Small cell lung cancer

Association between Receipt of Guideline-Concordant Lung Cancer Treatment and Individual- and Area-Level Factors: A Spatio-Temporal Analysis

BACKGROUND

Guideline-concordant treatment (GCT) of lung cancer has been observed to vary across geographic regions over the years. However, there is little evidence as to what extent this variation is explained by differences in patients' clinical characteristics versus contextual factors, including socioeconomic inequalities.

METHODS

This study evaluated the independent effects of individual- and area-level risk factors on geographic and temporal variation in receipt of GCT among patients with lung cancer. Receipt of GCT was defined on the basis of the National Comprehensive Cancer Network guidelines. We used Bayesian spatial-temporal multilevel models to combine individual and areal predictors and outcomes while accounting for geographically structured and unstructured correlation and linear and nonlinear trends.

RESULTS

Our study included 4,854 non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cases, reported to the Victorian Lung Cancer Registry between 2011 and 2018. Area-level data comprised socioeconomic disadvantage and remoteness data at the local government area level in Victoria, Australia. Around 60.36% of patients received GCT, and the rates varied across geographic areas over time. This variation was mainly associated with poor performance status, advanced clinical stages, NSCLC types, public hospital insurance, area-level deprivation, and comorbidities.

CONCLUSIONS

This study highlights the need to address disparities in receipt of GCT among patients with lung cancer with poor performance status, NSCLC, advanced clinical stage, stage I-III SCLC, stage III NSCLC, public hospital insurance, and comorbidities, and living in socioeconomically disadvantaged areas.

IMPACT

Two-year mortality outcomes significantly improved with GCT. Interventions aimed at reducing these inequalities could help to improve lung cancer outcomes.

Current and future strategies in radiotherapy for small-cell lung cancer

Small-cell lung cancer (SCLC) accounts for 13% of all lung tumors. The standard treatment in patients with limited-stage (LS) disease is thoracic radiotherapy (TRT) combined with chemotherapy. In extensive-stage (ES) SCLC, the importance of consolidation TRT in patients with a good treatment response has become increasingly recognized. In both LS and ES disease, prophylactic cranial irradiation is recommended in patients who respond to treatment. New therapeutic approaches such as immunotherapy are being increasingly incorporated into the treatment of SCLC, although more slowly than in non-small cell lung cancer. Diverse radiation dose and fractionation schemes, administered in varying combinations with these new drugs, are being investigated. In the present article, we review and update the role of radiotherapy in the treatment of SCLC. We also discuss the main clinical trials currently underway to identify future trends.

RELEVANCE FOR PATIENTS

Radiotherapy is a critical component of multimodality treatment of SCLC. This article can help physicians to improve medical knowledge and find better ways to treat their SCLC patients.

Antimicrobial peptides: a promising strategy for lung cancer drug discovery?

INTRODUCTION

Antimicrobial peptides (AMPs), also called host defense peptides (HDPs), are identified in almost any form of life, which play an important role in innate immune systems. They have a broad spectrum of antifungal, antiviral, antibacterial, and anticancer activities. Lung cancer remains the leading cause of global cancer-related death. Unfortunately, lung cancer chemotherapy is accompanied by serious side effects, nonspecific toxicity, and multidrug resistance. Hence, to overcome these drawbacks, anticancer peptides (ACPs) derived from AMPs may represent a potential promising synergistic treatment strategy for lung cancer.

AREAS COVERED

In this review, the authors provide the recent advancements in the use of AMPs for the treatment of lung cancer. Furthermore, the anti-lung cancer modes of action of these peptides have been fully reviewed. Importantly, various strategies for increasing the efficiency and safety of AMPs have been discussed.

EXPERT OPINION

The combination of AMPs and other cancer treatment approaches such as chemotherapy, nanoparticle-based delivery systems, and photodynamic therapy can be used as a promising revolutionary strategy for the treatment of lung cancer. The most significant limitations of this strategy that need to be focused on are low efficiency and off-target events.

Comparison of FDA accelerated vs regular pathway approvals for lung cancer treatments between 2006 and 2018

Regulatory agencies around the world have been using flexible requirements for approval of new drugs, especially for cancer drugs. The US Food and Drug Administration (FDA) is mostly the first agency to approve new drugs worldwide, mainly due to the faster terms of the accelerated pathway and breakthrough therapy designation. Surrogate endpoints and preliminary data (e.g. single-arm and phase 2 studies) are used for these new approvals, however larger effect sizes are expected. We aim to compare FDA Accelerated vs Regular Pathway approvals and Breakthrough therapy designations (BTD) for lung cancer treatments between 2006 and 2018 regarding study design, sample size, outcome measures and effect size. We assessed the FDA database to collect data from studies that formed the basis of approvals of new drugs or indications for lung cancer spanning from 2006 to 2018. We found that accelerated pathway approvals are based on significantly more single-arm studies with small sample sizes and surrogate primary endpoints. However, effect size was not different between the pathways. A large proportion of studies used to support regular pathway approvals also showed these characteristics that are related to low quality and uncertain evidence. Compared to other approvals, BTD were more frequently based on single-arm studies. There was no significant difference in use of surrogate endpoints or sample size. 44% of BTD were based on studies demonstrating large effect sizes, proportionally more than approvals not receiving this designation. In conclusion, based on the indicators of evidence quality we extracted, criteria’s for granting accelerated approval and breakthrough therapy designation seen not clear. Faster approvals are in the majority full of uncertainties which should be viewed with caution and the patient have to be communicated to allow shared decision making. Post-marketing validation is essential.

Use of Immunotherapy in Extensive-Stage Small Cell Lung Cancer

Lung cancer is a leading cause of cancer death in the United States and around the world. Approximately 13% of lung cancers are small cell lung cancer (SCLC). SCLC is generally classified as a limited-stage and extensive-stage disease depending on the extent of involvement. For patients with the extensive-stage disease, until recently, chemotherapy alone has been the recommended treatment, although radiotherapy could be used in select patients for palliation of symptoms. The standard of care for extensive-stage SCLC is platinum doublet chemotherapy with either cisplatin or carboplatin in combination with etoposide. Even though first-line therapy has an initial response rate of 60-80%, the prognosis is poor, with overall survival of 10-12 months. The only FDA-approved second line of therapy is topotecan, approved both as an intravenous formulation as well as an oral formulation, with response rates of 6-12% in chemorefractory disease and 15-37% in chemosensitive disease. Immunotherapy has recently been approved as a first-line agent in metastatic SCLC in combination with chemotherapy. It is also approved as a third-line agent in metastatic SCLC after the failure of two chemotherapy regimens. The FDA approved four drugs, two of them being PD-1 inhibitors (pembrolizumab, nivolumab), and two of them being PD-L1 inhibitors (atezolizumab and durvalumab) in SCLC. This review article summarizes the significance of immunotherapy in the treatment of extensive-stage SCLC, its side effects, and limitations.

Detection of somatic TP53 mutation in surgically resected small-cell lung cancer by targeted exome sequencing: association with longer relapse-free survival

OBJECTIVES

Few reports have explored clinical biomarkers, including those identified by targeted exome sequencing (TES) of surgically resected small-cell lung cancer (SCLC) and correlation with patient survival.

PATIENTS AND METHODS

We collected formalin-fixed paraffin-embedded tumor samples from 127 patients with SCLC who had undergone surgery and analysed nonsynonymous somatic gene mutation profiles by TES of 26 cancer-related genes using next-generation sequencing (NGS) and web databases (UMIN Registration No. 000010117).

RESULTS

We detected 38 nonsynonymous somatic tumor protein p53 (TP53) mutations in 43 (54.4%) patients. Among these TP53 lesions, we identified clinically relevant mutations including those encoding Y220C, R248W, R249M, M237I, and R273L substitutions in the p53 protein. These mutations have been reported to be associated with certain clinical outcomes or biology in other types of malignancies but not in SCLC. Moreover, nonsynonymous somatic mutations of TP53 were positively associated with relapse-free survival (RFS) (median, 17.33 months [95% confidence interval (CI), 3.86-30.79] in a mutation-positive group vs 10.39 months (6.96-13.82) in a mutation-negative group, p = 0.042). Multivariate analysis revealed that nonsynonymous somatic TP53 mutation was an independent factor of prolongation of RFS (hazard ratio: 0.51, 95% CI: 0.29-0.89, p = 0.019) but not overall survival (OS).

CONCLUSION

These data suggested that TES may play a critical role for promoting reverse-translational studies, including investigations of the biology of TP53 mutations in different stages of SCLC. Accumulation of the data using cancer panels with a broader range of genes, including TP53, is expected to be useful for future clinical applications for patients with SCLC.

Impact of Amrubicin Monotherapy as Second-Line Chemotherapy on Outcomes in Elderly Patients with Relapsed Extensive-Disease Small-Cell Lung Cancer

Purpose

Amrubicin (AMR) is an anticancer drug for patients with relapsed small-cell lung cancer (SCLC). However, the efficacy of AMR in elderly patients with relapsed SCLC after chemotherapy by carboplatin plus etoposide (CE) has not been sufficiently evaluated.

Patients and Methods

The medical records of patients with relapsed SCLC who received AMR as second-line chemotherapy were retrospectively reviewed, and their treatment outcomes were evaluated.

Results

Forty-one patients with a median age of 76 years were analyzed. The overall response rate was 26.8%. Median progression-free survival (PFS) and overall survival (OS) were 3.5 and 8.1 months, respectively. While the median PFS of 4.7 and 2.8 months in the sensitive relapse and the refractory relapse group differed significantly (P=0.043), respectively, the median OS of 10.7 and 6.8 months in the respective relapse groups did not indicate a statistically significant difference (P=0.24). The median PFS in a group with a modified Glasgow prognostic score (mGPS) of 0 and a group with a mGPS 1 or 2 were 4.5 and 1.6 months (P=0.052), respectively, and the median OS in the respective mGPS groups were 10.7 and 4.4 months (P=0.034). Multivariate analysis identified good performance status, limited disease, and mGPS 0 as favorable independent predictors of PFS and OS of AMR monotherapy. Grade 3 or higher neutropenia was observed in 23 patients (56%), and febrile neutropenia was observed in nine patients (22%). Non-hematological toxic effects were relatively mild, and pneumonitis and treatment-related deaths were not observed.

Conclusion

AMR is an effective and feasible regimen for elderly patients with relapsed SCLC after CE therapy.

Development and validation of a prognostic model of resectable small-cell lung cancer: a large population-based cohort study and external validation

Background

Survival outcomes of patients with resected SCLC differ widely. The aim of our study was to build a model for individualized risk assessment and accurate prediction of overall survival (OS) in resectable SCLC patients.

Methods

We collected 1052 patients with resected SCLC from the Surveillance, Epidemiology, and End Results (SEER) database. Independent prognostic factors were selected by COX regression analyses, based on which a nomogram was constructed by R code. External validation were performed in 114 patients from Shandong Provincial Hospital. We conducted comparison between the new model and the AJCC staging system. Kaplan–Meier survival analyses were applied to test the application of the risk stratification system.

Results

Sex, age, T stage, N stage, LNR, surgery and chemotherapy were identified to be independent predictors of OS, according which a nomogram was built. Concordance index (C-index) of the training cohort were 0.721, 0.708, 0.726 for 1-, 3- and 5-year OS, respectively. And that in the validation cohort were 0.819, 0.656, 0.708, respectively. Calibration curves also showed great prediction accuracy. In comparison with 8th AJCC staging system, improved net benefits in decision curve analyses (DCA) and evaluated integrated discrimination improvement (IDI) were obtained. The risk stratification system can significantly distinguish the ones with different survival risk. We implemented the nomogram in a user-friendly webserver.

Conclusions

We built a novel nomogram and risk stratification system integrating clinicopathological characteristics and surgical procedure for resectable SCLC. The model showed superior prediction ability for resectable SCLC.

ASCL1-regulated DARPP-32 and t-DARPP stimulate small cell lung cancer growth and neuroendocrine tumour cell proliferation

Background

Small cell lung cancer (SCLC) is the most aggressive form of lung cancer, and new molecular insights are necessary for prognostic and therapeutic advances.

Methods

Dopamine and cAMP-regulated phosphoprotein, Mr 32000 (DARPP-32) and its N-terminally truncated splice variant, t-DARPP, were stably overexpressed or ablated in human DMS-53 and H1048 SCLC cells. Functional assays and immunoblotting were used to assess how DARPP-32 isoforms regulate SCLC cell growth, proliferation, and apoptosis. DARPP-32-modulated SCLC cells were orthotopically injected into the lungs of SCID mice to evaluate how DARPP-32 and t-DARPP regulate neuroendocrine tumour growth. Immunostaining for DARPP-32 proteins was performed in SCLC patient-derived specimens. Bioinformatics analysis and subsequent transcription assays were used to determine the mechanistic basis of DARPP-32-regulated SCLC growth.

Results

We demonstrate in mice that DARPP-32 and t-DARPP promote SCLC growth through increased Akt/Erk-mediated proliferation and anti-apoptotic signalling. DARPP-32 isoforms are overexpressed in SCLC patient-derived tumour tissue, but undetectable in physiologically normal lung. Achaete-scute homologue 1 (ASCL1) transcriptionally activates DARPP-32 isoforms in human SCLC cells.

Conclusions

We reveal new regulatory mechanisms of SCLC oncogenesis that suggest DARPP-32 isoforms may represent a negative prognostic indicator for SCLC and serve as a potential target for the development of new therapies.

Mechanisms of drugs-resistance in small cell lung cancer: DNA-related, RNA-related, apoptosis-related, drug accumulation and metabolism procedure

Small-cell lung cancer (SCLC), the highest malignant cancer amongst different types of lung cancer, has the feature of lower differentiation, rapid growth, and poor survival rate. Despite the dramatically initial sensitivity of SCLC to various types of treatment methods, including chemotherapy, radiotherapy and immunotherapy, the emergence of drugs-resistance is still a grandly clinical challenge. Therefore, in order to improve the prognosis and develop new therapeutic approaches, having a better understanding of the complex mechanisms of resistance in SCLC is of great clinical significance. This review summarized recent advances in understanding of multiple mechanisms which are involved in the resistance during SCLC treatment, including DNA-related process, RNA-related process, apoptosis-related mechanism, and the process of drug accumulation and metabolism.

Peptide-Based Therapeutics for Oncology

The development of peptide-based drugs, which are usually synthetic analogues of endogenous peptides, is currently one of the most topical directions in drug development. Among them, antitumor peptide-based drugs are of great interest. Anticancer peptides can be classified into three main groups based on their mechanism of action: inhibitory, necrosis-inducing and pro-apoptotic peptides. As an antitumor therapy, peptides are considered to have at least the same efficacy as chemotherapy or surgical treatment, but offer advantages in terms of safety and tolerability, given that chemotherapy is usually characterized by severe adverse effects, and surgery carries additional risks for patients. Short peptides have a number of benefits over other molecules. First, compared with full-length proteins and antibodies, short peptides are less immunogenic, more stable ex-vivo (prolonged storage at room temperature), and have better tumor or organ permeability. Moreover, the production of such short peptide-based drugs is more cost effective. Second, in comparison with small organic molecules, peptides have higher efficacy and specificity. Finally, due to the fact that the main products of peptide metabolism are amino acids, these drugs are usually characterized by lower toxicity. Short peptides have a highly selective mechanism of action, thereby demonstrating low toxicity. Furthermore, with the addition of different stabilizing structural modifications, as well as novel drug delivery systems, the peptide-based drugs are proving to be promising therapeutics for cancer mono- or polytherapy. However, challenges remain including that endogenous and synthetic peptide molecules can be oncogenic. Therefore, it is important to investigate whether peptides contribute to tumor growth. In order to answer such questions, numerous preclinical and clinical studies of peptide-based therapeutics are currently being conducted.

Effects of Surgery on Survival of Early-Stage Patients With SCLC: Propensity Score Analysis and Nomogram Construction in SEER Database

Purpose: We aimed to assess the survival benefit of surgery for patients with stage IA–IIB small cell lung cancer (SCLC) and construct a nomogram for predicting overall survival (OS).

Methods: Patients who had been diagnosed with stage IA–IIB SCLC between 2004 and 2014 and who had received active treatment were selected from the Surveillance, Epidemiology, and End Results database. The primary endpoint was OS. Cox proportional hazards models and propensity score (PS) analyses were used to compare the associations between surgery and OS. The probability of 1- and 3-year OS was predicted using a nomogram.

Results: We reviewed 2,246 patients. The median OS of the surgery and non-surgery groups was 35 months and 19 months, respectively. Multivariable Cox proportional hazards models showed a survival benefit in the surgery group (hazards ratio [HR], 0.642; 95% confidence interval [CI], 0.557–0.740; P < 0.001). To balance the between-group measurable confounders, the impact of surgery on OS was assessed using PS matching. After PS matching, OS analysis still favored surgical resection. The PS-stratification, PS-weighting, and PS-adjustment models showed similar results to demonstrate a statistically significant benefit for surgery. Further, the nomogram was well calibrated and had good discriminative ability (Harrell's C-index = 0.645).

Conclusion: Our analysis suggests that surgery is a viable option for patients with early-stage SCLC. Our nomogram is a viable tool for quantifying treatment trade-off assumptions and may assist clinicians in decision-making. Future work is needed to validate our results and improve our tools.

New insights into small-cell lung cancer development and therapy

Small‐cell lung cancer (SCLC) accounts for approximately 15% of lung cancer cases; however, it is characterized by easy relapse and low survival rate, leading to one of the most intractable diseases in clinical practice. Despite decades of basic and clinical research, little progress has been made in the management of SCLC. The current standard first‐line regimens of SCLC still remain to be cisplatin or carboplatin combined with etoposide, and the adverse events of chemotherapy are by no means negligible. Besides, the immunotherapy on SCLC is still in an early stage and novel studies are urgently needed. In this review, we describe SCLC development and current therapy, aiming at providing useful advices on basic research and clinical strategy.

Metastatic Small-Cell Lung Cancer Presenting as Primary Adrenal Insufficiency

A 40-year-old male smoker with HIV was admitted for cough, hypotension, and abdominal pain for 5 days. Chest radiography showed a right lower lobe consolidation. CT of the chest, abdomen, and pelvis revealed paratracheal adenopathy, a 5.8 × 4.5 cm mass invading the right bronchus intermedius, and dense bilateral adrenal masses, measuring 5.4 × 4.0 cm on the right and 4.8 × 2.0 cm on the left. Laboratory studies showed white blood cell count of 18.5 K/mm³, sodium of 131 mmol/L, creatinine of 1.6 mg/dL, and CD4 count of 567 cells/mm³. The random morning cortisol level was 7.0 μg/dL, the ACTH stimulation test yielded inappropriate response, and a random serum ACTH was elevated at 83.4 pg/mL. MRI brain revealed no pituitary adenoma confirming primary adrenal insufficiency. The adrenal CT washout study was consistent with solid mass content, concerning for metastasis. Bronchoscopy with endobronchial mass and paratracheal lymph node biopsy confirmed small-cell lung cancer (SCLC). Intravenous steroids, 100 mg hydrocortisone every 8 hours, improved his hypotension and abdominal pain. PET scan revealed metabolically active right paratracheal mass, right hilar mass, and bilateral adrenal masses. Treatment included palliative chemotherapy consisting of carboplatin/etoposide/atezolizumab and chest radiation. We present this novel case to demonstrate SCLC's ability to cause primary adrenal insufficiency, as well as evaluate clinical response to chemotherapeutics.

A Prospective Study of Apatinib in Patients with Extensive-Stage Small Cell Lung Cancer After Failure of Two or More Lines of Chemotherapy

Background

Because of rapid disease progression and lack of optimal treatment strategies beyond the second‐line, the prognosis of patients with extensive‐stage (ES) small cell lung cancer (SCLC) still remains depressing. Alternative treatment strategies are required to improve their prognosis. In this prospective clinical study, we aimed to evaluate the feasibility of single‐agent apatinib, a vascular endothelial growth factor receptor‐2 tyrosine kinase inhibitor, as a treatment option for patients with ES‐SCLC after failure of at least two prior chemotherapy regimens.

Materials and Methods

Twenty‐two patients with ES‐SCLC treated with 500 mg single‐agent apatinib as subsequent‐line regimen in our institution from November 2016 to August 2018 were enrolled in the study. The primary endpoint was progression‐free survival (PFS). The secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), and adverse events (AEs).

Results

Clinical outcomes included partial response in 3 patients (13.6%), stable disease in 18 patients (81.8%), and disease progression in 1 patient (4.5%), with an ORR of 13.6% and DCR of 95.5%. The median PFS and OS were 5.4 and 10.0 months, respectively. Apatinib demonstrated a manageable toxicity profile, with grade I–III secondary hypertension and proteinuria as the most common AEs. No grade IV and V AEs were observed among the patients. Multivariate analysis revealed secondary hypertension as an independent predictor of OS (p = .047); however, the association became insignificant after Q correction (p = .455).

Conclusions

Apatinib was safe and effective in the management of patients with ES‐SCLC and can be considered as a treatment option after failure of at least two prior chemotherapy regimens. http://ClinicalTrials.govidentifier. NCT02995187

Implications for Practice

This study indicated the acceptable toxicity profile and promising efficacy of apatinib in the management of patients with extensive‐stage small cell lung cancer after failure from at least two prior chemotherapy regimens. Secondary hypertension can be a potential prognostic factor for apatinib treatment.

Alternative treatment strategies are needed to improve prognosis for patients with small‐cell lung cancer. This article evaluates the feasibility of single‐agent apatinib as a treatment option for patients with extensive‐stage small‐cell lung cancer.

Genomic based analyses reveal unique mutational profiling and identify prognostic biomarker for overall survival in Chinese small-cell lung cancer

OBJECTIVE

As an aggressive subtype of lung cancer, small-cell lung cancer (SCLC) presents a poor prognosis. Although molecular and clinical characteristics have been established for SCLC, limited investigation has been performed for predicting survival of SCLC patients.

METHODS

Genomic alterations were profiled in Chinese SCLC patients (N = 37) using targeted sequencing. Clonal mutation burden (CMB) integrated the number of mutations with the clonal structure of the tumor. Specific pathways involving DNA damage repair (DDR) and cell cycle as well as CMB were studied as potential biomarkers for prognosis of SCLC.

RESULTS

TP53 and RB1 gene mutations were the most common alterations (91.9% and 83.8%, respectively), followed by LRP1B, FAM135B, SPTA1, KMT2D, FAT1, and NOTCH3. Survival analysis revealed that mutation status of the DDR pathway was associated with worse OS in our cohort. Importantly, patients with higher CMB exhibited worse OS in our cohort and this observation was successfully validated in the cBioportal cohort. Moreover, multivariate analysis demonstrated CMB as a promising independent prognostic factor for OS in Chinese SCLC patients. Interestingly, patients with loss of function of RB1, validated by immunohistochemistry staining, appeared to have worse OS.

CONCLUSIONS

The mutational profiling of Chinese SCLC patients signified an ethnicity dependent component. CMB was firstly found to be associated with OS of Chinese SCLC patients and could be regarded as a prognostic marker for SCLC.

Utilization of Antineoplastic Agents and Medicare Spending in Elderly Patients With Extensive-Stage Small-Cell Lung Cancer Between 2001 and 2013

PURPOSE

Some elderly patients (≥ 65 years old) with small-cell lung cancer (SCLC) do not receive chemotherapy likely because of fear of toxicity and uncertainty regarding benefits. Thus, we aimed to study real-world trends in utilization of antineoplastics over the years and predictors of utilization, survival, and Medicare expenditure in elderly patients with extensive-stage (ES) SCLC.

PATIENTS AND METHODS

Using the linked SEER and Medicare database, we identified elderly patients with newly diagnosed ES-SCLC between 2001 and 2013. The Wald test was used to determine the significance of trends. Cox proportional hazards models were applied for survival analyses. We used SAS, version 9.4 (SAS Institute, Cary, NC).

RESULTS

We identified 15,763 patients with newly diagnosed ES-SCLC. Approximately 6,838 patients (43.38%) received antineoplastics, and 8,925 patients (56.61%) received supportive care only. Every year since 2001, the percentage of patients receiving antineoplastics has decreased (45.8% v 36.6% in 2001 and 2013, respectively; P_trend < .0001). Patients with advanced age (P < .001), patients from high-poverty areas (P < .001) or rural areas (P = .005), patients with Charlson comorbidity index ≥ 3 (P < .001), and non-Hispanic blacks (P = .003) and Hispanics (P = .001) were less likely to receive antineoplastics. Mean Medicare spending per patient decreased over the study period for patients treated with antineoplastics ($45,998 in 2001 and $35,053 in 2013; P_trend < .001) and for those receiving supportive care only ($34,197 in 2001 and $25,265 in 2013; P_trend < .001).

CONCLUSION

Decreasing utilization of antineoplastics in elderly patients with ES-SCLC since 2001 could be partly secondary to higher comorbidities and physiologic age, leading to poor candidacy. Medicare expenditures decreased likely as a result of value-based treatment initiatives by the Centers for Medicaid and Medicare Services. However, expenditures are likely to increase with use of expensive novel agents.

Prognostic value of 18F-FDG PET/CT metabolic parameters in small cell lung cancer

Objective

To compare the prognostic values of metabolic parameters from pretreatment PET/CT between limited disease (LD) and extensive disease (ED) small cell lung cancer (SCLC) patients.

Methods

Data on 118 newly diagnosed SCLC patients (50 LD and 68 ED) who underwent pretreatment positron emission tomography–computed tomography (PET/CT) were reviewed. For PET, metabolic parameters were measured for: (1) primary tumor, maximum standardized uptake value (SUVmax), metabolic tumor volume, and total lesion glycolysis; and (2) all tumor lesions, SUVmax of the hottest tumor, whole body metabolic tumor volume (WBMTV), and whole body total lesion glycolysis (WBTLG). Prognostic values of metabolic parameters and other clinical variables were analyzed to predict overall survival (OS).

Results

In LD, SUVmax of the primary tumor was an independent prognostic factor for OS. Patients with high SUVmax showed significantly worse OS than those with low SUVmax. In ED, WBMTV and WBTLG were independent prognostic factors for OS. Patients with high WBMTV or WBTLG showed significantly worse OS than those with low WBMTV or WBTLG.

Conclusions

SUVmax of primary tumor was the only independent prognostic factor for OS in LD SCLC patients. WBMTV and WBTLG were independent prognostic factors in ED SCLC patients.

Prevalence of DLL3, CTLA-4 and MSTN Expression in Patients with Small Cell Lung Cancer

Introduction

Immune-based and antibody-drug conjugate therapies have shown promise in the treatment of patients with small cell lung cancer (SCLC). However, better predictive biomarkers are needed for selection of the appropriate SCLC patients for these advanced therapies and also for evaluation of the efficacy of these treatments.

Objective

The aim of this study was to examine the expression of delta-like protein 3 (DLL3), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), and mesothelin (MSTN) in patients with SCLC and compare them with those patients’ clinical characteristics.

Methods

Immunohistochemical analyses of DLL3, CTLA-4 and MSTN expression were performed in 38 samples from patients with SCLC.

Results

We found that positive expression in patients of the biomarkers was as follows: for DLL3, 100% (38/38), for CTLA-4, 89.5% (36/38) and for MSTN 81.5% (31/38). The median survival time was 17.9 months in the DLL3 high expression group and 23 months in the DLL3 low expression group. Patients with a high expression of DLL3 showed a poorer prognosis than those with a low expression of DLL3 (HR=3.4; 95% CI, 1.34–8.6; p=0.01).

Conclusion

The expression of DLL3, CTLA-4 and MSTN was not correlated with patients’ age, sex, smoking status, stage, and tumor metastasis. The fact that there was a higher expression of DLL3, CTLA-4, and MSTN in SCLC suggested that these molecules could be used as predictive biomarkers for SCLC.

The KDM5A/RBP2 histone demethylase represses NOTCH signaling to sustain neuroendocrine differentiation and promote small cell lung cancer tumorigenesis

More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A ^+/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.

Prognostic value of tumor cavitation in extensive-stage small-cell lung cancer patients treated with anlotinib

PURPOSE

Anlotinib is a novel multi-target tyrosine kinase inhibitor (TKI) for tumor angiogenesis and tumor cell proliferation. The efficacy of anlotinib as a third-line or beyond therapy for SCLC was confirmed in the ALTER1202 trial. For lung cancer patients treated with antiangiogenesis agents, the phenomenon of cavitation is commonly seen in the lung target lesions. The impact of tumor cavitation on survival in lung cancer patients treated with vascular-targeted therapy remains controversial. Our retrospective study was to investigate the prognostic value of tumor cavitation in extensive-stage SCLC patients treated with anlotinib.

METHODS

A total of 73 extensive-stage SCLC patients confirmed by histopathology from January 2018 to January 2019 were retrospectively analyzed. All patients received anlotinib therapy at Shanghai Chest Hospital. We defined tumor cavitation of the lung target lesions as that part of solid component was changed to air-filled area according to chest CT. Progression-free survival (PFS) was calculated from the beginning of anlotinib therapy to the disease progression or the last follow-up visit.

RESULTS

Eleven (15.0%) patients had tumor cavitation during anlotinib therapy. The ORR of the 73 patients was 15.1%. Multivariate logistic regression analysis showed that tumor cavitation during anlotinib therapy was not associated with gender (P = 0.630), age (P = 0.190), smoking status (P = 0.165), anatomy type (P = 0.641), and the line of anlotinib therapy (P = 0.302). The median PFS of all patients was 2.6 months (95%CI 2.1-3.2). According to the univariate analysis, the median PFS in patients with and without tumor cavitation was 5.0 months and 2.2 months, respectively, and the difference was statistically significant (P = 0.041). According to the multivariate analysis, tumor cavitation was an independent factor for PFS after adjusting gender, age, smoking status, anatomy type, the line of anlotinib therapy, tumor cavitation, and response to anlotinib (adjusted HR 0.316, 95%CI 0.142-0.702; P = 0.005).

CONCLUSIONS

In 73 extensive-stage SCLC patients treated with anlotinib, no demographic/clinical characteristic was related to tumor cavitation, and tumor cavitation was an independent factor in predicting better PFS.

A case of metastasis of small cell lung cancer to the parotid gland: a case report and literature review

Small cell lung cancer metastasizing to the parotid gland is very rare and only a few cases have been reported. A 64-year-old man presented with a painless mass and peripheral facial paralysis. Neck ultrasound identified a solid mass in the right parotid gland with enlargement of the lymph nodes in the gland and the right submandibular lymph nodes. Lung computed tomography imaging demonstrated abnormalities in the upper and middle lobes of the right lung and intermediate bronchus, with obstructive pneumonia, as well as enlargement of the right hilar and mediastinal lymph nodes. Postoperative histopathological analysis identified small cell carcinoma in the right parotid gland with involvement of the right neck lymph nodes (one of eight). Bronchoscopy was performed and immunohistochemical analysis of the specimen demonstrated possible metastasis of small cell lung cancer to the parotid gland. From postoperative day 15, the patient started to undergo six cycles of an adjuvant chemotherapy regimen. No complications of the chemotherapy regimen were observed after three cycles. Treatment and follow-up are ongoing.

Treatment beyond four cycles of first line Platinum and Etoposide chemotherapy in real-life patients with stage IV Small Cell Lung Cancer: a retrospective study of the Merseyside and Cheshire Cancer network

Background

Dose intensity and dose density of first line Platinum and Etoposide (PE) do not influence Overall Survival (OS) of Small Cell Lung Cancer (SCLC) patients. The effect of treatment length, however, remains unclear. Current guidelines recommend treating beyond 4 cycles -up to 6-, in patients that respond to and tolerate systemic treatment. This has led to variable practice both in clinical practice and clinical research. Here we aimed at quantifying the possible clinical benefit of the extended regimen in our real-life patients treated with PE doublet.

Methods

Of all patients with SCLC treated in our network with non-concurrent first line PE chemotherapy between 2008 and 2015, we identified and described patients that received 4 cycles (4c) or more (> 4c), and analysed patients with stage IV disease.

Results

Two hundred forty-one patients with stage IV had 4c and 69 had > 4c. The latter were more likely to have sequential thoracic radiotherapy, which suggested a lower metastatic burden. Nevertheless, there were no statistically significant differences when comparing clinical outcomes. The median Duration of Response (DoR; time from last chemotherapy cycle to progression) was 5 months in both groups (HR 1.22; 95% CI 0.93–1.61). Median Progression Free Survival (PFS; time from diagnosis to radiological progression) was 8 months (4c) versus 9 months (> 4c) (HR 0.86; 95% CI 0.66–1.13) and median OS was 11 versus 12 months (HR 0.86, 95% CI 0.66–1.14).

Conclusion

Our results highlight a lack of clinical benefit by extending first line PE treatment in stage IV disease, and support limiting treatment to 4 cycles until superiority of a longer regimen is identified in a randomised study.

The road map of cancer precision medicine with the innovation of advanced cancer detection technology and personalized immunotherapy

The advancement of cancer genomics research due to the development of next generation sequencing technologies is going to bring the promise of cancer precision medicine, in turn revolutionizing cancer detection and treatment. In this review, we will discuss the possible road map for implementation of cancer precision medicine into the clinical practice by mainly focusing on the role of liquid biopsy, particularly circulating tumor DNA, as a potential tool for cancer screening, selection of an appropriate drug(s), surveillance of minimal residual diseases, and early detection of recurrence. We will also review the current status of genome-driven oncology and emerging field of immunotherapies that could be provided to patients to improve their clinical outcome and quality of life. Lastly, we will discuss the usefulness of artificial intelligence that facilitate complex data integration in our health care/medical care system.

Idiopathic pulmonary fibrosis in small cell lung cancer as a predictive factor for poor clinical outcome and risk of its exacerbation

Objective

Lung cancer frequently co-exists with idiopathic interstitial pneumonia (IIP), which can be subdivided into idiopathic pulmonary fibrosis (IPF) and IIP other than IPF (other IIP). Although chemotherapy in small cell lung cancer (SCLC) patients with IIP may result in the exacerbation of IIP, these patients commonly receive chemotherapy. This study aimed to assess the risks and benefits of chemotherapy in SCLC patients with IIP.

Methods

We retrospectively analyzed the medical records of 122 patients with SCLC who received chemotherapy. Patients with secondary interstitial lung disease (ILD) of known etiology were excluded. Eligible patients were divided into two groups: SCLC with and without IIP. The former group was subdivided into those with IPF and other IIP.

Results

Of the 47 (39.2%) SCLC patients with IIP, 20 had IPF and 27 had other IIP. The frequency of chemotherapy-induced ILD development or IIP exacerbation was higher in patients with IPF (40.0%) than in those with other IIP (3.7%) and non-IIP (1.4%). Logistic regression analysis demonstrated that ILD development or IIP exacerbation was independently associated with IPF (P = 0.007). Time to treatment failure (P < 0.001) and overall survival (P = 0.001) were different among the groups., Cox proportional hazard model revealed that IPF was independently associated with time to treatment failure (P = 0,017) and overall survival (P = 0.006). Other IIP had no impact on time to treatment failure or overall survival. Development of ILD or exacerbation of IIP independently reduced time to treatment failure and overall survival.

Conclusions

Comorbid IPF can be an independent, negative prognostic indicator and at high risk of ILD development or IIP exacerbation in SCLC patients. Early diagnosis and intervention for chemotherapy-induced IIP exacerbation will be beneficial for SCLC patients with IPF, who need close monitoring for its onset.

Contrast-Enhanced CT Texture Analysis: a New Set of Predictive Factors for Small Cell Lung Cancer

PURPOSE

The purpose of this study was to investigate the relationship between x-ray computed tomography (CT) texture features of small cell lung cancer (SCLC) and the survival of the patients.

PROCEDURES

Eighty-eight patients with unresectable SCLCs (extended stage, 57; limited stage, 31) underwent platinum-based chemotherapy at our institution between January 2010 and 2015. All the patients were followed up for at least 18 months or until death. The CT texture features of tumor tissue were extracted from contrast-enhanced CT images taken before antitumor treatment. Receiver operating characteristic (ROC) curve analysis was used to calculate the optimal cutoff values of each texture parameter, based on which the patients were dichotomized into two subgroups to evaluate the prognostic value of each feature. Kaplan-Meier survival analysis and the log rank test were performed to compare the differences of 18-month overall survival (OS) and 6-month event-free survival (EFS) in dichotomized subgroups. Multivariate Cox regression analysis was performed to determine if the features could be taken as independent prognostic factors.

RESULTS

A total number of 35 CT texture features were extracted from six matrixes. Four of them (GLCM-Contrast, GLCM-Dissimilarity, Histo-Energy, and Histo-Entropy) were shown to be significantly related to 18-month OS, and two (GLCM-Energy and GLCM-Entropy) were shown to be significantly related to 6-month EFS. Cox regression suggested that GLCM-Dissimilarity was independently associated with OS, while GLCM-Energy were independently associated with EFS.

CONCLUSIONS

The texture features of contrast-enhanced computed tomography image could potentially serve as radiological prognostic biomarkers for SCLC patients.

Current Diagnosis and Management of Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive disease with distinct pathological, clinical, and molecular characteristics from non-small-cell lung cancer. SCLC has high metastatic potential, resulting in a clinically poor prognosis. Early concurrent chemo-radiation is the standard of care for limited-stage SCLC (LS-SCLC). Prophylactic cranial irradiation (PCI) is recommended for patients with LS-SCLC without progression of disease after initial therapy. A combination of etoposide and cisplatin or carboplatin remains the mainstay of first-line treatment for ES-SCLC, with the addition of atezolizumab, now becoming standard. Most SCLCs initially respond to therapy but almost invariably recur. Topotecan and amrubicin (in Japan) remain the primary chemotherapy options for relapsed SCLC. Immunotherapy, including nivolumab with or without ipilimumab, is now available for refractory disease. In general, the poor prognosis of SCLC has not improved significantly for more than 3 decades. Recently, next-generation molecular profiling studies have identified new therapeutic targets for SCLC. A variety of proapoptotic agents, compounds capitalizing on DNA-repair defects, immunotherapy agents, and antibody-drug conjugates are being evaluated in SCLC, with a number of them showing early promise.

Dual-strand tumor suppressor miR-193b-3p and -5p inhibit malignant phenotypes of lung cancer by suppressing their common targets

Emerging studies suggest that microRNAs (miRNAs) play multiple roles in cancer malignancy, including proliferation and acquisition of metastatic potential. Differentially expressed miRNAs responsible for the malignancy of lung cancer were searched by miRNA microarray using a previously established brain metastatic lung cancer model. Twenty-five miRNAs were down-regulated in brain metastatic lung cancer cells. Among those, miR-193b-3p and -5p were chosen for further studies. Their function in metastatic potential and proliferation was examined using Transwell invasion, wound healing, and colony forming assays. The underlying mechanism of tumor-suppressor miR-193b-3p and -5p was explored using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), Western blot, Argonaute 2-RNA immunoprecipitation (Ago2-RIP), and reporter assays. Both strands of miR-193b were down-regulated in brain metastatic lung cancer cells and in tissues from lung cancer patients. Overexpression of miR-193b-3p and -5p inhibited invasive and migratory activities and diminished clonogenic ability. Conversely, inhibition of miR-193b-3p or -5p increased the metastatic potential and colony forming ability. Cyclin D1 (CCND1), Ajuba LIM Protein (AJUBA), and heart development protein with EGF like domains 1 (HEG1) were identified as common target genes of miR-193b-3p and -5p. A reporter assay and an Ago2-RIP experiment showed that both miRNAs directly bind to the 3′ untranslated region (3′UTR) of the target mRNA. Knockdown of target gene reduced the proliferative and metastatic potential of primary and metastatic lung cancer cells. Our results demonstrate miR-193b is a dual-strand tumor suppressor and a novel therapeutic target for lung cancer.

RRx-001 followed by platinum plus etoposide in patients with previously treated small-cell lung cancer

Background

This exploratory single-arm phase II study evaluated the efficacy and safety of RRx-001 followed by reintroduction of platinum plus etoposide in patients with previously treated small-cell lung cancer (SCLC).

Methods

Patients were treated with RRx-001 4 mg IV on day 1 of each week of a 21-day cycle followed at progression by re-challenge with etoposide 80–100 IV mg/m² on days 1, 2 and 3 and cisplatin 60–80 mg/m² IV on day 1 or carboplatin AUC 5–6 IV on day 1, every 21 days. The primary end points were overall survival (OS) and overall response rate to platinum regimen.

Results

Twenty-six patients were enroled and received at least one dose of RRx-001. The median number of prior lines of therapy was 2 (range 1–9) and 19 (73.1%) patients had platinum-resistant disease. In the intention-to-treat population, one patient (3.8%) had complete response and six (23.1%) had partial response on platinum plus etoposide. The estimated median and 12-month OS from enrolment were 8.6 months and 44.1%, respectively. The most common treatment-emergent adverse event from RRx-001 was mild discomfort at the infusion site (23%).

Conclusions

RRx-001 followed by re-challenge with platinum plus etoposide chemotherapy is feasible and associated with promising results.

Clinical trial registration

NCT02489903.

DLL3: an emerging target in small cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 15% of all lung cancers. Despite high rates of response to first-line chemotherapy and radiotherapy, patients with extensive-stage disease eventually relapse, and very few patients survive more than 5 years from diagnosis. Treatment options for recurrent or refractory disease are limited, and the treatments that do exist are associated with significant treatment-related toxicities. Delta-like ligand 3 (DLL3) is an inhibitory Notch ligand that is highly expressed in SCLC and other neuroendocrine tumors but minimally expressed in normal tissues. It is therefore being explored as a potential therapeutic target in SCLC. Here, we review the preclinical and clinical evidence for targeting DLL3 in SCLC and discuss several DLL3-specific therapies being developed for the treatment of SCLC: the antibody-drug conjugate rovalpituzumab tesirine, the bispecific T cell engager immuno-oncology therapy AMG 757, and the chimeric antigen receptor T cell therapy AMG 119.

Survival Outcomes With Thoracic Radiotherapy in Extensive-Stage Small-Cell Lung Cancer: A Propensity Score-Matched Analysis of the National Cancer Database

BACKGROUND

The prognosis of patients with extensive-stage small-cell lung carcinoma (ES-SCLC) is poor. The benefit of consolidative thoracic radiation therapy (TRT) in ES-SCLC has been inconclusive, and its use inconsistent. The objective of this study was to evaluate overall survival (OS) of ES-SCLC patients treated with chemotherapy (CT) with or without TRT using an administrative database approach.

PATIENTS AND METHODS

The National Cancer Database was queried to identify patients with ES-SCLC diagnosed between 2010 and 2014. Those with brain metastases, those who received radiotherapy before CT, or radiotherapy outside the thorax, were excluded. Propensity score-matching (PSM) was used to compare OS of patients treated with CT and TRT with those who received CT alone. Patients who received >10 radiotherapy fractions were also compared with those who received 10 or fewer.

RESULTS

We included 14,367 patients in the primary analysis; 12,019 received CT alone, and 2348 received CT with TRT. In multivariate analysis, CT was associated with an increased risk of death relative to CT with TRT (hazard ratio [HR], 1.74 [95% confidence interval (CI), 1.64-1.84]; log-rank P < .001), which remained significant with PSM. Median OS was 12.1 versus 8.2 months (CT with TRT vs. CT); 12-month OS was 50.5% versus 28.5%, and 5-year OS 7.6% versus 2.0% (HR, 1.80 [95% CI, 1.67-1.95], HR P < .001). Of 3099 patients who received TRT, >10 radiotherapy fractions was associated with superior OS (HR, 1.70 [95% CI, 1.49-1.95], log-rank P < .001); this finding remained significant with PSM.

CONCLUSION

Use of TRT after CT in ES-SCLC patients was associated with long-term survival; its use should be considered in addition to standard of care CT.

Clinical significance of progastrin-releasing peptide, neuron-specific enolase, chromogranin a, and squamous cell cancer antigen in pulmonary neuroendocrine tumors

Background/aim

It is not always easy to diagnose pulmonary neuroendocrine tumors (PNETs). The aim of the present study is to make a differential diagnosis by studying the same markers in patients with non-small-cell lung carcinoma (NSCLC), patients with benign lung disease (chronic obstructive pulmonary disease and pneumonia), and healthy volunteers to determine the roles of these markers in pulmonary neuroendocrine tumor diagnosis and to identify their power.

Materials and methods

A total of 100 participants including 23 PNET patients and 28 NSCLC patients who were pathologically diagnosed but not yet treated, 25 participants with benign disease, and 24 healthy volunteers were included in this cross-sectional study.

Results

No significant difference was found between the chromogranin A (CgA) and squamous cell carcinoma antigen 1 (SCCA1) values among the groups (PNET, NSCLC, benign, healthy volunteers), but the difference in progesterone-releasing peptide (ProGRP), neuron-specific enolase (NSE), and adjusted NSE was statistically significant (P values were respectively ProGRP, P = 0.006; NSE, P = 0.015; NSE adjusted, P = 0.09). In a comparison of the PNET and NSCLC groups, having a ProGRP value higher than 84.6 pg/mL revealed PNET with 60.9% sensitivity and 89.3% specificity (P = 0.001).

Conclusion

The ProGRP value is the only indicator that distinguishes the PNET group from the other 3 groups.

Comprehensive genomic profiling of small cell lung cancer in Chinese patients and the implications for therapeutic potential

Background

Small cell lung cancer (SCLC) is one of the deadliest malignancies and accounts for nearly 15% of lung cancers. Previous study had revealed the genomic characterization of SCLC in Western patients. However, little is known about that in Chinese SCLC patients.

Methods

Formalin‐fixed paraffin‐embedded tumor tissues and matched blood samples from 122 Chinese SCLC patients were collected for next generation sequencing to detect 450 cancer‐related genes. All pathological diagnoses were confirmed by independent pathologists.

Results

The most frequently altered genes were TP53 (93.4%), RB1 (78.7%), LRP1B (18.9%), KMT2D (15.6%), FAT1 (11.5%), KMT2C (11.5%), SPTA1 (11.5%), STK24 (11.5%), FAM135B (10.7%), and NOTCH1 (10.7%). The gene fusion/rearrangement detection rate was 16.4%, and mostly occurred in chromosomes 7 and 17. The rate of co‐occurring mutations of TP53 and RB1 in these Chinese SCLC patients was 74.6%, and lower than the reported Western patients (90.9%, P = 0.007). The most common gene mutations (83.6%) were found in cell cycle signaling pathway in Chinese SCLC patients. Mutation of Wnt and Notch signaling pathways in the Chinese cohort were lower than Western cohort (P = 0.0013 and 0.0068). A significant association was found between high tumor mutation burden and mutations involved in FAT1, TP53, SPTA1, KEAP1, KMT2D, MAGI2, NOTCH2, NOTCH3, FLT1, KDM6A, and FAT4.

Conclusions

In this study, we characterized the genomic alterations profile of Chinese SCLC patients. Compared with westerners, the genetic alterations of Chinese SCLC patients presented different patterns. Our data might provide useful information in targeted therapy and drug development for Chinese SCLC patients.

Novel targeted strategies to overcome resistance in small-cell lung cancer: focus on PARP inhibitors and rovalpituzumab tesirine

Introduction: Small-cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumour, and its outcome is strongly conditioned by the rapid onset of resistance to conventional chemotherapeutics. First-line treatment with a combination of platinum agents and topoisomerase inhibitors has been the standard of care for over 30 years, with disappointing clinical outcome caused by early-acquired chemoresistance. In this disheartening scenario, novel treatment strategies are being implemented in order to either revert or bypass resistance mechanisms. Areas covered: The general mechanism of action of the standard frontline treatment regimens for SCLC, as well as the known resistance mechanisms to these drugs, is reviewed. Moreover, we focus on the current preclinical and clinical evidence on the potential role of PARP inhibitors and rovalpituzumab tesirine (Rova-T) to tackle chemoresistance in SCLC. Expert opinion: Preliminary evidence supports PARP inhibitors and Rova-T as two promising approaches to either revert or bypass chemoresistance in SCLC, respectively. The identification of potential predictive biomarkers of response to these innovative treatments (SLFN11 and DLL3) has shortened the gap between SCLC and personalized targeted therapy. Further large-scale clinical studies are urgently needed for a better designation of PARP inhibitors and Rova-T in the therapeutic algorithm of SCLC patients.

Analysis of DLL3 and ASCL1 in Surgically Resected Small Cell Lung Cancer (HOT1702)

BACKGROUND

Delta-like protein 3 (DLL3) is a Notch ligand that has an important role in the tumorigenesis of small cell lung cancer (SCLC). Recently, rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, has been developed for treating SCLC. DLL3 is a transcriptional target of the achaete-scute homolog-1 (ASCL1) transcription factor, which is involved in pulmonary neuroendocrine cell development. However, the relationship between DLL3 and/or ASCL1 expression and the clinical features of SCLC remains unknown, especially for early-stage resected SCLC. This study aimed to investigate the expression of DLL3 and ASCL1 in resected SCLC samples using immunohistochemical analysis.

MATERIALS AND METHODS

We collected 95 surgically resected SCLC samples, which were formalin fixed and paraffin embedded. Immunohistochemistry staining was performed to investigate the correlation between the expression of either DLL3 or ASCL1 and clinicopathological features of study patients.

RESULTS

Seventy-seven (83%) of 93 immunohistochemically evaluable samples were positive for DLL3 (expression in ≥1% of tumor cells), and DLL3-high expression (≥75%) was observed in 44 samples (47%). Sixty-one (64%) of 95 samples were positive for ASCL1 (expression in ≥5% of tumor cells). A positive correlation was observed between DLL3 and ASCL1 expression. DLL3 and ASCL1 expression were not associated with survival in SCLC patients. DLL3 was more prevalent in patients with advanced clinical disease.

CONCLUSION

DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of SCLC.

IMPLICATIONS FOR PRACTICE

This article examines the relationship between delta-like protein 3 (DLL3) and achaete-scute homolog-1 (ASCL1) protein expression with the clinical features of 95 surgically resected small cell lung cancer (SCLC). DLL3 is attracting attention because rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, was developed recently. DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of early-stage SCLC, including with Rova-T.

Emerging therapies for small cell lung cancer

Currently, chemotherapy remains the standard treatment for first- and second-line management of small cell lung cancer (SCLC). Immunotherapy has made progress in the treatment of SCLC, and nivolumab, pembrolizumab, atezolizumab, and durvalumab have led to significant improvements in clinical outcomes of SCLC. Regarding options in other classes of therapy, the cytotoxic drug lurbinectedin was granted orphan drug status based on a remarkable objective response rate of 39.3%. In addition, an increase in progression-free survival (PFS) was achieved in a phase II study of anlotinib (ALTER 1202). Future prospects for even better outcomes in SCLC lie in novel ways to integrate immunotherapy and small-molecule TKI drugs. Innovative clinical trial designs are needed to efficiently explore the increasing number of options with new drugs and new combinations thereof for SCLC.

DLL3 regulates the migration and invasion of small cell lung cancer by modulating Snail

Delta‐like protein 3 (DLL3) is a ligand of Notch signaling, which mediates cell‐fate decisions and is tumor‐suppressive or oncogenic depending on the cellular context. Previous studies show that DLL3 is highly expressed in small cell lung cancer (SCLC) but not in normal lung tissue, suggesting that DLL3 might be associated with neuroendocrine tumorigenesis. However, its role in SCLC remains unclear. To investigate the role of DLL3 in tumorigenesis in SCLC, we performed loss‐of‐function and gain‐of‐function assays using SCLC cell lines. In vitro analysis of cell migration and invasion by transwell assay showed that DLL3 knockdown reduced migration and invasion of SCLC cells, whereas DLL3 overexpression increased these activities. In addition, DLL3 positively regulated SNAI1 expression and knockdown of SNAI1 attenuated the migration and invasion ability of SCLC cells. Moreover, upregulated DLL3 expression induced subcutaneous tumor growth in mouse models. These results indicate that DLL3 promoted tumor growth, migration and invasion in an SCLC model by modulating SNAI1/Snail.

Anti-angiogenesis treatment in a patient with appendix metastasis of small cell lung cancer: A case report

RATIONALE

Small-cell lung cancer (SCLC) is a common pathological type of lung cancer, but appendiceal metastasis of SCLC was rare. At present, clinical studies on the maintenance therapy of SCLC have not reached a significant conclusion.

PATIENT CONCERNS

We reported on a 52-year-old man who diagnosed as extensive stage SCLC with abdominal pain for 2 months, aggravated for 2 days.

DIAGNOSES

The patient was diagnosed with extensive-stage SCLC, relapsed with appendix metastasis after treatment by emergency abdominal surgery.

INTERVENTIONS

The patient received systemic treatments, including surgery, bevacizumab in combination with chemotherapy and bevacizumab alone was continued as maintenance therapy.

OUTCOMES

The patient had an overall survival would more than 23 months, and he gained another 8 months of progression-free survival after first-line radiochemotherapy.

LESSONS

Although SCLC appendix metastasis is rare, continuous anti-angiogenic therapy combined with bevacizumab maintenance therapy after surgical treatment can prolong survival.

Synthetic Lethality in Lung Cancer-From the Perspective of Cancer Genomics

Cancer is a genetic disease, and this concept is now widely exploited by both scientists and clinicians to develop new genotype-selective anticancer therapeutics. Although the quest of cancer genomics is in its dawn, recognition of the widespread applicability of genetic interactions with biological processes of tumorigenesis is propelling research throughout academic fields. Lung cancer is the most common cause of cancer death worldwide, with an estimated 1.6 million deaths each year. Despite the development of targeted therapies that inhibit oncogenic mutations of lung cancer cases, continued research into new therapeutic approaches is required for untreatable lung cancer patients, and the development of therapeutic modalities has proven elusive. The "synthetic lethal" approach holds the promise of delivering a therapeutic regimen that preferentially targets malignant cells while sparing normal cells. We highlight the potential challenges in synthetic lethal anticancer therapeutics that target untreatable genetic alterations in lung cancer. We also discuss both challenges and opportunities regarding the application of new synthetic lethal interactions in lung cancer.

Choice of surgical procedure - lobectomy, segmentectomy, or wedge resection - for patients with stage T1-2N0M0 small cell lung cancer: A population-based study

Background

To date, few studies have evaluated the impact of lobectomy versus sublobar resection for early small cell lung cancer (SCLC). We investigated the survival rates of patients with pathological stage T1‐2N0M0 SCLC who underwent lobectomy or sublobar resection.

Methods

We identified 548 SCLC patients in the Surveillance, Epidemiology, and End Results database who underwent lobectomy or sublobar resection. Propensity score matching (PSM) and Cox regression analysis were used to adjust for baseline characteristics.

Results

The three‐year overall survival (OS) of patients treated with lobectomy (n = 376, 60%) was significantly higher than those treated with sublobar resection (n = 172, 38%). PSM and Cox multivariable analysis further confirmed this result (hazard ratio [HR] 0.543, 95% confidence interval [CI] 0.421–0.680; P < 0.001). The three‐year OS of patients treated with segmentectomy (n = 24, 54%) and wedge resection (n = 148, 36%) was not significantly different (HR 0.639, 95% CI 0.393–1.039; P = 0.071). Based on PSM analysis, segmentectomy conferred a superior survival advantage to patients relative to wedge resection (HR 0.466, 95% CI 0.221–0.979; P = 0.040).

Conclusion

Lobectomy correlated with superior survival. For patients in which lobectomy is unsuitable, prognosis following segmentectomy appears to be better than after wedge resection.

Rovalpituzumab Tesirine: A Novel DLL3-Targeting Antibody-Drug Conjugate

Small cell lung cancer (SCLC) comprises about 15% of all cases of lung cancer. In recent years, owing to a change in the epidemiology of smoking habits, the incidence of the tumor has decreased; however, it remains a significant challenge to global health. While the tumor has a favorable initial response to chemoradiation, relapse is invariable, and second-line regimens may be intolerable given the severity of side effects. For patients with tumors resistant to second-line regimens, no current standard regimens exist. Rovalpituzumab tesirine is a novel antibody-drug conjugate, targeting delta-like protein 3, fundamental in the downstream cellular signaling for proliferation and apoptosis. This drug is reported to have shown promise in pre-clinical and phase I trials. It appears effective in decreasing tumor burden and is reported to be well tolerated, albeit with a significant adverse effect profile. Currently, it is being studied as part of initial and subsequent line chemotherapeutic regimens; it remains to be seen if this is a viable option in the treatment of SCLC. This may add to the agents that can be used against SCLC, and help improve outcomes.

2017-2018 Scientific Advances in Thoracic Oncology: Small Cell Lung Cancer

SCLC remains an aggressive, deadly cancer with only modest effect on survival from standard chemotherapy. However, with the advent of immunotherapy and comprehensive genomic and transcriptomic profiling, multiple new targets are showing promise in the clinical arena, and just recently programmed death ligand 1 inhibition has been shown to improve the efficacy of standard chemotherapy in extended-disease SCLC. Our increasing understanding of the interactions between different pathways will enable more tailored immunotherapy and targeted therapies based on specific biomarkers and rational combinations. Here we discuss the preclinical and clinical strides in 2017 and 2018 that put us on the threshold of a new era in therapeutics and will, it is hoped, translate into significant improvements in survival.

Surgical Resection of SCLC: Prognostic Factors and the Tumor Microenvironment

INTRODUCTION

Surgery in SCLC is limited to very early stages, but several reports suggest a potential broader role. Little is known of the influence of microenvironment on the biology of SCLC.

METHODS

We assessed the clinical prognostic factors in a large series of resected SCLC patients. The prognostic value of programmed cell death ligand 1 (PD-L1) expression in tumor cells and tumor infiltrating lymphocytes (TILs) and the percentage of CD3-, CD20-, CD45- and CD68-positive cells, were also investigated.

RESULTS

Two hundred five SCLC cases were resected between 2005 and 2015 and the median follow-up was 29 months (range: 2 to 135 months). Median survival of all patients was 69 months, and 5-year survival rates were 63.8%, 65.5%, 34.9%, and 0% for pathologic stages I, II, III, and IV, respectively. By multivariate analysis complete resection, cigarette index, lymph node metastatic rate, percentage of CD3-positive cells, PD-L1 expression in tumor cells, and TILs were independent prognostic factors. High PD-L1 expression was present in 3.2% and 33.5% of all tumor samples in tumor cells and TILs, respectively. High PD-L1 expression in tumor cells or TILs correlated with shorter survival, whereas high expression of CD3, CD20, and CD45 correlated with better survival.

CONCLUSIONS

Resected stage II SCLC patients have similar survival as stage I, suggesting that surgery could be extended to patients with hilar lymph node involvement. Survival was better in tumors with a higher percentage of T cells and B cells, whereas PD-L1 expression in tumor cells and TILs correlated with worse survival, which suggests a potential role of immunotherapy in resected SCLC.

Cells Lacking the RB1 Tumor Suppressor Gene Are Hyperdependent on Aurora B Kinase for Survival

Small cell lung cancer (SCLC) accounts for 15% of lung cancers and is almost always linked to inactivating RB1 and TP53 mutations. SCLC frequently responds, albeit briefly, to chemotherapy. The canonical function of the RB1 gene product RB1 is to repress the E2F transcription factor family. RB1 also plays both E2F-dependent and E2F-independent mitotic roles. We performed a synthetic lethal CRISPR/Cas9 screen in an RB1 -/- SCLC cell line that conditionally expresses RB1 to identify dependencies that are caused by RB1 loss and discovered that RB1 -/- SCLC cell lines are hyperdependent on multiple proteins linked to chromosomal segregation, including Aurora B kinase. Moreover, we show that an Aurora B kinase inhibitor is efficacious in multiple preclinical SCLC models at concentrations that are well tolerated in mice. These results suggest that RB1 loss is a predictive biomarker for sensitivity to Aurora B kinase inhibitors in SCLC and perhaps other RB1 -/- cancers. SIGNIFICANCE: SCLC is rarely associated with actionable protooncogene mutations. We did a CRISPR/Cas9-based screen that showed that RB1 -/- SCLC are hyperdependent on AURKB, likely because both genes control mitotic fidelity, and confirmed that Aurora B kinase inhibitors are efficacious against RB1 -/- SCLC tumors in mice at nontoxic doses.See related commentary by Dick and Li, p. 169.This article is highlighted in the In This Issue feature, p. 151.

Cullin5 deficiency promotes small-cell lung cancer metastasis by stabilizing integrin β1

Metastasis is the dominant cause of patient death in small-cell lung cancer (SCLC), and a better understanding of the molecular mechanisms underlying SCLC metastasis may potentially improve clinical treatment. Through genome-scale screening for key regulators of mouse Rb1-/- Trp53-/- SCLC metastasis using the pooled CRISPR/Cas9 library, we identified Cullin5 (CUL5) and suppressor of cytokine signaling 3 (SOCS3), two components of the Cullin-RING E3 ubiquitin ligase complex, as top candidates. Mechanistically, the deficiency of CUL5 or SOCS3 disrupted the functional formation of the E3 ligase complex and prevented the degradation of integrin β1, which stabilized integrin β1 and activated downstream focal adhesion kinase/SRC (FAK/SRC) signaling and eventually drove SCLC metastasis. Low expression levels of CUL5 and SOCS3 were significantly associated with high integrin β1 levels and poor prognosis in a large cohort of 128 clinical patients with SCLC. Moreover, the CUL5-deficient SCLCs were vulnerable to the treatment of the FDA-approved SRC inhibitor dasatinib. Collectively, this work identifies the essential role of CUL5- and SOCS3-mediated integrin β1 turnover in controlling SCLC metastasis, which might have therapeutic implications.

Prophylactic cranial irradiation in small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The efficacy of prophylactic cranial irradiation (PCI) in treating patients with small cell lung cancer (SCLC) has not been clear, and recent randomized studies have demonstrated conflicting results from previously published findings. The purpose of this study was to reevaluate the efficacy of PCI in patients with SCLC and to assess factors associated with its efficacy.

METHODS

We conducted a quantitative meta-analysis to explore the efficacy of PCI in patients with SCLC. A literature search was performed using EMBASE, MEDLINE, Cochrane and ClinicalTrials.gov databases. We pooled the data and compared overall survival (OS) and brain metastasis (BM) between patients treated with PCI (PCI group) and patients without PCI treatment (observation group).

RESULTS

Of the 1074 studies identified in our analysis, we selected seven studies including 2114 patients for the current meta-analysis. Our results showed that the PCI group showed decreased BM (HR = 0.45, 95% CI: 0.38-0.55, P < 0.001) and prolonged OS (HR = 0.81, 95% CI: 0.67-0.99, P < 0.001). However, in terms of OS, the pooled analysis showed a high heterogeneity (I² = 74.1%, P = 0.001). In subgroup analyses of OS, we found that the heterogeneity mainly came from patients with brain imaging after initial chemoradiotherapy (HR = 0.94, 95% CI: 0.74-1.18, P = 0.59).

CONCLUSIONS

The results of this study showed that PCI has a significant effect on decreasing BM but little benefit in prolonging OS when brain imaging was introduced to confirm lack of BM after initial chemoradiotherapy and before irradiation.

Risk factors for brain metastases in patients with non-small-cell lung cancer

Brain metastases (BM) are severe incidents in patients with non-small-cell lung cancer (NSCLC). The controversial value of prophylactic cranial irradiation (PCI) in NSCLC in terms of survival benefit prompted us to explore the possible risk factors for BM in NSCLC and identify the potential population most likely to benefit from PCI. Risk factors for brain metastases in NSCLC are reviewed in this article. Identifying patients with a higher risk of BM could possibly increase the benefit of PCI while reducing the discomfort and risks caused by unnecessary invasive procedures in the NSCLC patient population. Future studies might focus on finding a solid basis for the prediction of the occurrence of brain metastases and for the therapeutic decision on the use of PCI.

Prognostic Analysis of Limited Resection Versus Lobectomy in Stage IA Small Cell Lung Cancer Patients Based on the Surveillance, Epidemiology, and End Results Registry Database

Objective: The prognostic analysis of limited resection vs. lobectomy in stage IA small cell lung cancer (SCLC) remains scarce. Methods: Using the Surveillance, Epidemiology, and End Results registry (SEER) database, we identified patients who were diagnosed with pathological stage IA (T1a/bN0M0) SCLC from 2004 to 2013. The overall survival (OS) and lung cancer-specific survival (LCSS) rates of patients with different treatment schemes were compared in stratification analyses. Univariable and multivariable analyses were also performed to identify the significant predictors of OS and LCSS. Results: In total, we extracted 491 pathological stage IA SCLC patients, 106 (21.6%) of whom received lobectomy, 70 (14.3%) received sublobar resection and 315 (64.1%) received non-surgical treatment, respectively. There were significant differences among the groups based on different treatment schemes in OS (log-rank p < 0.0001) and LCSS (log-rank p < 0.0001). Furthermore, in subgroup analyses, we did not identify any differences between sublober resection group and lobectomy group in OS (log-rank p = 0.14) or LCSS (log-rank p = 0.4565). Patients with four or more lymph node dissection had better prognosis. Multivariable analyses revealed age, laterality, tumor location, and N number were still significant predictors of OS, whereas age, tumor location, and N number were significant predictors of LCSS. Conclusion: Surgery is an important component of multidisciplinary treatment for stage IA SCLC patients and sublober resection is not inferior to lobectomy for the specific patients.