New and emerging developments in extensive-stage small cell lung cancer therapeutics

The mechanism and application of traditional Chinese medicine extracts in the treatment of lung cancer and other lung-related diseases

Lung cancer stands as one of the most prevalent malignancies worldwide, bearing the highest morbidity and mortality rates among all malignant tumors. The treatment of lung cancer primarily encompasses surgical procedures, radiotherapy, and chemotherapy, which are fraught with significant side effects, unfavorable prognoses, and a heightened risk of metastasis and relapse. Although targeted therapy and immunotherapy have gradually gained prominence in lung cancer treatment, diversifying the array of available methods, the overall recovery and survival rates for lung cancer patients remain suboptimal. Presently, with a holistic approach and a focus on syndrome differentiation and treatment, Traditional Chinese Medicine (TCM) has emerged as a pivotal player in the prognosis of cancer patients. TCM possesses characteristics such as targeting multiple aspects, addressing a wide range of concerns, and minimizing toxic side effects. Research demonstrates that Traditional Chinese Medicine can significantly contribute to the treatment or serve as an adjunct to chemotherapy for lung cancer and other lung-related diseases. This is achieved through mechanisms like inhibiting tumor cell proliferation, inducing tumor cell apoptosis, suppressing tumor angiogenesis, influencing the cellular microenvironment, regulating immune system function, impacting signal transduction pathways, and reversing multidrug resistance in tumor cells. In this article, we offer an overview of the advancements in research concerning Traditional Chinese Medicine extracts for the treatment or adjunctive chemotherapy of lung cancer and other lung-related conditions. Furthermore, we delve into the challenges that Traditional Chinese Medicine extracts face in lung cancer treatment, laying the foundation for the development of diagnostic, prognostic, and therapeutic targets.

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.

Role of thoracic radiotherapy in extensive stage small cell lung cancer: a systemic review and meta-analysis

Background

The role of thoracic consolidation radiotherapy in patients with extensive stage small cell lung cancer (ES-SCLC) remains controversial. This study aimed to evaluate the efficacy of thoracic radiotherapy (TRT) in these patients.

Methods

A systematic literature search was performed in PubMed, Embase, and the Cochrane library to identify qualified clinical studies. The hazard ratios (HRs) and 95% confidence intervals (CIs) of overall survival (OS), progression-free survival (PFS) and local recurrence-free survival (LRFS) were extracted, and toxicity of the TRT group versus non-TRT group was analyzed.

Results

A total of 12 studies were included in this meta-analysis, including 936 patients in the TRT group and 1,059 patients in the non-TRT group. The combined results showed that TRT significantly improved OS (HR =0.65; 95% CI: 0.55–0.77, P<0.00001), PFS (HR =0.64; 95% CI: 0.56–0.72, P<0.00001) and LRFS (HR =0.38, 95% CI: 0.26–0.53, P<0.00001). Subgroup analysis showed that OS benefits were observed in patients receiving sequential TRT (HR =0.67; 95% CI: 0.54–0.84, P=0.0006). The addition of TRT significantly improved OS in patients over 65 years of age (HR =0.55; 95% CI: 0.40–0.74, P=0.0001). For patients with only one organ metastasis, there was no significant difference in OS between the two groups (HR =0.61; 95% CI: 0.36–1.01, P=0.06). There was no statistical difference in hematologic toxicity (leukopenia, thrombocytopenia, anemia) and non-hematologic toxicity (nausea or vomiting) between the two groups. The incidence of grade ≥3 esophageal toxicity was 4.6% in the TRT group and 0% in the non-TRT group (P=0.0001). Grade ≥3 bronchopulmonary toxicity was 2.9% in the TRT group and 0.8% in the non-TRT group (P=0.02).

Conclusions

TRT improves OS, PFS and LRFS in patients with ES-SCLC, with a low increase in esophageal and bronchopulmonary toxicity. More randomized controlled trials (RCTs) are expected to confirm our conclusions.

PROSPERO registration number

CRD42020190575.

Bioactive Compounds from Marine Heterobranchs

The natural products of heterobranch molluscs display a huge variability both in structure and in their bioactivity. Despite the considerable lack of information, it can be observed from the recent literature that this group of animals possesses an astonishing arsenal of molecules from different origins that provide the molluscs with potent chemicals that are ecologically and pharmacologically relevant. In this review, we analyze the bioactivity of more than 450 compounds from ca. 400 species of heterobranch molluscs that are useful for the snails to protect themselves in different ways and/or that may be useful to us because of their pharmacological activities. Their ecological activities include predator avoidance, toxicity, antimicrobials, antifouling, trail-following and alarm pheromones, sunscreens and UV protection, tissue regeneration, and others. The most studied ecological activity is predation avoidance, followed by toxicity. Their pharmacological activities consist of cytotoxicity and antitumoral activity; antibiotic, antiparasitic, antiviral, and anti-inflammatory activity; and activity against neurodegenerative diseases and others. The most studied pharmacological activities are cytotoxicity and anticancer activities, followed by antibiotic activity. Overall, it can be observed that heterobranch molluscs are extremely interesting in regard to the study of marine natural products in terms of both chemical ecology and biotechnology studies, providing many leads for further detailed research in these fields in the near future.

Liquid Biopsy in Small Cell Lung Cancer-A Route to Improved Clinical Care?

Small cell lung cancer (SCLC) has a particularly poor prognosis despite the high initial response to first-line systemic therapy, and there is a well-recognised lack of meaningful treatments beyond the second line. A number of reasons have been put forward to explain this, including a lack of common, easily-druggable genetic mutations in SCLC and rarity of high-quality tissue samples due to late presentation. Liquid biopsies, including circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA) are increasingly used as surrogates for tumour tissue and have the advantage of being easily obtained serially to inform on the biology of disease progression and acquired chemoresistance, and may provide a pathway to improve care in this notoriously refractory disease. Here we discuss the current evidence behind these liquid biopsy methods in SCLC, and how they could be employed in future clinical care.

Association of clinico-genomic characteristics with tumor mutational burden in small cell lung cancer patients

Aim: We evaluated the relationship between clinical and genomic characteristics and tumor mutational burden (TMB) in small cell lung cancer. Materials & methods: In a retrospective analysis of small cell lung cancer patients aged ≥18, we assessed treatment patterns and survival in relation to TMB; the association of clinical and genomic characteristics with TMB was determined by multivariate regression. High TMB (TMB-H) was defined as ≥10 mutations/megabase. Results: Among 186 patients, treatment patterns and overall survival were similar for TMB-H and non-TMB-H patients. TMB was determined for 179 patients, 41.9% of whom were TMB-H. Short variants of LRP1B, FAT3, MLL3, MED12 and NOTCH3 were significantly associated with TMB-H (p ≤ 0.01). Conclusion: Neither treatment patterns nor survival differed by TMB status.

Chinese Medicine Treatment Prolonged Survival in Small Cell Lung Cancer Patients: A Clinical Observation

OBJECTIVE

To evaluate the effect of Chinese medicine (CM) treatment on survival time and quality of life (QOL) in patients with small cell lung cancer (SCLC).

METHODS

This was an exploratory and prospective clinical observation. Patients diagnosed with SCLC receiving CM treatment were included and followed up every 3 months. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS) and QOL.

RESULTS

A total of 136 patients including 65 limited-stage SCLC (LS-SCLC) patients and 71 extensive-stage SCLC (ES-SCLC) patients were analyzed. The median OS of ES-SCLC patients was 17.27 months, and the median OS of LS-SCLC was 40.07 months. The survival time was 16.27 months for SCLC patients with brain metastasis, 9.83 months for liver metastasis, 13.43 months for bone metastasis, and 18.13 months for lung metastasis. Advanced age, pleural fluid, liver and brain metastasis were risk factors, while longer CM treatment duration was a protective factor. QOL assessment indicated that after 6 months of CM treatment, scores increased in function domains and decreased in symptom domains.

CONCLUSION

CM treatment might help prolong OS of SCLC patients. Moreover, CM treatment brought the trend of symptom amelioration and QOL improvement. These results provide preliminary evidence for applying CM in SCLC multi-disciplinary treatment.

Survival, Chemotherapy Treatments, and Health Care Utilization Among Patients with Advanced Small Cell Lung Cancer: An Observational Study

INTRODUCTION

Most cases of small cell lung cancer (SCLC) are diagnosed at an advanced stage. The objective of this study was to investigate patient characteristics, survival, chemotherapy treatments, and health care use after a diagnosis of advanced SCLC in subjects enrolled in a health system network.

METHODS

This was a retrospective cohort study of patients aged ≥ 18 years who either were diagnosed with stage III/IV SCLC or who progressed to advanced SCLC during the study period (2005-2015). Patients identified from the Indiana State Cancer Registry and the Indiana Network for Patient Care were followed from their advanced diagnosis index date until the earliest date of the last visit, death, or the end of the study period. Patient characteristics, survival, chemotherapy regimens, associated health care visits, and durations of treatment were reported. Time-to-event analyses were performed using the Kaplan-Meier method.

RESULTS

A total of 498 patients with advanced SCLC were identified, of whom 429 were newly diagnosed with advanced disease and 69 progressed to advanced disease during the study period. Median survival from the index diagnosis date was 13.2 months. First-line (1L) chemotherapy was received by 464 (93.2%) patients, most commonly carboplatin/etoposide, received by 213 (45.9%) patients, followed by cisplatin/etoposide (20.7%). Ninety-five (20.5%) patients progressed to second-line (2L) chemotherapy, where topotecan monotherapy (20.0%) was the most common regimen, followed by carboplatin/etoposide (14.7%). Median survival was 10.1 months from 1L initiation and 7.7 months from 2L initiation.

CONCLUSION

Patients in a regional health system network diagnosed with advanced SCLC were treated with chemotherapy regimens similar to those in earlier reports based on SEER-Medicare data. Survival of patients with advanced SCLC was poor, illustrating the lack of progress over several decades in the treatment of this lethal disease and highlighting the need for improved treatments.

Analysis of topoisomerase I expression and identification of predictive markers for efficacy of topotecan chemotherapy in small cell lung cancer

Background

We evaluated topoisomerase I (TOPO1) expression in patients with small cell lung cancer (SCLC) and identified predictive factors for the efficacy of second‐line topotecan chemotherapy.

Methods

We retrospectively evaluated the records of SCLC patients treated in our department from January 2007 to December 2016 who received second‐line topotecan chemotherapy. Patients with archived tumor samples were enrolled. TOPO1 expression levels were evaluated by immunohistochemistry, and the relationships between TOPO1 expression, clinical factors, chemotherapy efficacy, and survival were analyzed.

Results

Of the 78 patients enrolled, 67 showed TOPO1 expression (85.9%). Patients were divided into strong (n = 43) or weak (n = 35) expression groups based on staining intensity. Disease control rates for topotecan were 39.5% and 14.3% in the strong and weak groups, respectively (P = 0.014). Second‐line median progression‐free survival was 2.2 and 2.0 months (P = 0.057), and median overall survival was 8.1 and 6.0 months (P = 0.199) in the strong and weak positive groups, respectively. Patients were also divided into sensitive (n = 47) and refractory (n = 31) disease groups according to the duration from the onset of first‐line therapy to relapse. Median second‐line progression‐free survival was 2.2 and 1.8 months in the sensitive and refractory relapse groups, respectively (P = 0.005).

Conclusions

TOPO1 expression was prevalent in SCLC patients. Strong expression was associated with an elevated disease control rate after second‐line topotecan chemotherapy. Patients with sensitive disease that relapsed after first‐line chemotherapy had better survival than refractory patients who received second‐line topotecan chemotherapy.

A Curated Target Gene Pool Assisting Early Disease Prediction and Patient-Specific Treatment for Small Cell Lung Cancer

Hundreds of genes have been linked to small cell lung cancer (SCLC), presenting multiple levels of connections with the disease. The question is whether these genes are sufficient as genetic biomarkers for the early diagnosis and personalized treatment of SCLC. An SCLC genetic database was developed through comprehensive ResNet relationship data analysis, where 557 SCLC target genes were curated. Multiple levels of associations between these genes and SCLC were studied. Then, a sparse representation-based variable selection (SRVS) was employed for gene selection for four SCLC gene expression data sets, followed by a case-control classification. Results were compared with that of analysis of variance (ANOVA)-based gene selection approaches. Using SRVS, a gene vector was selected for each data set, leading to significant higher classification accuracy compared with randomly selected genes (100%, 77.12%, 100%, and 100%; permutation p values: 0.017, 0.00060, 0.012, and 0.0066). The SRVS method outperformed ANOVA in terms of classification ratio. The genes were selected within the 557 SCLC gene pool, showing data set and method specificity. Our results suggested that for a given SCLC patient group, there might exist a gene vector in the 557 curated SCLC genes that possess significant prediction power. SRVS is effective for identifying the optimum gene subset targeting personalized treatment.

Eribulin inhibits the growth of small cell lung cancer cell lines alone and with radiotherapy

Objectives

Small cell lung cancer (SCLC) patients of all stages are treated with etoposide and cisplatin or carboplatin with or without surgery or chest radiotherapy. Initial response rates are ≥70% however the majority of patients relapse and are resistant to additional therapies due to pan-resistance to these salvage therapies. Therefore, new treatments are urgently needed. The non-taxane microtubule inhibitor eribulin has produced responses in heavily pretreated breast cancer patients. We evaluated the efficacy of eribulin alone and in combination with radiation in a panel of SCLC cell lines established from patients prior to or after receiving chemotherapy and or radiation.

Material and methods

Growth inhibition by eribulin alone, radiation alone and the combination was assessed by MTS assay and clonogenic survival. Eribulin induced cell cycle arrest was evaluated by FACS. Apoptosis was evaluated by using the Caspase-GLO 3/7 luminescent plate assay and by the Vybrant apoptosis assay with analysis by FACS.

Results

Eribulin mesylate inhibited the growth of all 17-SCLC lines at concentrations of ≤10 nM which is a clinically achievable dose. Growth inhibition was not significantly different between cell lines established prior to or after chemotherapy (p = .5). Concurrent eribulin + radiation induced a greater G2-M arrest, an increase in apoptotic cells and increased growth inhibition over radiation alone.

Conclusions

Eribulin was highly active alone and in combination with radiation in treatment naïve SCLC lines and lines established from previously treated patients. In vivo pre-clinical studies of eribulin alone and in combination with radiation should be considered in SCLC cell lines.

MicroRNA-125a-5p plays a role as a tumor suppressor in lung carcinoma cells by directly targeting STAT3

Increasing evidence supports that the dysregulation of microRNA expression plays an important role in the process of tumor occurrence and development. Studies have found that mir-125a-5p expression was downregulated in a variety of tumors, but the effects and mechanism of mir-125a-5p in lung cancer are still unclear. The aim of this study is to detect the expression of mir-125a-5p in lung cancer tissues and lung cancer cell lines and to explore the effects of mir-125a-5p on the biological characteristics of lung cancer cells; thus, this study aims to provide new methods and new strategies for the treatment of lung cancer. The result from quantitative reverse transcription polymerase chain reaction showed that the expression of miR-125a-5p was significantly lower in lung cancer tissues and lung cancer cell lines (95-D, A549, HCC827, and NCI-H1299) than that in normal tissue adjacent to lung cancer or normal human bronchial epithelial cells. In order to explore the function and mechanism of mir-125a-5p in lung cancer cells, miR-125a-5p mimic or mir-125a-5p inhibitor was transfected into A549 cells. Mir-125a-5p displayed an obvious upregulation in A549 cells transfected with miR-125a-5p and an obvious downregulation in A549 cells transfected with mir-125a-5p inhibitor compared to that in A549 cells transfected with control miRNA. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, BrdU staining, flow cytometry, and Transwell assay showed that the upregulation of miR-125a-5p could significantly decrease the cell viability, proliferation, and invasion of lung cancer cells and increase apoptosis of lung cancer cells. The downregulation of miR-125a-5p provided very contrasting results. Computational algorithms predicted that the STAT3 is a target of miR-125a-5p. Here, we validated that miR-125a-5p could directly bind to the 3'-untranslated region of STAT3, and miR-125a-5p overexpression could significantly inhibit the protein expression of STAT3. These results suggested that mir-125a-5p can regulate the expression of STAT3 in lung cancer cells. To further verify whether mir-125a-5p can play a biological role through regulating STAT3, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, flow cytometry, and Transwell analysis demonstrated that overexpression of STAT3 can reverse the cells' biological effects induced by mir-125a-5p overexpression. Mir-125a-5p downregulated in lung cancer tissue and cell lines can negatively regulate STAT3 protein expression. Taken together, mir-125a-5p inhibited the proliferation and invasion of lung cancer cells and facilitated lung cancer cell apoptosis through suppressing STAT3. Enhancing the expression of miR-125a-5p is expected to benefit the therapy for the patients with lung cancer.

Marine Mollusk-Derived Agents with Antiproliferative Activity as Promising Anticancer Agents to Overcome Chemotherapy Resistance

The chemical investigation of marine mollusks has led to the isolation of a wide variety of bioactive metabolites, which evolved in marine organisms as favorable adaptations to survive in different environments. Most of them are derived from food sources, but they can be also biosynthesized de novo by the mollusks themselves, or produced by symbionts. Consequently, the isolated compounds cannot be strictly considered as "chemotaxonomic markers" for the different molluscan species. However, the chemical investigation of this phylum has provided many compounds of interest as potential anticancer drugs that assume particular importance in the light of the growing literature on cancer biology and chemotherapy. The current review highlights the diversity of chemical structures, mechanisms of action, and, most importantly, the potential of mollusk-derived metabolites as anticancer agents, including those biosynthesized by mollusks and those of dietary origin. After the discussion of dolastatins and kahalalides, compounds previously studied in clinical trials, the review covers potentially promising anticancer agents, which are grouped based on their structural type and include terpenes, steroids, peptides, polyketides and nitrogen-containing compounds. The "promise" of a mollusk-derived natural product as an anticancer agent is evaluated on the basis of its ability to target biological characteristics of cancer cells responsible for poor treatment outcomes. These characteristics include high antiproliferative potency against cancer cells in vitro, preferential inhibition of the proliferation of cancer cells over normal ones, mechanism of action via nonapoptotic signaling pathways, circumvention of multidrug resistance phenotype, and high activity in vivo, among others. The review also includes sections on the targeted delivery of mollusk-derived anticancer agents and solutions to their procurement in quantity.

Timing of thoracic radiotherapy in the treatment of extensive-stage small-cell lung cancer: important or not?

Background

This study evaluated the prognosis of patients with extensive-stage small-cell lung cancer (ES-SCLC) that may be associated with timing of thoracic radiotherapy (TRT).

Methods

ES-SCLC patients (n = 232) without progression were retrospectively analyzed after first-line induction chemotherapy. Patients in the TRT group were stratified as early-TRT (ERT; ≤3 cycles of induction chemotherapy received prior to TRT, n = 65) or late-TRT (LRT; >3 cycles, n = 122). To avoid selection bias, we conducted Propensity Score Matching (PSM) for patients. Overall survival (OS), progression-free survival (PFS), and locoregional recurrence-free survival (LRRFS) were assessed and compared.

Results

Overall, the median survival time, PFS, and LRRFS were 13.2, 8.7, and 14.6 months, respectively. After matching by PSM, there were 45 patients total in the TRT/non-TRT groups, and 56 patients total in the ERT/LRT groups. OS, PFS, and LRRFS were significantly longer in the TRT group than the non-TRT group (P < 0.001, all). However, between the ERT and LRT groups these survival parameters were similar (P > 0.05, all).

Conclusion

For ES-SCLC patients without progression, the addition of TRT after first-line chemotherapy benefited survival greatly. Early TRT showed no significant benefit over late TRT.

Advances in Circulating Tumor DNA Analysis

The analysis of cell-free circulating tumor DNA (ctDNA) is a very promising tool and might revolutionize cancer care with respect to early detection, identification of minimal residual disease, assessment of treatment response, and monitoring tumor evolution. ctDNA analysis, often referred to as "liquid biopsy" offers what tissue biopsies cannot-a continuous monitoring of tumor-specific changes during the entire course of the disease. Owing to technological improvements, efforts for the establishment of preanalytical and analytical benchmark, and the inclusion of ctDNA analyses in clinical trial, an actual clinical implementation has come within easy reach. In this chapter, recent advances of the analysis of ctDNA are summarized starting from the discovery of cell-free DNA, to methodological approaches and the clinical applicability.

MicroRNA-451 sensitizes lung cancer cells to cisplatin through regulation of Mcl-1

As one of the most widely used chemotherapy drugs for lung cancer, chemoresistance of cisplatin (DPP) is one of the major hindrances in treatment of this malignancy. The microRNAs (miRNAs) have been identified to mediate chemotherapy drug resistance. MiR-451 as a tumor suppressor has been evaluated its potential effect on the sensitivity of cancer cells to DDP. However, the role of miR-451 in regulatory mechanism of chemosensitivity in lung cancer cells is still largely unknown. In this study, we first constructed a cisplatin-resistant A549 cell line (A549/DPP) accompanied with a decreased expression of miR-451 and an increased expression of Mcl-1in the drug resistant cells compared with the parental cells. Exogenous expression of miR-451 level in A549/DPP was found to sensitize their reaction to the treatment of cisplatin, which coincides with reduced expression of Mcl-1. Interestingly, Mcl-1 knockdown in A549/DPP cells increased the chemosensitivity to DPP, suggesting the dependence of Mcl-1 regulation in miR-451 activity. Moreover, miR-451 can restore cisplatin treatment response in cisplatin-resistant xenografts in vivo, while Mcl-1 protein levels were decreased. Thus, these findings provided that in lung cancer cells, tumor suppressor miR-451 enhanced DPP sensitivity via regulation of Mcl-1 expression, which could be served as a novel therapeutic target for the treatment of chemotherapy resistant in lung cancer.