Small Cell Lung Carcinoma: Current Diagnosis, Biomarkers, and Treatment Options with Future Perspectives

Prevalence, treatment patterns, and survival of patients with brain metastases from small cell lung cancer: A retrospective study using the TriNetX Oncology Database

Background

Brain metastases (BM) portend increased morbidity and mortality in patients with small cell lung cancer (SCLC). We aimed to characterize the prevalence, timing, treatment patterns, and survival outcomes of BM associated with SCLC over the past decade.

Methods

Data from 4014 patients with histologically confirmed SCLC were extracted from the TriNetX Oncology database. Clinical and demographic variables were compared between patients with and without BM using Chi-squared and t-tests. Kaplan-Meier and Cox regression analyses were used to evaluate overall survival (OS), after propensity score matching cohorts for age at diagnosis, sex, cancer stage at diagnosis, extracranial metastases, and cancer-directed therapy.

Results

Among 4014 patients with SCLC, 35.0% had BM (9.9% synchronous, 21.2% metachronous, 3.9% precocious). Patients who developed BM were younger (P < .001) at SCLC diagnosis, more likely Black/African American (P = .0068), and presented with more advanced cancer stages (P < .001) than patients who did not develop BM. The median BM-free survival from the time of SCLC diagnosis was 27.9 months. Patients with BM received higher rates of cancer-directed therapies than those without BM. Synchronous BM was associated with lower OS than metachronous BM after the diagnosis of SCLC (HR[95% CI] = 1.56[1.32-1.83]), but there was no difference in OS after the BM diagnosis. OS did not differ between patients with BM and patients with extracranial metastases only, following the diagnosis of metastatic disease.

Conclusions

Our findings support that independently of the chronicity of BM diagnosis, patients with SCLC have poor survival once the diagnosis of BM is conferred.

Increasing cisplatin exposure promotes small-cell lung cancer transformation after a shift from glucose metabolism to fatty acid metabolism

OBJECTIVES

Lung cancer is a leading cause of global cancer mortality. Clinical observations reveal that histological transformation from non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is accompanied by mutations in TP53 and RB1. By applying gradually increasing cisplatin concentrations to mimic the escalating drug pressure within the tumor microenvironment, this study investigated the link between phenotypic transformation to SCLC in cisplatin-resistant human lung adenocarcinoma cells and alterations in cellular energy production pathways.

MATERIALS AND METHODS

We established two cisplatin-resistant NSCLC cell lines with varying resistance levels. RNAseq analyses identified TP53 and RB1 gene mutations. Comprehensive functional assays were performed to characterize A549/DDP1 μg/mL and A549/DDP3 μg/mL cells, focusing on proliferation and migratory capabilities. Cellular bioenergetics were assessed through glycolysis and oxidative phosphorylation analyses. Western blotting was employed to examine epithelial-mesenchymal transition (EMT), glucose metabolism, and lipid metabolism markers. Cell cycle distribution was analyzed by flow cytometry. Additionally, a xenograft mouse model was developed for in vivo validation.

RESULTS

TP53 and RB1 mutations were associated with cisplatin concentration-dependent phenotypic transformation, with A549/DDP cells acquiring a more aggressive SCLC-like phenotype (In the article we call the A549/DDPSCLC cells). Analysis of cell bioenergetics profiling and Western blot analyses revealed enhanced glucose metabolism in A549/DDP1 μg/mL cells, while A549/DDPSCLC cells exhibited predominant lipid metabolism. Compound3K and Etomoxir specifically inhibit the activity of PKM2 and CPT1A, respectively, with Etomoxir demonstrating substantially inhibited A549/DDPSCLC cells growth and more cell cycle arrest in the G0/G1 phase. Combinatorial of Compound3K and Etomoxir effectively induced cell death in A549/DDPSCLC phenotype cells in vitro. Etomoxir alone or combined with Compound3K significantly inhibited tumor growth in vivo, with enhanced efficacy in the combination group.

CONCLUSIONS

This study provides the first evidence of cisplatin concentration-dependent metabolic reprogramming during NSCLC-to-SCLC transformation. We identified a phenotypic transition from NSCLC to SCLC accompanied by a metabolic shift from glucose to fatty acid metabolism, offering new insights into therapeutic strategies for treatmentresistant lung cancer.

Construction of an imaging diagnostic model based on computed tomograph signs for peripheral small cell lung cancer

Objective

To construct an imaging diagnostic model for peripheral small cell lung cancer (pSCLC) with a diameter of ≤ 3cm to improve differential diagnostic efficiency.

Methods

As a retrospective study, patients with pathologically confirmed lung cancer with tumor diameter ≤ 3 cm who were treated at the Guang'anmen Hospital South Campus, China Academy of Chinese Medical Sciences from May 2018 to May 2024 were retrospectively selected. All patients underwent computer tomography (CT) imaging. Patients with pSCLC (n=38) were identified first and then matched them to patients with peripheral non-small cell lung cancer (pNSCLC) (n=114) during the same period in a 1:3 ratio. Predictive factors of pSCLC were identified by logistic regression analysis, and a predictive model was constructed.

Results

Logistic regression analysis confirmed that male gender, smooth edges, less spiculation sign, less air bronchogram sign, and lymph node enlargement are independent predictive factors for pSCLC. A predictive model that combines the above five predictive factors has high diagnostic efficacy for pSCLC. The receiver operating characteristic (ROC) analysis results showed the area under the curve AUC of 0.842 (95% confidence interval (CI): 0.759~0.925), with a sensitivity of 84.2% and specificity of 78.1%.

Conclusions

Male sex, smooth edges, less spiculation and air bronchogram signs, and lymph node enlargement identified by the CT scan were shown as independent predictive factors for pSCLC. Combining the above features has a high diagnostic efficacy for pSCLC.

Identification of a Potent and Selective CDK9 Degrader as a Targeted Therapeutic Option for the Treatment of Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) represents a significant public health challenge due to its increasing incidence and high mortality. Most SCLC patients are diagnosed at advanced stages, and there are limited effective targeted therapies available. In this study, a potent and selective CDK9 degrader, C3, was developed through PROTAC modification of the CDK9 inhibitor, AT-7519. C3 effectively induced apoptosis in various SCLC cell lines at low nanomolar concentrations and demonstrated favorable in vivo tolerance and adequate oral bioavailability. Notably, PROTAC C3 significantly reduced the proliferation of primary tumor samples from patients in mini-PDX models. Our findings indicate that the targeted degradation of CDK9 could become a viable strategy for treating SCLC, highlighting its potential therapeutic value. Additionally, this research offers a general structural optimization and evaluation strategy to improve the degradative selectivity, metabolic stability, and oral availability of PROTAC molecules.

Recent Advances in the Clinical Translation of Small-Cell Lung Cancer Therapeutics

Small-cell lung cancer (SCLC) is a recalcitrant form of cancer, representing 15% of lung cancer cases globally. SCLC is classified within the range of neuroendocrine pulmonary neoplasms, exhibiting shared morphologic, ultrastructural, immunohistochemical, and molecular genomic features. It is marked by rapid proliferation, a propensity for early metastasis, and an overall poor prognosis. The current conventional therapies involve platinum-etoposide-based chemotherapy in combination with immunotherapy. Nonetheless, the rapid emergence of therapeutic resistance continues to pose substantial difficulties. The genomic profiling of SCLC uncovers significant chromosomal rearrangements along with a considerable mutation burden, typically involving the functional inactivation of the tumor suppressor genes TP53 and RB1. Identifying biomarkers and evaluating new treatments is crucial for enhancing outcomes in patients with SCLC. Targeted therapies such as topoisomerase inhibitors, DLL3 inhibitors, HDAC inhibitors, PARP inhibitors, Chk1 inhibitors, etc., have introduced new therapeutic options for future applications. In this current review, we will attempt to outline the key molecular pathways that play a role in the development and progression of SCLC, together with a comprehensive overview of the most recent advancements in the development of novel targeted treatment strategies, as well as some ongoing clinical trials against SCLC, with the goal of improving patient outcomes.

Combined treatment of small cell lung cancer using radiotherapy and immunotherapy: Challenges and updates

Currently, chemotherapy remains the standard first- and second-line treatment for small cell lung cancer (SCLC). Research concerning immunotherapy has brought about a remarkable development in the treatment pattern of SCLC. Atirizumab, duvalizumab, atezolizumab, and serplulimab can significantly improve the clinical outcomes of SCLC. Given the rapidly evolving concept that combining immunotherapy with radiotherapy can increase therapeutic effectiveness, clinicians are devoted to further improving local tumor control by integrating immunotherapy with radiotherapy. This paper reviews the research progress in this field to date and explores ways to further enhance the efficacy of this combination therapy. We first discussed that immunotherapy combined with radiotherapy can improve the abscopal effect, progression-free survival, and overall survival rates of SCLC patients. Then, the biomarkers related to the radiation immune microenvironment, such as programmed death ligand-1 (PD-L1), tumor mutational burden (TMB), and the immune function of patients were discussed. Next, we explored the occurrence and underlying mechanisms of immune resistance during radiotherapy implementation. Finally, we clarified that the emerging trend of low-dose radiotherapy help overcome the inhibitory signals that limit T-cell infiltration in the tumor matrix. In summary, considering the rapid development of this field, these combined therapy strategies may have unlimited potential to further improve the efficacy of radiotherapy combined with immunotherapy for patients.

Histological Subtype Classification of Non-Small Cell Lung Cancer with Radiomics and 3D Convolutional Neural Networks

Non-small cell lung carcinoma (NSCLC) is the most common type of pulmonary cancer, one of the deadliest malignant tumors worldwide. Given the increased emphasis on the precise management of lung cancer, identifying various subtypes of NSCLC has become pivotal for enhancing diagnostic standards and patient prognosis. In response to the challenges presented by traditional clinical diagnostic methods for NSCLC pathology subtypes, which are invasive, rely on physician experience, and consume medical resources, we explore the potential of radiomics and deep learning to automatically and non-invasively identify NSCLC subtypes from computed tomography (CT) images. An integrated model is proposed that investigates both radiomic features and deep learning features and makes comprehensive decisions based on the combination of these two features. To extract deep features, a three-dimensional convolutional neural network (3D CNN) is proposed to fully utilize the 3D nature of CT images while radiomic features are extracted by radiomics. These two types of features are combined and classified with multi-head attention (MHA) in our proposed model. To our knowledge, this is the first work that integrates different learning methods and features from varied sources in histological subtype classification of lung cancer. Experiments are organized on a mixed dataset comprising NSCLC Radiomics and Radiogenomics. The results show that our proposed model achieves 0.88 in accuracy and 0.89 in the area under the receiver operating characteristic curve (AUC) when distinguishing lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SqCC), indicating the potential of being a non-invasive way for predicting histological subtypes of lung cancer.

Current Status and Future Prospects of TROP-2 ADCs in Lung Cancer Treatment

Lung cancer is the leading cause of mortality worldwide, and non-small cell lung cancer accounts for the majority of lung cancer cases. Chemotherapy and radiotherapy constitute the mainstays of lung cancer treatment; however, their associated side effects involving the kidneys, nervous system, gastrointestinal tract, and liver further add to dismal outcomes. The advent of antibody‒drug conjugates (ADCs) could change this situation. Trophoblast surface antigen 2 (TROP-2), a human trophoblast surface antigen, is a tumor-associated antigen that is expressed at low levels in normal tissues and is overexpressed in a variety of malignant tumors. The differential expression of the TROP-2 protein in a variety of tumors makes tumor immunotherapy with ADCs targeting TROP-2 a promising approach. Previous studies have shown that the expression of TROP-2 is related to the prognosis of patients with lung cancer and that TROP-2 expression is different across different histological types; however, research on TROP-2 and TROP-2 ADCs in patients with lung cancer is not comprehensive. The aims of this study were to review the mechanism of action and clinical efficacy of TROP-2 and related drugs in the treatment of lung cancer, to elucidate the prognostic value of TROP-2 in lung cancer, and to discuss the future prospects of TROP-2 ADCs to provide a reference for the precise treatment of lung cancer.

Identification of N-linked glycans recognized by WGA in saliva from patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related deaths. Saliva diagnosis is an essential approach for clinical applications owing to its noninvasive and material-rich features. The purpose of this study was to investigate differences in wheat germ agglutinin (WGA)-based recognition of salivary protein N-linked glycan profiles to distinguish non-small cell lung cancer (NSCLC) patients from controls. We used WGA-magnetic particle conjugates to isolate glycoproteins in the pooled saliva of healthy volunteers (HV, n = 35), patients with benign pulmonary disease (BPD, n = 35), lung adenocarcinoma (ADC, n = 35), and squamous cell carcinoma (SCC, n = 35), following to release the N-linked glycans from the isolated proteins with PNGase F, and further identified and annotated the released glycans by MALDI-TOF/TOF-MS, respectively. The results showed that 34, 35, 39, and 44 N-glycans recognized by WGA were identified and annotated from pooled saliva samples of HV, BPD, ADC, and SCC, respectively. Furthermore, the proportion of N-glycans recognized by WGA in BPD (81.2 %), ADC (90.1 %), and SCC (88.7 %), increased compared to HV (71.9 %). Two N-glycan peaks (m/z 2286.799, and 3399.211) specifically recognized by WGA were present only in NSCLC. These findings suggest that altered salivary glycopatterns such as sialic acids and GlcNAc containing N-glycans recognized by WGA might serve as potential personalized biomarkers for the diagnosis of NSCLC patients.

Personalized treatment using predictive biomarkers in solid organ malignancies: A review

In recent years, the influence of specific biomarkers in the diagnosis and prognosis of solid organ malignancies has been increasingly prominent. The relevance of the use of predictive biomarkers, which predict cancer response to specific forms of treatment provided, is playing a more significant role than ever before, as it affects diagnosis and initiation of treatment, monitoring for efficacy and side effects of treatment, and adjustment in treatment regimen in the long term. In the current review, we explored the use of predictive biomarkers in the treatment of solid organ malignancies, including common cancers such as colorectal cancer, breast cancer, lung cancer, prostate cancer, and cancers associated with high mortalities, such as pancreatic cancer, liver cancer, kidney cancer and cancers of the central nervous system. We additionally analyzed the goals and types of personalized treatment using predictive biomarkers, and the management of various types of solid organ malignancies using predictive biomarkers and their relative efficacies so far in the clinical settings.

Immune-Cell-Derived Exosomes as a Potential Novel Tool to Investigate Immune Responsiveness in SCLC Patients: A Proof-of-Concept Study

Small cell lung cancer (SCLC) is a highly invasive and rapidly proliferating lung tumor subtype. Most patients respond well to a combination of platinum-based chemotherapy and PD-1/PDL-1 inhibitors. Unfortunately, not all patients benefit from this treatment regimen, and few alternative therapies are available. In this scenario, the identification of new biomarkers and differential therapeutic strategies to improve tumor response becomes urgent. Here, we investigated the role of exosomes (EXs) released from the peripheral blood mononuclear cells (PBMCs) of SCLC patients in mediating the functional crosstalk between the immune system and tumors in response to treatments. In this study, we showed that PBMC-EXs from SCLC patients with different responses to chemoimmunotherapy showed different levels of immune (STING and MAVS) and EMT (Snail and c-Myc) markers. We demonstrated that PBMC-EXs derived from best responder (BR) patients were able to induce a significant increase in apoptosis in SCLC cell lines in vitro compared to PBMC-EXs derived from non-responder (NR) SCLC patients. PBMC-EXs were able to affect cell viability and modulate apoptotic markers, DNA damage and the replication stress pathway, as well as the occurrence of EMT. Our work provides proof of concept that PBMC-EXs can be used as a tool to study the crosstalk between cancer cells and immune cells and that PBMC-EXs exhibit an in vitro ability to promote cancer cell death and reduce tumor aggressiveness.

The Genetic Analysis and Clinical Therapy in Lung Cancer: Current Advances and Future Directions

Lung cancer, including both non-small cell lung cancer and small cell lung cancer, remains the leading cause of cancer-related mortality worldwide, representing 18% of the total cancer deaths in 2020. Many patients are identified already at an advanced stage with metastatic disease and have a worsening prognosis. Recent advances in the genetic understanding of lung cancer have opened new avenues for personalized treatments and targeted therapies. This review examines the latest discoveries in the genetics of lung cancer, discusses key biomarkers, and analyzes current clinical therapies based on this genetic information. It will conclude with a discussion of future prospects and potential research directions.

Comprehensive molecular and clinical insights into non-small cell lung cancer transformation to small cell lung cancer with an illustrative case report

Histologic transformation to small cell lung cancer (tSCLC) is a rare but increasingly recognised mechanism of acquired resistance to tyrosine kinase inhibitors (TKI) in patients with epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC). Beyond its acknowledged role in TKI resistance, histologic transformation to SCLC might be an important, yet under-recognised, mechanism of resistance in NSCLC treated with immunotherapy. Our review identified 32 studies that investigated tSCLC development in patients with EGFR-mutated NSCLC treated with TKI therapy and 16 case reports of patients treated with immunotherapy. It revealed the rarity of tSCLC, with a predominance of EGFR exon 19 mutations and limited therapeutic options and outcomes. Across all analysed studies in EGFR-mutated NSCLC treated with TKI therapy, the median time to tSCLC development was ∼17 months, with a median overall survival of 10 months. Histologic transformation of EGFR-mutated NSCLC to SCLC is a rare, but challenging clinical problem with a poor prognosis. A small number of documented cases of tSCLC after immunotherapy highlight the need for rebiopsies at progression to diagnose this potential resistance mechanism. Further research is needed to better understand the mechanisms underlying this phenomenon and to develop more effective treatment strategies for patients with tSCLC.

Achieving long-term survival in extensive-stage SCLC: a case report and mini literature review

Managing extensive-stage SCLC (ES-SCLC) has long been challenging for clinicians and oncologists due to its aggressive nature and poor prognosis. We report a case of a 41-year-old female with ES-SCLC who survived for six years, defying the disease's typically poor prognosis. Through a heavy treatment strategy involving chemotherapy, targeted therapy, and immunotherapy, the patient experienced robust responses and avoided distant metastasis, including brain involvement. The long-term survival case in SCLC highlights the need for further research into personalized strategies and prognostic biomarkers. This case holds significant value for both clinicians and researchers as it challenges the conventional strategies for ES-SCLC and sets the stage for future evidence-based studies aimed at extending survival in SCLC.

Alterations in Peripheral Lymphocyte Subsets under Immunochemotherapy in Stage IV SCLC Patients: Th17 Cells as Potential Early Predictive Biomarker for Response

UICC stage IV small-cell lung cancer (SCLC) is a highly aggressive malignancy without curative treatment options. Several randomized trials have demonstrated improved survival rates through the addition of checkpoint inhibitors to first-line platin-based chemotherapy. Consequently, a combination of chemo- and immunotherapy has become standard palliative treatment. However, no reliable predictive biomarkers for treatment response exist. Neither PD-L1 expression nor tumor mutational burden have proven to be effective predictive biomarkers. In this study, we compared the cellular immune statuses of SCLC patients to a healthy control cohort and investigated changes in peripheral blood B, T, and NK lymphocytes, as well as several of their respective subsets, during treatment with immunochemotherapy (ICT) using flow cytometry. Our findings revealed a significant decrease in B cells, while T cells showed a trend to increase throughout ICT. Notably, high levels of exhausted CD4+ and CD8+ cells, alongside NK subsets, increased significantly during treatment. Furthermore, we correlated decreases/increases in subsets after two cycles of ICT with survival. Specifically, a decrease in Th17 cells indicated a better overall survival. Based on these findings, we suggest conducting further investigation into Th17 cells as a potential early predictive biomarkers for response in patients receiving palliative ICT for stage IV SCLC.

Applied models and molecular characteristics of small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive type of cancer frequently diagnosed with metastatic spread, rendering it surgically unresectable for the majority of patients. Although initial responses to platinum-based therapies are often observed, SCLC invariably relapses within months, frequently developing drug-resistance ultimately contributing to short overall survival rates. Recently, SCLC research aimed to elucidate the dynamic changes in the genetic and epigenetic landscape. These have revealed distinct subtypes of SCLC, each characterized by unique molecular signatures. The recent understanding of the molecular heterogeneity of SCLC has opened up potential avenues for precision medicine, enabling the development of targeted therapeutic strategies. In this review, we delve into the applied models and computational approaches that have been instrumental in the identification of promising drug candidates. We also explore the emerging molecular diagnostic tools that hold the potential to transform clinical practice and patient care.

Jaundice and Higher Procalcitonin Level Revealing a Small-Cell Lung Cancer With Pancreatic Metastasis: A Case Report From Eastern Morocco

Small-cell lung cancer (SCLC) is highly aggressive, with a severe tendency for metastasis. Pancreatic metastasis in SCLC is uncommon, also jaundice as a major symptom of small-cell lung cancer is even rarer. The diagnosis of pancreatic metastasis is a real challenge for the medical team, it relies on both radiological and pathological details. We report a case of a 58-year-old male admitted for SCLC with pancreatic metastasis and a higher level of procalcitonin. He received platinum-based chemotherapy with a swell response. The focus of this study will be on the characteristics of pancreatic metastasis, along with their diagnosis and treatment approaches. Procalcitonin as a paraneoplastic syndrome will also be discussed in this study.

ncRNAs Orchestrate Chemosensitivity Induction by Neddylation Blockades

We performed an integrative transcriptomic in silico analysis using lung adenocarcinoma A549 cells treated with the neddylation inhibitor MLN4924 and the gefitinib-resistant PC9 cell line (PC9GR). We focused on the transcriptional effects of the top differentially expressed ncRNA biotypes and their correlating stemness factors. Interestingly, MLN4924-treated cells showed a significant upregulation of mRNAs involved in carcinogenesis, cell attachment, and differentiation pathways, as well as a parallel downregulation of stemness maintenance and survival signaling pathways, an effect that was inversely observed in PC9GR cells. Moreover, we found that stemness factor expression could be contrasted by selected up-regulated ncRNAs upon MLN4924 treatment in a dose and time-independent manner. Furthermore, upregulated miRNAs and lncRNA-targeted mRNAs showed an evident enrichment of proliferation, differentiation, and apoptosis pathways, while downregulated ncRNA-targeted mRNAs were implicated in stem cell maintenance. Finally, our results proved that stemness (KLF4 and FGFR2) and epithelial-mesenchymal transition (ZEB2, TWIST2, SNAI2, CDH2, and VIM) factors, which are highly expressed in PC9GR cells compared to gefitinib-sensitive PC9 cells, could be abrogated with the neddylation inhibitor MLN4924 mainly through activation of epithelial differentiation pathways, thus exerting a protective role in lung cancer cells and chemosensitivity against lung tumorigenic transformation.

Proteomic Profiling of Small-Cell Lung Cancer: A Systematic Review

The accurate diagnosis of small-cell lung cancer (SCLC) is crucial, as treatment strategies differ from those of other lung cancers. This systematic review aims to identify proteins differentially expressed in SCLC compared to normal lung tissue, evaluating their potential utility in diagnosing and prognosing the disease. Additionally, the study identifies proteins differentially expressed between SCLC and large cell neuroendocrine carcinoma (LCNEC), aiming to discover biomarkers distinguishing between these two subtypes of neuroendocrine lung cancers. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search was conducted across PubMed/MEDLINE, Scopus, Embase, and Web of Science databases. Studies reporting proteomics information and confirming SCLC and/or LCNEC through histopathological and/or cytopathological examination were included, while review articles, non-original articles, and studies based on animal samples or cell lines were excluded. The initial search yielded 1705 articles, and after deduplication and screening, 16 articles were deemed eligible. These studies revealed 117 unique proteins significantly differentially expressed in SCLC compared to normal lung tissue, along with 37 unique proteins differentially expressed between SCLC and LCNEC. In conclusion, this review highlights the potential of proteomics technology in identifying novel biomarkers for diagnosing SCLC, predicting its prognosis, and distinguishing it from LCNEC.