EGFR mutation in gefitinib-responsive small-cell lung cancer

Primary de novo Epidermal Growth Factor Receptor Mutant Small Cell Lung Carcinomas: Clinicopathological Study of a Rare Entity Presenting in Treatment-Naïve Setting with Review of Literature

Introduction: Small cell lung carcinomas (SCLC) are characterized by loss of function mutations in genes encoding for p53 (tumor protein p53-TP53) and retinoblastoma transcriptional corepressor 1 (RB1) proteins in the majority of tumors. They are aggressive, usually present with metastatic disease, and are treated with platinum-based chemotherapy with overall poor outcomes. Epidermal growth factor receptor (EGFR) mutations, classically associated with primary lung adenocarcinomas, have been reported in rare de novo SCLC outside the context of the relatively more common transformed SCLC that arise with emergence of tyrosine kinase inhibitor resistance in EGFR-mutant adenocarcinomas. Aim: To analyze the clinicopathological features of EGFR-mutant de novo SCLC. Methods: EGFR-mutant de novo SCLCs were retrieved over 5 years and reviewed for clinicopathological parameters. Results: Five patients were identified harboring either exon 19 deletion (n = 4) or exon 21 L858R mutation (n = 1) in EGFR. Median age at diagnosis was 48 years (30-58 years). Four patients were never-smokers of whom three were tobacco chewers. Three biopsies showed pure small cell carcinoma while others showed composite adenocarcinoma. Diffuse loss of RB1 (5/5) and mutant type p53 staining pattern (3/3) were noted in all tested samples. Among two patient samples subjected to sequencing, additional pathogenic mutations in TP53 (2/2), RB1 (1/2), PTEN (1/2), neurofibromatosis type 1 (1/2), and CREBB1 (1/2) were identified. Conclusion: EGFR-mutant de novo SCLCs are extremely rare and show frequent inactivation of p53 and RB1, like the more common transformed SCLCs. Given the lack of tyrosine kinase inhibitor exposure, these tumors highlight the inherent lineage plasticity of EGFR/TP53/RB1 triple mutant lung carcinomas.

Neuroendocrine Transformation as a Mechanism of Resistance to Targeted Lung Cancer Therapies: Emerging Mechanisms and Their Therapeutic Implications

Lung cancer is the leading cause of cancer-related deaths worldwide, highlighting a major clinical challenge. Lung cancer is broadly classified into two histologically distinct subtypes, termed small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). Identification of various oncogenic drivers of NSCLC has facilitated the development of targeted therapies that have dramatically improved patient outcomes. However, acquired resistance to these targeted therapies is common, which ultimately results in patient relapse. Several on-target and off-target resistance mechanisms have been described for targeted therapies in NSCLC. One common off-target mechanism of resistance to these therapies is histological transformation of the initial NSCLC into SCLC, a highly aggressive form of lung cancer that exhibits neuroendocrine histology. This mechanism of resistance presents a significant clinical challenge, since there are very few treatments available for these relapsed patients. Although the phenomenon of NSCLC-to-SCLC transformation was described almost 20 years ago, only recently have we begun to understand the mechanisms underlying this therapy-driven response. These recent discoveries will be key to identifying novel biomarkers and therapeutic strategies to improve outcomes of patients that undergo NSCLC-to-SCLC transformation. Here, we highlight these recent advances and discuss the potential therapeutic strategies that they have uncovered to target this mechanism of resistance.

Clinical features and prognostic factors of IV combined small cell lung cancer: A propensity score matching analysis

BACKGROUND

Nowadays, the characteristics and treatment of combined small-cell lung carcinoma (CSCLC) remain controversial. This study aimed to analyze the features of clinical demographics, survival outcomes and treatment modalities among IV CSCLC, IV SCLC and IV NSCLC, to provide more evidence for the study of IV CSCLC.

METHODS

All CSCLC, SCLC and NSCLC patient data were obtained from the SEER database (2010-2020). Pearson's χ2 test was used to compare the differences in clinical characteristics. Propensity score matching (PSM) was utilized to balance the bias of the variables between patients. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify prognostic factors. KM analysis was used to calculate survival. Adjusted analyses for the primary outcome of different treatment modalities of IV CSCLC, IV SCLC and IV NSCLC were performed using Cox regression models.

RESULTS

A total of 493 patients with IV CSCLC, 35503 patients with SCLC, 122807 patients with IV NSCLC were included in this study. The demographic characteristics and tumor characteristics of the three groups were different. Before PSM, there were significant differences in OS and CSS among IV CSCLC, IV SCLC and IV NSCLC, After PSM, there was a significant difference in OS and CSS between the IV CSCLC and IV NSCLC. Risk/protective factors for OS and CSS were different in three groups. Chemotherapy, radiotherapy, and surgery can improve IV CSCLC's survival time. The combination of surgery and chemoradiotherapy treatment group for patients with IV CSCLC demonstrated best OS compared to control treatment groups, and the surgery combined chemotherapy treatment group exhibited the best CSS. Additionally, for select patients with stage IV CSCLC who have missed the window for surgical intervention at the time of initial diagnosis, chemoradiotherapy presents a viable and effective treatment option.

CONCLUSIONS

The clinical characteristics IV CSCLC, IV SCLC and IV NSCLC were significantly different. The prognosis for IV CSCLC is notably poorer than IV NSCLC, similar to IV SCLC. Surgery combined therapy emerged as the preferred treatment modalities and chemoradiotherapy was a good choice for patients who have lost the indication of surgery for patients diagnosed with IV CSCLC.

Exploring the prognostic impact of differences in treatment strategies for SCLC with different histologies and prognostic factors for C-SCLC: A SEER population-based study

Background

Combined small cell lung cancer (C-SCLC) is a rare type of small cell lung cancer (SCLC), and it is controversial whether to choose the same treatment regimen as SCLC due to its multiple histologic components.

Study methods and results

Records of patients with small cell lung cancer diagnosed between 2010 and 2020 were extracted using the SEER database. The OS of patients with different histological types under the same staging and treatment regimen was analyzed. It was found that early-stage (stage IA-IIA) surgical treatment, systemic chemotherapy alone, and chemoradiotherapy were more efficacious than C-SCLC and P-SCLC in patients with limited-stage (P = 0.054, P = 0.001, P = 0.019). In patients with extensive staging, the OS of patients with systemic chemotherapy regimens differed (P = 0.045) and was better in C-SCLC than in P-SCLC. We further explored the treatment strategy for patients with C-SCLC, which was shown by a COX regression model based on prognostic factors screened by Random Forest and LASSO regression models. Surgery, radiotherapy, and chemotherapy would be beneficial for survival. In a subgroup analysis based on stage and treatment regimen, it was shown that patients with early staging (stage IA-IIA) had a better prognosis with surgery (P < 0.001); in patients with extensive staging, chemoradiotherapy was favorable to the patient's prognosis (P = 0.022).

Conclusion

Both limited-stage and extensive-stage C-SCLC patients are more sensitive to chemotherapy than P-SCLC patients. Patients with C-SCLC who have access to surgery should undergo surgery as early as possible, while chemoradiotherapy is recommended for patients with extensive staging. Patient age, gender, tumor size, surgery, chemotherapy, radiotherapy, and metastasis may individually affect patient prognosis.

Molecular and Genetic Advances in Small Cell Lung Cancer Landscape: From Homogeneity to Diversity

Small cell lung cancer (SCLC) has been historically considered a homogeneous disease and thus approached as a single entity when it comes to clinical studies design and new treatments developments. However, increasing knowledge in the genetic and molecular landscape of this disease challenges this concept, opening the possibility that different subtypes might show differential vulnerability to treatments. In this narrative review, we gather the most relevant advances in genetic and molecular characterization of SCLC, focusing on how these discoveries may be used to design the path for a personalized treatment approach. Indeed, we discuss the new classification based on differential protein expression, the prevalence and significance of oncogenic drivers (e.g., EGFR mutations and ALK rearrangements) in SCLC, the genetic characteristics of SCLC in patients with no smoking history, and the existing evidence supporting the use of liquid biopsy for capturing the heterogeneity of the disease. We use the keywords "small cell lung cancer", "SCLC", "EGFR", "ALK", "histological transformation", and "transcriptional factors" to identify original research manuscripts, clinical trials, case reports, and case series from PubMed.

Efficacy of Tyrosine Kinase Inhibitors in Primary Driver-Gene-Positive Combined Small-Cell Lung Cancer: A Retrospective Study

BACKGROUND

Combined small-cell lung cancer (c-SCLC) with gene mutations is a rare subtype often found alongside adenocarcinoma. Targeted therapy may be effective because of the presence of specific molecular targets. However, due to its rarity and unconventional genetic testing, the efficacy remains uncertain.

METHODS

A total of 31 c-SCLC patients with gene mutations were retrospectively included and grouped according to their treatment regimens. Treatment outcomes were evaluated. Kaplan-Meier method was used for survival analysis, with Log Rank test applied for comparison between groups.

RESULTS

We divided the 31 patients into 3 groups according to first-line treatment: group A (chemotherapy, n = 16), group B (targeted monotherapy, n = 7), and group C (targeted combination therapy, n = 8). The overall response rates (ORR) were 43.8%, 42.9%, and 62.5%. The disease control rates (DCR) were 87.5%, 85.7%, and 100%. The median progression-free survival (PFS) was 4.0, 5.0, and 7.93 months (P = .024), with a significant difference between group A and C (P = .010). The median overall survival (OS) was 14.10, 17.43, and 12.93 months (P = .313). Seven patients in group A received targeted therapy in later-line. Of the total 22 patients received targeted monotherapy or combination therapy, the ORR and DCR were 54.5% and 90.9%. The median PFS and OS were 5.87 and 17.30 months. Additionally, adverse events (AEs) occurred in 53.8% and 88.9% of monotherapy and combination therapy. The most common AEs in monotherapy were elevated transaminases (23.1%) and in combination anemia (66.7%).

CONCLUSIONS

TKIs showed encouraging efficacy in driver-gene-positive c-SCLC. While monotherapy may be a supplementary option, combination with chemotherapy appears to be preferable and superior.

Detection of clinically-relevant <em>EGFR</em> variations in <em>de novo</em> small cell lung carcinoma by droplet digital PCR

Targeted therapy that utilizes tyrosine kinase inhibitors (TKIs), specific to epidermal growth factor receptors (EGFR) has changed the landscape of treatment of non-small cell lung cancer (NSCLC). The success or failure of this approach depends on presence of certain variations in the tyrosine kinase domain of EGFR gene. Generally, patients diagnosed with Small cell lung cancer (SCLC) are considered ineligible for TKI therapy owing to the absence of EGFR variations. . However, there is evidence of these variations being detected in SCLCs, both in de-novo and in transformed SCLCs (TKI-treated adenocarcinomas). Despite the presence of clinically-relevant EGFR variations in SCLCs, the response to TKIs has been inconsistent.  Liquid biopsy is a well-established approach in lung cancer management with proven diagnostic, prognostic and predictive applications. It relies on detection of circulating tumor-derived nucleic acids present in plasma of the patient. In this study, a liquid biopsy approach was utilized to screen 118 consecutive lung cancer patients for four clinically-relevant variations in EGFR gene, which included three activating/sensitizing variations (Ex18 G719S, Ex19del E746-A750 and Ex21 L858R) and one acquired/resistance (Ex20 T790M, de novo) variation by droplet digital PCR, the most advanced third generation PCR technique. As expected, clinically-relevant EGFR variations were found in majority of the non-small cell lung cancer cases. However, among the handful of small cell lung cancer samples screened, sensitizing variations (Ex18 G719S and Ex21 L858R) were seen in almost all of them. Interestingly, Ex20 T790M variation was not detected in any of the cases screened.  The results of our study indicate that EGFR variations are present in SCLCs and highly sensitive liquid biopsy techniques like ddPCR can be effectively utilized for this purpose of screening EGFR variations in such samples.

A Rare Case of Small Cell Lung Cancer With an Epidermal Growth Factor Receptor Mutation and Its Response to Osimertinib

Small cell lung cancer (SCLC) accounts for less than 15% of the cases of lung cancer. Epidermal growth factor receptor (EGFR) mutations are rarely reported in association with SCLC. EGFR tyrosine kinase inhibitors (TKI) are approved as the first-line therapy for metastatic non-small cell lung cancer (NSCLC). The clinical effect of EGFR mutations and its response to osimertinib are unknown in SCLC. We report a case of EGFR-positive metastatic SCLC in a 63-year-old female who was treated with the third-generation TKI, osimertinib. 

Extensive-Stage Small Cell Carcinoma Transformation From EGFR Del19-Mutant Lung Adenocarcinoma on Gefitinib at the Twelfth-Year Follow-Up Case Report

INTRODUCTION

The acquired resistance mechanisms in patients with epidermal growth factor receptor (EGFR)-mutant lung cancer, particularly adenocarcinoma (ADC), following treatment with an EGFR tyrosine kinase inhibitor (TKI) have received extensive investigations. The phenotypic transformation to small cell carcinoma (SCCT) has been estimated to occur in approximately 3 to 10% of patients treated with an EGFR-TKI. The prognosis after SCCT is extremely poor.

CASE STUDY

We report about SCCT that occurred 45 months after the initial diagnosis of ADC in an East Asian never-smoker woman with advanced-stage EGFR Del-19-mutant lung ADC treated with combined chemoradiotherapy before the era of insurance coverage for EGFR-TKIs in this country and subsequently gefitinib; deletion at codon 746-750 in exon 19 of the EGFR gene was ascertained in the original formalin-fixed paraffin-embedded lung biopsy tissue. Spinal cord compression at thoracic-12 level from SCCT was successfully relieved with neurosurgical treatment, chemotherapy with etoposide and cisplatin, and radiotherapy, while gefitinib treatment was maintained. Eleven months later, SCCT relapsed in the lung parenchyma, which was resected and was found to be sensitive to second-line weekly topotecan. Prophylactic cranial irradiation was subsequently administered. SCCT was confirmed by MALDI-TOF MS analysis of formalin-fixed paraffin-embedded tissues demonstrating the same exon 19 deletion. At the 12th-year follow-up, the patient remains relapse free with very good performance status. The novelty of this case is the successful interdisciplinary team effort to correct the spinal cord compression by maintaining the patient in an ambulatory state, non-stop use of gefitinib justified by the presence of activating EGFR mutation in SCCT tumor cells, and aggressive dose-intensive chemotherapy and radiotherapy for the SCCT that leads to an unprecedented prolonged remission and survival. This case also supports the observation that SCCT is chemotherapy sensitive, and thus, re-biopsy or complete tumor excision is recommended to understand the mutation profiles of the current tumor. Aggressive prudent administration of systemic chemotherapy obtaining optimal dose intensity leads to the successful management of the patient.

Resistance to Both Chemotherapy and EGFR-TKI in Small Cell Lung Cancer With EGFR 19-Del Mutation: A Case Report

Epidermal growth factor receptor (EGFR) mutations are common in non-small cell lung cancers, but rare in small cell lung cancers (SCLCs). In previous reports, some SCLC patients with EGFR mutations could benefit from EGFR tyrosine kinase inhibitors (TKIs). In this study, we reported a case in which an SCLC patient with EGFR exon 19 deletion (19-Del) mutation did not benefit from EGFR-TKIs. Interestingly, the standard treatment strategies for SCLC also failed to control tumor progression. Moreover, we screened 43 SCLC patients in China and found that the frequency of EGFR mutations in Chinese SCLC patients was about 4.65% by next-generation sequencing (NGS). Collectively, this case illustrated a rare subtype of SCLCs which harbored EGFR mutations and was intrinsically resistant to standard treatments and EGFR-TKIs. We also tried to explore the mechanisms underlying drug resistance. The literature concerning SCLCs with EGFR mutations is reviewed.

Primary tumor standardized uptake value (SUVmax) measured on 18F-FDG PET/CT and mixed NSCLC components predict survival in surgical-resected combined small-cell lung cancer

Purpose

The combined small-cell lung cancer (c-SCLC) is rare and has unique clinicopathological futures. The aim of this study is to investigate ¹⁸F-FDG PET/CT parameters and clinicopathological factors that influence the prognosis of c-SCLC.

Methods

Between November 2005 and October 2014, surgical-resected tumor samples from c-SCLC patients who received preoperative ¹⁸F-FDG PET/CT examination were retrospectively reviewed. The maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to evaluate metabolic parameters in primary tumors. The survivals were evaluated with the Kaplan–Meier method. Univariate and multivariate analyses were used to evaluate potential prognostic factors.

Results

Thirty-one patients were enrolled, with a median age of 62 (range: 35 − 79) years. The most common mixed component was squamous cell carcinoma (SCC, n = 12), followed by large-cell carcinoma (LCC, n = 7), adenocarcinoma (AC, n = 6), spindle cell carcinoma (n = 4), adenosquamous carcinoma (n = 1) and atypical carcinoid (n = 1). The median follow-up period was 53.0 (11.0–142.0) months; the 5-year overall survival (OS) and progression-free survival(PFS) rate were 48.4% and 35.5%, respectively. Univariate survival analysis showed that gender, smoking history, tumor location were associated with PFS (P = 0.036, P = 0.043, P = 0.048), SUVmax and TNM stage were closely related to PFS in both Mixed SCC and non-SCC component groups (P = 0.007, P = 0.048). SUV_max, smoking history, tumor size and mixed SCC component were influencing factors of OS in patients (P = 0.040, P = 0.041, P = 0.046, P = 0.029). Multivariate survival analysis confirmed that TNM stage (HR = 2.885, 95%CI: 1.323–6.289, P = 0.008) was the most significantly influential factor for PFS. High SUV_max value (HR = 9.338, 95%CI: 2.426–35.938, P = 0.001) and mixed SCC component (HR = 0.155, 95%CI: 0.045–0.530, P = 0.003) were poor predictors for OS.

Conclusion

Surgical-resected c-SCLCs have a relatively good prognosis. TNM stage is the most significant factor influencing disease progression in surgical-resected c-SCLCs. SUVmax and mixed NSCLC components within c-SCLCs had a considerable influence on the survival. Both high SUVmax and mixed SCC component are poor predictors for patients with c-SCLCs.

Pathological transition as the arising mechanism for drug resistance in lung cancer

Despite the tremendous efforts for improving therapeutics of lung cancer patients, its prognosis remains disappointing. This can be largely attributed to the lack of comprehensive understanding of drug resistance leading to insufficient development of effective therapeutics in clinic. Based on the current progresses of lung cancer research, we classify drug resistance mechanisms into three different levels: molecular, cellular and pathological level. All these three levels have significantly contributed to the acquisition and evolution of drug resistance in clinic. Our understanding on drug resistance mechanisms has begun to change the way of clinical practice and improve patient prognosis. In this review, we focus on discussing the pathological changes linking to drug resistance as this has been largely overlooked in the past decades.

Multigene Mutation Profiling and Clinical Characteristics of Small-Cell Lung Cancer in Never-Smokers vs. Heavy Smokers (Geno1.3-CLICaP)

Objectives: Lung cancer is a heterogeneous disease. Presentation and prognosis are known to vary according to several factors, such as genetic and demographic characteristics. Small-cell lung cancer incidence is increasing in never-smokers. However, the disease phenotype in this population is different compared with patients who have a smoking history.

Material and Methods: To further investigate the clinical and genetic characteristics of this patient subgroup, a cohort of small cell lung cancer patients was divided into smokers (n = 10) and never/ever-smokers (n = 10). A somatic mutation profile was obtained using a comprehensive NGS assay. Clinical outcomes were compared using the Kaplan-Meier method and Cox proportional models.

Results: Median age was 63 years (46–81), 40% were men, and 90% had extended disease. Smoker patients had significantly more cerebral metastases (p = 0.04) and were older (p = 0.03) compared to their non-smoker counterparts. For never/ever smokers, the main genetic mutations were TP53 (80%), RB1 (40%), CYLD (30%), and EGFR (30%). Smoker patients had more RB1 (80%, p = 0.04), CDKN2A (30%, p = 0.05), and CEBPA (30%, p = 0.05) mutations. Response rates to first-line therapy with etoposide plus cisplatin/carboplatin were 50% in smokers and 90% in never/ever smokers (p = 0.141). Median overall survival was significantly longer in never smokers compared with smokers (29.1 months [23.5–34.6] vs. 17.3 months [4.8–29.7]; p = 0.0054). Never/ever smoking history (HR 0.543, 95% CI 0.41–0.80), limited-stage disease (HR 0.56, 95% CI 0.40–0.91) and response to first-line platinum-based chemotherapy (HR 0.63, 95% CI 0.60–0.92) were independently associated with good prognosis.

Conclusion: Our data supports that never/ever smoker patients with small-cell lung cancer have better prognosis compared to their smoker counterparts. Further, patients with never/ever smoking history who present with small-cell lung cancer have a different mutation profile compared with smokers, including a high frequency of EGFR, MET, and SMAD4 mutations. Further studies are required to assess whether the differential mutation profile is a consequence of a diverse pathological mechanism for disease onset.

Molecular genetic profiling of small cell lung carcinoma in a Chinese cohort

Background

Small cell lung cancer (SCLC) has unique biology and chromosomal modifications; however, only a few studies have investigated the molecular map of SCLC. The present study aimed to evaluate the genomic aberrations in patients with SCLC in a Chinese cohort.

Methods

Tumor samples of SCLC were prospectively collected from Zhejiang Cancer Hospital. A total of 5 genes [EGFR (epidermal growth factor receptor) E18, EGFR E19, EGFR E20, EGFR E21, KRAS (Kirsten rat sarcoma viral oncogene homolog) E2, BRAF E15, PTEN (phosphatase and tensin homolog deleted on chromosome ten) E5, PTEN E6, PTEN E8, PIK3CA (phosphatidylinositol 3-kinase/protein kinase B) E9, PIK3CA E20] were evaluated using direct sequencing.

Results

Between November 2012 and November 2016, 30 SCLC patients were prospectively enrolled in the study. A total of 10 genomic aberrations were detected in 30 cases (33.3%): an EGFR mutation (n=6, E19, E21), a KRAS mutation (n=1, E2), PIK3CA mutations (n=1, E20), a PTEN mutation (n=2, E5, E8). No significant differences were detected in the characteristics of patients with and without genomic aberrations or patients with and without EGFR mutation.

Conclusions

The genomic aberrations of SCLC occur, offering mutational data to clinicians might be helpful for assigning patients to appropriate clinical studies, especially the anti-EFGR and PIK3CA treatment. Moreover, whether the molecular genetic profile of the SCLC patients is correlated with the effect of anti-tumor treatment, necessitating further investigation.

Overcoming T790M mutant small cell lung cancer with the third-generation EGFR-TKI osimertinib

A large number of EGFR mutant non-small cell lung cancer patients primordially benefit from first-line treatment with first-generation EGFR-tyrosine kinase inhibitors (TKIs), such as gefitinib and erlotinib. However, multiple acquired resistance mechanisms have been described that limit the clinical efficacy of first-generation EGFR-TKIs. Herein, we report a rare case of lung adenocarcinoma harboring an EGFR exon 19-deletion mutation before the administration of target therapy. This patient acquired resistance to first-generation EGFR-TKIs through small cell lung cancer (SCLC) transformation accompanied by the T790M mutation. Unexpectedly, this SCLC patient maintained a sensitive response to the third-generation EGFR-TKI osimertinib. This special case may indicate that osimertinib represents an effective target drug for SCLC patients who harbor an EGFR T790M mutation.

Clinicopathological and genomic comparisons between different histologic components in combined small cell lung cancer and non-small cell lung cancer

OBJECTIVE

Histologic transformation from adenocarcinoma to small cell lung cancer (SCLC) is one of the mechanisms of acquired resistance after epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. Furthermore, de novo combined SCLC/non-small cell lung cancer (NSCLC) have occasionally been reported; however, their mutational statuses and clinicopathological features have not yet been elucidated. In this study, we aimed to profile the genetic backgrounds of these 2 different histologic components by investigating patients with de novo combined SCLC/NSCLC as well as those with lung adenocarcinoma who experienced SCLC transformation after TKI treatment.

MATERIALS AND METHODS

Four patients with de novo combined SCLC/NSCLC were investigated, as were 4 other patients with lung adenocarcinoma who experienced SCLC transformation after TKI treatment. The different histologic components of the tumors in each patient were tested for thyroid transcription factor-1, p40, synaptophysin, chromogranin A, p53, retinoblastoma protein (Rb), and achaete-scute homolog 1 (ASCL1) via immunohistochemistry, and were macroscopically dissected for mutational analysis using next-generation sequencing with the Oncomine Focus Assay and Comprehensive Assay panel.

RESULTS

The distinct histologic components in patients with de novo combined SCLC/NSCLC and those with adenocarcinoma exhibiting small cell transformation showed high consistency in EGFR/TP53/RB1 mutations, and expression patterns of p53 and Rb. A high frequency of activating mutations involving PI3K/AKT1 signaling pathway was observed in SCLC. Nuclear ASCL1 expression was present in SCLC but absent or barely present in adenocarcinoma in 7 cases.

CONCLUSIONS

Our data imply that inactivation of TP53/RB1 function is a possible early event in the histogenesis of synchronous and metachronous SCLC/NSCLC. Moreover, the non-adenocarcinoma (SCLC) component might arise from the adenocarcinoma (NSCLC) component through a mechanism that involves the activation of the ASCL1 and PI3K/AKT1 signaling pathways.

Combined small-cell lung carcinoma

Currently, studies assessing combined small-cell lung carcinoma (C-SCLC) are relatively scarce and limited. Indeed the clinicopathological features, treatment, and prognosis of patients with C-SCLC have not been fully determined. The incidence of C-SCLC ranges from 5%–28% in different studies, which is related to the specimen types used. The clinical features of C-SCLC are characterized by the higher proportion of peripheral locations, earlier stage, and more opportunity to experience surgery. Surgery is more important for earlier stage C-SCLC. There have been no recent changes in the chemotherapy of C-SCLC, which is recommended by the treatment guidelines for SCLC, neither showing survival benefit from the 3-agent regimen. Meanwhile, the efficacy of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) in EGFR-mutated C-SCLC patients remains inconclusive. This review focuses on clinical and pathologic features, prognostic factors, and optimized treatment model in C-SCLC.

EGFR, KRAS, BRAF, PTEN, and PIK3CA mutation in plasma of small cell lung cancer patients

Background

Small cell lung cancer (SCLC) is an aggressive and deadly neuroendocrine tumor derived from bronchial epithelial cells. Although it results in a 95% mortality rate, the development of targeted therapies for SCLCs has lagged behind. The aim of this study is to better research mutation characteristics of SCLC and identify potential biomarkers for target therapy.

Methods

We utilized high-resolution melting analysis to identify the mutations in epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene (KRAS), v-raf murine sarcoma viral oncogene homolog B1 (BRAF), phosphatase and tensin homolog (PTEN), and phosphatidylinositol-3-kinase catalytic (PIK3CA) from the blood. A cohort of 99 SCLC patients including 44 limited-stage disease patients and 55 extensive-stage disease patients were prospectively collected.

Results

EGFR 18 (G719X) mutation was found in 5 patients, EGFR 19 (del) mutation in 2, EGFR 20 (T790M) in 3, EGFR 21 (L858R) in 2, KRAS 2 (G13D) in 5, BRAF 15 (V600E) in 1, PIK3CA 9 (E542K) in 1, and no mutations in PTEN 5 (R130G), PTEN 6 (R173C), PTEN 8 (T319fs*1), and PIK3CA 20 (H1047R) were identified. Among these patients, two harbored EGFR double mutation, one patient with EGFR double mutation and KRAS 2 (G13D) mutation.

Conclusion

The mutation form of EGFR may differ from lung adenocarcinoma, and mutations of KRAS, BRAF, and PIK3CA were rare in SCLC. These results aided us in comprehensively analyzing genetic features and laid the foundation for exploring the possibility of target therapy.

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.

24-Methyl-Cholesta-5,24(28)-Diene-3β,19-diol-7β-Monoacetate Inhibits Human Small Cell Lung Cancer Growth In Vitro and In Vivo via Apoptosis Induction

24-methyl-cholesta-5,24(28)-diene-3β,19-diol-7β-monoacetate (MeCDDA) is a natural steroid compound isolated from a wild-type soft coral (Nephthea erecta). The present study aimed to investigate the anti-small cell lung cancer (SCLC) effects of MeCDDA in vitro and in vivo, as well as to elucidate its underlying mechanism. Our results indicated that H1688 and H146 cells show relevant sensitivity to MeCDDA, and the exposure to MeCDDA in SCLC cells caused dose-dependent growth inhibitory responses. In addition, MeCDDA treatment promoted cell apoptosis and increased the activities of caspases in H1688 cells, reducing the mitochondrial membrane potential and stimulating the release of cytochrome c into the cytosol. Along with the increase in Bax expression and reduction in Bcl-2, the MeCDDA treatment also significantly decreased Akt and mTOR phosphorylation. Finally, MeCDDA treatment in the mouse xenograft model of H1688 cells exhibited significant inhibition of tumor growth, corroborating MeCDDA as a potential pre-clinical candidate for the treatment of SCLC. Overall, our results demonstrate that the cytotoxic effects of MeCDDA towards H1688 and H146 cells, possibly through the activation of the mitochondrial apoptotic pathway and inhibition of the PI3K/Akt/mTOR pathway, merit further studies for its possible clinical application in chemotherapy.

Biopsy and re-biopsy in lung cancer: the oncologist requests and the role of endobronchial ultrasounds transbronchial needle aspiration

As the leading cause of death worldwide, lung cancer has proven itself incurable in the advanced stages. For early stages, endobronchial ultrasounds transbronchial needle aspiration (EBUS-TBNA) is now considered the standard to assess mediastinal lymph node, to define the multimodality therapeutic approach. In recent years, EBUS-TBNA has extended its use also in the metastatic and locally recurrent disease. New molecules, with specific mutations that give resistance to current target therapies, have made re-biopsy at disease progression an important assessment, with therapeutic and clinical implication. Here we present the oncologist's point of view on EBUS-TBNA in the staging process, at recurrence and progression.

Molecular Profiling and Survival of Completely Resected Primary Pulmonary Neuroendocrine Carcinoma

BACKGROUND

Currently, molecular profiles and prognosis of primary pulmonary neuroendocrine carcinoma (PNC) are poorly elucidated. The present study was designed to evaluate genomic abnormalities and survival in patients with primary PNC.

METHODS

Completely resected PNC samples were collected from Zhejiang Cancer Hospital during the period of 2008 to 2015. Nine driver genes, including 6 mutations (EGFR, KRAS, NRAS, PIK3CA, BRAF, and HER2) and 3 fusions (ALK, ROS1, and RET), were evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Survival analysis was conducted by the Kaplan-Meier method.

RESULTS

A total of 108 patients with pathologically confirmed PNC were enrolled. The types were pulmonary large-cell neuroendocrine carcinoma (PLCNC, n = 52), small-cell lung cancer (SCLC, n = 44), and carcinoid (n = 12). Twelve patients (11.1%) harbored genomic aberrations. The most frequent gene abnormalities in decreasing order were PIK3CA (n = 5, 4.6%), EGFR (n = 3, 2.8%), KRAS (n = 2, 1.9%), ALK (n = 1, 0.9%), and RET (n = 1, 0.9%). No ROS1, BRAF, NRAS, or HER2 mutation was detected. The frequencies of gene aberrations were 15.4%, 6.8%, and 8.3% in PLCNC, SCLC, and carcinoid, respectively. Survival differences existed among PLCNC, SCLC, and carcinoid groups (37.0 vs. 34.0 vs. not reached, P = .035); however, no difference existed between PLCNC and SCLC groups (P = .606).

CONCLUSIONS

Genomic abnormality is rare in patients with PNC and it is the most frequently observed in PLCNC.

Lung Cancer in Never Smokers

Lung cancer is predominantly associated with cigarette smoking; however, a substantial minority of patients with the disease have never smoked. In the US it is estimated there are 17,000-26,000 annual deaths from lung cancer in never smokers, which as a separate entity would be the seventh leading cause of cancer mortality. Controversy surrounds the question of whether or not the incidence of lung cancer in never-smokers is increasing, with more data to support this observation in Asia. There are several factors associated with an increased risk of developing lung cancer in never smokers including second hand smoke, indoor air pollution, occupational exposures, and genetic susceptibility among others. Adenocarcinoma is the most common histology of lung cancer in never smokers and in comparison to lung cancer in smokers appears less complex with a higher likelihood to have targetable driver mutations.

Epidermal growth factor receptor (EGFR) mutations in small cell lung cancers: Two cases and a review of the literature

Activating mutations in the epidermal growth factor receptor (EGFR) gene are exceedingly rare in small cell lung cancer (SCLC). We present two cases of SCLC harboring EGFR mutations, one in an 82 year-old male smoker with a combined SCLC and adenocarcinoma with a novel D855H point mutation in exon 21, and the second in a 68 year-old female never smoker with the L858R point mutation in exon 21. The cases, accompanied by a review of the literature, highlight the importance of integration of clinicopathologic considerations and adherence to recently promulgated Guideline recommendations for molecular testing in lung cancer.

Small-cell lung cancer in never-smokers: A case series

Small-cell lung cancer (SCLC) is closely correlated with smoking and only sporadic cases have been reported in non-smoking patients. Environmental tobacco smoke and/or occupational risk factors have been suggested as possible causes of lung cancer in this subset of patients. However, particularly in relation to SCLC there is not enough reliable information. All patients with lung cancer in follow-up for a period of three-months at the Pulmonology Unit of Coimbra University Hospital were retrospectively assessed. From a total of 303 patients, 35 had SCLC, 4 of which were never-smokers and their clinical cases are hereby presented. A detailed questionnaire was given to all patients, which excluded second-hand smoking or occupational hazards. They were all female with a mean age of 63.0 ± 15.7 years. The most frequent complaints were cough, dyspnoea, anorexia and significant weight loss. Diagnosis was obtained by transbronchial biopsies in all cases. Two patients had locally advanced disease and the other two had extensive-disease due to distant metastases. Treatment approaches included first-line chemotherapy with platin and etoposide duplet and partial remission was achieved in half the cases. All patients died; mean survival was 15.8 ± 3.8 months. Further studies are needed for a better understanding of the pathogenicity of non-smoking related SCLC and we hope that this case series with its meticulous exclusion of potential risk factors will be a useful contribution.

Small-cell lung cancer in a young, female, never-smoker

Small-cell lung cancer accounts for approximately 13% of lung cancers diagnosed worldwide. The vast majority of patients are elderly and current or past heavy smokers. Cases rarely occur in the young or never-smokers. We report a case of a 21-year-old female who had never smoked and initially presented with a history of cough and exertional dyspnoea. Histology showed a small-cell neuroendocrine tumor and imaging confirmed extensive stage disease. Literature review found five other cases of small-cell lung cancer in patients under 30 years. This case highlights the need for international studies to determine genomic differences between the young and elderly and never-smokers and smokers to aid the development of new targeted therapies in this rare and difficult to treat malignancy.

Transformation from non-small-cell lung cancer to small-cell lung cancer: molecular drivers and cells of origin

Lung cancer is the most common cause of cancer deaths worldwide. The two broad histological subtypes of lung cancer are small-cell lung cancer (SCLC), which is the cause of 15% of cases, and non-small-cell lung cancer (NSCLC), which accounts for 85% of cases and includes adenocarcinoma, squamous-cell carcinoma, and large-cell carcinoma. Although NSCLC and SCLC are commonly thought to be different diseases owing to their distinct biology and genomic abnormalities, the idea that these malignant disorders might share common cells of origin has been gaining support. This idea has been supported by the unexpected findings that a subset of NSCLCs with mutated EGFR return as SCLC when resistance to EGFR tyrosine kinase inhibitors develops. Additionally, other case reports have described the coexistence of NSCLC and SCLC, further challenging the commonly accepted view of their distinct lineages. Here, we summarise the published clinical observations and biology underlying tumours with combined SCLC and NSCLC histology and cancers that transform from adenocarcinoma to SCLC. We also discuss pre-clinical studies pointing to common potential cells of origin, and speculate how the distinct paths of differentiation are determined by the genomics of each disease.

RB loss in resistant EGFR mutant lung adenocarcinomas that transform to small-cell lung cancer

Tyrosine kinase inhibitors are effective treatments for non-small-cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, relapse typically occurs after an average of 1 year of continuous treatment. A fundamental histological transformation from NSCLC to small-cell lung cancer (SCLC) is observed in a subset of the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of tumour samples and cell lines derived from resistant EGFR mutant patients revealed that Retinoblastoma (RB) is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC. Further, increased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared with resistant NSCLCs. Together, these findings suggest that this subset of resistant cancers ultimately adopt many of the molecular and phenotypic characteristics of classical SCLC.

Resistance to tyrosine kinase inhibitors occurs in treatments of non-small-cell lung cancers (NSCLCs) with EGFR mutations but the mechanisms underlying this acquired resistance are unknown. Here the authors examine the molecular changes that occur in resistant cancers that transition from NSCLC to small-cell lung cancer phenotype and implicate loss of retinoblastoma in this process.

Cancer stem cells in basic science and in translational oncology: can we translate into clinical application?

Since their description and identification in leukemias and solid tumors, cancer stem cells (CSC) have been the subject of intensive research in translational oncology. Indeed, recent advances have led to the identification of CSC markers, CSC targets, and the preclinical and clinical evaluation of the CSC-eradicating (curative) potential of various drugs. However, although diverse CSC markers and targets have been identified, several questions remain, such as the origin and evolution of CSC, mechanisms underlying resistance of CSC against various targeted drugs, and the biochemical basis and function of stroma cell-CSC interactions in the so-called ‘stem cell niche.’ Additional aspects that have to be taken into account when considering CSC elimination as primary treatment-goal are the genomic plasticity and extensive subclone formation of CSC. Notably, various cell fractions with different combinations of molecular aberrations and varying proliferative potential may display CSC function in a given neoplasm, and the related molecular complexity of the genome in CSC subsets is considered to contribute essentially to disease evolution and acquired drug resistance. In the current article, we discuss new developments in the field of CSC research and whether these new concepts can be exploited in clinical practice in the future.

Genomic profiling of small-cell lung cancer: the era of targeted therapies

The molecular profiling of small-cell lung cancer is challenging because of the difficulty in obtaining suitable tumor samples for integrative genomic analysis. While an urgent need exists for well-defined and effective therapeutic targets in small-cell lung cancer, no significant improvement has been made in treating this disease over the past 30 years. Recently, three reports describing comprehensive genomic analyses of small-cell lung cancer have been published. These reports have provided a framework of biologically relevant genes in small-cell lung cancer and have demonstrated that the genomic landscape of small-cell lung cancer was almost equivalent between Asian and Caucasian populations. Of note, these three comprehensive genomic analyses and other molecular analyses of small-cell lung cancer have contributed to the identification of patient populations that may benefit from promising targeted agents, such as those affecting the PI3K/AKT/mTOR pathway, FGFR1, RET or AURORA kinase inhibitors. Targeting small-cell lung cancer cells with tumor suppressor gene alteration based on synthetic lethality is also promising. The present review provides an overview of the biologically relevant genetic alterations and targeted therapies of small-cell lung cancer focusing on recent discoveries that could impact the management of small-cell lung cancer.

Small-cell lung cancer detection in never-smokers: clinical characteristics and multigene mutation profiling using targeted next-generation sequencing

BACKGROUND

Once regarded as a smoker's disease, small-cell lung cancer (SCLC) has been occasionally detected in never-smokers as smoking rates decrease worldwide. We investigated the clinical and genetic characteristics of SCLC in never-smokers.

PATIENTS AND METHODS

Patients diagnosed with SCLC were grouped into smokers and never-smokers. The clinical outcomes of the two groups were compared. For SCLC in never-smokers, somatic mutation profiling was carried out using the AmpliSeq™ Cancer Hotspot Panel v2 and semiconductor sequencing technology. Epidermal growth factor receptor (EGFR) mutation was confirmed by PNAClamp™.

RESULTS

In total, 391 SCLC patients treated over a 5-year period were analyzed. Fifty patients (13%) were never-smokers. The median overall survival was 18.2 months in never-smokers and 13.1 months in smokers (P = 0.054). Never-smoking history was independently a good prognostic factor [hazard ratio = 0.645, 95% confidence interval (CI) 0.456-0.914], as were limited disease (HR = 0.372, 95% CI 0.294-0.471), and lower age (HR = 0.709, 95% CI 0.566-0.888). The objective response rates to first-line etoposide/cisplatin therapy were similar between never-smokers and smokers (75% versus 81%). Of 28 genetically evaluable never-smokers, EGFR mutations were detected in four cases (two L858R, one deletion in exon 19, and one G719A). Other mutations were in TP53 (n = 26), RB1 (n = 7), PTEN (n = 5), MET (n = 4), and SMAD4 (n = 3).

CONCLUSIONS

Never-smokers with SCLC are increasingly prevalent and have a better prognosis than smokers with SCLC in Korea. Our study warrants further investigation in this group.

Gene mutations in small-cell lung cancer (SCLC): results of a panel of 6 genes in a cohort of Italian patients

BACKGROUND

No target therapies are presently available in the treatment of small-cell lung cancer (SCLC). We investigated the presence of potentially drugable mutations in the EGFR, c-MET, BRAF, KRAS, PDGFRa and c-KIT genes in a retrospective series of SCLC from 2 Italian Institutions. Correlations with immunohistochemical, clinical and outcome features were evaluated.

MATERIALS AND METHODS

Genes were studied by direct sequencing of DNA extracted from formalin-fixed paraffin-embedded tissues. Immunohistochemical expression of TTF-1, p63, chromogranin, synaptophysin, CD56 and bcl-2 was assessed.

RESULTS

Samples from 113 SCLC patients were analyzed. All cases were wild-type for BRAF, KRAS, PDGFRa and c-KIT (data available for 82 patients). Two (1.8%) patients were EGFR-mutated (exon 19 delE746-A750 and exon 21 L858R); both were females, non-smoker and had limited disease. Overall survival of EGFR-mutated patients was 21 months as compared to 11 months in wild-type. Five (4.4%) patients were c-MET-mutated (4 on exon 14: 2 R988C, 1 D990N, 1 D102Y; 1 on exon 17 R1166Q); all were smokers, 3 were males and 4 had extensive disease. Their OS was comparable to wild-type cases (12 vs. 11 months). EGFR and c-MET mutations were mutually exclusive. Gene mutations did not correlate with immunophenotype.

CONCLUSIONS

Targetable mutations are uncommon in SCLC. EGFR-mutated patients tended to be female and non-smoker and experienced a prolonged OS suggesting a possible positive prognostic effect. c-MET mutations did not affect survival. Target therapy might be considered in EGFR and c-MET-mutated patients.

Small-cell carcinoma in the setting of pulmonary adenocarcinoma: new insights in the era of molecular pathology

INTRODUCTION

Transformation into small-cell lung carcinoma (SCLC) has been reported as an evolution of lung adenocarcinoma acquiring resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI). However, spontaneous association of SCLC and adenocarcinoma also exists. We sought to compare patients' clinical features and mutation status of EGFR in each tumor component in these conditions.

METHODS

Our study is based on nine consecutive cases of SCLC, occurring synchronously or after a previous diagnosis of pulmonary adenocarcinoma, with or without TKI-based therapy, diagnosed in Marie Lannelongue Surgical Center, France, between 2001 and 2013. Molecular analysis by DNA direct sequencing was performed to detect EGFR mutations on formalin-fixated tissue mostly from surgically resected tumors.

RESULTS

Six patients had a metachronous occurrence of SCLC after adenocarcinoma (2 after TKI); three had a synchronous form. There were four combined SCLCs/adenocarcinomas. Seven adenocarcinoma components were EGFR mutated: five exon 19 deletions and two mutations in exon 21 (L833_V834delinsFL and L858R). Four SCLC components were EGFR mutated. Two cases occurred in never-smoker women with adenocarcinoma treated with TKI: one with E872 mutation in exon 21 and one combined SCLC/adenocarcinoma with exon 19 deletion in both components. Two cases were spontaneous: a SCLC with exon 19 deletion occurring after a nonmutated adenocarcinoma and a combined SCLC/adenocarcinoma with exon 21 mutation (L833_V834delinsFL) in both components.

CONCLUSION

SCLC developing in association with adenocarcinoma, either synchronously or metachronously, seem linked to EGFR mutation, regardless of TKI use. Our findings suggest that such associated cases should be tested for EGFR mutations.

Tyrosine Kinase Inhibitors in EGFR-Mutated Large-Cell Neuroendocrine Carcinoma of the Lung? A Case Report

Large-cell neuroendocrine carcinoma (LCNEC) of the lung is a high-grade carcinoma belonging to the neuroendocrine tumors of the lung and is different from typical lung large-cell carcinoma. It represents about 3% of all pulmonary malignancies and is characterized by neuroendocrine cytologic features. The treatment usually is platinum-based chemotherapy, however the outcome remains poor. Therefore new therapeutic options are needed. Tyrosine kinase inhibitors have demonstrated greater efficacy and better tolerability than standard chemotherapy in non-small-cell lung cancer harboring epidermal growth factor receptor (EGFR) mutations. EGFR gene mutations were also rarely identified in LCNEC. We report a patient with lung LCNEC activating EGFR mutations who showed an impressive response to gefitinib.

Acquired resistance L747S mutation in an epidermal growth factor receptor-tyrosine kinase inhibitor-naïve patient: A report of three cases

The purpose of the present study was to report cases of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-naïve patients carrying a mutation associated with acquired resistance to the drug. Gene alterations in 77 lung carcinoma patients were analyzed by collecting and studying curette lavage fluid at the time of diagnosis. PCRs were performed to amplify mutation hotspot regions in EGFR genes. The PCR products were direct-sequenced and the mutations confirmed by resequencing using different primers. Case 1 was a 78-year-old Japanese male diagnosed with stage IB lung adenocarcinoma who was found to have two EGFR mutations, G719S and L747S. Case 2 was a 73-year-old Japanese male diagnosed with stage IV squamous cell lung carcinoma and bone metastasis who had the EGFR mutation, L747S. Case 3 was an 82-year-old Japanese male diagnosed with hyponatremia due to inappropriate secretion of antidiuretic hormone and stage IIIB small cell lung carcinoma (SCLC) who had the EGFR mutation, L747S. Thus, the EGFR mutation L747S associated with acquired EGFR-TKI resistance was detected in two non-small cell lung carcinoma (NSCLC) patients and one SCLC patient, none of whom had ever received EGFR-TKI. The patients were current smokers with stages at diagnosis ranging from IB to IV, and their initial tumors contained resistant clones carrying L747S. L747S may be associated with primary resistance. To the best of our knowledge, this study is the first report of an EGFR mutation associated with resistance to EGFR-TKI in SCLC patients. The early detection of EGFR-TKI resistance mutations may be beneficial in making treatment decisions for lung carcinoma patients, including those with SCLC.

Neuroendocrine differentiation in acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor

Background

Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms.

Methods

We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment.

Results

Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib.

Conclusion

NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

Combining erlotinib and cetuximab is associated with activity in patients with non-small cell lung cancer (including squamous cell carcinomas) and wild-type EGFR or resistant mutations

Preclinical data suggest that combined EGF receptor (EGFR) targeting with an EGFR tyrosine kinase inhibitor and an anti-EGFR monoclonal antibody may be superior over single-agent targeting. Therefore, as part of a phase I study, we analyzed the outcome of 20 patients with non-small cell lung cancer treated with the combination of erlotinib and cetuximab. EGFR mutation status was ascertained in a Clinical Laboratory Improvement Amendment-approved laboratory. There were 10 men; median number of prior therapies was five. Overall, two of 20 patients (10%) achieved partial response (PR), one of whom had a TKI-resistant EGFR insertion in exon 20, time to treatment failure (TTF) = 24+ months, and the other patient had squamous cell histology (EGFR wild-type), TTF = 7.4 months. In addition, three of 20 patients (15%) achieved stable disease (SD) ≥6 six months (one of whom had wild-type EGFR and squamous cell histology, and two patients had an EGFR TKI-sensitive mutation, one of whom had failed prior erlotinib therapy). Combination therapy with ertotinib plus cetuximab was well tolerated. The most common toxicities were rash, diarrhea, and hypomagnesemia. The recommended phase II dose was erlotinib 150 mg oral daily and cetuximab 250 mg/m(2) i.v. weekly. In summary, erlotinib and cetuximab treatment was associated with SD ≥ six months/PR in five of 20 patients with non-small cell lung cancer (25%), including individuals with squamous histology, TKI-resistant EGFR mutations, and wild-type EGFR, and those who had progressed on prior erlotinib after an initial response. This combination warrants further study in select populations of non-small cell lung cancer.

Large-cell neuroendocrine carcinoma of lung with epidermal growth factor receptor (EGFR) gene mutation and co-expression of adenocarcinoma markers: a case report and review of the literature

Purpose

A high rate of response to treatment with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has been observed in certain patients (women, of East Asian ethnicity, with non-smoking history and adenocarcinoma histology) with mutations in exons 18 to 21 of the tyrosine kinase domain of EGFR. Some cases of high-grade neuroendocrine carcinoma of the lung harboring mutations have been sporadically reported.

Methods

We describe the case of a 78-year-old woman with large-cell neuroendocrine carcinoma of the lung, with mutation in exon 21 L858R and co-expression of adenocarcinoma markers.

Results

A mass (3.0 cm in diameter) was identified in the inferior lobe of the left lung, accompanied by metastases into ipsilateral mediastinal lymph nodes and elevations of serum pro-gastrin-releasing peptide and carcinoembryonic antigen. Initial transbronchial brushing cytology suggested high-grade neuroendocrine carcinoma favoring small-cell carcinoma in poorly smeared and degenerated preparations, and revealed exon 21 L858R mutation. Re-enlargement of the cancer and bone metastases was observed after chemotherapy, and further testing suggested large-cell neuroendocrine carcinoma with immunoreactivity to markers of primary lung adenocarcinoma and L858R mutation. High-grade neuroendocrine carcinoma with mutations in the tyrosine kinase domain of EGFR may be associated with adenocarcinoma, as reviewed from the literature and may also apply to our case.

Conclusions

EGFR-TKI could provide better quality of life and survival in patients with advanced or relapsed high-grade neuroendocrine carcinoma with EGFR gene mutations. Further studies in this respect are warranted.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture published articles from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. EVIDENCE was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology

OBJECTIVE

To establish evidence-based recommendations for the molecular analysis of lung cancers that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed.

PARTICIPANTS

Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies.

EVIDENCE

Three unbiased literature searches of electronic databases were performed to capture articles published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation.

CONSENSUS PROCESS

Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4).

CONCLUSIONS

The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed by expert practitioners are vital for communicating emerging clinical standards. Already, new treatments targeting genetic alterations in other, less common driver oncogenes are being evaluated in lung cancer, and testing for these may be addressed in future versions of these guidelines.

Revisiting clinical trials using EGFR inhibitor-based regimens in patients with advanced non-small cell lung cancer: a retrospective analysis of an MD Anderson Cancer Center phase I population

PURPOSE

Single-agent EGFR inhibitor therapy is effective mainly in patients with lung cancer and EGFR mutations. Treating patients who develop resistance, or who are insensitive from the outset, often because of resistant mutations, other aberrations or the lack of an EGFR mutation, probably requires rational combinations. We therefore investigated the outcome of EGFR inhibitor-based combination regimens in patients with heavily-pretreated non-small cell lung cancer (NSCLC) referred to a Phase I Clinic.

METHODS

We reviewed the electronic records of patients with NSCLC treated with an EGFR inhibitor-based combination regimen: erlotinib and cetuximab; erlotinib, cetuximab and bevacizumab; erlotinib and dasatinib; erlotinib and bortezomib; or cetuximab and sirolimus.

RESULTS

EGFR mutations were detected in 16% of patients (21/131). EGFR inhibitor-based combination regimens were administered to 15 patients with EGFR-mutant NSCLC and 24 with EGFR wild-type disease. Stable disease (SD) ≥6 months/partial remission (PR) was attained in 20% of EGFR-mutant patients (3/15; two with sensitive mutations and secondary resistance to prior erlotinib, and one with a resistant mutation), as well as 26% of evaluable patients (5/19) with wild-type disease. One of three evaluable patients with squamous cell histology achieved SD for 26.5 months (EGFR wild-type, TP53-mutant, regimen=erlotinib, cetuximab and bevacizumab).

CONCLUSIONS

Eight of 34 evaluable patients (24%) with advanced, refractory NSCLC evaluable for response achieved SD ≥6 months/PR (PR=3; SD ≥6 months=5) on EGFR inhibitor-based combination regimens (erlotinib, cetuximab; erlotinib, cetuximab and bevacizumab; and, erlotinib, bortezomib), including patients with secondary resistance to single-agent EGFR inhibitors, resistant mutations, wild-type disease, and, squamous histology.