Construction of a prognostic model for extensive-stage small cell lung cancer patients undergoing immune therapy in northernmost China and prediction of treatment efficacy based on response status at different time points

BACKGROUND AND PURPOSE

Recently, the emergence of immune checkpoint inhibitors has significantly improved the survival of patients with extensive-stage small cell lung cancer. However, not all patients can benefit from immunotherapy; therefore, there is an urgent need for precise predictive markers to screen the population for the benefit of immunotherapy. However, single markers have limited predictive accuracy, so a comprehensive predictive model is needed to better enable precision immunotherapy. The aim of this study was to establish a prognostic model for immunotherapy in ES-SCLC patients using basic clinical characteristics and peripheral hematological indices of the patients, which would provide a strategy for the clinical realization of precision immunotherapy and improve the prognosis of small cell lung cancer patients.

METHODS

This research retrospectively collected data from ES-SCLC patients treated with PD-1/PD-L1 inhibitors between March 1, 2019, and October 31, 2022, at Harbin Medical University Cancer Hospital. The study data was randomly split into training and validation sets in a 7:3 ratio. Variables associated with patients' overall survival were screened and modeled by univariate and multivariate Cox regression analyses. Models were presented visually via Nomogram plots. Model discrimination was evaluated by Harrell's C index, tROC, and tAUC. The calibration of the model was assessed by calibration curves. In addition, the clinical utility of the model was assessed using a DCA curve. After calculating the total risk score of patients in the training set, patients were stratified by risk using percentile partitioning. The Kaplan-Meier method was used to plot OS and PFS survival curves for different risk groups and response statuses at different milestone time points. Differences in survival time groups were compared using the chi-square test. Statistical analysis software included R 4.1.2 and SPSS 26.

RESULTS

This study included a total of 113 ES-SCLC patients who received immunotherapy, including 79 in the training set and 34 in the validation set. Six variables associated with poorer OS in patients were screened by Cox regression analysis: liver metastasis (P = 0.001), bone metastasis (P = 0.013), NLR < 2.14 (P = 0.005), LIPI assessed as poor (P < 0.001), PNI < 51.03 (P = 0.002), and LDH ≥ 146.5 (P = 0.037). A prognostic model for immunotherapy in ES-SCLC patients was constructed based on the above variables. The Harrell's C-index in the training and validation sets of the model was 0.85 (95% CI 0.76-0.93) and 0.88 (95% CI 0.76-0.99), respectively; the AUC values corresponding to 12, 18, and 24 months in the tROC curves of the training set were 0.745, 0.848, and 0.819 in the training set and 0.858, 0.904 and 0.828 in the validation set; the tAUC curves show that the overall tAUC is > 0.7 and does not fluctuate much over time in both the training and validation sets. The calibration plot demonstrated the good calibration of the model, and the DCA curve indicated that the model had practical clinical applications. Patients in the training set were categorized into low, intermediate, and high risk groups based on their predicted risk scores in the Nomogram graphs. In the training set, 52 patients (66%) died with a median OS of 15.0 months and a median PFS of 7.8 months. Compared with the high-risk group (median OS: 12.3 months), the median OS was significantly longer in the intermediate-risk group (median OS: 24.5 months, HR = 0.47, P = 0.038) and the low-risk group (median OS not reached, HR = 0.14, P = 0.007). And, the median PFS was also significantly prolonged in the intermediate-risk group (median PFS: 12.7 months, HR = 0.45, P = 0.026) and low-risk group (median PFS not reached, HR = 0.12, P = 0.004) compared with the high-risk group (median PFS: 6.2 months). Similar results were obtained in the validation set. In addition, we observed that in real-world ES-SCLC patients, at 6 weeks after immunotherapy, the median OS was significantly longer in responders than in non-responders (median OS: 19.5 months vs. 11.9 months, P = 0.033). Similar results were obtained at 12 weeks (median OS: 20.7 months vs 11.9 months, P = 0.044) and 20 weeks (median OS: 20.7 months vs 11.7 months, P = 0.015). Finally, we found that in the real world, ES-SCLC patients without liver metastasis (P = 0.002), bone metastasis (P = 0.001) and a total number of metastatic organs < 2 (P = 0.002) are more likely to become long-term survivors after receiving immunotherapy.

CONCLUSION

This study constructed a new prognostic model based on basic patient clinical characteristics and peripheral blood indices, which can be a good predictor of the prognosis of immunotherapy in ES-SCLC patients; in the real world, the response status at milestone time points (6, 12, and 20 weeks) can be a good indicator of long-term survival in ES-SCLC patients receiving immunotherapy.

Efficacy and safety of different immunotherapies combined with chemotherapy as first-line therapy in patients with small cell lung cancer: a network meta-analysis

Background

The efficacy and safety of different immunosuppressants combined with chemotherapy in treating patients with small-cell lung cancer (extensive-disease small-cell lung cancer, limited-disease small-cell lung cancer and relapsed small-cell lung cancer) are still unknown, and there are no reports directly comparing the efficacy and safety of other immunotherapies.

Objective

This study aimed to compare the efficacy and safety of first-line immunotherapy combined with chemotherapy in patients with small-cell lung cancer.

Method

We searched Pubmed, Embase, Cochrane Library, CNKI, and Wanfang databases for relevant articles published from inception to November 11, 2020. The risk of bias of the included studies was conducted using the Cochrane risk-of-bias (RoB) tool. Multiple Bayesian network meta-analyses were performed. They conducted data analysis using R Studio and STATA version 15.1. The outcomes comprised overall survival (OS), progression-free survival (PFS), stability of response (SOR), duration of response (DOR) and adverse events of grade 3 or higher (AE grade≥3). A 95% confidence interval (CI) was provided for each estimate.

Results

This meta-analysis included 16 RCT studies with 5898 patients. For OS, relative to chemotherapy (MD=-4.49; 95%CI [-7.97, -1.03]), durvalumab plus tremelimumab (MD=-4.62; 95%CI [-9.08, -0.11]), ipilimumab (MD=-4.26; 95%CI [-8.01, -0.3]) and nivolumab(MD=-5.66; 95%CI [-10.44, -1.11]) and nivolumab plus ipilimumab (MD=-4.56; 95%CI [-8.7, -0.1]), serplulimab can significantly increase the OS of SCLC patients. There was no significant difference between PFS, SOR and DOR. Analysis of AE showed that different immunotherapy combined chemotherapy regimens were similar to single chemotherapy regarding the overall incidence of AE grade≥3. However, after the cumulative ranking of the common symptoms of different adverse reactions, it was found that nivolumab ranked first in the occurrence probability of anemia (99.08%), fatigue (84.78%), and decreased appetite (89.66%). durvalumab was the most likely in nausea (75.4%). Pembrolizumab (76.24%) was most likely to cause pruritus. Chemotherapy combined with immunotherapy caused less diarrhea than chemotherapy alone (80.16%).

Conclusions

According to our analysis, serplulimab combined with chemotherapy is more likely to show better efficacy with a manageable safety profile for small-cell lung cancer. However, the evidence for this comparison shows some limitations due to the number of literature.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023486053.

Small-Cell Lung Cancer: Is Liquid Biopsy a New Tool Able to Predict the Efficacy of Immunotherapy?

Small-cell lung cancer (SCLC) cases represent approximately 15% of all lung cancer cases, remaining a recalcitrant malignancy with poor survival and few treatment options. In the last few years, the addition of immunotherapy to chemotherapy improved clinical outcomes compared to chemotherapy alone, resulting in the current standard of care for SCLC. However, the advantage of immunotherapy only applies to a few SCLC patients, and predictive biomarkers selection are lacking for SCLC. In particular, due to some features of SCLC, such as high heterogeneity, elevated cell plasticity, and low-quality tissue samples, SCLC biopsies cannot be used as biomarkers. Therefore, the characterization of the tumor and, subsequently, the selection of an appropriate therapeutic combination may benefit greatly from liquid biopsy. Soluble factors, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and extracellular vesicles (EVs) are now useful tools in the characterization of SCLC. This review summarizes the most recent data on biomarkers detectable with liquid biopsy, emphasizing their role in supporting tumor detection and their potential role in SCLC treatment choice.

Evolutionary trajectories of small cell lung cancer under therapy

The evolutionary processes that underlie the marked sensitivity of small cell lung cancer (SCLC) to chemotherapy and rapid relapse are unknown1-3. Here we determined tumour phylogenies at diagnosis and throughout chemotherapy and immunotherapy by multiregion sequencing of 160 tumours from 65 patients. Treatment-naive SCLC exhibited clonal homogeneity at distinct tumour sites, whereas first-line platinum-based chemotherapy led to a burst in genomic intratumour heterogeneity and spatial clonal diversity. We observed branched evolution and a shift to ancestral clones underlying tumour relapse. Effective radio- or immunotherapy induced a re-expansion of founder clones with acquired genomic damage from first-line chemotherapy. Whereas TP53 and RB1 alterations were exclusively part of the common ancestor, MYC family amplifications were frequently not constituents of the founder clone. At relapse, emerging subclonal mutations affected key genes associated with SCLC biology, and tumours harbouring clonal CREBBP/EP300 alterations underwent genome duplications. Gene-damaging TP53 alterations and co-alterations of TP53 missense mutations with TP73, CREBBP/EP300 or FMN2 were significantly associated with shorter disease relapse following chemotherapy. In summary, we uncover key processes of the genomic evolution of SCLC under therapy, identify the common ancestor as the source of clonal diversity at relapse and show central genomic patterns associated with sensitivity and resistance to chemotherapy.

WEE1 inhibition enhances the antitumor immune response to PD-L1 blockade by the concomitant activation of STING and STAT1 pathways in SCLC

Small cell lung cancers (SCLCs) have high mutational burden but are relatively unresponsive to immune checkpoint blockade (ICB). Using SCLC models, we demonstrate that inhibition of WEE1, a G2/M checkpoint regulator induced by DNA damage, activates the STING-TBK1-IRF3 pathway, which increases type I interferons (IFN-α and IFN-β) and pro-inflammatory chemokines (CXCL10 and CCL5), facilitating an immune response via CD8⁺ cytotoxic T cell infiltration. We further show that WEE1 inhibition concomitantly activates the STAT1 pathway, increasing IFN-γ and PD-L1 expression. Consistent with these findings, combined WEE1 inhibition (AZD1775) and PD-L1 blockade causes remarkable tumor regression, activation of type I and II interferon pathways, and infiltration of cytotoxic T cells in multiple immunocompetent SCLC genetically engineered mouse models, including an aggressive model with stabilized MYC. Our study demonstrates cell-autonomous and immune-stimulating activity of WEE1 inhibition in SCLC models. Combined inhibition of WEE1 plus PD-L1 blockade represents a promising immunotherapeutic approach in SCLC.

Intrinsic Immunogenicity of Small Cell Lung Carcinoma Revealed by Its Cellular Plasticity

Small cell lung carcinoma (SCLC) is highly mutated, yet durable response to immune checkpoint blockade (ICB) is rare. SCLC also exhibits cellular plasticity, which could influence its immunobiology. Here we discover that a distinct subset of SCLC uniquely upregulates MHC I, enriching for durable ICB benefit. In vitro modeling confirms epigenetic recovery of MHC I in SCLC following loss of neuroendocrine differentiation, which tracks with derepression of STING. Transient EZH2 inhibition expands these nonneuroendocrine cells, which display intrinsic innate immune signaling and basally restored antigen presentation. Consistent with these findings, murine nonneuroendocrine SCLC tumors are rejected in a syngeneic model, with clonal expansion of immunodominant effector CD8 T cells. Therapeutically, EZH2 inhibition followed by STING agonism enhances T-cell recognition and rejection of SCLC in mice. Together, these data identify MHC I as a novel biomarker of SCLC immune responsiveness and suggest novel immunotherapeutic approaches to co-opt SCLC's intrinsic immunogenicity. SIGNIFICANCE: SCLC is poorly immunogenic, displaying modest ICB responsiveness with rare durable activity. In profiling its plasticity, we uncover intrinsically immunogenic MHC Ihi subpopulations of nonneuroendocrine SCLC associated with durable ICB benefit. We also find that combined EZH2 inhibition and STING agonism uncovers this cell state, priming cells for immune rejection.This article is highlighted in the In This Issue feature, p. 1861.

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 .

Prognostic role of pretreatment lung immune prognostic index in extensive-stage small-cell lung cancer treated with platinum plus etoposide chemotherapy

BACKGROUND

To investigate the prognostic role of lung immune prognostic index (LIPI) in extensive-stage small-cell lung cancer (ES-SCLC) patients treated with platinum plus etoposide chemotherapy.

METHODS

Data were obtained from two randomized controlled trials (NCT00119613 and NCT00363415). Overall survival (OS) and progression-free survival (PFS) was assessed according to LIPI score through Kaplan-Meier analysis. Univariate and multivariate Cox-regression analysis were performed to investigate predictors for OS and PFS.

RESULTS

A total of 911 patients with ES-SCLC treated with platinum plus etoposide chemotherapy (CT) were included for analysis. The median age at diagnosis was 62 years, and 760 (83.4%) had performance status of 1 or less. 1-year OS for ES-SCLC with poor, intermediate, and good LIPI was 20%, 30% and 31%, respectively, and 1-year PFS was 7%, 15% and 21%, respectively. Cox-regression analysis showed that the PFS and OS of ES-SCLC with a poor LIPI score was significantly worse than those with good LIPI scores (HR 1.81, 95% CI: 1.38-2.36; p< 0.001 and HR 1.35, 95% CI: 1.07-1.72, p= 0.012), while no significant difference was observed between intermediate and poor LIPI groups in terms of OS (HR 1.01, 95% CI: 0.82-1.23, p= 0.82), but not for PFS (HR 1.27, 95% CI: 1.00-1.61, p= 0.048). In addition, LIPI score was significantly associated with disease control rate and objective response rate (both p< 0.0001).

CONCLUSION

Prognosis of patients with pretreatment LIPI score of 2 is poorer than those with LIPI score of 0-1 among ES-SCLC who received first-line platinum plus etoposide chemotherapy; Further studies are still recommended to confirm our findings in prospective studies.

Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis: A case report

INTRODUCTION

: Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) is a subtype of glutamate receptor that mediates most of the fast excitatory neurotransmission in the brain. Anti-AMPAR encephalitis is an autoimmune-mediated neurological disorder, frequently accompanied by the presence of neoplasms, comprising a spectrum of paraneoplastic syndrome.

PATIENT CONCERNS

A 56-year-old man was admitted for deterioration in memory and aberrant psychological behaviors, which lasted for at least 20 days.

DIAGNOSIS

The patient was diagnosed as anti-AMPAR encephalitis and 4 months later, he was diagnosed with small cell lung cancer.

INTERVENTIONS

Once diagnosis for anti-AMPAR encephalitis was confirmed, methylprednisolone was prescribed with initial dose 500 mg/d for 14 days until the patient returned to pre-illness state. Then he was discharged with oral treatment with corticosteroids. Following the diagnosis of small cell lung cancer, he received 5 rounds of chemotherapy, including carboplatin and etoposide.

OUTCOMES

After taken the prescription of Methylprednisolone for anti-AMPAR encephalitis, he returned to pre-illness state and was discharged. In April 21, 2017, after symptoms of respiratory system showed up, he was diagnosed with small cell lung cancer and he eventually died of respiratory failure.

CONCLUSION

Though progress has been made in recent years in diagnosis and treatment for autoimmune encephalitis, it is challenging to diagnose due to the similarity in clinical findings with other autoimmune or infectious encephalitis. In addition, it is necessary for these patients to regularly have tumor screening, considering AMPAR antibody encephalitis is closely associated with neoplasm, and the incidence of paraneoplastic syndrome is 63% to 70%.

Patterns of transcription factor programs and immune pathway activation define four major subtypes of SCLC with distinct therapeutic vulnerabilities

Despite molecular and clinical heterogeneity, small cell lung cancer (SCLC) is treated as a single entity with predictably poor results. Using tumor expression data and non-negative matrix factorization, we identify four SCLC subtypes defined largely by differential expression of transcription factors ASCL1, NEUROD1, and POU2F3 or low expression of all three transcription factor signatures accompanied by an Inflamed gene signature (SCLC-A, N, P, and I, respectively). SCLC-I experiences the greatest benefit from the addition of immunotherapy to chemotherapy, while the other subtypes each have distinct vulnerabilities, including to inhibitors of PARP, Aurora kinases, or BCL-2. Cisplatin treatment of SCLC-A patient-derived xenografts induces intratumoral shifts toward SCLC-I, supporting subtype switching as a mechanism of acquired platinum resistance. We propose that matching baseline tumor subtype to therapy, as well as manipulating subtype switching on therapy, may enhance depth and duration of response for SCLC patients.

AMG 757, a Half-Life Extended, DLL3-Targeted Bispecific T-Cell Engager, Shows High Potency and Sensitivity in Preclinical Models of Small-Cell Lung Cancer

PURPOSE

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine tumor with a high relapse rate, limited therapeutic options, and poor prognosis. We investigated the antitumor activity of AMG 757, a half-life extended bispecific T-cell engager molecule targeting delta-like ligand 3 (DLL3)-a target that is selectively expressed in SCLC tumors, but with minimal normal tissue expression.

EXPERIMENTAL DESIGN

AMG 757 efficacy was evaluated in SCLC cell lines and in orthotopic and patient-derived xenograft (PDX) mouse SCLC models. Following AMG 757 administration, changes in tumor volume, pharmacodynamic changes in tumor-infiltrating T cells (TILs), and the spatial relationship between the appearance of TILs and tumor histology were examined. Tolerability was assessed in nonhuman primates (NHPs).

RESULTS

AMG 757 showed potent and specific killing of even those SCLC cell lines with very low DLL3 expression (<1,000 molecules per cell). AMG 757 effectively engaged systemically administered human T cells, induced T-cell activation, and redirected T cells to lyse tumor cells to promote significant tumor regression and complete responses in PDX models of SCLC and in orthotopic models of established primary lung SCLC and metastatic liver lesions. AMG 757 was well tolerated with no AMG 757-related adverse findings up to the highest tested dose (4.5 mg/kg weekly) in NHP. AMG 757 exhibits an extended half-life in NHP, which is projected to enable intermittent administration in patients.

CONCLUSIONS

AMG 757 has a compelling safety and efficacy profile in preclinical studies making it a viable option for targeting DLL3-expressing SCLC tumors in the clinical setting.

An update on the immune landscape in lung and head and neck cancers

Immunotherapy has dramatically changed the treatment landscape for patients with cancer. Programmed death-ligand 1/programmed death-1 checkpoint inhibitors have been in the forefront of this clinical revolution. Currently, there are 6 US Food and Drug Administration-approved checkpoint inhibitors for approximately 18 different histologic types of cancer. Lung cancer and head and neck squamous cell carcinoma (HNSCC) are 2 diseases that have led the way in the development of immunotherapy. Atezolizumab, durvalumab, nivolumab, and pembrolizumab are all currently used as part of standard-of-care treatment for different stages of lung cancer. Similarly, nivolumab and pembrolizumab have US regulatory approval as treatment for advanced metastatic HNSCC. This is significant because lung cancer represents the most common and most fatal cancer globally, and HNSCC is the sixth most common. Currently, most of the approvals for the use of immunotherapy agents are for patients diagnosed in the metastatic setting. However, research is ongoing to evaluate these drugs in earlier stage disease. There is plausible biological rationale to expect that pharmacologic activation of the immune system will be effective for early-stage and smaller tumors. In addition, selecting patients who are more likely to respond to immunotherapy and understanding why resistance develops are crucial areas of ongoing research. The objective of this review was to provide an overview of the current immune landscape and future directions in lung cancer and HNSCC.

Neuroendocrine subtypes of small cell lung cancer differ in terms of immune microenvironment and checkpoint molecule distribution

Small cell lung cancer (SCLC) has recently been subcategorized into neuroendocrine (NE)-high and NE-low subtypes showing 'immune desert' and 'immune oasis' phenotypes, respectively. Here, we aimed to characterize the tumor microenvironment according to immune checkpoints and NE subtypes in human SCLC tissue samples at the protein level. In this cross-sectional study, we included 32 primary tumors and matched lymph node (LN) metastases of resected early-stage, histologically confirmed SCLC patients, which were previously clustered into NE subtypes using NE-associated key RNA genes. Immunohistochemistry (IHC) was performed on formalin-fixed paraffin-embedded TMAs with antibodies against CD45, CD3, CD8, MHCII, TIM3, immune checkpoint poliovirus receptor (PVR), and indoleamine 2,3-dioxygenase (IDO). The stroma was significantly more infiltrated by immune cells both in primary tumors and in LN metastases compared to tumor nests. Immune cell (CD45⁺ cell) density was significantly higher in tumor nests (P = 0.019), with increased CD8⁺ effector T-cell infiltration (P = 0.003) in NE-low vs NE-high tumors. The expression of IDO was confirmed on stromal and endothelial cells and was positively correlated with higher immune cell density both in primary tumors and in LN metastases, regardless of the NE pattern. Expression of IDO and PVR in tumor nests was significantly higher in NE-low primary tumors (vs NE-high, P < 0.05). We also found significantly higher MHC II expression by malignant cells in NE-low (vs NE-high, P = 0.004) tumors. TIM3 expression was significantly increased in NE-low (vs NE-high, P < 0.05) tumors and in LN metastases (vs primary tumors, P < 0.05). To our knowledge, this is the first human study that demonstrates in situ that NE-low SCLCs are associated with increased immune cell infiltration compared to NE-high tumors. PVR, IDO, MHCII, and TIM3 are emerging checkpoints in SCLC, with increased expression in the NE-low subtype, providing key insight for further prospective studies on potential biomarkers and targets for SCLC immunotherapies.

Increased IL-10+CD206+CD14+M2-like macrophages in alveolar lavage fluid of patients with small cell lung cancer

There are significant differences in pathology, etiology, clinical features, and treatment options between small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). However, the differences of macrophage distribution and its associated function between SCLC and NSCLC are not fully investigated. Through methods of flow cytometry and cytometric bead array, we examined the levels of various subtypes of macrophages, monocytes, and regulatory T cells (Tregs) as well as interleukin (IL)-10 in bronchoalveolar lavage fluid (BALF) of patients with SCLC or NSCLC. Our study showed that the frequency of CD14+, CD206+CD14+ and IL-10+CD206+CD14+M2-like macrophages were significantly increased, with simultaneously elevated IL-10 in BALF of SCLC patients, as compared to those in BALF of NSCLC patients. Furthermore, the increased frequency of IL-10+CD206+CD14+M2-like macrophages and elevated level of IL-10 in BALF of SCLC patients were positively correlated with advanced tumor stage, but negatively correlated with their survival time. On the other hand, the level of supernatant IL-10 and frequency of IL-10+CD206+CD14+M2-like macrophages in SCLC patients were positively correlated. The frequency of above mentioned macrophages was also positively correlated with that of Foxp3+CD25+CD4+Tregs. Compared to NSCLC patients, the level of circulating IL-10+CD206+CD14+M2-like monocytes in SCLC patients were significantly increased after chemotherapy. Overall, increased IL-10+CD206+CD14+M2-like macrophages were an important feature of SCLC, rather than NSCLC, and it is associated with development of SCLC.

Treatment- and immune-related adverse events of immune checkpoint inhibitors in advanced lung cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) emerged as the preferred therapy in advanced lung cancer, understanding the treatment- and immune-related adverse events of these drugs is of great significance for clinical practice.

MATERIALS AND METHODS

PubMed, Embase, Cochrane library and major conference proceedings were systematically searched for all randomized controlled trials (RCTs) in lung cancer using PD-1/PD-L1/CTLA-4 inhibitors. The outcomes included treatment-related adverse events (TRAEs) and several organ specific immune-related adverse events (IRAEs).

RESULTS

24 RCTs involving 14,256 patients were included. There was a significant difference for ICI therapy in the incidence of any grade of TRAEs (RR: 0.90; 95%CI: 0.84-0.95; P=0.001) and a lower frequency of grade 3-5 of TRAEs (RR: 0.65; 95%CI: 0.51-0.82; P<0.001). Patients treated with ICI therapy in non-small-cell lung cancer (NSCLC) were less reported TRAEs than in small cell lung cancer (SCLC). A lower risk of TRAEs was favored by anti-PD-1 inhibitors over anti-PD-L1 antibodies and anti-CTLA-4 drugs. The most common organ specific IRAE was hypothyroidism that occurred 8.7%. The incidence of pneumonitis and hepatitis reached 4.5% and 4.0% respectively. Compared with patients treated in control arms, those treated with ICI drugs were at higher risk for each organ specific adverse event including colitis, hepatitis, pneumonitis, hypothyroidism and hypophysitis.

CONCLUSIONS

ICI therapy was safer than chemotherapy, especially ICI monotherapy such as anti-PD-1 antibodies in NSCLC. Compared with standard treatments, ICI drugs increased the risk of organ-specific IRAEs, although the overall incidence remained low.

CDK7 Inhibition Potentiates Genome Instability Triggering Anti-tumor Immunity in Small Cell Lung Cancer

Cyclin-dependent kinase 7 (CDK7) is a central regulator of the cell cycle and gene transcription. However, little is known about its impact on genomic instability and cancer immunity. Using a selective CDK7 inhibitor, YKL-5-124, we demonstrated that CDK7 inhibition predominately disrupts cell-cycle progression and induces DNA replication stress and genome instability in small cell lung cancer (SCLC) while simultaneously triggering immune-response signaling. These tumor-intrinsic events provoke a robust immune surveillance program elicited by T cells, which is further enhanced by the addition of immune-checkpoint blockade. Combining YKL-5-124 with anti-PD-1 offers significant survival benefit in multiple highly aggressive murine models of SCLC, providing a rationale for new combination regimens consisting of CDK7 inhibitors and immunotherapies.

Variation in the Assessment of Immune-Related Adverse Event Occurrence, Grade, and Timing in Patients Receiving Immune Checkpoint Inhibitors

IMPORTANCE

Toxic effects of conventional chemotherapy and molecularly targeted cancer therapies are generally well defined and occur at predictable points. By contrast, owing to their heterogeneous manifestations, unpredictable timing, and clinical overlap with other conditions, immune-related adverse events (irAE) may be more difficult to diagnose and characterize.

OBJECTIVE

To determine concordance of algorithm-driven medical record review by medical oncologists for the characterization of 8 irAE in patients treated with immune checkpoint inhibitors.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of patients treated with immune checkpoint inhibitors at a National Cancer Institute-designated comprehensive cancer center from November 30, 2015, to March 7, 2018. A sample size of 52 patients provided 80% power to distinguish substantial agreement (κ = 0.85) from poor agreement (κ = 0.5) based on the Cohen κ.

MAIN OUTCOMES AND MEASURES

Interrater agreement of 2 observers in the occurrence and grade of irAE.

RESULTS

Of 52 patients (32 [61.5%] male; mean [SD] age, 69 [9] years) analyzed, 42 (80.8%) had non-small cell lung cancer and all received anti-programmed cell death 1 or anti-programmed cell death ligand 1 antibodies, with 3 patients (5.8%) receiving combinations with anti-cytotoxic T-lymphocyte antigen 4 antibodies. A median (interquartile range) of 82 (47-180) documents were reviewed per case. There was limited or poor interrater agreement on irAE occurrence (Cohen κ, 0.37-0.64), with the exception of hypothyroidism (κ = 0.8). Weighted κ similarly showed limited or poor agreement for irAE grade (κ = 0.31-0.75). Differences in assessed time of onset ranged from 5 to 188 days. As a control for data availability and access, observers had a high degree of agreement for the exact start date (98%) and end date (96%) of immunotherapy administration, suggesting that information interpretation rather than identification largely accounted for assessment differences. In multivariable analysis, therapy duration (adjusted odds ratio, 4.80; 95% CI, 1.34-17.17; P = .02) and Charlson Comorbidity Index (adjusted odds ratio, 4.09; 95% CI, 1.10-15.18; P = .03) were significantly associated with discordant irAE assessment.

CONCLUSIONS AND RELEVANCE

These findings underscore critical challenges in assessing the occurrence, type, timing, and severity of irAE. Apart from hypothyroidism (a condition that has a discrete diagnostic laboratory test and few other likely etiologies during immunotherapy treatment), interobserver agreement was poor. Given the importance of accurate and timely assessment of toxic effects for clinical trials and real-world disease management, efforts to improve irAE diagnosis and characterization are needed.

The evolving landscape of immunotherapy in small-cell lung cancer: A focus on predictive biomarkers

Small cell lung cancer (SCLC) was defined as a "recalcitrant cancer" because of its dismal prognosis and lack of outcome improvements in the last 30 years. Immunotherapy with checkpoint inhibitors revolutionized treatment in many cancer types and results from the IMpower133 study, a double-blind placebo-controlled phase III trial, showed overall survival benefit for atezolizumab when added to standard platinum-etoposide chemotherapy in first-line SCLC setting for the first time since years. Trials with other checkpoint inhibitors, e.g. pembrolizumab, durvalumab, nivolumab and ipilimumab, are ongoing in various settings, but, to date, there are no defined factors to identify patients who are more likely to benefit from such treatments. This review summarizes results of immunotherapy trials in SCLC for first-line, maintenance and further-line therapies for single-agents and combinations with checkpoint inhibitors. Predictive factors from these trials are reviewed in order to identify their clinical value, with particular emphasis on PD-L1 expression on both tumor cells and in stroma, especially in pembrolizumab-treated patients, and tumor mutational burden, for patients treated with the ipilimumab and nivolumab combination.

Potential immune escape mechanisms underlying the distinct clinical outcome of immune checkpoint blockades in small cell lung cancer

Small cell lung cancer (SCLC) is one of the deadliest cancer types in the world. Despite the high response rate to frontline platinum-containing doublets, relapse is inevitable for the majority of patients and the prognosis is poor. Topotecan, which has limited efficacy, has remained the standard second-line therapy for approximately three decades. Although SCLC has a high mutation burden, the clinical efficacy of immune checkpoint blockades (ICBs) in SCLC is far less pronounced than that in non-small cell lung cancer (NSCLC). Only atezolizumab in combination with chemotherapy improved overall survival over chemotherapy alone in the phase III CheckMate 133 trial and has recently received FDA approval as first-line therapy. Most studies concerning ICBs in SCLC are limited to early-phase studies and found that ICBs were not superior to traditional chemotherapy. Why is there such a large difference between SCLC and NSCLC? In this review, comparative analyses of previous studies indicate that SCLC is even more immunodeficient than NSCLC and the potential immune escape mechanisms in SCLC may involve the low expression of PD-L1 and the downregulation of major histocompability complex (MHC) molecules and regulatory chemokines. In consideration of these immune dysfunctions, we speculate that chemotherapy and radiotherapy prior to immunotherapy, the combination of ICBs with antiangiogenic treatment, and selecting tumor mutation burden in combination with PD-L1 expression as biomarkers could be promising strategies to improve the clinical efficacy of immunotherapy for SCLC.

Beyond chemotherapy: Emerging biomarkers and therapies as small cell lung cancer enters the immune checkpoint era

For decades, clinicians have seen no therapeutic advances for SCLC, including no FDA-approved targeted therapies; recently, immune checkpoint blockade has emerged as a promising new option for the treatment of relapsed SCLC (including recent FDA approval of nivolumab in the third-line setting) and may soon represent the frontline standard of care in combination with chemotherapy. However, we need to uncover biomarkers to guide patient selection and develop novel approaches to enhance response to immunotherapies.

Retrospect and Prospect for Lung Cancer in China: Clinical Advances of Immune Checkpoint Inhibitors

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related deaths in China. The recent emergence of immunotherapy treatment options, such as the use of programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) checkpoint inhibitors, has also led to a paradigm shift in the treatment of non-small cell lung cancer, and has provided promising directions for the treatment of small cell lung cancer. This review provides a summary of the developmental process of immunotherapy, especially immune checkpoint inhibitors in lung cancer, ongoing international and domestic clinical trials in this field, and the challenges and considerations related to the use of immunotherapy in Chinese patients with lung cancer, with the aim of providing detailed information for future immunotherapy-related clinical trials in China. Research regarding immune checkpoint inhibitors in China is several years behind similar research in several developed countries. However, although PD-1/PD-L1 inhibitor-related clinical trials remain in their early stages in China, increased efforts by Chinese clinicians, researchers, and government staff have been directed toward trying to introduce novel drugs into the clinical setting. Because of the specific characteristics of Chinese patients with lung cancer (such as high epidermal growth factor receptor mutation rates, later disease stages, and different toxicity profiles), large-scale clinical trials targeting the Chinese population or Chinese participation in multinational trials should be promoted. IMPLICATIONS FOR PRACTICE: As the leading cause of cancer-related morbidity and mortality, lung cancer is a major public health problem in China. Immunotherapy based on programmed cell death protein 1/programmed death-ligand 1 checkpoint inhibitors may result in new treatment directions and a paradigm shift for Chinese patients with lung cancer. Although checkpoint inhibitor-related clinical trials remain in their early stages in China, increased efforts by Chinese clinicians, researchers, and government staff have been directed toward trying to introduce novel drugs into the clinical setting by encouraging the development of large-scale clinical trials targeting the Chinese population and promoting Chinese patients with lung cancer to participate in international trials.

Small Cell Lung Cancer Patient with Anti-transcriptional Intermediary Factor 1γ Antibody Who Developed Dermatomyositis after Successful Chemoradiotherapy

We herein report a 63-year-old woman with small-cell lung cancer (SCLC) who developed dermatomyositis (DM) after initial chemoradiotherapy despite tumor reduction. Serum anti-transcriptional in termediary factor (TIF) 1γ antibody was detected before the development of DM, and its levels increased over time. She died five months after the diagnosis of SCLC. Anti-TIF1γ antibody is known to be a marker for cancer-associated DM (CAM); however, the present case indicates that the antibody can be found in cancer patients without DM. This case is also unusual, as DM developed later despite successful chemoradiotherapy.

A new hope: the immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is of a high-grade malignancy with a high metastatic potential and poor clinical prognosis. Unfortunately, SCLC initially exhibits a good response to chemotherapy and radiation therapy, but inevitably, relapses decrease patients' chance of survival. Despite tremendous advances on the development of new chemotherapeutic agents, the prognosis of this disease remains poor. Immunotherapy plays a role in eliciting an anticancer response by modulating the patient's immune response of the tumor. Several studies have demonstrated that abnormal autoimmune regulation has a close relationship with SCLC. Thus, several immunotherapy trials are focused on SCLC treatment, including such approaches as immune checkpoints blockers, tumor vaccine, antigenic targets and adoptive cellular immunotherapy to benefit patients with SCLC. To date, the results from immunotherapy in SCLC have not been promising. For example, tumor vaccines have not been demonstrated to have a significant survival benefit. However, there have been many promising advances with immune checkpoints blockers. This review will provide a general overview of immunotherapy in SCLC. The landmark clinical trials in previous successful immunotherapy studies are summarized here. Finally, the challenges of immunotherapy in SCLC are discussed to facilitate the prediction of possible and valuable strategies for future therapy.

Advances in antibody therapeutics targeting small-cell lung cancer

The proportion of small-cell lung cancer (SCLC) among all lung cancers decreased from 17.26% in 1986 to 12.95% in 2002. Chemotherapy is the key mode of treatment. However, novel therapeutic strategies and drugs are imperative, as the prognosis remains poor. In recent years, antibody therapies have shown promising prospects against malignancy. This review focuses on the advances in antibody therapies in SCLC. Although the results of pembrolizumab, nivolumab, ipilimumab, and rovalpituzumab tesirine are inspiring, all of the clinical trials on these drugs are phase I/II and have been verified for further phase III clinical trials. It was demonstrated that chemotherapy in combination with bevacizumab can improve the progression-free survival (PFS) in phase III trials. The insulin-like growth factor-1 receptor (IGF-1R) is associated with a poor prognosis in SCLC, while the anti-IGF-1R monoclonal antibody figitumumab has a potential therapeutic value. Tarextumab, an antibody that blocks both Notch2 and Notch3 signaling, in combination with etoposide and platinum (EP) in patients with untreated extensive-stage SCLC, proved to be well-tolerated and showed dosedependent anti-tumor activity. The therapeutic effect of sacituzumab govitecan, BW-2 and lorvotuzumab mertansine in SCLC warranted further evaluation. Bec2/BCG as an adjuvant vaccination in patients with limited-disease SCLC could not improve the survival, PFS, or quality of life. Thus, clinical studies are essential to confirm the anti-tumor efficacy of trastuzumab in SCLC.

Paraneoplastic limbic encephalitis associated with lung cancer

Paraneoplastic limbic encephalitis (PLE) is a rare autoimmune neurological syndrome observed in lung cancer patients. We retrospectively investigated the clinical characteristics, treatment responses, and prognoses in 16 PLE patients who were subsequently diagnosed with lung cancer. Fifteen patients initially presented with disturbance of consciousness, 13 with disorientation, and 12 with seizures. Thirteen patients had autoantibodies, including eight with gamma aminobutyric acid B receptor (GABABR) antibodies and eight with Hu antibodies. PET-CT revealed lung neoplasms in 13 patients, nine of whom exhibited abnormal metabolic activity in the temporal lobe and hippocampus. Fifteen cases were confirmed as limited-stage small cell lung cancer and one as stage IV large cell neuroendocrine carcinoma. Eleven patients received immunomodulatory therapy, and four showed neurological improvement, who all had antibodies against GABABR. Fifteen patients received chemotherapy, of which 14 maintained or improved their PLE status. The overall cancer response rate was 75%, and two-year overall survival was 74.7%. Our results suggest patients with GABAB encephalitis might respond better to immunotherapy than the classical PLE patients with anti-Hu antibodies. Anti-cancer treatment could further improve neurological symptoms. Lung cancer patients with PLE, especially those in limited stage, might have better outcome due to earlier diagnosis and prompt anti-cancer treatment.

Acetylcholine receptor antibody-positive myasthenia gravis associated with small-cell lung cancer: A case report

RATIONALE

Only few cases of myasthenia gravis (MG) associated with small-cell lung cancer (SCLC) have been reported, and cases positive for acetylcholine receptor antibody (AChR-ab) are even rarer. The efficacy of standard MG treatment, such as cholinesterase inhibitor therapy, immunosuppressive therapy using steroids and immunosuppressive drugs, plasma exchange, and intravenous immune globulin (IVIg), for these cases is unclear.

PATIENT CONCERNS AND DIAGNOSES

A 71-year-old man complained of bilateral eyelid ptosis. He also presented with dysphagia and masticatory muscle fatigue after chewing. The edrophonium test was positive, and the serum AChR-ab level was increased; therefore, the patient was diagnosed with MG. Computed tomography scan showed a nodule on the left upper lobe of the lung and mediastinal lymphadenopathy. Further examination revealed the lesion as SCLC. Finally, he was diagnosed with AChR-ab-positive MG associated with SCLC.

INTERVENTIONS AND OUTCOMES

Oral pyridostigmine and tacrolimus were administered to treat MG; however, his symptoms worsened. Therefore, methylprednisolone and IVIg were administrated, which temporarily improved his symptoms. However, they remained uncontrolled. Meanwhile, chemotherapy with carboplatin and etoposide was administered to treat his SCLC. The lesions shrunk, and the MG symptoms and serum AChR-ab level also improved.

LESSONS

AChR-ab-positive MG may develop as a comorbidity of SCLC. In such cases, management might require treatment for SCLC in addition to the standard MG treatment to stabilize the MG symptoms.

Rovalpituzumab tesirine, a DLL3-targeted antibody-drug conjugate, in recurrent small-cell lung cancer: a first-in-human, first-in-class, open-label, phase 1 study

BACKGROUND

Rovalpituzumab tesirine is a first-in-class antibody-drug conjugate directed against delta-like protein 3 (DLL3), a novel target identified in tumour-initiating cells and expressed in more than 80% of patients with small-cell lung cancer. We aimed to assess the safety and activity of rovalpituzumab tesirine in patients who progressed after one or more previous regimen.

METHODS

We conducted a phase 1 open-label study at ten cancer centres in the USA. Eligible patients were aged 18 years or older and had histologically or cytologically confirmed small-cell lung cancer or large-cell neuroendocrine tumours with progressive measurable disease (according to Response Evaluation Criteria in Solid Tumors [RECIST], version 1.1) previously treated with one or two chemotherapeutic regimens, including a platinum-based regimen. We assigned patients to dose-escalation or expansion cohorts, ranging from 0·05 mg/kg to 0·8 mg/kg rovalpituzumab tesirine intravenously every 3 weeks or every 6 weeks, followed by investigation of the dose schedules 0·3 mg/kg and 0·4 mg/kg every 6 weeks and 0·2 mg/kg every 3 weeks. Primary objectives were to assess the safety of rovalpituzumab tesirine, including the maximum tolerated dose and dose-limiting toxic effects. The primary activity endpoint was objective response by intention-to-treat analysis. This study is registered with ClinicalTrials.gov, number NCT01901653. The study is closed to enrolment; this report focuses on the cohort with small-cell lung cancer.

FINDINGS

Between July 22, 2013, and Aug 10, 2015, 82 patients were enrolled, including 74 patients with small-cell lung cancer and eight with large-cell neuroendocrine carcinoma, all of whom received at least one dose of rovalpituzumab tesirine. Dose-limiting toxic effects of rovalpituzumab tesirine occurred at a dose of 0·8 mg/kg every 3 weeks, including grade 4 thrombocytopenia (in two of two patients at that dose level) and grade 4 liver function test abnormalities (in one patient). The most frequent grade 3 or worse treatment-related adverse events in 74 patients with small-cell lung cancer were thrombocytopenia (eight [11%]), pleural effusion (six [8%]), and increased lipase (five [7%]). Drug-related serious adverse events occurred in 28 (38%) of 74 patients. The maximum tolerated dose of rovalpituzumab tesirine was 0·4 mg/kg every 3 weeks; the recommended phase 2 dose and schedule is 0·3 mg/kg every 6 weeks. At active doses of rovalpituzumab tesirine (0·2 mg/kg or 0·4 mg/kg every 3 weeks or 0·3 mg/kg or 0·4 mg/kg every 6 weeks), 11 (18%) of 60 assessable patients had a confirmed objective response. 11 (18%) of 60 assessable patients had a confirmed objective response, including ten (38%) of 26 patients confirmed to have high DLL3 expression (expression in 50% or more of tumour cells).

INTERPRETATION

Rovalpituzumab tesirine shows encouraging single-agent antitumour activity with a manageable safety profile. Further development of rovalpituzumab tesirine in DLL3-expressing malignant diseases is warranted.

FUNDING

Stemcentrx Inc.

Isoaspartylation appears to trigger small cell lung cancer-associated autoimmunity against neuronal protein ELAVL4

Autoantibodies against SCLC-associated neuronal antigen ELAVL4 (HuD) have been linked to smaller tumors and improved survival, but the antigenic epitope and mechanism of autoimmunity have never been solved. We report that recombinant human ELAVL4 protein incubated under physiological conditions acquires isoaspartylation, a type of immunogenic protein damage. Specifically, the N-terminal region of ELAVL4, previously implicated in SCLC-associated autoimmunity, undergoes isoaspartylation in vitro, is recognized by sera from anti-ELAVL4 positive SCLC patients and is highly immunogenic in subcutaneously injected mice and in vitro stimulated human lymphocytes. Our data suggest that isoaspartylated ELAVL4 is the trigger for the SCLC-associated anti-ELAVL4 autoimmune response.

PD-L1 Expression by Two Complementary Diagnostic Assays and mRNA In Situ Hybridization in Small Cell Lung Cancer

INTRODUCTION

Therapeutic antibodies to immune checkpoints show promising results. Programmed death-ligand 1 (PD-L1), an immune checkpoint ligand, blocks the cancer immunity cycle by binding the PD-L1 receptor (programmed death 1). We investigated PD-L1 protein expression and messenger RNA (mRNA) levels in SCLC.

METHODS

PD-L1 protein expression and mRNA levels were determined by immunohistochemistry (IHC) with SP142 and Dako 28-8 PD-L1 antibodies and in situ hybridization in primary tumor tissue microarrays in both tumor cells and tumor-infiltrating immune cells (TIICs) obtained from a limited-disease SCLC cohort of 98 patients. An additional cohort of 96 tumor specimens from patients with extensive-disease SCLC was assessed for PD-L1 protein expression in tumor cells with Dako 28-8 antibody only.

RESULTS

The overall prevalence of PD-L1 protein expression in tumor cells was 16.5%. In the limited-disease cohort, the prevalences of PD-L1 protein expression in tumor cells with SP142 and Dako 28-8 were 14.7% and 19.4% (tumor proportion score cutoff ≥1%) and PD-L1 mRNA ISH expression was positive in 15.5% of tumor samples. Increased PD-L1 protein/mRNA expression was associated with the presence of more TIICs (p < 0.05). The extensive-disease cohort demonstrated a 14.9% positivity of PD-L1 protein expression in tumor cells with Dako 28-8 antibody.

CONCLUSIONS

A subset of SCLCs is characterized by positive PD-L1 and/or mRNA expression in tumor cells. Higher PD-L1 and mRNA expression correlate with more infiltration of TIICs. The prevalence of PD-L1 in SCLC is lower than that published for NSCLC. The predictive role of PD-L1 expression in SCLC treatment remains to be established.

The Future of Immunotherapy in the Treatment of Small Cell Lung Cancer

: Small cell lung cancer (SCLC), which accounts for 10%-15% of lung cancer cases, is an aggressive disease characterized by rapid growth and early widespread metastasis. Although up to 80% of patients respond to first-line chemotherapy, most eventually relapse, and there are no approved agents beyond the second line. Despite the high incidence of mutations in SCLC, to date no targeted therapy has shown a benefit for this patient population, and systemic treatment has not changed significantly during the past 3 decades. Given that extensive-stage SCLC has a 5-year survival rate of only 1%-2%, novel therapies are desperately needed. Recent evidence shows that the immune system is capable of generating antitumor responses against various tumors, including lung cancer, suggesting that immunotherapy may be a viable therapeutic approach to the treatment of patients with SCLC. Of the immunotherapies being investigated for patients with SCLC, antibodies that target the programmed cell death protein-1 (nivolumab and pembrolizumab) and cytotoxic T-lymphocyte antigen-4 (ipilimumab) immune checkpoint pathways are perhaps the most promising. Because these immune checkpoint pathways, which under normal circumstances function to protect healthy tissues from damage during inflammatory responses and maintain self-tolerance, can help tumor cells evade elimination by the immune system, they represent potential therapeutic targets. This review discusses the rationale for immunotherapy and the early clinical results of immunotherapeutic agents being investigated in SCLC.

IMPLICATIONS FOR PRACTICE

Small cell lung cancer (SCLC) is an aggressive lung cancer subtype. Despite sensitivity to first-line chemotherapy, SCLC has high recurrence rates, and responses to second-line treatments are poor. Recent evidence shows that the immune system is capable of generating responses against various tumors, including lung cancer, suggesting that immunotherapy may be a viable approach for patients with SCLC. Of several immunotherapies being investigated, antibodies that target the programmed cell death protein-1 (nivolumab and pembrolizumab) and cytotoxic T-lymphocyte antigen-4 (ipilimumab) immune checkpoint pathways are among the most promising for patients with SCLC and are the focus of this review.

CD47-blocking immunotherapies stimulate macrophage-mediated destruction of small-cell lung cancer

Small-cell lung cancer (SCLC) is a highly aggressive subtype of lung cancer with limited treatment options. CD47 is a cell-surface molecule that promotes immune evasion by engaging signal-regulatory protein alpha (SIRPα), which serves as an inhibitory receptor on macrophages. Here, we found that CD47 is highly expressed on the surface of human SCLC cells; therefore, we investigated CD47-blocking immunotherapies as a potential approach for SCLC treatment. Disruption of the interaction of CD47 with SIRPα using anti-CD47 antibodies induced macrophage-mediated phagocytosis of human SCLC patient cells in culture. In a murine model, administration of CD47-blocking antibodies or targeted inactivation of the Cd47 gene markedly inhibited SCLC tumor growth. Furthermore, using comprehensive antibody arrays, we identified several possible therapeutic targets on the surface of SCLC cells. Antibodies to these targets, including CD56/neural cell adhesion molecule (NCAM), promoted phagocytosis in human SCLC cell lines that was enhanced when combined with CD47-blocking therapies. In light of recent clinical trials for CD47-blocking therapies in cancer treatment, these findings identify disruption of the CD47/SIRPα axis as a potential immunotherapeutic strategy for SCLC. This approach could enable personalized immunotherapeutic regimens in patients with SCLC and other cancers.

Small Cell Lung Cancer Accompanied by Tonsillar Metastasis and Anti-Hu Antibody-Associated Paraneoplastic Neuropathy: A Rare Case Report With Long-Term Survival

Tonsillar metastatic small cell lung cancer (SCLC) is rare, while anti-Hu antibodies are frequently found in SCLC. A 66-year-old man was admitted to our hospital with painful dysesthesia and muscle weakness in the distal extremities for over 1 year, progressive dysphagia for over 1 month, and severe cough and dyspnea for over 1 week. He was diagnosed with SCLC accompanied by tonsillar metastasis and anti-Hu antibody-associated paraneoplastic sensory neuropathy (PSN). The patient tolerated 6 cycles of sequential chemoradiotherapy and gradually recovered. The patient's disease remained in remission 2 years after the diagnosis with a remarkable reduction of tumor burden and a persisting high titer of anti-Hu antibodies. To our knowledge, this is the first case of tonsillar metastatic SCLC accompanied by anti-Hu antibody-associated PSN, whereby the anticancer immune response was presumed to play a vital role in disease control. Unilateral tonsillar metastasis of SCLC accompanied by anti-Hu antibody-associated PSN can occur and in certain circumstances, may have a favorable prognosis.

Anti-Hu Positive Antibodies and Small Cell Carcinoma: A Single Center Review

INTRODUCTION

Small cell lung cancer (SCLC), having properties of neuroendocrine cells, accounts for a small (15 percent) but significant percent of all newly diagnosed lung cancers and is distinguished from non-small cell lung cancer by its rapid doubling time, high growth fraction and the early development of widespread metastases. Therefore, investigation into early diagnosis and treatment is crucial. One sequela of SCLC is a paraneoplastic neurological syndrome usually mediated by a high titer of anti-Hu antibodies, a disease which can present in several variations of paraneoplastic encephalomyelitis. The presence of anti-Hu antibodies in patient serum, even at a low titer, may serve as a diagnostic marker for SCLC and as a model for antibody-based early cancer detection. Furthermore, anti-Hu titers may eventually function as a prognostic indicator and trending titers may be a way to monitor treatment of SCLC and associated paraneoplastic syndromes.

METHODS

In this retrospective chart review from a single hospital, we review all patients who had positive anti-Hu antibodies and discuss level of titers at diagnosis, outcomes, and length of survival.

RESULTS

We describe three cases of positive anti-Hu antibodies and document their diagnosis of SCLC and outcomes.

CONCLUSIONS

Anti-Hu antibodies can be used as a diagnostic tool for aiding in the diagnosis of SCLC. Anti-Hu antibodies may be able to be followed as a marker of progression of the disease.

Small Cell Lung Cancer Expressing Glutamate Decarboxylase with Latent Autoimmune Diabetes in Adults

Small cell lung cancer (SCLC) causes paraneoplastic syndromes, such as diabetes mellitus, by eliciting the expression of various antibodies including anti-glutamate decarboxylase (GAD) antibody. A 62-year-old woman presented to our hospital with a 1-week history of progressive dyspnea and difficulty in walking. Computed tomography showed a tumor obstructing the left bronchus and obstructive lung abscesses with pleural effusions. A biopsy during bronchoscopy revealed SCLC, and the clinical stage was ultimately determined to be IIIB. SCLC was complicated by diabetes mellitus with high titers of serum anti-GAD antibody. An immunohistochemical analysis showed GAD expression in the cancer cells, which is a novel finding.

[Diagnosis of paraneoplastic polyneuropathy in patients with breast cancer and small cell lung cancer]

OBJECTIVES

To study possibilities of immunological and electrophysiological methods for the diagnosis of paraneoplastic polyneuropathy in cancer.

METHODS

We studied 88 cancer patients using electromyography and immunological assay (serum neuronal antibodies).

RESULTS

A symmetrical, distal, sensory-motor, axonal-demyelinating form of polyneuropathy can develop in breast cancer and small cell lung cancer. Onconeural antibodies were detected in the serum of more than half of study participants as well as in some healthy donors. Symptoms of polyneuropathy appeared earlier than the diagnosed tumor.

CONCLUSION

The diagnostic value of the methods used for the early diagnosis of breast cancer and small cell lung cancer is emphasized.

Occam's Razor or Hickam's dictum: a paraneoplastic or coincidental occurrence of lung cancer and Guillain-Barré syndrome

A 67-year-old man was admitted due to weakness, coughing, shortness of breath and fever. He had decreased breath sounds in the left lung and muscle weakness in the lower and upper extremities. Chest imaging showed a mass in the left lung, and a biopsy revealed small cell lung cancer. The nerve conduction velocity was decreased, and anti-GM1 IgG antibodies were positive. The patient showed a temporary neurologic recovery following the administration of cancer chemotherapy, although he eventually died of progression of lung cancer. As a result of the almost simultaneous symptomatic development of lung cancer and Guillain-Barré syndrome, this case may be considered to involve a paraneoplastic neurologic syndrome.

Therapeutic regulation of myeloid-derived suppressor cells and immune response to cancer vaccine in patients with extensive stage small cell lung cancer

Myeloid-derived suppressor cells (MDSC) are one of the major factors limiting the efficacy of immune therapy. In a clinical trial of patients with extensive stage small cell lung cancer (SCLC), we tested the possibility that targeting MDSC can improve the induction of immune responses by a cancer vaccine. Forty-one patients with extensive stage SCLC were randomized into three arms: arm A--control, arm B--vaccination with dendritic cells transduced with wild-type p53, and arm C--vaccination in combination with MDSC targeted therapy with all-trans-retinoic acid (ATRA). Interim results of the ongoing clinical trial are presented. Pre-treatment levels of MDSC populations in patients from all three arms were similar. Vaccine alone did not affect the proportion of MDSC, whereas in patients treated with ATRA, the MDSC decreased more than twofold (p = 0.02). Before the start of treatment, no patients had detectable p53-specific responses in IFN-γ ELISPOT. Sequential measurements did not show positive p53 responses in any of the 14 patients from arm A. After immunization, only 3 out of 15 patients (20 %) from arm B developed a p53-specific response (p = 0.22). In contrast, in arm C, 5 out of 12 patients (41.7 %) had detectable p53 responses (p = 0.012). The proportion of granzyme B-positive CD8(+) T cells was increased only in patients from arm C but not in arm B. Depletion of MDSC substantially improved the immune response to vaccination, suggesting that this approach can be used to enhance the effect of immune interventions in cancer.

Antibodies to active zone protein ERC1 in Lambert-Eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome (LEMS) is characterized by fluctuating muscle weakness and autonomic dysfunction. In 90% of the LEMS patients the disease is associated with auto-antibodies against the voltage-gated calcium channels (VGCC). Several auto-immune responses against other antigenic targets have been described to (co)-occur in LEMS patients. To identify new LEMS associated small cell lung cancer (SCLC) markers immunoprecipitation with a SCLC cell line was performed. We discovered strong immunoreactivity against the 120 kDa large ERC1 protein in one tumor-negative VGCC-positive LEMS patient. A recombinant ELISA assay and a cellular assay expressing GFP-tagged full length ERC1 were used to confirm the presence of auto-antibodies against ERC1 in this patient. Additional testing of 58 LEMS patients including 9 VGCC auto-antibody negative LEMS patients, 48 myasthenia gravis patients, 84 control patients with other diseases and 12 healthy controls revealed no other cases. ERC1 is therefore a new, but rare, antigen in LEMS.

[Autoantibody against the presynaptic P/Q-type voltage-gated calcium channel in Lambert-Eaton myasthenic syndrome]

Antibodies against the muscle acetylcholine receptor (AChR) were recognized as the cause of myasthenia gravis in the 1970s'. Since then, other neurological disorders associated with autoantibodies have been identified, each associated with an antibody against a ligand- or voltage-gated ion channel. Autoantibodies against P/Q-type voltage-gated calcium channels (VGCCs) are detected in patients with Lambert-Eaton myasthenic syndrome (LEMS). These antibodies interfere with the calcium-dependent release of acetylcholine from the presynaptic membrane. LEMS is an autoimmune disorder affecting the neuromuscular junction, and is characterized by proximal muscle weakness, reduction of tendon reflex, and autonomic dysfunction. Electrophysiological examinations show small-amplitude compound muscle action potentials and increments on rapid repetitive nerve stimulation. Fifty to sixty percent of LEMS patients present with tumors, mostly small cell lung carcinoma (SCLC), as a paraneoplastic syndrome. SCLC is a neuroendocrine tumor, which expresses neuronal VGCCs. Some patients present cerebellar ataxia, which is always accompanied by SCLC. These patients tend to show higher titers of VGCC antibodies than that by LEMS patients with no ataxia. The diagnosis can be confirmed by finding reduced compound muscle action potential amplitudes at rest that shows increments greater than 100% with repetitive nerve stimulation and antibody detection by using radioimmunoprecipitation assays. The treatment options are generally categorized as anti-tumor, immunomodulating, immunosuppressing, and symptomatic treatments. In cases with SCLC, effective treatment against the tumor can improve LEMS. Plasmapheresis and intravenous administration of high-dose immunoglobulins have a short effect. Prednisone, alone or in combination with immunosuppressants can achieve long-term control of the disorder.

Utility of the quantitative Ki-67 proliferation index and CD56 together in the cytologic diagnosis of small cell lung carcinoma and other lung neuroendocrine tumors

BACKGROUND

Distinction of small cell lung carcinoma (SCLC) from non-small cell lung carcinoma (NSCLC) is critical because of the differences in prognosis and management. Patients with SCLC usually present with distant metastasis, and clinicians demand an accurate diagnosis in order to initiate appropriate therapy. Limited cytology material, occasionally with crush artifact, is not uncommon. Therefore, robust cytomorphologic features and a small immunostaining panel would be ideal to differentiate SCLC from NSCLC and other neuroendocrine neoplasms. We evaluated CD56 and the quantitative Ki-67 immunohistochemical panel in comparison to synaptophysin and chromogranin, along with cytomorphology to diagnose SCLC.

DESIGN

Eighty-eight cases of SCLC were retrieved from the cytology archives of The Johns Hopkins Hospital. Forty neuroendocrine neoplasms were used as control cases.

RESULTS

SCLCs included 33 lung cases and 55 metastatic lesions. The specimens were obtained by fine needle aspiration, thoracocentesis, bronchoalveolar lavage and abdominal paracentesis. CD56 was expressed in 98.9% of SCLCs, which is significantly more sensitive than synaptophysin and chromogranin. The Ki-67 labeling index was high (>70%) in all cases, which is a reliable marker to differentiate SCLC from other neuroendocrine neoplasms and NSCLC.

CONCLUSION

CD56 and quantitative Ki-67 along with cytomorphology is a robust immunohistochemical panel to differentiate SCLC from other neuroendocrine neoplasms and NSCLC.

Local CD4+, CD8+ and CD56+ reactions to lung cancer in regard to pathohistological type and clinical stage

AIM

To determinate the difference of abundance of CD4+, CD8+ and CD56+ bronchoalveolar fluid's lymphocytes and their subpopulations between non- and small cell lung cancer. Also, the differences of abundance of examined lymphocytes were compared between main clinical stages of lung cancer.

METHODS

Mini-bronchoalveolar lavate was taken from lungs of 55 patients with cancer. After laboratory processing and adding CD3, CD4, CD8, CD27, CD28 and CD56 antibody, the material was analysed by flow cytometer. Results of Mini-BAL for non- and small cell lung cancer were compared, as well as the different clinical stages of the disease.

RESULTS

Immature and regulatory forms of lymphocytes are more activated, while mature and activated forms are less activated in small cell lung cancer compared to non small type. With an increase of the clinical stage of disease, immunological reaction of T lymphocytes is better expressed because of increasing of abundance of immature and regulatory forms of different subpopulations of lymphocytes.

CONCLUSION

All components of local CD4+ and CD8+ T lymphocyte, as well as NK and NKT cells response were more activated in lungs with small cell lung cancer, and these reactions were more expressed with an increase in the clinical stage.

[Long-term survival case of small-cell lung cancer with Lambert-Eaton myasthenic syndrome without anticancer therapy]

A 78-year-old man with complaints of appetite loss and weight loss visited our hospital in November 2006. Positron-emission tomography and computed tomography (PET/CT) showed swollen lymph nodes in the abdominal para-aorta, mediastinum and neck, with intense FDG accumulation. The pathological findings of the cervical lymph nodes revealed small-cell cancer. We diagnosed extensive small-cell lung cancer (SCLC), which occurred primarily in the left upper lobe. As subsequent CT revealed spontaneous shrinkage of the pulmonary nodule and swollen lymph nodes, the clinical course was monitored without anticancer therapy. In February 2007, progressive muscle weakness of the lower extremities developed. In July he was admitted with respiratory failure and required mechanical ventilation. Although we did not administer anticancer therapy due to his poor performance status, he survived for 30 months receiving mechanical ventilation, and the tumors continued to grow moderately. We diagnosed Lambert-Eaton myasthenic syndrome (LEMS) based on the clinical symptoms, the presence of anti-VGCC antibodies and waxing phenomenon on electromyography obtained in April 2009. Chemotherapy with amrubicin shrank the tumors, but his muscle weakness did not improve. Previous reports showed that a prognosis of SCLC with LEMS was better than that without LEMS. In this case, the tumors showed spontaneous regression without any anticancer therapy, and then increased moderately. The immune response was considered to have affected tumor growth.

[Paraneoplastic retinopathy and optic neuropathy]

Paraneoplastic retinopathy including cancer-associated retinopathy (CAR) and melanoma-associated retinopathy (MAR), and paraneoplastic optic neuropathy (PON) are visual disorders associated with systemic cancer. Patients with CAR typically present with progressive loss of vision and photopsia, which are related to dysfunction of both cones and rods in photoreceptors. The triad of photosensitivity, ring scotoma, and a reduced caliber of the retinal arteriole along with undetectable signals in electroretinogram (ERG) are specific manifestations of CAR. CAR is associated most commonly with small-cell lung cancer (SCLC) and occasionally with gynecologic tumors, and it is usually caused by autoantibodies against recovering, which is a calcium-binding photoreceptor protein that participates in the transduction of light. MAR is characterized by shimmering, flickering, or pulsating photopsias, and usually occurs in the patients with a cutaneous melanoma. MAR differs from CAR in terms of visual acuity and color vision and is associated with a characteristic pattern detected in ERG. Autoantibodies against the bipolar cells of the retina have been identified in patients with MAR. Patients with PON frequently present with progressive visual loss and optic disc edema, or with other paneoplastic neurologic syndromes related to SCLC, such as paraneoplastic encephalomyelitis or retinitis, ophthalmoplegia, and subacute cerebellar syndrome. Autoantibodies against collapsin-responsive mediator protein-5 (CRMP-5, also called anti-CV2) are considered to be as the causative factor. Treatments with corticosteroids, plasma exchange, and intravenous immune globulin as well as treatment of the tumor itself, occasionally improves these paraneoplastic visual syndromes. However, the prognosis depends on their underlying malignancy.

p52-Independent nuclear translocation of RelB promotes LPS-induced attachment

The NF-kappaB signaling pathways have a critical role in the development and progression of various cancers. In this study, we demonstrated that the small cell lung cancer cell line (SCLC) H69 expressed a unique NF-kappaB profile as compared to other cancer cell lines. The p105/p50, p100/p52, c-Rel, and RelB protein and mRNA transcripts were absent in H69 cells but these cells expressed RelA/p65. The activation of H69 cells by lipopolysaccharide (LPS) resulted in the induction of RelB and p100 expression. The treatment also induced the nuclear translocation of RelB without the processing of p100 to p52. Furthermore, LPS-induced beta1 integrin expression and cellular attachment through an NF-kappaB-dependent mechanism. Blocking RelB expression prevented the increase in the expression of beta1 integrin and the attachment of H69. Taken together, the results suggest that RelB was responsible for the LPS-mediated attachment and may play an important role in the progression of some cancers.

The yin-yang of tumor-associated neutrophils

Cancer-related inflammation is a key component of the tumor microenvironment. A report in this issue of Cancer Cell now indicates that tumor-associated neutrophils in lung cancer can polarize to either "N1" or "N2" phenotype that inhibits or promotes cancer development, respectively.

CD11c+ and CD123+ dendritic cell subsets in peripheral blood of lung cancer patients

Dendritic cells (DCs) play a central role in antitumor immune responses. Recent studies however have emphasized an immunosuppressive tumor influence on DCs in various types of cancer. We evaluated the percentages of myeloid and plasmacytoid related DCs in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Myeloid CD11c+ DCs (mDC) and plasmacytoid CD123+ DCs (pDC) cells were assessed by Flowcytometry in peripheral blood of twenty untreated lung cancer patients (13 NSCLC and 7 SCLC) and 15 healthy subjects. Lower percentages of pDCs and mDCs were found in patient with NSCLC and SCLC as compared to controls, with significant value only between NSCLC patients and controls (P= 0.001and P=0.000 respectively). The percentages of pDCs and mDCs subsets were significantly lower in patient with SCLC than NSCLC (P=0.013 and P=0.005 for pDCs and mDCs respectively). Our results suggest that NSCLC and SCLC might hamper the maturation of DCs, thus escaping an efficient immune response.

[Case of anti P/Q type VGCC antibody positive small lung cell carcinoma that occured with subacute cerebellar degeneration, Lambert-Eaton myasthenic syndrome, and brainstem encephalitis]

A 62-year-old man was admitted to our hospital because of rapidly progressive dysarthria, truncal ataxia, and gait disturbance. High titers of the ProGRP and anti-P/Q-type VGCC antibody were detected in the serum. High accumulation of [18F] was detected at the hilus of the left lung on [18F]-FDG-PET scan. A high-frequency repetitive stimulation test of the median nerve yielded an incremental response. On the basis of these findings, a diagnosis of paraneoplastic cerebellar degeneration (PCD) and Lambert-Eaton myasthenic syndrome (LEMS) associated with small cell lung carcinoma (SCLC) was diagnosed. After intravenous immunoglobulin therapy (IVIg), methylprednisolone (m-PSL) pulse therapy, and other multidisciplinary concurrent treatments, a partial regression of the SCLC and a significant improvement in neurological symptoms were observed. However, ataxia relapsed and brainstem encephalitis developed 6 months later. A marginal improvement in neurological symptoms was observed with IVIg, m-PSL pulse therapy, and intravenous cyclophosphamide pulse therapy (IVCY). SCLC also recurred later. We hypothesized that VGCC of the brainstem was damaged by anti-P/Q-type VGCC antibody.

The value of gamma camera and computed tomography data set coregistration to assess Lewis Y antigen targeting in small cell lung cancer by (111)Indium-labeled humanized monoclonal antibody 3S193

AIM

To assess the value of data set coregistration of gamma camera and computed tomography (CT) in the assessment of targeting of humanized monoclonal antibody 3S193 labeled with indium-111 ((111)In-hu3S193) to small cell lung cancer (SCLC).

METHODS AND MATERIALS

Ten patients (6 male and 4 female; mean age+/-S.D., 60+/-4 years), from an overall population of 20 patients with SCLCs expressing Lewis Y antigen at immunohistochemical analysis, completed a four weekly injections of (111)In-hu3S193 and underwent gamma camera imaging. All had had, as part of their baseline evaluation, Fluorine18 fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Two readers in consensus retrospectively coregistered the gamma camera images with the CT component of the FDG PET/CT by automatic or manual alignment. The resulting image sets were visually examined and SCLC lesions targeting at coregistered gamma camera and CT was correlated side-by-side with the (18)F-FDG uptake.

RESULTS

A total number of 31 lesions from SCLC with a thoracic (n=13) or extrathoracic location (n=18) were all positive on FDG PET/CT. Coregistration of the gamma camera to the CT demonstrated targeting of antibody to all lesions >2 cm (n=20) and in a few lesions < or =2 cm (n=2), with no visualization of most lesions < or = 2 cm (n=9). No (111)In-hu3S193 uptake in normal tissues was observed.

CONCLUSION

Coregistration of antibody gamma camera imaging to FDG PET/CT is feasible and allows valuable assessment of (111)In-hu3S193 antibody targeting to SCLC lesions >2cm, while lesions < or =2 cm reveal a limited targeting.