed at baseline and then every 2 cycles (6 weeks) during treatment (CT2). Responders and nonresponders were identified with FDG-PET, and metabolic response was then compared with morphologic changes detected by spiral CT. RESULTS Twenty-one of 22 patients completed this study. In terms of progression-free survival (PFS) (45 vs. 22.2 weeks) and overall survival (OS) (77 vs. 47.7 weeks), we observed a trend that was not statistically significant for patients whose response after 2 weeks of treatment was seen on FDG-PET (P = .22 for PFS; P = .15 for OS). CONCLUSION Patients with advanced NSCLC who had a positive outcome, as evidenced by prolonged survival, were those who showed a tumor metabolic response seen on FDG-PET.

ATF2 contributes to cisplatin resistance in non-small cell lung cancer and celastrol induces cisplatin resensitization through inhibition of JNK/ATF2 pathway.

ATF2 is a transcription factor involved in stress and DNA damage. A correlation between ATF2 JNK‐mediated activation and resistance to damaging agents has already been reported. The purpose of the present study was to investigate whether ATF2 may have a role in acquired resistance to cisplatin in non‐small cell lung cancer (NSCLC). mRNA and protein analysis on matched cancer and corresponding normal tissues from surgically resected NSCLC have been performed. Furthermore, in NSCLC cell lines, ATF2 expression levels were evaluated and correlated to platinum (CDDP) resistance. Celastrol‐mediated ATF2/cJUN activity was measured. High expression levels of both ATF2 transcript and proteins were observed in lung cancer specimens (p << 0.01, Log2(FC) = +4.7). CDDP‐resistant NSCLC cell lines expressed high levels of ATF2 protein. By contrast, Celastrol‐mediated ATF2/cJUN functional inhibition restored the response to CDDP. Moreover, ATF2 protein activation correlates with worse outcome in advanced CDDP‐treated patients. For the first time, it has been shown NSCLC ATF2 upregulation at both mRNA/protein levels in NSCLC. In addition, we reported that in NSCLC cell lines a correlation between ATF2 protein expression and CDDP resistance occurs. Altogether, our results indicate a potential increase in CDDP sensitivity, on Celastrol‐mediated ATF2/cJUN inhibition. These data suggest a possible involvement of ATF2 in NSCLC CDDP‐resistance.

Maintenance therapy in NSCLC: why? To whom? Which agent?

Maintenance therapy is emerging as a treatment strategy in the management of advanced non small cell lung cancer (NSCLC). Initial trials addressing the question of duration of combination chemotherapy failed to show any overall survival benefit for the prolonged administration over a fixed number of cycles with an increased risk for cumulative toxicity. Nowadays several agents with different ways of administration and a different pattern of toxicity have been formally investigated in the maintenance setting. Maintenance strategies include continuing with an agent already present in the induction regimen or switching to a different one. Taking into consideration that no comparative trials of maintenance with different chemotherapy drugs or targeted agents have been conducted, the choice and the duration of maintenance agents is largely empirical. Furthermore, it is still unknown and it remains an open question if this approach needs to be proposed to every patient in the case of partial/complete response or stable disease after the induction therapy. Here, we critically review available data on maintenance treatment, discussing the possibility to tailor the right treatment to the right patient, in an attempt to optimize costs and benefits of an ever-growing panel of different treatment options.

Lung cancer and women

In the early 1900s, lung cancer was a rare malignancy in women, but starting from the 1960s it has progressively reached epidemic proportions, surpassing breast cancer in 1987 and becoming the leading cause of cancer deaths in many countries. Retrospective data show that the 5-year survival rate for women who have lung cancer is 15.6%, compared with 12.5% for men, and this improved survival could have important implications in the design and interpretation of lung cancer trials. Women have major responses to therapy regardless of stage, therapeutic modalities or histology. The increase of lung cancer incidence among women is reflected in their clinical trial participation, causing a survival improvement and suggesting the need of stratification by sex in future studies. No specific drugs for women with lung cancer are currently available, but researchers are devoting energies in this area in order to better understand the implication of gender differences in epidemiology, pathogenesis, prognosis and tumor response.

Does Immunohistochemistry Represent a Robust Alternative Technique in Determining Drugable Predictive Gene Alterations in Non-Small Cell Lung Cancer?

Immunohistochemistry (IHC) is a widely-tested, low-cost and rapid ancillary technique available in all laboratories of pathology. This method is generally used for diagnostic purposes, but several studies have investigated the sensitivity and specificity of different immunohistochemical antibodies as a surrogate test in the determination of predictive biomarkers in non-small cell lung cancer (NSCLC), particularly for Epidermal Growth Factor Receptor (EGFR) gene mutations, Anaplastic Lymphoma Kinase (ALK) gene and ROS1 rearrangements. In this review, a critical examination of the works comparing the consistency of IHC expression and conventional molecular techniques to identify genetic alterations with predictive value in NSCLC is discussed. Summarizing, data on sensitivity and specificity of antibodies against ALK and ROS1 are very consistent and time has come to trust in IHC at least as a cost-effective screening tool to identify patients with rearranged tumors in clinical practice. On the other hand, mutant-specific antibodies against EGFR demonstrate a good specificity but a lowto- fair sensitivity, raising some cautions on their employment as robust predictive biomarkers. A brief comment on preliminary experiences with antibodies against BRAF, RET, HER2 and c-MET is also included.

Functional imaging in predicting response to antineoplastic agents and molecular targeted therapies in lung cancer: A review of existing evidence

The increasing use of FDG-PET ((18)F-2-fluoro-2-deoxy-d-glucose positron emission tomography) imaging in the staging of non-small-cell lung cancer (NSCLC) may result in a significant shift in stage distribution, with an increased percentage of patients staged as having metastatic disease and consequently a higher percentage of patients treated with systemic therapy. The amount of FDG-PET uptake in primary lung lesions has been shown to be correlated with tumour growth rate. Data suggest that tumours with increased glucose uptake are presumably more metabolically active and more biologically aggressive, and standardized uptake value (SUV) at PET may be regarded as a prognostic factor. Growing evidence suggests that PET may be used as a predictive marker to assess the activity of antineoplastic agents, allowing close monitoring of the efficacy of the treatment in order to be able to switch earlier to alternative therapies according to the individual chemosensitivity of the tumour. Currently the value of FDG-PET for monitoring response is complicated by the heterogeneity of the published data on the methods used for FDG quantification and the selection of the primary targets and clinical endpoints. As a result, objective validation of proposed thresholds of responsiveness is lacking. This article discusses the assessment of treatment response in NSCLC patients using functional imaging, and emphasizes advantages and limitations in clinical management.

Impact of Non–Small-Cell Lung Cancer-Not Otherwise Specified Immunophenotyping on Treatment Outcome

Introduction: The vast majority of non–small-cell lung cancers (NSCLCs) presents as advanced disease, and histological diagnosis is widely based on small samples. The differential activity and toxicity profile of new cytotoxic and molecular-targeted therapies according to histotypes requires a precise subtyping of NSCLC. Immunohistochemistry (IHC) contributes to define the most probable histotype; however, the real impact of IHC characterization of NSCLC-not otherwise specified (NOS) in terms of outcome is not well established. Methods: A large series of 224 advanced “nonsquamous” NSCLC diagnosed on small biopsy or cytological samples and homogeneously treated was retrospectively selected, all having adequate follow-up data available. Reviewed diagnoses resulted into two groups: adenocarcinoma (ADC) and NSCLC-NOS. The latter was further characterized by IHC (TTF-1, Napsin-A, p40, and Desmocollin-3) –identify a possible, most probable differentiation lineage. Results: Sixty-seven percentage of cases were classified as ADC based on morphological examination only (“morphological ADC”) and 33% as NSCLC-NOS. IHC profiling of NSCLC-NOS identified 43.2% of cases with an ADC immunophenotype (“NSCLC favor ADC”), 10.8% with a phenotype favoring squamous lineage, and 46% lacking differentiation features. Survival curves confirmed no difference in terms of outcome between the morphological ADC and the NSCLC favor ADC groups, while a significantly poorer outcome was found in the “null” group in terms of best response, progression-free survival or overall survival (OS). Conclusion: Tumors with an IHC profile ADC-like had an OS comparable with that of morphological ADCs. These findings support the use of IHC to optimize lung cancer histological typing and therapy.

Risk Stratification Model for Resected Squamous-Cell Lung Cancer Patients According to Clinical and Pathological Factors

Introduction: The aim of this analysis (AIRC-MFAG project no. 14282) was to define a risk classification for resected squamous-cell lung cancer based on the combination of clinicopathological predictors to provide a practical tool to evaluate patients’ prognosis. Methods: Clinicopathological data were retrospectively correlated to disease-free/cancer-specific/overall survival (DFS/CSS/OS) using a Cox model. Individual patient probability was estimated by logistic equation. A continuous score to identify risk classes was derived according to model ratios and dichotomized according to prognosis with receiver operating characteristic analysis. Results: Data from 573 patients from five institutions were gathered. Four hundred ninety-four patients were evaluable for clinical analysis (median age: 68 years; male/female: 403/91; T-descriptor according to TNM 7th edition 1–2/3–4: 330/164; nodes 0/>0: 339/155; stages I and II/III and IV: 357/137). At multivariate analysis, age, T-descriptor according to TNM 7th edition, nodes, and grading were independent predictors for DFS and OS; the same factors, except age and grading, predicted CSS. Multivariate model predict individual patient probability with high prognostic accuracy (0.67 for DFS). On the basis of receiver operating characteristic-derived cutoff, a two-class model significantly differentiated low-risk and high-risk patients for 3-year DFS (64.6% and 32.4%, p < 0.0001), CSS (84.4% and 44.5%, p < 0.0001), and OS (77.3% and 38.8%, p < 0.0001). A three-class model separated low-risk, intermediate-risk, and high-risk patients for 3-year DFS (64.6%, 39.8%, and 21.8%, p < 0.0001), CSS (84.4%, 55.4%, and 30.9%, p< 0.0001), and OS (77.3%, 47.9%, and 27.2%, p < 0.0001). Conclusions: A risk stratification model including often adopted clinicopathological parameters accurately separates resected squamous-cell lung cancer patients into different risk classes. The project is currently ongoing to integrate the clinicopathological model with investigational molecular predictors.

Outcomes of First-Generation EGFR-TKIs Against Non-Small-Cell Lung Cancer Harboring Uncommon EGFR Mutations: A Post Hoc Analysis of the BE-POSITIVE Study

Background Beyond progression after tyrosine kinase inhibitor in EGFR‐positive non‐small‐cell lung cancer patients (BE‐POSITIVE) was the first Italian multicenter observational study that reported the outcomes of first‐generation epidermal growth factor receptor (EGFR)‐tyrosine kinase inhibitors (TKIs) in a “real‐life” Caucasian EGFR‐mutated non‐small‐cell lung cancer (NSCLC) population. The sharing of multi‐institutional experiences represents a crucial strategy to enrich knowledge about uncommon EGFR mutations. Therefore, we performed a post hoc analysis of the BE‐POSITIVE study. Patients and Methods Data of advanced NSCLC patients with uncommon EGFR mutations who received first‐line first‐generation EGFR‐TKIs in 24 Italian Hospitals were collected. In this analysis we aimed to evaluate overall survival (OS), progression‐free survival (PFS), and overall response rate (ORR) of EGFR‐TKIs in NSCLC patients harboring uncommon EGFR mutations. Results Thirty‐five patients harboring uncommon EGFR mutations (any mutation other than deletion 19 or substitution of leucine by arginine at codon 858) were included of the original 312 EGFR‐mutated cases. Most of them were female (n = 20, 57.1%), former smokers (n = 23, 65.7%), with adenocarcinoma (n = 31, 88.6%). The most frequent EGFR mutations were G719X (n = 6, 17.2%) and L861Q (n = 5, 14.2%). The population presented an ORR of 25.7%, a median PFS of 5.19 months, and a median OS of 14.49 months. When stratified according to type of EGFR mutation, median OS ranged from 3.65 months for unspecified mutations to 21.29 for double EGFR mutations. Median PFS ranged from 1.77 months for unspecified mutations to 20.83 months for concomitant EGFR‐anaplastic lymphoma kinase alteration. ORR varied from 0% in exon 18, 20 and double gene alteration to 66.6% in exon 19. Conclusion Our study supports the existence of a strong outcome heterogeneity within patients harboring uncommon EGFR mutations, which needs to be clarified to achieve a real personalized treatment strategy. Micro‐Abstract Non‐small‐cell lung cancer harboring uncommon epidermal growth factor receptor (EGFR) mutations (any mutation other than deletion 19 or substitution of leucine by arginine at codon 858) presents a variable sensitivity to EGFR‐tyrosine kinase inhibitors. With the final aim to enrich knowledge about uncommon EGFR mutations, we performed a post hoc analysis of the beyond progression after tyrosine kinase inhibitor in EGFR‐positive non‐small‐cell lung cancer patients (BE‐POSITIVE) trial. Thirty‐five patients were included of the original 312 EGFR‐mutated cases. The results of our analysis support the existence of a strong heterogeneity within patients harboring uncommon EGFR mutations, which implies the necessity to stratify the subgroups of rare mutations in individual entities with different clinical perspectives.