Management of Small Cell Lung Cancer: Progress and Updates

Disparities and Underutilization of Surgery for Early Stage Small Cell Lung Cancer

BACKGROUND

The National Comprehensive Cancer Network recommends surgical resection for stage I small cell lung cancer (SCLC). Despite these recommendations and the curative potential of such surgery, many continue to underutilize surgery. Our aim is to investigate factors that contribute to underutilization of surgery for stage I SCLC.

METHODS

The National Cancer Database was queried to identify patients with SCLC stage I-IV from 2004 to 2018. Staging was defined by the American Joint Committee on Cancer guidelines. Cochran-Armitage analysis was performed to analyze trends in surgical treatment for patients diagnosed with stage I SCLC. Multivariable logistic regression assessed relationships between patient factors and surgical treatment.

RESULTS

A total of 296,583 patients were diagnosed with SCLC. Of the stage I patients (n = 13,003), only 29.4.% (n = 3823) underwent surgery. Trend analysis demonstrated increased frequency of surgical treatment for stage I SCLC over years 2004 to 2017, from 14.9% to 39.6% (P < .0001). Factors that were associated with underutilization of surgery for stage I SCLC include African American race, lower median income, nonprivate insurance or Medicare, community facility, and geographic regions other than the Northeast.

CONCLUSIONS

Surgical treatment for stage I SCLC remains underutilized and our study identifies notable associated factors. The recognition of these factors may help patients overcome barriers to receiving recommended treatments, improve guideline adherence, and overall quality of care for stage I SCLC patients.

CT Imaging Patterns in Major Histological Types of Lung Cancer

Lung cancer ranks as the second most prevalent cancer globally and is the primary contributor to neoplastic-related deaths. The approach to its treatment relies on both tumour staging and histological type determination. Data indicate that the prognosis of lung cancer is strongly linked to its clinical stage, underscoring the importance of early diagnosis in enhancing patient outcomes. Consequently, the choice of an appropriate diagnostic method holds significant importance in elevating both the early detection rate and prognosis of lung cancer. This paper aims to assess computer tomography features specific to the most common lung cancer types (adenocarcinoma, squamous cell carcinomas and small cell lung cancer). Data were collected retrospectively from CT scans of 58 patients pathologically diagnosed with lung cancer. The following CT features were evaluated and recorded for each case: location, margins, structure, lymph node involvement, cavitation, vascular bundle-thickening, bronchial obstruction, and pleural involvement. Squamous cell carcinoma (SQCC) and small cell lung cancer (SCLC) showed a higher incidence of central location, while adenocarcinoma (ADC) showed a significant predilection for a peripheral location. Internal cavitation was mostly observed in SQCC, and a solid structure was observed in almost all cases of ADC. These features can provide information about the prognosis of the patient, considering that NSCLCs are more frequent but tend to demonstrate positive results for targetable driver mutations, such as EGFR, thereby increasing the overall survival. In addition, SCLC presents with early distant spreads, which limits the opportunity to investigate the evolution of tumorigenesis and gene alterations at early stages but can have a rapidly positively response to chemotherapy. The location of the lung cancer exhibits distinct forecasts, with several studies suggesting that peripheral lung tumours offer a more favourable prognosis. Cavity formation appears correlate with a poorer prognosis. Histopathological analysis is the gold standard for diagnosing the type of lung cancer; however, using CT scanning for the purpose of a rough, but fast, preliminary diagnosis has the potential to shorten the waiting time for treatment by helping clinicians and patients to know more about the diagnosis and prognosis.

Survival among lung cancer patients: comparison of the U.S. military health system and the surveillance, epidemiology, and end results (SEER) program by health insurance status

PURPOSE

The U.S. military health system (MHS) provides beneficiaries with universal health care while health care access varies in the U.S. general population by insurance status/type. We divided the patients from the U.S. general population by insurance status/type and compared them to the MHS patients in survival.

METHODS

The MHS patients were identified from the Department of Defense's Automated Central Tumor Registry (ACTUR). Patients from the U.S. general population were identified from the Surveillance, Epidemiology, and End Results (SEER) program. Multivariable Cox regression analysis was conducted to compare different insurance status/type in SEER to ACTUR in overall survival.

RESULTS

Compared to ACTUR patients with non-small cell lung cancer (NSCLC), SEER patients showed significant worse survival. The adjusted hazard ratios (HRs) were 1.08 [95% Confidence Interval (CI) = 1.03-1.13], 1.22 (95% CI = 1.16-1.28), 1.40 (95% CI = 1.33-1.47), 1.50 (95% CI = 1.41-1.59), for insured, insured/no specifics, Medicaid, and uninsured patients, respectively. The pattern was consistently observed in subgroup analysis by race, gender, age, or tumor stage. Results were similar for small cell lung cancer (SCLC), although they were only borderline significant in some subgroups.

CONCLUSION

The survival advantage of patients receiving care from a universal health care system over the patients from the general population was not restricted to uninsured or Medicaid as expected, but was present cross all insurance types, including patients with private insurance. Our findings highlight the survival benefits of universal health care system to lung cancer patients.

Excellent survival of pathological N0 small cell lung cancer patients following surgery

BACKGROUND

Current clinical guidelines recommend surgery only for cT1-2N0M0 small cell lung cancer (SCLC) patients. In light of recent studies, the role of surgery in the treatment of SCLC needs to be reconsidered.

METHODS

We reviewed all SCLC patients who underwent surgery from November 2006 to April 2021. Clinicopathological characteristics were retrospectively collected from medical records. Survival analysis was performed by the Kaplan-Meier method. Independent prognostic factors were evaluated by Cox proportional hazard model.

RESULTS

196 SCLC patients undergoing surgical resection were enrolled. The 5-year overall survival for the entire cohort was 49.0% (95% CI: 40.1-58.5%). PN0 patients had significantly superior survival to pN1-2 patients (p < 0.001). The 5-year survival rate of pN0 and pN1-2 patients were 65.5% (95% CI: 54.0-80.8%) and 35.1% (95% CI: 23.3-46.6%), respectively. Multivariate analysis revealed that smoking, older age, and advanced pathological T and N stages were independently associated with poor prognosis. Subgroup analyses demonstrated similar survival among pN0 SCLC patients regardless of pathological T stages (p = 0.416). Furthermore, multivariate analysis showed factors, including age, smoking history, type of surgery, and range of resection, were not independently prognostic factors for the pN0 SCLC patients.

CONCLUSION

Pathological N0 stage SCLC patients have significantly superior survival to pN1-2 patients, regardless of features, including T stage. Thorough preoperative evaluation should be applied to estimate the status of lymph node involvement to achieve better selection of patients who might be candidate for surgery. Studies with larger cohort might help verify the benefit of surgery, especially for T3/4 patients.

Antigene MYCN Silencing by BGA002 Inhibits SCLC Progression Blocking mTOR Pathway and Overcomes Multidrug Resistance

Small-cell lung cancer (SCLC) is the most aggressive lung cancer type, and is associated with smoking, low survival rate due to high vascularization, metastasis and drug resistance. Alterations in MYC family members are biomarkers of poor prognosis for a large number of SCLC. In particular, MYCN alterations define SCLC cases with immunotherapy failure. MYCN has a highly restricted pattern of expression in normal cells and is an ideal target for cancer therapy but is undruggable by traditional approaches. We propose an innovative approach to MYCN inhibition by an MYCN-specific antigene-PNA oligonucleotide (BGA002)-as a new precision medicine for MYCN-related SCLC. We found that BGA002 profoundly and specifically inhibited MYCN expression in SCLC cells, leading to cell-growth inhibition and apoptosis, while also overcoming multidrug resistance. These effects are driven by mTOR pathway block in concomitance with autophagy reactivation, thus avoiding the side effects of targeting mTOR in healthy cells. Moreover, we identified an MYCN-related SCLC gene signature comprehending CNTFR, DLX5 and TNFAIP3, that was reverted by BGA002. Finally, systemic treatment with BGA002 significantly increased survival in MYCN-amplified SCLC mouse models, including in a multidrug-resistant model in which tumor vascularization was also eliminated. These findings warrant the clinical testing of BGA002 in MYCN-related SCLC.

PARP inhibitor plus radiotherapy reshapes an inflamed tumor microenvironment that sensitizes small cell lung cancer to the anti-PD-1 immunotherapy

Small cell lung cancer (SCLC) is a highly malignant tumor with extremely poor prognosis. The treatment strategy is very limited, and patient outcomes remain dismal with the 5-year survival rate being mere 3-6%. Thus, novel therapeutic strategies for SCLC patients are urgently needed. In this study, we found that the triple-therapy of poly (ADP-ribose) polymerase (PARP) inhibitor, radiotherapy (RT) and anti-PD-1 treatment significantly inhibited tumor growth and prolonged survival in the syngeneic SCLC models in immunocompetent C57BL/6 mice. Mechanistically, we demonstrated that the combination of PARP inhibitor niraparib and RT reshaped an inflamed tumor microenvironment, including activation of the cGAS/STING immune response pathway, induction of immunogenic cell death, and upregulation of PD-L1 on tumor cells. Furthermore, this triple-therapy substantially augmented CD8⁺ T cell infiltration and activation, and enhanced anti-tumor effects as revealed by increased median survival time and reduced tumor volume without additional myelosuppression or hepatic injury. Together, our studies demonstrated that PARP inhibitor combined with RT potentiated anti-tumor immunity and enhanced the efficacy of anti-PD-1 immunotherapy in preclinical study, which provided a promising therapeutic strategy for SCLC patients in clinic.

PFKFB3 regulates cancer stemness through the hippo pathway in small cell lung carcinoma

PFKFB3 (6-phosphofructo-2-kinase) is the rate-limiting enzyme of glycolysis and is overexpressed in several human cancers that are associated with poor prognosis. High PFKFB3 expression in cancer stem cells promotes glycolysis and survival in the tumor microenvironment. Inhibition of PFKFB3 by the glycolytic inhibitor PFK158 and by shRNA stable knockdown in small cell lung carcinoma (SCLC) cell lines inhibited glycolysis, proliferation, spheroid formation, and the expression of cancer stem cell markers CD133, Aldh1, CD44, Sox2, and ABCG2. These factors are also associated with chemotherapy resistance. We found that PFK158 treatment and PFKFB3 knockdown enhanced the ABCG2-interacting drugs doxorubicin, etoposide, and 5-fluorouracil in reducing cell viability under conditions of enriched cancer stem cells (CSC). Additionally, PFKFB3 inhibition attenuated the invasion/migration of SCLC cells by downregulating YAP/TAZ signaling while increasing pLATS1 via activation of pMST1 and NF2 and by reducing the mesenchymal protein expression. PFKFB3 knockdown and PFK158 treatment in a H1048 SCLC cancer stem cell-enriched mouse xenograft model showed significant reduction in tumor growth and weight with reduced expression of cancer stem cell markers, ABCG2, and YAP/TAZ. Our findings identify that PFKFB3 is a novel target to regulate cancer stem cells and its associated therapeutic resistance markers YAP/TAZ and ABCG2 in SCLC models.

A New Nomogram and Risk Stratification of Brain Metastasis by Clinical and Inflammatory Parameters in Stage III Small Cell Lung Cancer Without Prophylactic Cranial Irradiation

Background

This study was conducted to determine risk factors for developing brain metastasis (BM) and to predict brain metastasis free survival (BMFS) and overall survival (OS) by combining several clinical parameters and inflammatory indexes.

Materials and Methods

A nomogram and risk stratification were developed based on multivariate analysis results. The prognostic index (PI) predicting the high risk of BM was calculated by multiplying the weighted factor (β coefficient) with each variable.

Results

Thirty-two of one hundred patients (32.0%) developed BM. Multivariate cox regression analysis revealed that concurrent chemoradiotherapy (CCRT; hazard ratio (HR), 3.356; p = 0.020), monocyte–lymphocyte ratio (MLR; HR, 4.511; p = 0.002), neutrophil–lymphocyte ratio (NLR; HR, 4.023; p = 0.033), and prognostic-nutrition index (PNI; HR, 2.902; p = 0.018) were independent prognostic factors of BMFS. The nomogram has good accuracy in predicting BMFS, and the C-index was 0.73. The ROC curve showed that these risk factors have good discriminant ability. Similarly, tumor location (HR, 1.675; p = 0.035) and MLR (HR, 2.076; p = 0.013) were independent prognostic factors of OS. In the subgroup analysis of OS, the good group had a better prognosis than the other groups. Risk stratification by PI: the high-risk group had worse BMFS than the low-risk group, which also has certain practical significance for clinical practice in OS.

Conclusion

We developed a nomogram and corresponding risk stratification in stage III SCLC patients who developed BM. This model and risk stratification can help clinicians improve patient treatment management and better deliver personalized therapy.

The Controversial Role of IL-33 in Lung Cancer

Interleukin-33 (IL-33) belongs to the interleukin-1 (IL-1) family, and its structure is similar to IL-18. When cells are damaged or undergo necrosis, mature form of IL-33 is secreted as a cytokine, which can activate the immune system and provide danger signals. The IL-33/ST2 signaling pathway is composed of IL-33, suppression of tumorigenicity 2 (ST2), and IL-1 receptor accessory protein (IL-1RAcP). IL-33 has been reported to be strongly associated with lung cancer progression, and can exhibit opposite effects on lung cancer under different conditions. In this review, we have summarized the structure and basic functions of IL-33, its possible function in immune regulation, and its role in pulmonary fibrosis as well as in lung cancer. We have highlighted the dual regulation of IL-33 in lung cancer and proposed potential lung cancer treatment regimens, especially new immunotherapies, based on its mechanism of action.

Extracellular vesicles containing PD-L1 contribute to CD8+ T-cell immune suppression and predict poor outcomes in small cell lung cancer

Programmed death ligand-1 (PD-L1) is expressed on the surface of tumor cells and binds to programmed cell death protein-1 (PD1) on the surface of T cells, leading to cancer immune evasion via inhibition of T-cell function. One of the characteristics of small cell lung cancer (SCLC) is its ineffective anti-tumor immune response and highly immunosuppressive status in the tumor microenvironment. SCLC cells have been shown to generate extracellular vesicles (EVs), which may play an important role in tumor progression. We thus hypothesized that SCLC EVs may be important mediators of immunosuppression and that PD-L1 could play a role. Herein, we showed that PD-L1 was expressed on the surface of SCLC-derived EVs, with the potential to directly bind to PD1. Experimentally, we further showed that EVs secreted by SCLC cells can inhibit CD8+ T-cell activation and cytokine production in vitro in response to T-cell receptor stimulation. Importantly, an anti-PD-L1 blocking antibody significantly reversed the EV-mediated inhibition of CD8+ T-cell activation. Furthermore, we performed a retrospective study of patients with SCLC to determine the prognostic value of PD-L1 harvested from plasm circulating EVs. The results showed that EVs containing PD-L1 was an independent prognostic factor and significantly correlated with progression-free survival. Together, these results indicate that EVs containing PD-L1 can be served as a diagnostic biomarker for predicting the effectiveness of therapy, as well as a new strategy to enhance T-cell-mediated immunotherapy against SCLC cancers.

Comparative study of survival among small cell lung cancer patients in the U.S. military health system and those in the surveillance, epidemiology, and end results (SEER) program

PURPOSE

The U.S. military health system provides universal health care access to beneficiaries. However, whether the universal access has translated into improved patient outcome is unknown. We compared survival of small-cell lung cancer patients in the military health system with that in the U.S. general population. Stage and receipt of cancer treatment were also compared to see if they could contribute to survival difference.

METHODS

The data were obtained from The Department of Defense's Automated Central Tumor Registry (ACTUR) and the national Surveillance, Epidemiology, and End Results (SEER) program, respectively. ACTUR (N = 3040) and SEER patients (N = 12,160) were matched on age, sex, race and diagnosis year. Multivariable Cox regression model was used to compare all-cause mortality between ACTUR and SEER. Multivariable logistic regression was performed to compare cancer stage and treatment.

RESULTS

ACTUR patients exhibited significantly better survival than SEER counterparts (HR = 0.77, 95% CI= 0.71-0.83). ACTUR and SEER patients had similar stage, but ACTUR patients were more likely to receive radiation treatment (OR = 1.26, 95% CI = 1.12-1.42). The survival advantage of ACTUR patients remained across all tumor stages and radiation groups.

CONCLUSIONS

Survival of small-cell lung cancer patients with universal health care access had better survival than similar patients in the U.S. general population. Future studies are warranted to identify factors that may contribute to the improved survival.

Prognostic Value and Related Regulatory Networks of MRPL15 in Non-Small-Cell Lung Cancer

Background

Mitochondrial ribosomal protein L15 (MRPL15), a member of mitochondrial ribosomal proteins whose abnormal expression is related to tumorigenesis. However, the prognostic value and regulatory mechanisms of MRPL15 in non-small-cell lung cancer (NSCLC) remain unclear.

Methods

GEPIA, ONCOMINE, Gene Expression Omnibus (GEO), UALCAN, Kaplan–Meier plotter, PrognoScan, LinkedOmics and GeneMANIA database were utilized to explore the expression and prognostic value of MRPL15 in NSCLC. Additionally, immune infiltration patterns were evaluated via ESTIMATE algorithm and TISIDB database. Furthermore, the expression and prognostic value of MRPL15 in lung cancer were validated via immunohistochemistry (IHC) assays.

Results

In NSCLC, multiple cohorts including GEPIA, ONCOMINE and 8 GEO series (GSE8569, GSE101929, GSE33532, GSE27262, GSE21933, GSE19804, GSE19188, GSE18842) described that MRPL15 was up-regulated. Moreover, MRPL15 was notably linked to gender, clinical stage, lymph node status and the TP53 mutation status. And patients with high MRPL15 expression showed poor overall survival (OS), progression-free survival (PFS), disease-free survival (DFS) and relapse-free survival (RFS) in NSCLC. Then, functional network analysis suggested that MRPL15 participated in metabolism-related pathways, DNA replication and cell cycle signaling via pathways involving several kinases, miRNAs and transcription factors. Additionally, it was found that MRPL15 expression was negatively related to immune infiltration, including immune scores, stromal scores and several tumor-infiltrating lymphocytes (TILs). Furthermore, IHC results further confirmed the high MRPL15 expression and its prognostic potential in lung cancer.

Conclusions

These findings demonstrate that high MRPL15 expression indicates poor prognosis in NSCLC and reveal potential regulatory networks as well as the negative relationship with immune infiltration. Thus, MRPL15 may be an attractive predictor and therapeutic strategy for NSCLC.

Effect of chemoradiotherapy on the proportion of circulating lymphocyte subsets in patients with limited-stage small cell lung cancer

OBJECTIVE

Chemoradiotherapy (CRT) is the standard treatment for limited-stage small cell lung cancer (LS-SCLC), which can exert anti-tumor effects by regulating immune cells. Different immune cell subsets are associated with a specific sensitivity to CRT. The purpose of this study was to characterize the proportion or composition of peripheral lymphocytes in patients with LS-SCLC before and after CRT, and evaluate their prognostic value.

METHODS

A total of 98 patients with LS-SCLC were enrolled. The expression of CD3, CD4, CD8, CD45RA, CD45RO, CD38, CD56, and CD19 on the surface of peripheral blood cells was detected by flow cytometry and retrospectively analyzed. The relationship between the proportion of lymphocyte subsets, progression-free survival (PFS), and overall survival (OS) was evaluated using a log-rank test and Cox regression model.

RESULTS

The median PFS was 12.3 months and the median OS was 21.7 months. Compared with the pre-treatment specimens, post-treatment lymphocytes had increased proportions of CD3⁺, CD3⁺CD8⁺, CD8⁺CD38⁺ T cells, and NKT cells, and a decreased proportion of CD3⁺CD4⁺ T cells, CD4⁺CD45RA⁺ T cells, B cells, NK cells, and CD4/CD8 ratio. Univariate and multivariate analyses showed that prophylactic cranial irradiation, high percentages of CD4⁺CD45RA⁺, CD8⁺CD38⁺ T cells after CRT independently predicted superior PFS. Male patients with a high baseline CD4⁺CD45RO⁺ T cell ratio predicted a poor OS.

CONCLUSIONS

CRT induced changes in the proportion of circulating lymphocyte subsets in LS-SCLC, which is helpful for designing a regimen of immune drugs to be combined with CRT. The prognostic value of the proportion of lymphocytes aids in understanding the role of peripheral immune profiles in LS-SCLC.

Prophylactic cranial irradiation in patients with small cell lung cancer in The Netherlands: A population-based study

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Prophylactic cranial irradiation (PCI) use declined in The Netherlands.

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Independent predictors for prescription of PCI were identified.

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An alarming increase of practice variation was observed.

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Alternative MRI surveillance is not strictly adhered to.

Introduction

Controversy has arisen regarding the benefit of prophylactic cranial irradiation (PCI) in patients with small cell lung cancer (SCLC), particularly since the 2017 Takahashi trial publication that supports MRI surveillance in extensive-stage (ES-)SCLC. The primary aim of this study was to assess trends and determinants in PCI use over the years 2010–2018. A secondary aim was to determine contemporary practice considerations among radiation oncologists (ROs).

Methods

A nationwide population-based cohort study was conducted using the Netherlands Cancer Registry data on all newly diagnosed SCLC patients (2010–2018). The change in PCI frequency over the years and determinants for PCI were analyzed using logistic regression models. Second, an online survey was performed among Dutch lung cancer ROs in 2020.

Results

Among 10,264 eligible patients, 4,894 (47%) received PCI. Compared to 2010–2014, PCI use significantly decreased in 2017–2018 in ES-SCLC (OR 0.68, 95%CI 0.60–0.77) and LS-SCLC (OR 0.56, 95%CI 0.47–0.67). Incidence year, age, performance status, and thoracic radiotherapy were independent determinants for PCI. Among 41 survey participants, PCI was recommended always/sometimes/never by 22%/71%/7% in ES-SCLC and 54%/44%/2% in LS-SCLC. For ES-SCLC and LS-SCLC, 63% and 25% of ROs, respectively, confirmed influence of the Takahashi trial on PCI recommendations. Denial of such influence was associated with insufficient institutional MRI capacity.

Conclusions

A significant declining trend of PCI use in both ES-SCLC and LS-SCLC was observed in The Netherlands since 2017. The Takahashi trial seems an explanation for this trend even in LS-SCLC, with differential influence of the trial depending on institutional MRI capacity. An alarming increase in practice variation regarding PCI was found which stresses the importance of ongoing trials.

Predictors of prognosis of synchronous brain metastases in small-cell lung cancer patients

Patients with small cell lung cancer (SCLC) are more likely to have synchronous brain metastasis (SBM) at the time of diagnosis than patients with any other extracranial primary malignancy. We sought to identify which factors predicted an increased risk of SBM in SCLC as well as which factors affected the prognosis of these patients. 38,956 Patients in the Surveillance, Epidemiology, and End Results (SEER) database with microscopically confirmed SCLC from 2010 to 2016 were identified. 6264 (16.1%) Patients with SCLC had SBM at the time of diagnosis. In the multivariable logistic regression, disease specific factors that were predictive of SBM were primary tumor size > 7 cm (adjusted OR = 1.14, 95% CI [1.02, 1.28], p = 0.02), synchronous lung metastases, and synchronous bone metastases. Demographic specific factors predictive of increased SBM risk in this model were younger age, male sex, and race (American Indian/Alaska Native and black patients). Patients insured through Medicaid were less likely to present with SBM. In the multivariate Cox proportional hazards model, lack of insurance was the strongest predictor of mortality (adjusted HR = 1.47, 95% CI [1.26, 1.73], p < 0.001). Other factors associated with an increased risk of mortality include male sex, older age, health insurance coverage through Medicaid, synchronous liver metastasis, synchronous lung metastasis, and primary tumor size > 7 cm. In contrast, Asian patients had a lower risk of mortality. This study identifies risk factors for SBM among patients with SCLC, as well as indicators of prognosis among this patient population.

New insights into small-cell lung cancer development and therapy

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

SOX2 mediates cisplatin resistance in small-cell lung cancer with downregulated expression of hsa-miR-340-5p

Background

This study is aimed to unravel the genetic factors associated with microRNA (miRNA) expression in regulating sex‐determining region Y‐box 2 (SOX2)‐mediated cisplatin resistance in small‐cell lung cancer (SCLC).

Methods

The relevance of SOX2 expression in SCLC was analyzed in a panel of SCLC cells by quantitative real‐time PCR (qPCR) and western blot (WB). We selected DMS114 cell line, in which SOX2 was amplified via lentiviral vector‐mediated transfection of the SOX2 genes and tested for the half‐maximal inhibitory concentration (IC₅₀) by MTS assay. High‐throughput sequencing and screening of differentially expressed miRNAs between SOX2‐overexpressing and normal control cells were performed. Finally, miRanda software was used to verify the miRNAs bound with SOX2 and qPCR was used to identify the expression of miRNAs which were binding with SOX2.

Results

Cisplatin‐resistant SOX2‐overexpressing DMS114 cell lines were successfully developed, showing a statistically significant increase in SOX2 expression by qPCR and WB. Our results showed a typically higher IC₅₀ value in SOX2‐overexpressing cells compared with the negative controls. The high‐throughput sequencing analysis revealed that 68 miRNAs were upregulated and 24 miRNAs were downregulated in the SOX2‐overexpressing cells. The 24 downregulated miRNAs were further verified. Of them, a cancer‐related miRNA, hsa‐miR‐340‐5p, showed a higher binding affinity with SOX2 in network regulation mapping, which was also found to be markedly downregulated under qPCR analysis.

Conclusion

We demonstrated that downregulated expression of hsa‐miR‐340‐5p may affect cisplatin resistance by mediating SOX2 expression in SCLC cells, which may provide a potential target for the therapy of chemoresistant SCLCs.

Characterization of PD-L1 protein expression and CD8+ tumor-infiltrating lymphocyte density, and their associations with clinical outcome in small-cell lung cancer

Background

This study aimed to characterize programmed death ligand-1 (PD-L1) expression and CD8⁺ tumor-infiltrating lymphocytes (TILs) density, and their impact on survival in patients with surgically resected small-cell lung cancer (SCLC).

Methods

Fifty-six patients with surgically resected SCLC were included. PD-L1 protein expression and CD8⁺ TILs were tested by immunohistochemistry. A meta-analysis of 15 articles with 1,505 patients that investigated the prevalence and prognostic significance of PD-L1 expression in SCLC was conducted.

Results

Twenty-two (39.3%) patients had positive PD-L1 protein expression and 42 (75.0%) had high CD8⁺ TILs density. PD-L1 expression level was not associated with CD8⁺ TILs density (P=0.528). No any association between clinicopathological features and PD-L1 expression level or CD8⁺ TILs density was observed. Positive PD-L1 expression [hazard ratio (HR) =0.374, P=0.002] and high CD8⁺ TILs density (HR =0.429, P=0.008) were independently associated with significantly longer overall survival (OS), which remain the statistical significance in multivariate analyses (P=0.007, P=0.002; respectively). Meta-analysis showed that the prevalence of positive PD-L1 expression was 0.35 [95% confidence interval (CI), 0.22-0.48] and positive PD-L1 expression was correlated with markedly longer OS (HR =0.61; 95% CI, 0.31-0.91) in patients with SCLC.

Conclusions

The prevalence of PD-L1 expression in surgically resected SCLC is lower than that published for NSCLC. There was no association between PD-L1 expression or CD8⁺ TILs density and clinicopathological parameters. PD-L1 expression and CD8⁺ TILs density was independently correlated with better outcome in patients with SCLC.

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

Background

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

Methods

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

Results

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

Conclusion

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

Expression and clinical significance of PD-L1, B7-H3, B7-H4 and TILs in human small cell lung Cancer (SCLC)

Background

Small cell lung cancer (SCLC) accounts for 10–15% of all lung malignancies and its prognosis is dismal. Although early studies have shown promising clinical activity of immune checkpoint blockers, the immune composition and expression of potentially actionable immunostimulatory targets in this malignancy are poorly understood.

Methods

Using multiplexed quantitative immunofluorescence (QIF), we measured the levels of 3 different B7 family ligands PD-L1, B7-H3, B7-H4 and major tumor infiltrating lymphocyte (TIL) subsets in 90 SCLC samples represented in tissue microarray format. Associations between the marker levels, clinicopathological variables and survival were studied.

Results

PD-L1 protein was detected in 7.3%, B7-H3 in 64.9% and B7-H4 in 2.6% of SCLC cases. The markers showed limited co-expression and were not associated with the level of TILs, age, gender and stage. Elevated B7-H4 was associated with shorter 5-year overall survival. The levels of CD3+, CD8+ and CD20+ TILs and the ratio of total/effector T-cells were significantly lower in SCLC than in non-small cell lung cancer. High levels of CD3+, but not CD8+ or CD20+ TILs were significantly associated with longer survival.

Conclusions

Taken together, our study indicate variable expression and clinical role of B7-family ligands in SCLC with predominant expression of the candidate target B7-H3 and the presence of a limited cytotoxic anti-tumor immune response. These results support the evaluation of B7-H3 blockers and/or pro-inflammatory therapies in SCLC.

Clinical utility of quantitative dual-energy CT iodine maps and CT morphological features in distinguishing small-cell from non-small-cell lung cancer

AIM

To evaluate the clinical usefulness of quantitative dual-energy (DE) computed tomography (CT) iodine enhancement metrics combined with morphological CT features in distinguishing small-cell lung cancer (SCLC) from non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

One hundred and six untreated lung cancer patients who underwent DECT before biopsy or surgery were prospectively enrolled. Twenty-seven routine CT descriptors, including tumour location, size, shape, margin, enhancement heterogeneity, and internal and surrounding structures, and associated findings were assessed and DECT parameters were measured in all patients. Multiple logistic regression analyses were applied to identify independent predictors of SCLC. The area under the receiver operating characteristic curve was compared between CT features combined with DECT metrics and CT features alone for distinguishing SCLC from NSCLC.

RESULTS

Histology revealed NSCLC in 80 and SCLC in 26 patients. In univariate analysis, 12 morphological CT features and two DECT metrics differed significantly between NSCLC and SCLC. When DECT parameters were combined with CT features for multivariate analysis, the independent predictors of SCLC were large tumour size, central location, confluent mediastinal lymphadenopathy, homogeneous enhancement, absence of coarse spiculation, and lower iodine density and iodine ratio (all p<0.05). The area under the receiver operating characteristic curve was improved from 0.908 to 0.981 after adding DECT metrics compared with CT features alone (p=0.007).

CONCLUSION

The combination of DECT measures and CT morphological features can be used to distinguish SCLC from NSCLC, with higher diagnostic performance compared with CT morphological features alone.

Potential synergistic effect of phosphodiesterase inhibitors with chemotherapy in lung cancer

Purpose: Lung cancer remains the leading cause of cancer-related deaths worldwide and novel therapeutic approaches targeting crucial pathways are urgently needed to improve its treatment. Differentiation-based therapeutics (Methylxanthines) and phosphodiesterase inhibitors (type 4 and 5), have been implicated in cancer treatment. Our objectives were to capture any potential anti-tumor effect of these drug combinations with chemotherapeutic agents in vitro. Methods: Theophylline as Methylxanthines, Roflumilast as phosphodiesterase type 4 (PDE4) inhibitor and Sildenafil as phosphodiesterase type 5 (PDE5) inhibitor are the drugs that we combined with the chemotherapeutic agents (Docetaxel, Cisplatin and Carboplatin) in vitro. Lung cancer cell lines (NCI-H1048-Small cell lung cancer-SCLC, A549- Non-small cell lung cancer-NSCLC) were purchased from ATCC LGC Standards. At indicated time-point, following 24h and 48h incubation, cell viability and apoptosis were measured with Annexin V staining by flow cytometry. Statistical analysis was performed by GraphPad Prism. Results: In SCLC, following 48h incubation, platinum combinations of carboplatin with roflumilast and sildenafil (p<0.001) and carboplatin with theophylline and sildenafil showed increased apoptosis when compared to carboplatin alone. Concerning the combinations of cisplatin, when combined with roflumilast, theophylline and sildenafil appeared with increased apoptosis of that alone (p<0.001, 24h and 48h incubation). In NSCLC, the 24h incubation was not enough to induce satisfactory apoptosis, except for the combination of cisplatin with roflumilast and theophylline (p<0.05) when compared to cisplatin alone. However, following 48h incubation, carboplatin plus sildenafil, carboplatin plus sildenafil, theophylline and roflumilast showed more cytotoxicity when compared to carboplatin alone (p<0.001). Docetaxel combinations showed no statistically significant results. Conclusion: The synergistic effect of PDE inhibitors with platinum-based agents has been demonstrated in lung cancer. Our suggestion is that these combinations could be used as additive and maintenance treatment in combination to antineoplastic agents in lung cancer patients.

A study on different therapies and prognosis-related factors for 101 patients with SCLC and brain metastases

OBJECTIVE

There is a need to explore multi-discipline general treatment modes to improve the survival period of patients with SCLC and brain metastases undergoing standard radiotherapy treatment.

METHODS

A total of 101 patients with SCLC and brain metastases were included into this study. These patients were classified into 4 groups, based on different treatment modes: chemotherapy group, brain radiotherapy group, brain radiotherapy combined with sequential chemotherapy, and chemotherapy combined with sequential brain radiotherapy. Recent and long-term curative effects were compared among the 4 groups.

RESULTS

A RR of 42.57% was determined for all 4 groups, and median PFS and OS was 11.56 and 17.32 months, respectively. After SCLC with brain metastases manifested in the limited stage, the difference in median survival period was not statistically significant among the 4 treatment groups (P = 0.29). At the extensive stage of SCLC, survival period was superior in the brain radiotherapy combined with sequential chemotherapy group, compared with other groups (P<0.05). Furthermore, median survival period in the brain radiotherapy combined with sequential chemotherapy group was 15.5 ± 1.03 months. This was followed by 12.0 ± 3.06 months in the chemotherapy combined with sequential brain radiotherapy group, 8.0 ± 1.49 months in the chemotherapy group, and 8.0 ± 0.43 months in the brain radiotherapy group.

CONCLUSION

Combining chemotherapy with brain radiotherapy is a better treatment mode compared with single therapy for treating SCLC with brain metastases. Furthermore, it is recommended for patients in the extensive stage to initially receive brain radiotherapy.

Paraneoplastic limbic encephalitis in a patient with extensive disease small-cell lung cancer

Paraneoplastic limbic encephalitis (PLE) is a rare disorder infrequently accompanying malignancy, coexisting in ~50% of the cases with small-cell lung cancer (SCLC). The pathomechanism of PLE is considered to be immune-mediated, with production of specific anti-Hu antibodies and activation of T-cells directed against onconeural antigens present on both tumor cells and neurons. We herein report the case of a 50-year-old male patient who, prior to being diagnosed with SCLC, presented with typical symptoms of PLE (seizures, subacute cognitive dysfunction with severe memory impairment, anxiety and hallucinations). The initial brain magnetic resonance imaging examination revealed mild enlargement and hyperintensity of the hippocampal gyri bilaterally, with narrowed temporal horns of the lateral ventricles; the findings of the cerebrospinal fluid examination were compatible with the diagnosis of lymphocytic meningitis. Due to the suspected infectious origin of the disease, treatment with acyclovir and antibiotics was initially applied. However, following subsequent diagnosis of the underlying SCLC and the presence of antineuronal anti-Hu antibodies in the patient's serum, the diagnosis of PLE accompanying extensive-disease (ED) SCLC was confirmed. In addition to the standard cytotoxic therapy, throughout the course of his disease the patient also continued treatment with valproic acid (VPA) as prophylaxis for the initial seizures. VPA is known to be a potent histone deacetylase inhibitor that may reverse epigenetic changes in tumor cells and potentially improve the outcome of cancer patients. The patient succumbed to the disease 25 months after the diagnosis of malignancy; such a long course is observed in only ~5% of patients with ED SCLC. Therefore, it was hypothesized that the accompanying paraneoplasia and treatment with VPA may have improved the outcome in this patient.