Small cell lung cancer: have we made any progress over the last 25 years?

Advances in predictive biomarkers associated with immunotherapy in extensive-stage small cell lung cancer

Small cell lung cancer (SCLC) is a highly malignant and poor-prognosis cancer, with most cases diagnosed at the extensive stage (ES). Amidst a landscape marked by limited progress in treatment modalities for ES-SCLC over the past few decades, the integration of immune checkpoint inhibitors (ICIs) with platinum-based chemotherapy has provided a milestone approach for improving prognosis, emerging as the new standard for initial therapy in ES-SCLC. However, only a minority of SCLC patients can benefit from ICIs, which frequently come with varying degrees of immune-related adverse events (irAEs). Therefore, it is crucial to investigate predictive biomarkers to screen potential beneficiaries of ICIs, mitigate the risk of side effects, and improve treatment precision. This review summarized potential biomarkers for predicting ICI response in ES-SCLC, with a primary focus on markers sourced from tumor tissue or peripheral blood samples. The former mainly included PD-L1 expression, tumor mutational burden (TMB), along with cellular or molecular components related to the tumor microenvironment (TME) and antigen presentation machinery (APM), molecular subtypes of SCLC, and inflammatory gene expression profiles. Circulating biomarkers predominantly comprised circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), cytokines, plasma autoantibodies, inflammation-related parameters, and blood TMB. We synthesized and analyzed the research progress of these potential markers. Notably, investigations into PD-L1 expression and TMB have been the most extensive, exhibiting preliminary predictive efficacy in salvage immunotherapy; however, consistent conclusions have yet to be reached across studies. Additionally, novel predictive markers developed based on TME composition, APM, transcriptomic and genomic features provide promising tools for precision immunotherapy. Circulating biomarkers offer the advantages of convenience, non-invasiveness, and a comprehensive reflection of tumor molecular characteristics. They may serve as alternative options for predicting immunotherapy efficacy in SCLC. However, there is a scarcity of studies, and the significant heterogeneity in research findings warrants attention.

Right eye metastasis of small‑cell lung carcinoma: A case report

The incidence of eye metastasis from primary malignant tumors is low. Predominantly, these primary malignant tumors consist of breast and lung carcinoma. Ocular metastatic carcinoma is often clinically overlooked. In clinical practice, it is rare for small-cell lung carcinoma (SCLC) to metastasize to the right eye. Early detection and treatment via the monitoring of clinical symptoms and auxiliary examinations of the eye are of great significance in preserving the patient's vision and improving their quality of life. Such treatments include radiotherapy or enucleation of the eyeball. A 54-year-old male patient with SCLC experienced a decline in vision and blurred vision during his systemic treatment using combined enverolumab and etoposide and cisplatin. Upon examination, including fundus photography, ocular B-scan and magnetic resonance imaging, a right eye metastasis was suspected. Within a short period of time, the patient experienced significant pain and blindness in the right eye, which required surgical removal of the right eyeball. Postoperative pathology confirmed metastasis. After six cycles of treatment, the primary lesion in the lung reduced in size. By reporting this case of SCLC metastasis to the right eye, we aim to provide a reference for the clinical diagnosis and treatment of ocular metastatic carcinoma.

In silico and in vitro investigation of dual targeting Prima-1MET as precision therapeutic against lungs cancer

This study emphasizes the explorations of binding of Prima-1MET with two targets, p53 a tumor suppressor protein, and tyrosine kinase of epidermal growth factor receptor. In silico investigations reveal that Prima-1MET showed robust binding with both targets. Molecular docking simulations demonstrated the binding affinity of Prima-1MET with p53 and tyrosine kinase was found to be -38.601 kJ/mol and -38.976 kJ/mol. In addition, the stability of Prima-1MET was explored by molecular dynamics simulation. Prima-1MET attains stability in the binding site of the respective protein till the simulation period is over. Moreover, the free binding energy ΔGbind was calculated by the molecular mechanics Poisson Boltzmann surface area method. The ΔGbind of Prima-1MET with tyrosine kinase was found to be -58.585 ± 0.327 kJ/mol and with p53 it was -35.910 ± 0.335 kJ/mol. Next, cytotoxicity of the Prima-1MET was evaluated using multiple cancer cell lines and the IC50 value were ranging between 4.5 and 30 μM. The cell death was identified by apoptosis assay. Further, the p53 and tyrosine kinase expression was monitored using immunofluorescence techniques, it was found Prima-1MET induces the expression of p53 protein and mimics the level of tyrosine kinase oncogenic target. Also, reactive oxygen species (ROS) and membrane potential activity of Prima-1MET was evaluated by using a lung cancer cell line. A significant decrease in intracellular ROS was observed and resulted in disruption of mitochondrial transmembrane potential. This study uncovers the underlying mechanism of Prima-1MET and could be helpful to design further leads against lung cancers.Communicated by Ramaswamy H. Sarma.

Advances in new targets for immunotherapy of small cell lung cancer

Small cell lung cancer (SCLC) is one of the highly aggressive malignancies characterized by rapid growth and early metastasis, but treatment options are limited. For SCLC, carboplatin or cisplatin in combination with etoposide chemotherapy has been considered the only standard of care, but the standard first-line treatment only results in 10-month survival. The majority of patients relapse within a few weeks to months after treatment, despite the relatively sensitive response to chemotherapy. Over the past decade, immunotherapy has made significant progress in the treatment of SCLC patients. However, there have been limited improvements in survival rates for SCLC patients with the current immune checkpoint inhibitors PD-1/PD-L1 and CTLA-4. In the face of high recurrence rates, small beneficiary populations, and low survival benefits, the exploration of new targets for key molecules and signals in SCLC and the development of drugs with novel mechanisms may provide fresh hope for immunotherapy in SCLC. Therefore, the aim of this review was to explore four new targets, DLL3, TIGIT, LAG-3, and GD2, which may play a role in the immunotherapy of SCLC to find useful clues and strategies to improve the outcome for SCLC patients.

Real-world predictors of survival in patients with limited-stage small-cell lung cancer in Manitoba, Canada

Background

Although therapy for limited-stage small-cell lung cancer (LS-SCLC) is administered with curative intent, most patients relapse and eventually die of recurrent disease. Chemotherapy (CT) with concurrent radiotherapy (RT) remains the standard of care for LS-SCLC; however, this could evolve in the near future. Therefore, understanding the current prognostic factors associated with survival is essential.

Objective

This real-world analysis examines factors associated with long-term survival in patients with LS-SCLC treated with CT in Manitoba, Canada.

Methods

A retrospective cohort study was conducted using Manitoba Cancer Registry and CancerCare Manitoba records. Eligible patients were aged >18 years and had cytologically confirmed LS-SCLC diagnosed between January 1, 2004, and December 31, 2018, for which they received CT ± RT. Baseline patient, disease, and treatment characteristics and survival duration, characterized as short (<6 months), medium (6-24 months), and long term (>24 months), were extracted. Overall survival (OS) was estimated at one, two, and five years and assessed using Kaplan-Meier methods and Cox proportional hazards models.

Results

Over the 15-year study period, 304 patients met the eligibility criteria. Long-term survivors comprised 39.1% of the cohort; at diagnosis, this subgroup was younger, more likely to have Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0, and have normal lactate dehydrogenase, sodium, and hemoglobin levels. OS estimates for the entire cohort at one, two, and five years were 66%, 38%, and 18%, respectively. In the ECOG PS 0 subgroup, OS estimates at one, two, and five years were 85%, 52%, and 24%, respectively; OS estimates were 60%, 35%, and 17%, respectively, for ECOG PS 1-2 and were 47%, 23%, and 10%, respectively, for ECOG PS 3-4. OS was significantly higher among patients with normal serum sodium and hemoglobin levels than those with abnormal levels. Univariable hazard regression models found that ECOG PS, age at diagnosis, receipt of prophylactic cranial irradiation (PCI), and thoracic RT were associated with survival. On multivariable hazard regression, ECOG PS and receipt of PCI were associated with survival.

Conclusion

Survival for greater than two years in patients with LS-SCLC treated with CT ± RT was associated with ECOG PS and receipt of PCI.

GBP5 Expression Predicted Prognosis of Immune Checkpoint Inhibitors in Small Cell Lung Cancer and Correlated with Tumor Immune Microenvironment

Background

The discovery and development of immune checkpoint inhibitors (ICIs) has significantly enhanced the arsenal of immunotherapy treatments available for cancer patients. The identification of biomarkers that are indicative of an individual's sensitivity to treatment with ICIs is useful for screening SCLC patients prior to commencement of any ICIs based immunotherapy. However, the relationship between GBP5 and the prognosis of SCLC immunotherapy is still unclear and requires further study.

Methods

We downloaded two SCLC datasets, namely the George-SCLC and Jiang-SCLC cohorts. We used the TIDE algorithm to predict the efficacy of immunotherapy for SCLC patients. The QuanTIseq, MCPcounter, and EPIC algorithms are used to calculate the proportions of immune cells in SCLC patients. Additionally, we retrospectively collected 35 SCLC samples from the first affiliated hospital of the Hengyang Medical school.

Results

Patients in each cohort were devided into two groups with high (GBP5-High) and low (GBP5-Low) expression of GBP5. In both cohorts, the GBP5-High population had a higher proportion of patients that responded well to immunotherapy (responders) (p < 0.05). In addition, both GBP5-High subgroups had significantly increased cytotoxicity, chemokines, antigen presenting, and TNF family related genes. We also determined that GBP5 was related to high-level infiltration of B cells, CD4+T cells, CD8+T cells and NK cells.

Conclusion

In this study, we found that GBP5 has the potential to be used as a biomarker of ICIs efficacy for SCLC patients. GBP5 is related to the quantity of inflammatory molecules, a high level of immune infiltration, and a highly activated immune response pathway.

Real-world predictors of survival in patients with extensive-stage small-cell lung cancer in Manitoba, Canada: a retrospective cohort study

Background

Extensive-stage small-cell lung cancer (ES-SCLC) is an incurable cancer with poor prognosis in which characteristics predictive of long-term survival are debated. The utility of agents such as immune checkpoint inhibitors highlights the importance of identifying key characteristics and treatment strategies that contribute to long-term survival and could help guide therapeutic decisions.

Objective

This real-world analysis examines the characteristics, treatment patterns, and clinical outcomes of patients receiving chemotherapy without immunotherapy for ES-SCLC in Manitoba, Canada.

Methods

A retrospective cohort study assessed patient characteristics, treatment, and survival duration (short: <6 months; medium: 6-24 months; long: >24 months) using the Manitoba Cancer Registry and CancerCare Manitoba records. Eligible patients were aged >18 years with cytologically confirmed ES-SCLC diagnosed between January 1, 2004, and December 31, 2018, and received cytotoxic chemotherapy (CT). The one-, two-, and five-year probabilities of overall survival (OS) were assessed relative to patient, disease, and treatment characteristics using Kaplan-Meier methods and Cox proportional hazards models.

Results

This analysis included 537 patients. Cisplatin was used in 56.1% of patients, 45.6% received thoracic radiotherapy (RT), and few received prophylactic cranial irradiation (PCI). In the overall cohort, one-, two- and five-year OS rates were 26%, 8%, and 3%, respectively. For patients with Eastern Cooperative Oncology Group Performance Status (ECOG PS) 0, OS rates at one, two, and five years were 43%, 17%, and 10%, respectively, vs. 27%, 8%, and 2% for those with ECOG PS 1-2, and 16%, 3%, and 3% for those with ECOG PS 3-4. In long-term survivors, ECOG PS scores were lower and abnormal laboratory test results were less frequent. Overall, 74.4% of long-term survivors received thoracic RT and 53.5% received PCI. Known poor prognostic factors - including brain/liver metastases, high lactate dehydrogenase (LDH), abnormal sodium, and low hemoglobin levels - were less common but still seen in long-term survivors.

Conclusion

Although rare, patients with ES-SCLC may experience long-term survival with CT ± thoracic RT ± PCI. Factors predicting long-term survival include traditional prognostic factors such as ECOG PS, LDH level, and receipt of thoracic RT or PCI. These findings support current treatment algorithms for ES-SCLC and provide baseline survival estimates to assess the real-world impact of adding immune checkpoint inhibitors in the future.

Identification of a visualized web-based nomogram for overall survival prediction in patients with limited stage small cell lung cancer

Small-cell lung cancer (SCLC) is an aggressive lung cancer subtype with an extremely poor prognosis. The 5-year survival rate for limited-stage (LS)-SCLC cancer is 10-13%, while the rate for extensive-stage SCLC cancer is only 1-2%. Given the crucial role of the tumor stage in the disease course, a well-constructed prognostic model is warranted for patients with LS-SCLC. The LS-SCLC patients' clinical data extracted from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018 were reviewed. A multivariable Cox regression approach was utilized to identify and integrate significant prognostic factors. Bootstrap resampling was used to validate the model internally. The Area Under Curve (AUC) and calibration curve evaluated the model's performance. A total of 5463 LS-SCLC patients' clinical data was collected from the database. Eight clinical parameters were identified as significant prognostic factors for LS-SCLC patients' OS. The predictive model achieved satisfactory discrimination capacity, with 1-, 2-, and 3-year AUC values of 0.91, 0.88, and 0.87 in the training cohort; and 0.87, 0.87, and 0.85 in the validation cohort. The calibration curve showed a good agreement with actual observations in survival rate probability. Further, substantial differences between survival curves of the different risk groups stratified by prognostic scores were observed. The nomogram was then deployed into a website server for ease of access. This study developed a nomogram and a web-based predictor for predicting the overall survival of patients with LS-SCLC, which may help physicians make personalized clinical decisions and treatment strategies.

A multicenter, single-arm, open study of neoadjuvant or conversion atezolizumab in combination with chemotherapy in resectable small cell lung cancer (Cohort Study)

BACKGROUND

This study aimed to investigate the prospects of using chemotherapy in combination with atezolizumab in the neoadjuvant or conversion treatment of small cell lung cancer (SCLC).

METHODS

Prior to surgery, untreated patients with limited-stage SCLC received three cycles of neoadjuvant or conversion atezolizumab combined with chemotherapy of etoposide and platinum. The primary endpoint of the trial was pathological complete response (pCR) in the per-protocol (PP) cohort. In addition, safety was assessed based on treatment-related adverse events (AEs) and postoperative complications.

RESULTS

Overall, 13 of 17 patients (including 14 males and 3 females) underwent surgery. In the PP cohort, pCR and major pathological response were observed in 8 (8/13, 61.5%) and 12 (12/13, 92.3%) patients, respectively. According to the intention-to-treat (ITT) analysis, the pCR and major pathological response in the ITT cohort were 47.1% (8/17) and 70.6% (12/17), respectively. In addition, an overall response rate of 100% was recorded in the PP cohort. Moreover, 15 (15/17, 88.2%) patients and 1 (1/17, 5.9%) in the ITT cohort attained partial remission (PR), and complete remission, respectively, with an overall response rate of 94.1%. The median overall survival of the patients of pCR and the median event-free survival of the patients on surgery had not achieved. However, the median overall survival of the patients of non-pCR was 18.2 months and the median event-free survival of the nonsurgical patients was 9.5 months. During the neoadjuvant treatment, the incidence of grade 3 or higher AEs was 58.8% (10/17). Additionally, three patients (17.6%) developed immune-related adverse event (grades 1-2).

CONCLUSION

In patients with SCLC, neoadjuvant or conversion atezolizumab combined with chemotherapy significantly improved pCR with manageable AEs. Therefore, this regimen may be considered a safe and effective treatment for SCLC.

Role of microRNAs in regulation of doxorubicin and paclitaxel responses in lung tumor cells

Lung cancer as the leading cause of cancer related mortality is always one of the main global health challenges. Despite the recent progresses in therapeutic methods, the mortality rate is still significantly high among lung cancer patients. A wide range of therapeutic methods including chemotherapy, radiotherapy, and surgery are used to treat lung cancer. Doxorubicin (DOX) and Paclitaxel (TXL) are widely used as the first-line chemotherapeutic drugs in lung cancer. However, there is a significant high percentage of DOX/TXL resistance in lung cancer patients, which leads to tumor recurrence and metastasis. Considering, the side effects of these drugs in normal tissues, it is required to clarify the molecular mechanisms of DOX/TXL resistance to introduce the efficient prognostic and therapeutic markers in lung cancer. MicroRNAs (miRNAs) have key roles in regulation of different pathophysiological processes including cell division, apoptosis, migration, and drug resistance. MiRNA deregulations are widely associated with chemo resistance in various cancers. Therefore, considering the importance of miRNAs in chemotherapy response, in the present review, we discussed the role of miRNAs in regulation of DOX/TXL response in lung cancer patients. It has been reported that miRNAs mainly induced DOX/TXL sensitivity in lung tumor cells by the regulation of signaling pathways, autophagy, transcription factors, and apoptosis. This review can be an effective step in introducing miRNAs as the non-invasive prognostic markers to predict DOX/TXL response in lung cancer patients.

Advances in immune checkpoint inhibitors therapy for small cell lung cancer

BACKGROUND

As one of the most aggressive neuroendocrine tumors, small cell lung cancer (SCLC) has the most disappointing prognosis of all lung cancers. Although SCLC responds well to initial chemotherapy, the majority of patients experience disease recurrence within one year, and patient survival is poor. It is still necessary to explore the application of ICIs in SCLC since the beginning of the road to immunotherapy, which broke the 30-year treatment deadlock of SCLC.

METHODS

We searched PubMed, Web of Science, and Embase with search terms such as "SCLC", "ES-SCLC", "ICIs", and "ICBs", and categorized and summarized the relevant literature obtained, and we compiled the latest progress about the application of ICIs in SCLC.

RESULTS

We listed 14 clinical trials on ICIs, including 8 clinical trials on first-line SCLC treatment, 2 clinical trials on second-line SCLC treatment, 3 clinical trials on third-line SCLC treatment, and 1 clinical trial on SCLC maintenance treatment.

CONCLUSION

ICIs in combination with chemotherapy can improve OS in SCLC patients, but the extent to which SCLC patients can benefit from ICIs is limited, and ICIs' combination treatment strategies still need to be continuously explored.

PTEN Loss Expands the Histopathologic Diversity and Lineage Plasticity of Lung Cancers Initiated by Rb1/Trp53 Deletion

INTRODUCTION

High-grade neuroendocrine tumors of the lung such as SCLC are recalcitrant cancers for which more effective systemic therapies are needed. Despite their histopathologic and molecular heterogeneity, they are generally treated as a single disease entity with similar chemotherapy regimens. Whereas marked clinical responses can be observed, they are short-lived. Inter- and intratumoral heterogeneity is considered a confounding factor in these unsatisfactory clinical outcomes, yet the origin of this heterogeneity and its impact on therapeutic responses is not well understood.

METHODS

New genetically engineered mouse models are used to test the effects of PTEN loss on the development of lung tumors initiated by Rb1 and Trp53 tumor suppressor gene deletion.

RESULTS

Complete PTEN loss drives more rapid tumor development with a greater diversity of tumor histopathology ranging from adenocarcinoma to SCLC. PTEN loss also drives transcriptional heterogeneity as marked lineage plasticity is observed within histopathologic subtypes. Spatial profiling indicates transcriptional heterogeneity exists both within and among tumor foci with transcriptional patterns correlating with spatial position, implying that the growth environment influences gene expression.

CONCLUSIONS

These results identify PTEN loss as a clinically relevant genetic alteration driving the molecular and histopathologic heterogeneity of neuroendocrine lung tumors initiated by Rb1/Trp53 mutations.

Lung cancer immunotherapy: progress, pitfalls, and promises

Lung cancer is the primary cause of mortality in the United States and around the globe. Therapeutic options for lung cancer treatment include surgery, radiation therapy, chemotherapy, and targeted drug therapy. Medical management is often associated with the development of treatment resistance leading to relapse. Immunotherapy is profoundly altering the approach to cancer treatment owing to its tolerable safety profile, sustained therapeutic response due to immunological memory generation, and effectiveness across a broad patient population. Different tumor-specific vaccination strategies are gaining ground in the treatment of lung cancer. Recent advances in adoptive cell therapy (CAR T, TCR, TIL), the associated clinical trials on lung cancer, and associated hurdles are discussed in this review. Recent trials on lung cancer patients (without a targetable oncogenic driver alteration) reveal significant and sustained responses when treated with programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint blockade immunotherapies. Accumulating evidence indicates that a loss of effective anti-tumor immunity is associated with lung tumor evolution. Therapeutic cancer vaccines combined with immune checkpoint inhibitors (ICI) can achieve better therapeutic effects. To this end, the present article encompasses a detailed overview of the recent developments in the immunotherapeutic landscape in targeting small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Additionally, the review also explores the implication of nanomedicine in lung cancer immunotherapy as well as the combinatorial application of traditional therapy along with immunotherapy regimens. Finally, ongoing clinical trials, significant obstacles, and the future outlook of this treatment strategy are also highlighted to boost further research in the field.

Mutational landscape of homologous recombination-related genes in small-cell lung cancer

BACKGROUND

Homologous recombination deficiency (HRD) is a well-known biomarker which could predict poly-ADP ribose polymerase 1 (PARP) inhibitor and platinum drug response. As an aggressive cancer, small-cell lung cancer (SCLC) is sensitive to platinum drugs, but relapse occurs rapidly. Herein, we aim to illustrate the genomic alteration patterns of homologous recombination repair (HRR)-related genes in a Chinese SCLC cohort and further analyze the relationship among HRR gene mutations and known biomarkers of immune checkpoint inhibitor (ICI) response, including tumor mutation burden (TMB) and programmed cell death-ligand 1 (PD-L1) expression.

METHODS

Next-generation sequencing (NGS)-based target capture sequencing of 543 cancer-related genes was performed to analyze the genomic profiles of 133 Chinese SCLC patients, and TMB was calculated. PD-L1 expression was evaluated in 90 out of 133 patients using the SP142 PD-L1 immunohistochemistry assay.

RESULTS

Among the 133 patients with SCLC, 47 (35.3%) had HRR gene mutations. ATM (8.3%) was the most frequently mutated HRR gene in the cohort, followed by NBN (4.5%). Pathogenic somatic and germline mutations of HRR genes were identified in 11 (23.4%) and 4 (8.5%) patients, respectively. HRR gene mutations cooccurred with KMT2D gene mutations. There were several differences in genomic alterations between patients with HRR gene mutations (HRR-Mut) and without HRR mutations (HRR-WT). The results revealed that TP53 and RB1 were commonly mutated genes in both groups. Mutations in the KMT2D gene and genes in the RTK-RAS pathway occurred more frequently in the HRR-Mut group. Furthermore, we found that mutations in HRR genes were associated with high TMB (Wilcoxon, p = 0.048), but there was no correlation of HRR gene mutation status with PD-L1 expression.

CONCLUSIONS

We exhaustively describe the genomic alteration profile of Chinese SCLC patients and provide further evidence that HRR gene mutations are prevalent in SCLC patients.

Toripalimab and anlotinib as a maintenance treatment for extensive-stage small-cell lung cancer: a case report

Small-cell lung cancer (SCLC) is characterized by rapid proliferation, high growth fraction and early locoregional and distant metastases. SCLC has been found to be significantly sensitive to platinum–etoposide chemotherapy, but most patients relapse within 6 months of completing initial treatment and median overall survival is about 10 months. Despite the current immunotherapy-treatment approach, median survival time and progression-free survival remain short. This case shows the potential efficacy of maintenance therapy with toripalimab and anlotinib after first-line platinum–etoposide chemotherapy in a patient with extensive-stage SCLC. The combination treatment prolonged the progression-free survival to approximately 13 months and overall survival to 25 months; this is well above the existing standard, and this patient did not experience any major adverse effects during the course of therapy.

Whole-Exome Sequencing Uncovers Specific Genetic Variation Difference Based on Different Modes of Drug Resistance in Small Cell Lung Cancer

The poor survival rate of small cell lung cancer (SCLC) is mainly related to the condition that patients with SCLC often have good responses to first-line chemotherapy initially, but later on, most of these patients relapse rapidly due to resistance to further treatment. In this study, we attempted to analyze whole-exome sequencing data based on the largest sample size to date, to develop a classifier to predict whether a patient will be chemorefractory or chemosensitive and to explicate the risk of recurrence that affects the prognosis of patients. We showed the different characteristics of somatic mutational signatures, somatic mutation genes, and distinct genome instability between chemorefractory and chemosensitive SCLC patients. Amplified mutations in the chemosensitive group inhibited the regulation of the cell cycle process, transcription factor binding, and B-cell differentiation. Analysis of deletion mutation also suggested that detection of the chromosomal-level variation might influence our treatment decisions. Higher PD-L1 expressions (based on TPS methods) were mostly present among chemosensitive patients (p = 0.026), while there were no differences in PD-L1 expressions (based on CPS methods) and CD8⁺ TILs between the two groups. According to the model determined by logistic regression, each sample was endowed with a predictive probability value (PV). The samples were divided into a high-risk group (>0.55) and a low-risk group (≤0.55), and the survival analysis showed obvious differences between the two groups. This study provides a reference basis to translate this knowledge into practice, such as formulating personalized treatment plans, which may benefit Chinese patients with SCLC.

Treatment and Prevention of Brain Metastases in Small Cell Lung Cancer

Central nervous system (CNS) metastasis will develop in 50% of small cell lung cancer (SCLC) patients throughout disease course. Development of CNS metastasis poses a particular treatment dilemma due to the accompanied cognitive changes, poor permeability of the blood-brain barrier to systemic therapy and relatively advanced state of disease. Survival of patients with untreated SCLC brain metastases is generally <3 months with whole brain radiotherapy used as first-line management in most SCLC patients. To prevent development of CNS metastasis prophylactic cranial irradiation (PCI) is recommended in limited stage disease, after response to chemotherapy and radiation, while PCI may be considered in extensive stage disease after favorable response to upfront treatment. Neurocognitive toxicity with whole brain radiotherapy and PCI is a concern and remains difficult to predict. The mechanism of toxicity is likely multifactorial, but a potential mechanism of injury to the hippocampus has led to hippocampal sparing radiation techniques. Treatment of established non-small cell lung cancer CNS metastases has increasingly focused on using stereotactic radiotherapy (SRS) and it is tempting to extrapolate these results to SCLC. In this review, we explore the evidence surrounding the prediction, prevention, detection, and treatment of CNS metastases in SCLC. We further review whether existing evidence supports extrapolating less toxic treatments to SCLC patients with CNS metastases and discuss trials that may shed more light on this question.

Prognostic Value of the Pretreatment Lung Immune Prognostic Index in Advanced Small Cell Lung Cancer Patients Treated With First-Line PD-1/PD-L1 Inhibitors Plus Chemotherapy

Background

Lung immune prognostic index (LIPI) refers to a biomarker combining derived neutrophil-to-lymphocyte ratio (dNLR) and lactate dehydrogenase (LDH). Its prognostic effect on advanced small cell lung cancer (SCLC) patients receiving programmed cell death 1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors plus chemotherapy as first-line treatment remains unclear. Our research investigated the relationship between pretreatment LIPI and the prognosis of patients receiving first-line PD-1/PD-L1 inhibitors plus chemotherapy.

Methods

Advanced SCLC patients receiving PD-1/PD-L1 inhibitors plus chemotherapy as first-line treatment from Jan 2015 to Oct 2020 were included. Based on the values of dNLR and LDH, the study population was divided into two groups: LIPI good and LIPI intermediate/poor. The Kaplan-Meier method was used to compute the median survival time and the log-rank test was used to compare the two groups. Univariate and multivariate analyses were used to examine the correlation between the pretreatment LIPI and clinical outcomes.

Results

One hundred patients were included in this study, of which, 64% were LIPI good (dNLR < 4.0 and LDH < 283 U/L), 11% were LIPI poor (dNLR ≥ 4.0 and LDH ≥ 283 U/L), and the remaining 25% were LIPI intermediate. The LIPI good group had better progression-free survival (PFS) (median: 8.4 vs 4.7 months, p = 0.02) and overall survival (OS) (median: 23.8 vs 13.3 months, p = 0.0006) than the LIPI intermediate/poor group. Multivariate analysis showed that pretreatment LIPI intermediate/poor was an independent risk factor for OS (HR: 2.34; 95%CI, 1.13, 4.86; p = 0.02). Subgroup analysis showed that pretreatment LIPI good was associated with better PFS and OS in males, extensive disease (ED), PD-1 inhibitor treatment, smokers, and liver metastasis (p < 0.05).

Conclusions

Pretreatment LIPI could serve as a prognostic biomarker for advanced SCLC patients receiving first-line PD-1/PD-L1 inhibitors plus chemotherapy.

Octogenarians may benefit from stage-specific small cell lung cancer treatment

BACKGROUND

Our study investigates treatment profiles in octogenarian patients with small cell lung cancer (SCLC) and assesses each treatment's role in a stage-specific manner.

METHODS

Patient data from individuals with SCLC aged 80 years and older between 1988 and 2015 in the Surveillance, Epidemiology, and End Results Program (SEER) database were extracted. Cancer-specific survival (CSS) between patients with no treatment and different treatment groups were compared by the Kaplan-Meier method, with stratifications by stage. Cox Proportional Hazard model further identified independent prognostic factors.

RESULTS

A total of 7,290 patients were included in this study. Notably, 3,358 (46.1%) patients did not receive active treatment. Compared with the no active treatment group, the CSS of patients who received treatment was significantly improved (median 6 vs. 0 months, P<0.001) and further validated in stage subgroups. Chemotherapy combined with local therapy was associated with the best CSS in regional and distant disease stages, with the hazard ratios (HR) and 95% confidence intervals (CI) being 0.30 (0.26-0.34) and 0.27 (0.25-0.30), respectively. Local therapy only appeared to confer better oncological outcomes (HR =0.33; 95% CI: 0.25-0.42) than chemotherapy only (HR =0.37; 95% CI: 0.29-0.47) in the localized disease stage.

CONCLUSIONS

Although nearly half of octogenarians with SCLC did not receive active treatment in the real clinical setting, these patients may benefit from treatment. Chemotherapy combined with local therapy may provide the best treatment choice in octogenarians with advanced SCLC, while local therapy appears to play a more critical role in treating those with early-stage disease.

Efficacy and safety of PD-L1 inhibitors versus PD-1 inhibitors in first-line treatment with chemotherapy for extensive-stage small-cell lung cancer

OBJECTIVES

Programmed cell death-ligand 1 inhibitors plus chemotherapy (PD-L1 + Chemo) have achieved substantial progress in extensive-stage small-cell lung cancer (ES-SCLC). However, evidence about programmed cell death 1 inhibitors plus chemotherapy (PD-1 + Chemo) in SCLC is relatively lacking. Whether PD-1 inhibitors differ from PD-L1 inhibitors in their clinical outcomes remains controversial.

MATERIALS AND METHODS

We performed a meta-analysis to compare efficacy and safety of PD-L1 + Chemo vs PD-1 + Chemo in ES-SCLC by searching PubMed, Embase, the Cochrane Library, and major oncology conferences. We examined overall survival (OS) as the primary outcome. Secondary outcomes included progression-free survival (PFS), objective response rate (ORR), and treatment-related adverse events (AEs).

RESULTS

We included four randomized trials (IMpower133, CASPIAN, KEYNOTE-604, and EA5161) with a total of 1553 patients. Direct comparison showed that PD-L1 + Chemo (PFS: hazard ratio [HR] 0.79; OS: HR 0.75) and PD-1 + Chemo (PFS: HR 0.72; OS: HR 0.77) significantly prolonged survival time compared with chemotherapy alone. But PD-L1 + Chemo (relative risk [RR]: 1.07) and PD-1 + Chemo (RR: 1.13) were not superior to chemotherapy alone in terms of ORR. Indirect comparison showed no significant difference in clinical efficacy between PD-L1 + Chemo and PD-1 + Chemo (OS: HR 0.99; PFS: HR 1.10; ORR: RR 0.95). We further stratified patients according to subgroups in terms of OS. In the subgroup of patients with brain metastasis, PD-L1 + Chemo tended to prolong OS (HR: 0.61, 0.28 to 1.32). There were no significant differences between PD-L1 + Chemo and PD-1 + Chemo regarding safety analyses. However, PD-L1 + Chemo exhibited a better safety profile in reducing the risk of treatment discontinuation due to AEs (RR: 0.43, 0.19 to 0.95) and pneumonia (pneumonia of any grade, RR: 0.59, 0.24 to 1.42; pneumonia of grade ≥ 3, RR: 0.37, 0.10 to 1.39).

CONCLUSIONS

PD-L1 + Chemo and PD-1 + Chemo provided a significant survival benefit relative to chemotherapy alone for ES-SCLC. The efficacy and safety of PD-L1 + Chemo and PD-1 + Chemo were similar based on current evidence.

Small cell lung cancer stem cells display mesenchymal properties and exploit immune checkpoint pathways in activated cytotoxic T lymphocytes

Small cell lung cancer (SCLC) is an aggressive tumor type with early dissemination and distant metastasis capacity. Even though optimal chemotherapy responses are observed initially in many patients, therapy resistance is almost inevitable. Accordingly, SCLC has been regarded as an archetype for cancer stem cell (CSC) dynamics. To determine the immune-modulatory influence of CSC in SCLC, this study focused on the characterization of CD44⁺CD90⁺ CSC-like subpopulations in SCLC. These cells displayed mesenchymal properties, differentiated into different lineages and further contributed to CD8⁺ cytotoxic T lymphocytes (CTL) responses. The interaction between CD44⁺CD90⁺ CSC-like cells and T cells led to the upregulation of checkpoint molecules PD-1, CTLA-4, TIM-3, and LAG3. In the patient-derived lymph nodes, CD44⁺ SCLC metastases were also observed with T cells expressing PD-1, TIM-3, or LAG3. Proliferation and IFN-γ expression capacity of TIM-3 and LAG3 co-expressing CTLs are adversely affected over long-time co-culture with CD44⁺CD90⁺ CSC-like cells. Moreover, especially through IFN-γ secreted by the T cells, the CSC-like SCLC cells highly expressed PD-L1 and PD-L2. Upon a second encounter with immune-experienced, IFN-γ-stimulated CSC-like SCLC cells, both cytotoxic and proliferation capacities of T cells were hampered. In conclusion, our data provide evidence for the superior potential of the SCLC cells with stem-like and mesenchymal properties to gain immune regulatory capacities and cope with cytotoxic T cell responses. With their high metastatic and immune-modulatory assets, the CSC subpopulation in SCLC may serve as a preferential target for checkpoint blockade immunotherapy .

Surgery Plus Chemotherapy Versus Surgery Alone for Limited-Stage Small-Cell Lung Cancer: A Population-Based Survival Outcome Analysis

Introduction

For patients with limited-stage small-cell lung cancer (LS-SCLC), effective treatment methods still remain a clinical challenge. The aim of this study is to evaluate the survival outcome of surgery plus chemotherapy vs. surgery alone in patients with LS-SCLC.

Methods

LS-SCLC patients selected from the Surveillance, Epidemiology and End Results (SEER) database diagnosed between January 1, 2004, and December 31, 2015. Comparison of overall survival (OS) and cancer-specific survival (CSS) between two groups performed propensity score matching (PSM), inverse probability of treatment weight (IPTW), and overlap weighting analysis.

Results

Of the 477 LS-SCLC patients identified from the SEER database between 2004 and 2015, 262 (54.9%) received surgery-plus-chemotherapy treatment and the others received surgery-alone treatment. Univariate and multivariate analyses showed that treatment option (P< 0.001), tumor location (P= 0.02) and AJCC stage (P< 0.001) were independent prognostic predictors of OS in LS-SCLC patients. Median OS was 35 months in surgery-plus-chemotherapy group vs. 23 months in surgery-alone group. Survival analysis showed that surgery plus chemotherapy offered significantly improved OS as compared with surgery-alone treatment before and after IPTW, PSM and overlap weighting method (all P< 0.05). According to AJCC stage stratification, OS of the unmatched patients with stage I (P= 0.049) and II (P= 0.001) SCLC who received surgery-plus-chemotherapy treatment was significantly better than that of surgery-alone patients.

Conclusions

This cohort study showed that surgery plus chemotherapy was associated with longer survival time than surgery alone in LS-SCLC patients, especially in those with stage I and II SCLC. Further prospective studies are required to confirm our conclusions.

Curative efficacy might be an early predictor of prognosis in patients with small cell lung cancer treated with 2 cycles of platinum-based first-line chemotherapy

BACKGROUND

Platinum-based chemotherapy remains the essential therapy for small cell lung cancer (SCLC). Here, we conducted a statistical analysis to explore whether the curative efficacy of 2-cycle platinum-based chemotherapy can predict the survival of patients with SCLC.

METHODS

Fifty-six SCLC patients who had each received 2 cycles of platinum-based chemotherapy were enrolled. The curative efficacy of the chemotherapy was evaluated, mainly by chest computed tomography, and the treatment response was categorized according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Patients were continuously followed up for progression-free survival (PFS) and overall survival. The 55 patients were separated into 2 groups by the curative efficacy of the 2-cycle first-line platinum-based chemotherapy. All statistical analyses were performed with SPSS software (version 17.0; SPSS, Inc.; Chicago, IL, USA).

RESULTS

Patients who responded to 2-cycle chemotherapy (partial response, PR) had significantly better survival than others who did not (stable disease, SD or progressive disease, PD). The median progression-free survival (mPFS) in the PR group was 6.330 months, which was significantly longer than the 2.870 months seen in SD+PD group (95% CI: 4.631-8.029 vs. 0.000-5.790, P=0.022). The median overall survival (mOS) was 10.870 months in the PR group, which was remarkably longer than the 8.970 months observed in the SD+PD group (95% CI: 9.546-12.194 vs. 6.517-11.423, P=0.028). Curative efficacy had no correlation with clinical features.

CONCLUSIONS

The curative efficacy of 2-cycle first-line platinum-based chemotherapy was significantly correlated with PFS and OS, and showed prognostic value in SCLC patients. Patients who were sensitive to chemotherapy had superior survival to those who were chemotherapy insensitive.

Front Line Applications and Future Directions of Immunotherapy in Small-Cell Lung Cancer

After being stagnant for decades, there has finally been a paradigm shift in the treatment of small-cell lung cancer (SCLC) with the emergence and application of immune checkpoint inhibitors (ICIs). Multiple trials of first-line ICI-chemotherapy combinations have demonstrated survival benefit compared to chemotherapy alone in patients with extensive-stage SCLC, establishing this as the new standard of care. ICIs are now being applied in the potentially curative limited-stage setting, actively being investigated as concurrent treatment with chemoradiation and as adjuvant treatment following completion of chemoradiation. This review highlights the evidence behind the practice-changing addition of ICIs in the first-line setting of extensive-stage SCLC, the potentially practice-changing immunotherapy trials that are currently underway in the limited-stage setting, and alternate immunotherapeutic strategies being studied in the treatment of SCLC.

Myeloid cell leukemia-1 is an important predictor of survival and progression of small cell lung cancer

Background

Small cell lung cancer (SCLC) is the most fatal malignancy for which more effective therapies are urgently needed. Overexpression of myeloid cell leukemia-1 (Mcl-1) has been demonstrated to be one of the most common genetic alterations among different types of tumor/cancer, which induces resistance against various anti-cancer therapies including cisplatin. The study aimed to explore the role of Mcl-1 in the prognosis and resistance to anti-cancer therapy in patients with SCLC.

Methods

Patients with SCLC were recruited from those enrolled/treated in Sun Yat-sen University Cancer Center. Their specimens were collected for immunohistochemical evaluation. We compared the baseline characteristics, response to chemotherapy and overall survival (OS) of the patients with different expression levels of Mcl-1.

Results

The expression level of Mcl-1 was significantly lower in patients with limited stage SCLC than in those with extensive stage SCLC (P=0.014). Based on the median value of Mcl-1 expression level, the patients were divided into high and low Mcl-1 groups, respectively. Univariate analysis revealed that low Mcl-1 expression was associated with a significant improvement in OS, with a hazard ratio (HR) of 0.538. Multivariate analysis confirmed the independent prognostic value of Mcl-1 expression level (P=0.014). Moreover, we found a significantly close relationship between higher Mcl-1 expression level and shorter time to progression (TTP) of the patients received chemotherapy (P=0.040).

Conclusions

Our findings demonstrated that Mcl-1 expression level was a prognostic biomarker for survival outcomes and cancer progression in the patients with SCLC. Thus, it could be used as a valuable biomarker in identifying those patients with high risk of treatment failure.

Real World Analysis of Small Cell Lung Cancer Patients: Prognostic Factors and Treatment Outcomes

In this observational study, we assessed treatment patterns and prognostic factors in patients with small cell lung cancer (SCLC) in a large state-mandated healthcare organization in Israel. Methods: All incident cases with histologically confirmed SCLC who initiated systemic anti-cancer treatment between 2011 and 2017 were identified. Treatment patterns and overall survival (OS) were evaluated for each line of therapy. Results: A total of 235 patients were identified (61% male, median age 64 years, 95% ever smokers, 64% had extensive stage). The first-line treatment was platinum-etoposide regimen for 98.7% of the cohort. The second and third-line regimen were given to 43% and 12% of patients, respectively. Mean OS for extensive and limited stage patients was 9.1 and 23.5 months respectively. In a multivariable model, increased risk for mortality was observed among patients with an ECOG performance status (PS) of 2 compared to a PS of 0-1 for the extensive stage patients (Hazard ratio (HR) = 1.63, 95% confidence ratios (CI): 1.00-2.65); and for males compared to females for the limited stage patients (HR = 2.17; 95% CI: 1.12-4.20). Regarding all 2nd line patients in a multivariable model incorporating relevant confounding factors, demonstrated a significantly better outcome with platinum-based regimens compared to topotecan. Median survival after initiation of 2nd line in platinum-sensitive patients was longer (p = 0.056) for those re-challenged with platinum-based regimen (n = 7): 6.8mo (6.1-not reported (NR)), compared with those switched to a different treatment (n = 27): 4.5 mo (2.6-6.6) for extensive stage patients, and a non-significant difference was also observed for limited stage patients. Conclusion: To our knowledge, this is one of the largest real-world studies of SCLC patients. OS for SCLC patients was similar to that reported in clinical trials. PS for extensive stage patients and sex for limited stage patients were significant correlates of prognosis. Re-challenge of the platinum-based doublet was associated with longer OS compared to switching treatment in extensive stage patients.

Combination therapy: Future directions of immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC), an aggressive and devastating malignancy, is characterized by rapid growth and early metastasis. Although most patients respond to first-line chemotherapy, the majority of patients rapidly relapse and have a relatively poor prognosis. Fortunately, immunotherapy, mainly including antibodies that target the cytotoxic T lymphocyte antigen-4 (CTLA-4), checkpoints programmed death-1 (PD-1), and programmed death-ligand 1 (PD-L1) to block immune regulatory checkpoints on tumor cells, immune cells, fibroblasts cells and endothelial cells, has achieved the milestone in several solid tumors, such as melanoma and non-small-cell lung carcinomas (NSCLC). In recent years, immunotherapy has made progress in the treatment of patients with SCLC, while its response rate is relatively low to monotherapy. Interestingly, the combination of immunotherapy with other therapy, such as chemotherapy, radiotherapy, and targeted therapy, preliminarily achieve greater therapeutic effects for treating SCLC. Combining different immunotherapy drugs may act synergistically because of the complementary effects of the two immune checkpoint pathways (CTLA-4 and PD-1/PD-L1 pathways). The incorporation of chemoradiotherapy in immunotherapy may augment antitumor immune responses because chemoradiotherapy can enhance tumor cell immunogenicity by rapidly inducing tumor lysis and releasing tumor antigens. In addition, since immunotherapy drugs and the molecular targets drugs act on different targets and cells, the combination of these drugs may achieve greater therapeutic effects in the treatment of SCLC. In this review, we focused on the completed and ongoing trials of the combination therapy for immunotherapy of SCLC to find out the rational combination strategies which may improve the outcomes for SCLC.

Cost-effectiveness of nivolumab monotherapy in the third-line treatment of small cell lung cancer

AIMS

Present cost-effectiveness analysis of nivolumab monotherapy vs. commonly prescribed third-line (3 L+) treatment in small cell lung cancer (SCLC).

MATERIALS AND METHODS

A three health states partitioned survival model (progression-free, progressed disease, and death; US payer perspective) was developed. The systematic literature review identified no randomized controlled or single-arm trials with separate outcomes for 3 L + SCLC patients. Topotecan was chosen as a comparator because it is frequently prescribed in real-world practice for 3 L SCLC. Clinical inputs for topotecan were derived from the Flatiron database with inclusion/exclusion criteria matched to patients treated with 3 L + nivolumab in CheckMate 032. Intravenous (IV) and oral topotecan clinical efficacy were assumed equivalent. Base-case analysis used a 20-year lifetime horizon. An annual discount rate of 3.0% for costs and outcomes was applied. Uncertainty was assessed using sensitivity analyses adjusted for key parameters.

RESULTS

Incremental cost per quality-adjusted life-year (QALY) gained with nivolumab was US$153,312 vs. IV topotecan and US$123,003 vs. oral topotecan, respectively. When results were disaggregated, nivolumab-related costs were mainly driven by drug acquisition costs, and topotecan-related costs were primarily due to adverse event treatment. Mean overall survival (OS) was 21.69 months with nivolumab and 5.80 months with IV or oral topotecan. More favorable outcomes were found by the landmark response analyses. Deterministic sensitivity analyses showed that changes to the discount rate for costs and outcomes and body weight had the greatest impacts on results.

LIMITATIONS

Included use of real-world data for OS outcomes associated with 3 L topotecan, use of second-line topotecan data for progression-free survival, and no indirect costs.

CONCLUSIONS

Based on the literature on willingness-to-pay for a QALY in metastatic cancer, nivolumab monotherapy might represent a cost-effective option for 3 L + treatment of SCLC compared with IV and oral topotecan. Sensitivity analysis using response-based methods yielded further favorable cost-effectiveness estimates.

Systematic evaluation of the efficacy-effectiveness gap of systemic treatments in extensive disease small cell lung cancer

PURPOSE

The aim of this study is to assess how clinical outcomes in real-world (effectiveness) correspond to the outcomes in clinical trials (efficacy) of systemic treatments for extensive disease small cell lung cancer (ED SCLC).

METHODS

All patients diagnosed with ED SCLC between 2008 and 2014 in six Dutch large teaching hospitals (Santeon network) were identified and followed-up from date of diagnosis until death or end of data collection. For every patient, an efficacy-effectiveness factor (EE factor) was calculated by dividing individual patients' overall survival (OS) by the pooled median OS assessed from clinical trials with the respective treatment.

RESULTS

From 792 diagnosed patients, 568 (72%) started with first-line treatment. Overall, the median EE factor was 0.79 (P < .001 from 1.00). Poor performance status (ECOG≥2) and a higher age at diagnosis (age ≥ 65 years) were independent predictors for a lower EE factor. The EE gap was 43% in patients with both age ≥ 65 years and ECOG ≥2 (EE factor 0.57). The mean age and the proportion of patients with ECOG≥2 in real-world were different from those in clinical trials (mean age of 66 versus 62 years, and ECOG≥2 25% versus 17%; both P < .001).

CONCLUSION

OS of patients with ED SCLC treated with systemic therapy in real-world practice is 21% shorter than for patients included in trials. Age at diagnosis and performance status partly explain this gap.

Gray E. Tumour PD-L1 Expression in Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Antibodies against programmed death-1 (PD-1), and its ligand, (PD-L1) have been approved recently for the treatment of small-cell lung cancer (SCLC). Although there are previous reports that addressed PD-L1 detection on tumour cells in SCLC, there is no comprehensive meta-analysis on the prevalence of PD-L1 expression in SCLC. We performed a systematic search of the PubMed, Cochrane Library and EMBASE databases to assess reports on the prevalence of PD-L1 expression and the association between PD-L1 expression and overall survival (OS). This meta-analysis included 27 studies enrolling a total of 2792 patients. The pooled estimate of PD-L1 expression was 26.0% (95% CI 17.0–37.0), (22.0% after removing outlying studies). The effect size was significantly heterogeneous (I² = 97.4, 95% CI: 95.5–98.5, p < 0.0001).Positive PD-L1 expression was a favourable prognostic factor for SCLC but not statistically significant (HR = 0.86 (95% CI (0.49–1.50), p = 0.5880; I² = 88.7%, p < 0.0001). Begg’s funnel plots and Egger’s tests indicated no publication bias across included studies (p > 0.05). Overall, there is heterogeneity in the prevalence of PD-L1 expression in SCLC tumour cells across studies. This is significantly moderated by factors such as immunohistochemistry (IHC) evaluation cut-off values, and assessment of PD-L1 staining patterns as membranous and/or cytoplasmic. There is the need for large size, prospective and multicentre studies with well-defined protocols and endpoints to advance the clinical value of PD-L1 expression in SCLC.

Comparison of First-Line Treatments for Patients With Extensive-Stage Small Cell Lung Cancer: A Systematic Review and Network Meta-analysis

IMPORTANCE

Combinations of chemotherapy with immunotherapy or bevacizumab in first-line treatments of extensive-stage small cell lung cancer (ES-SCLC) have been evaluated in various clinical trials. However, it remains unclear what the optimal combination regimen is.

OBJECTIVE

To clarify which first-line combination regimen is associated with the best tumor response among patients with ES-SCLC.

DATA SOURCES

Electronic databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science) were systematically searched to extract eligible literature from database inception to December 2019.

STUDY SELECTION

Head-to-head randomized clinical trials on first-line treatments for patients with ES-SCLC were included with outcomes and toxic effects reported, including objective response rate (ORR, involving complete response and partial response), disease control rate (DCR, involving complete response, partial response, and stable disease), progression-free survival (PFS), overall survival (OS), and treatment related adverse events (TRAEs) of grades 3 to 5. Of 199 eligible articles, 14 were included.

DATA EXTRACTION AND SYNTHESIS

Data were independently extracted and collected by 2 reviewers based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

Main outcomes were OS, PFS, DCR, ORR, and TRAEs of grades 3 to 5.

RESULTS

A total of 3 phase 2 and 11 phase 3 randomized clinical trials involving 4838 patients were included. Programmed cell death ligand 1 (PD-L1) inhibitor (durvalumab and atezolizumab) plus etoposide-based chemotherapy, compared with etoposide-based chemotherapy alone, showed the most favorable OS (hazard ratio, 1.40; 95% CI, 1.09-1.80) and the best DCR (odds ratio [OR], 0.42; 95% CI, 0.21-0.81). Bevacizumab plus etoposide-based chemotherapy provided the best PFS compared with etoposide-based chemotherapy alone (hazard ratio, 1.54; 95% CI, 1.09-2.27), although this was not translated into OS benefit. The addition of PD-L1 inhibitors to etoposide-platinum chemotherapy caused no more toxic effects in general (compared with etoposide-based chemotherapy alone: OR, 1.14; 95% CI, 0.36-2.31), while bevacizumab plus etoposide-platinum regimen induced the most TRAEs grades 3 to 5 among all first-line treatments (eg, compared with irinotecan-platinum regimen: OR, 4.24; 95% CI, 1.26-14.57). Based on the surface under the cumulative ranking curve value, PD-L1 inhibitor plus etoposide-platinum had the highest probability of being ranked first for OS (0.87) and DCR (0.97).

CONCLUSIONS AND RELEVANCE

The findings of this systematic review and network meta-analysis suggest that the combination of a PD-L1 inhibitor (durvalumab and atezolizumab) and etoposide-based chemotherapy may be an optimal first-line treatment option for patients with ES-SCLC patients.

Neutrophil-to-lymphocyte ratio can predict outcome in extensive-stage small cell lung cancer

Background

The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were analyzed in various carcinomas and their potential prognostic significance was determined. The objective of present study was to determine the correlation between these parameters and the survival of patients with small cell lung cancer (SCLC), since very few studies have been published on this type of carcinoma.

Patients and methods

One hundred and forty patients diagnosed with SCLC at University Hospital Center Zagreb, between 2012 and 2016 were retrospectively analyzed. Extensive-stage disease (ED) was verified in 80 patients and limited-stage disease (LD) in 60 patients. We analyzed the potential prognostic significance of various laboratory parameters, including NLR, PLR, and LMR, measured before the start of treatment.

Results

Disease extension, response to therapy, chest irradiation and prophylactic cranial irradiation (PCI), as well as hemoglobin, monocyte count, C-reactive protein (CRP), and lactate dehydrogenase (LDH) showed a prognostic significance in all patients. When we analyzed the patients separately, depending on the disease extension, we found that only skin metastases as well as LDH and NLR values, regardless of the cut-off value, had a prognostic significance in ED. Meanwhile, the ECOG performance status, chest irradiation, PCI, and hemoglobin and creatinine values had a prognostic significance in LD.

Conclusions

NLR calculated before the start of the treatment had a prognostic significance for ED, while PLR and LMR had no prognostic significance in any of the analyzed groups of patients.

Emerging drugs for small cell lung cancer: a focused review on immune checkpoint inhibitors

INTRODUCTION

Small cell lung cancer (SCLC) is an aggressive malignancy that accounts for 15% of all lung cancers. It is characterized by initial responsiveness to therapy followed by rapid disease progression that is relatively resistant to further treatment. Recently, the addition of an immune checkpoint inhibitor (ICI) to chemotherapy has improved survival in patients with advanced disease, the first advance in systemic therapy in SCLC in over 30 years.

AREAS COVERED

In this review, we present an overview of SCLC with a focus on the scope of the problem and standard treatment, followed by a critical assessment of scientific rationale for immunotherapy in SCLC and the clinical trials that have been performed with ICIs in SCLC. Finally, we address ongoing hurdles for the development of ICIs in SCLC and potential avenues for further study.

EXPERT OPINION

Despite solid biological rationale, the results of clinical trials of ICIs in SCLC have yielded modest benefits. A small subset of patients does achieve long-term benefit, but further development of ICIs in SCLC will depend on the identification of predictive biomarkers and the design of combination regimens that take advantage of the molecular alterations that drive the immune-avoidance mechanisms and survival of SCLC cells.

Real-world treatment patterns and outcomes of patients with extensive disease small cell lung cancer

OBJECTIVE

Clinical outcome data on patients with extensive disease small cell lung cancer (ED SCLC) treated in routine practice is limited. The aim of this retrospective study is to present data on treatment patterns and survival in an unselected patient population with ED SCLC.

METHODS

All patients diagnosed with ED SCLC between 2008 and 2014 in six Dutch large teaching hospitals (Santeon network) were included. We collected data on patient characteristics, systemic treatments, overall survival (OS), dose reductions (<80% of initial dose) and early discontinuation (<4 cycles).

RESULTS

From 792 diagnosed patients, 568 (72%) started with first-line treatment. Of these patients, 41% received second-line treatment. Only 68 patients received third-line treatment. For all treated patients, the mean age was 66 years. The majority (72%) had a performance status (ECOG) of 0 or 1 at diagnosis. Median OS of treated patients was 7.4 months. Of all patients with first-line treatment, 26% received <4 cycles and dose reductions were observed in 29%.

CONCLUSION

After first-line systemic treatment in ED SCLC the fraction of patients receiving subsequent lines of treatment is rapidly decreasing. This information is necessary as background for evaluation of the added value of future drugs under study for ED SCLC.

SIRT3 increases cisplatin sensitivity of small-cell lung cancer through apoptosis

Small-cell lung cancer (SCLC) is the most invasive of all lung cancer subtypes, and is characterized by its rapid response to chemotherapy resistance. Overcoming chemotherapy resistance is therefore the key to treating SCLC. P53 is mutated in most SCLCs, which has an effect of enhancing chemotherapy resistance. Regulation of p53 proteins by a variety of post-translational modifications, such as acetylation, which affects their function. Acetylation and deacetylation of p53 may be potential targets for modulating chemosensitivity. Recent studies have shown that SIRT3 acts as a deacetylase that regulates acetylation of p53. However, whether SIRT3 can regulate the post-translational modification of mutant p53 has not been studied. In the present study, we found that SIRT3 can deacetylate mutant p53, thus reducing its expression, inducing apoptosis in SCLC cells, and increasing SCLC chemosensitivity. The relationship between SIRT3 and mutant p53 could be the basis of a new SCLC treatment approach.

[Apatinib Combined with CCI-779 Inhibits the Proliferation and Migration of Small Cell Lung Cancer NCI-H446 Cells In Vitro]

背景与目的

肺癌是世界上最常见的恶性肿瘤，其中小细胞肺癌是恶性程度最高的亚型，具有生长迅速、早期转移和高度血管化等特点。阿帕替尼（Apatinib）是我国自主研发的血管内皮生长因子受体2抑制剂，在多种实体瘤中疗效显著。本研究旨在探讨Apatinib对小细胞肺癌细胞株NCI-H446的体外作用以及联合哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin, mTOR）抑制剂CCI-779对小细胞肺癌的体外作用。

方法

体外培养小细胞肺癌细胞株NCI-H446，CCK8法、细胞凋亡实验、细胞周期实验及Transwell实验检测Apatinib及联合mTOR抑制剂CCI-779对NCI-H446细胞增殖、凋亡、周期及迁移的影响；Western blot实验检测血管内皮生长因子受体和细胞周期相关蛋白的表达。

结果

CCK8实验结果显示高浓度Apatinib能抑制NCI-H446细胞增殖；细胞凋亡实验结果显示高浓度Apatinib诱导NCI-H446细胞凋亡；Transwell实验结果显示高浓度Apatinib抑制NCI-H446细胞迁移；联合mTOR抑制剂CCI-779后，低浓度Apatinib便能抑制NCI-H446细胞增殖和迁移，诱导细胞凋亡。

结论

Apatinib对小细胞肺癌细胞株NCI-H446的作用具有浓度依赖性特征，高浓度Apatinib能够抑制NCI-H446细胞增殖和迁移，诱导细胞凋亡，与mTOR抑制剂CCI-779联用能增加NCI-H446细胞对Apatinib的敏感性。

Dysregulated Pyrimidine Biosynthesis Contributes to 5-FU Resistance in SCLC Patient-Derived Organoids but Response to a Novel Polymeric Fluoropyrimidine, CF10

Chemo-immunotherapy is central to the treatment of small cell lung cancer (SCLC). Despite modest progress made with the addition of immunotherapy, current cytotoxic regimens display minimal survival benefit and new treatments are needed. Thymidylate synthase (TS) is a well-validated anti-cancer drug target, but conventional TS inhibitors display limited clinical efficacy in refractory or recurrent SCLC. We performed RNA-Seq analysis to identify gene expression changes in SCLC biopsy samples to provide mechanistic insight into the potential utility of targeting pyrimidine biosynthesis to treat SCLC. We identified systematic dysregulation of pyrimidine biosynthesis, including elevated TYMS expression that likely contributes to the lack of efficacy for current TS inhibitors in SCLC. We also identified E2F1-3 upregulation in SCLC as a potential driver of TYMS expression that may contribute to tumor aggressiveness. To test if TS inhibition could be a viable strategy for SCLC treatment, we developed patient-derived organoids (PDOs) from human SCLC biopsy samples and used these to evaluate both conventional fluoropyrimidine drugs (e.g., 5-fluorouracil), platinum-based drugs, and CF10, a novel fluoropyrimidine polymer with enhanced TS inhibition activity. PDOs were relatively resistant to 5-FU and while moderately sensitive to the front-line agent cisplatin, were relatively more sensitive to CF10. Our studies demonstrate dysregulated pyrimidine biosynthesis contributes to drug resistance in SCLC and indicate that a novel approach to target these pathways may improve outcomes.

Low-dose apatinib monotherapy in advanced chemotherapy-refractory small cell lung cancer: a case series and literature review

The therapeutic regimen for small cell lung cancer (SCLC) has changed little in the past several decades. Apatinib is a small molecule inhibitor of vascular endothelial growth factor receptor-2 tyrosine kinase. Apatinib has demonstrated efficacy against advanced gastric cancer and breast cancer, and recent studies have also reported its successful use in non-SCLC; however, its efficacy in SCLC remains unclear. In this study, we used apatinib as salvage therapy for chemotherapy-refractory SCLC. Five male patients with advanced SCLC were administered oral apatinib (250 mg/day) as 2nd- to 4th-line treatment. One patient showed a partial response to apatinib, one showed stable disease, and three patients showed progressive disease. The progression-free survival durations in the patients with stable disease and partial response were 1.5 and 3 months, respectively. Only three patients showed adverse effects, including mild hypertension, vomiting, and hand–foot syndrome, respectively, all of which were manageable. Apatinib might thus be a salvage option in patients with advanced SCLC after chemotherapy.

Irinotecan, topotecan, paclitaxel or docetaxel for second-line treatment of small cell lung cancer: a single-center retrospective study of efficiency comparation and prognosis analysis

Background

The main aim of this study was to evaluate the efficiency of second-line chemotherapy irinotecan (CPT-11), topotecan (TPT), paclitaxel (PTX) and docetaxel (DTX) in small cell lung cancer (SCLC) patients who have failure to the first-line standard treatment. The secondary aim was to evaluate the independent prognostic factors of patients who received a second line treatment.

Methods

Retrospective analysis of 116 patients who received second-line chemotherapy. Patients were divided into 4 groups according to the therapy they were treated with, which were CPT-11, TPT, PTX and DTX. Progress free survival (PFS), overall survival (OS), objective response rate (ORR) and disease control rate (DCR) were evaluated for each group. Patients' data of clinical character and blood index were collected, and the prognostic factors were assessed both at univariate and multivariate levels.

Results

Patients treated with CPT-11 achieved the best median PFS and OS of 91 and 595 days, while the median PFS of TPT, PTX and DTX were 74.5, 81 and 50 days respectively. The median OS of them were 154, 168.5 and 184 days respectively. The survival curves of OS were significantly different (P=0.0069). The reaction to second-line therapy is positively correlate to the reaction to first-line therapy (P=0.012). In the multivariate analysis, treatment free interval (TFI) <90 days, lactate dehydrogenase (LDH) ≥225 U/L, neutrophil-to-lymphocyte ratio (NLR) ≥3.5 were identified as independent risk factors for poor prognosis in second-line SCLC patients.

Conclusions

Second-line chemotherapy with TPT in SCLC patients may provide better overall survival benefits. TFI <90 days, LDH ≥225 U/L and NLR ≥3.5 are independent risk factors for second-line SCLC patients.

Nivolumab for the treatment of small cell lung cancer

Introduction: Treatment of extensive-stage SCLC is still a challenge but immunotherapy with checkpoint inhibitors is showing promising results. Nivolumab alone or in combination with ipilimumab has demonstrated a benefit in terms of response and survival in patients with pre-treated extensive-stage disease and has been approved as third-line therapy after failure of chemotherapy. However, data from two phase III trials with nivolumab are negative. In the first trial, nivolumab was administered as a single agent compared to second-line chemotherapy, while in the second it was given alone or in combination with ipilimumab as maintenance treatment after platinum-based chemotherapy.Areas covered: Our review focuses on the role of immunotherapy, and in particular nivolumab, in the treatment of SCLC, describing the results of the main trials and its future perspectives, with reference to clinical trials with other checkpoint inhibitors.Expert opinion: The future of nivolumab in the treatment of SCLC needs to be clarified with further clinical trials, in which improved patient selection and a more specific setting and/or timepoint of the disease may be identified.

A Case of Long-term Survival of 36 Months in the Setting of Extensive-disease Small-cell Lung Cancer

Small-cell lung cancer (SCLC) is an extremely aggressive disease characterized by early regional spread and distant metastases. Patients with extensive-disease (ED) SCLC have a median survival rate of 8-11 months. Despite high response rates to initial therapy, relapses are frequent. Systemic therapy after the first-line failure remains vital in the treatment paradigm of SCLC. The National Comprehensive Cancer Network (NCCN) guidelines dictate that previously administered first-line chemotherapy can be used in relapses that occur after six months from the completion of initial therapy. For relapses within six months of initial therapy, sequential treatment with single agents is recommended. In this report, we discuss the case of a long-term SCLC survivor with an ED. The patient underwent several lines of chemotherapy and prophylactic cranial irradiation (PCI) and survived for 36 months.

Immunotherapy in Small Cell Lung Cancer

Small-cell lung cancer (SCLC) is extremely sensitive to standard treatments, including conventional cytotoxic chemotherapies and radiotherapy, and has poor prognosis and short survival. Standard therapies have reached a plateau of effectiveness and new therapeutic strategies are needed to improve SCLC patient outcomes going forward. Immunotherapy has revolutionised the treatment of solid malignancies, offering a novel way to harness the host immune system to target malignant cells in patients whose disease may no longer respond to cytotoxic therapy. This review describes the available data for the checkpoint inhibitors, such as anti-cytotoxic T-lymphocyte antigen-4 protein (CTLA-4), anti-programmed cell death-1 protein receptor (PD-1), and ligands (PD-L1 and PD-L2) alone or in combination with first-line chemotherapy or in relapsed SCLC. Several trials investigating immunotherapy in SCLC patients are ongoing and the results are awaited soon. Moreover, further immune checkpoint inhibitors directed against other targets, such as the killer-cell immunoglobulin-like receptor and lymphocyte-activation gene-3, are in clinical development. Overall, the high expectations from the oncology community are that the drugs under development will offer new and improved treatment options for SCLC patients.

Ex vivo culture of cells derived from circulating tumour cell xenograft to support small cell lung cancer research and experimental therapeutics

BACKGROUND AND PURPOSE

Small cell lung cancer (SCLC) is an aggressive disease with median survival of <2 years. Tumour biopsies for research are scarce, especially from extensive-stage patients, with repeat sampling at disease progression rarely performed. We overcame this limitation for relevant preclinical models by developing SCLC circulating tumour cell derived explants (CDX), which mimic the donor tumour pathology and chemotherapy response. To facilitate compound screening and identification of clinically relevant biomarkers, we developed short-term ex vivo cultures of CDX tumour cells.

EXPERIMENTAL APPROACH

CDX tumours were disaggregated, and the human tumour cells derived were cultured for a maximum of 5 weeks. Phenotypic, transcriptomic and pharmacological characterization of these cells was performed.

KEY RESULTS

CDX cultures maintained a neuroendocrine phenotype, and most changes in the expression of protein-coding genes observed in cultures, for up to 4 weeks, were reversible when the cells were re-implanted in vivo. Moreover, the CDX cultures exhibited a similar sensitivity to chemotherapy compared to the corresponding CDX tumour in vivo and were able to predict in vivo responses to therapeutic candidates.

CONCLUSIONS AND IMPLICATIONS

Short-term cultures of CDX provide a tractable platform to screen new treatments, identify predictive and pharmacodynamic biomarkers and investigate mechanisms of resistance to better understand the progression of this recalcitrant tumour.

Phase II Study of Roniciclib in Combination with Cisplatin/Etoposide or Carboplatin/Etoposide as First-Line Therapy in Patients with Extensive-Disease Small Cell Lung Cancer

INTRODUCTION

This phase II study evaluated the efficacy and safety of the pan-cyclin-dependent kinase inhibitor roniciclib with platinum-based chemotherapy in patients with extensive-disease SCLC.

METHODS

In this randomized, double-blind study, unselected patients with previously untreated extensive-disease SCLC received roniciclib, 5 mg, or placebo twice daily according to a 3 days-on, 4 days-off schedule in 21-day cycles, with concomitant cisplatin or carboplatin on day 1 and etoposide on days 1 to 3. The primary end point was progression-free survival. Other end points included overall survival, objective response rate, and safety.

RESULTS

A total of 140 patients received treatment: 70 with roniciclib plus chemotherapy and 70 with placebo plus chemotherapy. Median progression-free survival times was 4.9 months (95% confidence interval [CI]: 4.2-5.5) with roniciclib plus chemotherapy and 5.5 months (95% CI: 4.6-5.6) with placebo plus chemotherapy (hazard ratio [HR] = 1.242, 95% CI: 0.820-1.881, p = 0.8653). Median overall survival times was 9.7 months (95% CI: 7.9-11.1) with roniciclib plus chemotherapy and 10.3 months (95% CI: 8.7-11.9) with placebo plus chemotherapy (HR = 1.281, 95% CI: 0.776-1.912, p = 0.7858). The objective response rates were 60.6% with roniciclib plus chemotherapy and 74.6% with placebo plus chemotherapy. Common treatment-emergent adverse events in both groups included nausea, vomiting, and fatigue. Serious treatment-emergent adverse events were more common with roniciclib plus chemotherapy (57.1%) than with placebo plus chemotherapy (38.6%).

CONCLUSIONS

Roniciclib combined with chemotherapy demonstrated an unfavorable risk-benefit profile in patients with extensive-disease SCLC, and the study was prematurely terminated.

[Establishment of A Patient-derived Xenotransplantation Animal Model for Small Cell Lung Cancer and Drug Resistance Model]

背景与目的

小细胞肺癌（small cell lung cancer, SCLC）是细胞分化程度低，恶性程度高，生长速度快，早期容易发生转移的恶性肿瘤。目前SCLC患者的临床治疗以化疗为主，但是在治疗6个月-9个月后极易发生获得性耐药而复发。因此，构建有效的临床前SCLC动物模型具有重要的临床价值。人源性肿瘤异种移植动物模型（patient-derived xenotransplantation, PDX）能够较好地保留原发肿瘤的特性，是比较理想的临床前动物模型。本研究旨在构建中国人来源的SCLC PDX动物模型，并诱导构建化疗耐药的PDX模型，为研究SCLC耐药机制及个体化治疗提供实验模型。

方法

取临床SCLC患者的新鲜手术切除标本或穿刺标本，移植至重度免疫缺陷小鼠NOD-PrkdcscidIL2rgtm1/Bcgen（B-NSGTM）皮下，HE染色及免疫组化对比移植肿瘤组织与患者肿瘤组织的病理学一致性。给予可稳定传代的每一代PDX模型小鼠腹腔注射8个周期的化疗药物（顺铂8 mg/kg+依托泊苷5mg/kg），定期监测荷瘤小鼠体质量和肿瘤体积，对长至1, 000 mm³大小的肿瘤进行传代移植。

结果

本研究收集并移植9例SCLC肿瘤标本，成功构建可多次传代SCLC PDX模型3例并成功诱导其耐药模型，模型较好地保留了原发肿瘤的特征。

结论

成功构建了SCLC PDX模型及其耐药模型，建模成功率为33%。为后续研究人的SCLC耐药机制、临床药物筛选以及个体化治疗提供了实验平台。

Role of Immune Checkpoint Inhibitors in Small Cell Lung Cancer

BACKGROUND

Small cell lung cancer (SCLC) accounts for approximately 13% of all lung cancer diagnoses each year. SCLC is characterized by a rapid doubling time, early metastatic spread, and an unfavorable prognosis overall.

AREAS OF UNCERTAINTY

Most patients with SCLC will respond to initial treatment; however, the majority will experience a disease recurrence and response to second-line therapies is poor. Immune checkpoint inhibitors may be an option given the success in other diseases.

DATA SOURCES

A literature search was conducted using Medline (1946-July week 1, 2017) and Embase (1996-2017 week 28) with the search terms small cell lung cancer combined with nivolumab or ipilimumab or pembrolizumab or atezolizumab or tremelimumab or durvalumab. Five clinical trials, including extended follow-up for 2, that evaluated immune checkpoint inhibitors in limited stage or extensive stage SCLC were included.

RESULTS

In 2 phase 2 trials, ipilimumab was added to upfront chemotherapy. In both trials, an improvement in progression-free survival was seen. Toxicity, when combined with a platinum and etoposide, was significant. In a confirmatory phase 3 trial, ipilimumab did not prolong overall survival when added to first-line chemotherapy. Overall, response rates were similar between the placebo and ipilimumab groups. A phase 1/2 trial evaluated nivolumab alone or in combination with ipilimumab in recurrent SCLC. Results revealed that nivolumab monotherapy and the combination of nivolumab and ipilimumab were relatively safe and had antitumor activity. Pembrolizumab has been evaluated in a multicohort, phase 1b trial. Preliminary data showed a durable response in the second-line setting.

CONCLUSION

Given the lack of overall survival data and significant toxicity associated with the combination of ipilimumab with first-line chemotherapy, this treatment is not a reasonable option at this time. Nivolumab alone or in combination with ipilimumab is a valid option for recurrent SCLC.