Targeting angiogenesis in small cell lung cancer

The Evolving Scenario of ES-SCLC Management: From Biology to New Cancer Therapeutics

Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma accounting for 15% of lung cancers with dismal survival outcomes. Minimal changes in therapy and prognosis have occurred in SCLC for the past four decades. Recent progress in the treatment of extensive-stage disease (ES-SCLC) has been marked by incorporating immune checkpoint inhibitors (ICIs) into platinum-based chemotherapy, leading to modest improvements. Moreover, few second-line-and-beyond treatment options are currently available. The main limitation for the molecular study of SCLC has been the scarcity of samples, because only very early diseases are treated with surgery and biopsies are not performed when the disease progresses. Despite all these difficulties, in recent years we have come to understand that SCLC is not a homogeneous disease. At the molecular level, in addition to the universal loss of retinoblastoma (RB) and TP53 genes, a recent large molecular study has identified other mutations that could serve as targets for therapy development or patient selection. In recent years, there has also been the identification of new genetic subtypes which have shown us how intertumor heterogeneity exists. Moreover, SCLC can also develop intratumoral heterogeneity linked mainly to the concept of cellular plasticity, mostly due to the development of resistance to therapies. The aim of this review is to quickly present the current standard of care of ES-SCLC, to focus on the molecular landscapes and subtypes of SCLC, subsequently present the most promising therapeutic strategies under investigation, and finally recap the future directions of ongoing clinical trials for this aggressive disease which still remains a challenge.

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.

Assessment of Naples prognostic score in predicting survival for small cell lung cancer patients treated with chemoradiotherapy

BACKGROUNDS

The Naples prognosis score (NPS) is a novel prognostic biomarker-based immune and nutritional status and that can be used to evaluate prognosis. Our study aimed to investigate the prognostic role of NPS in SCLC patients.

METHODS

Patients treated with chemoradiotherapy were retrospectively analyzed between June 2012 and August 2017. We divided patients into three groups depending on the NPS: group 0, n = 31; group 1, n = 100; and group 2, n = 48, and associations between clinical characteristics and NPS group were analyzed. The univariable and multivariable Cox analyses were used to evaluate the prognostic value of clinicopathological characteristics and laboratory indicators for overall survival (OS) and progression-free survival (PFS).

RESULTS

Data from 179 patients were analyzed. Treatment modality (p < 0.001) and serum CEA (p = 0.03) were significantly different among the NPS groups. The age, sex, smoking status, KPS, Karnofsky performance score (KPS), disease extent, and number of metastatic sites were not correlated with NPS (all p > 0.05). KPS, disease extent, prophylactic cranial irradiation, treatment response and NPS Group were associated with OS. In addition, KPS, disease extent, prophylactic cranial irradiation, treatment response and NPS Group were associated with PFS. Multivariate analysis results showed that NPS was identified as an independent prognostic factor for OS (Group 1: hazard ratio [HR] = 2.704, 95% confidence interval [CI] = 1.403-5.210; p = 0.003; Group 2: HR = 5.154, 95% CI = 2.614-10.166; p < 0.001) and PFS (Group 1: HR = 2.018, 95% CI = 1.014-4.014; p = 0.045; Group 2: HR = 3.339, 95% CI = 1.650-6.756; p = 0.001).

CONCLUSIONS

NPS is related to clinical outcomes in patients with SCLC.

Preventive and therapeutic effects of green tea on lung cancer: a narrative review of evidence from clinical and basic research

Background and Objective

Green tea is a popular beverage worldwide and has numerous health-promoting properties. Accumulating evidence indicates that green tea has preventive and therapeutic effects on lung cancer. This study aimed to investigate the association between green tea consumption and lung cancer.

Methods

We performed a narrative review to summarized the association between green tea consumption and lung cancer.

Key Content and Findings

Green tea consumption is known to decrease lung cancer risk in the general population, as indicated by meta-analyses of observational studies. Two active components of green tea, theabrownin and (-)-epigallocatechin gallate (EGCG), mediate the antitumor activity of green tea. Theabrownin promotes apoptosis, induces cell cycle arrest, and inhibits the migration, clone formation, and proliferation of lung cancer cell lines in vitro and in vivo. EGCG inhibits lung cancer cell proliferation and promotes apoptosis, agenesis, and epithelial-mesenchymal transition (EMT). In addition, EGCG sensitizes lung cancer cells to cisplatin and tyrosine kinase inhibitors (TKIs). The possible molecular mechanisms underlying the antitumor activity of EGCG and theabrownin were reviewed.

Conclusions

Observational studies have indicated that green tea has preventive effects on lung cancer. In vitro and animal studies have indicated that green tea has therapeutic effects on lung cancer. Further clinical trials are needed to illustrate the therapeutic effects of green tea or its active components (i.e., theabrownin, EGCG) on lung cancer.

Comprehensive Characterization of the Genomic Landscape in Chinese Pulmonary Neuroendocrine Tumors Reveals Prognostic and Therapeutic Markers (CSWOG-1901)

BACKGROUND

Pulmonary neuroendocrine tumors (pNETs) include typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung carcinoma (SCLC). The optimal treatment strategy for each subtype remains elusive, partly due to the lack of comprehensive understanding of their molecular features. We aimed to explore differential genomic signatures in pNET subtypes and identify potential prognostic and therapeutic biomarkers.

METHODS

We investigated genomic profiles of 57 LCNECs, 49 SCLCs, 18 TCs, and 24 ACs by sequencing tumor tissues with a 520-gene panel and explored the associations between genomic features and prognosis.

RESULTS

Both LCNEC and SCLC displayed higher mutation rates for TP53, PRKDC, SPTA1, NOTCH1, NOTCH2, and PTPRD than TC and AC. Small cell lung carcinoma harbored more frequent co-alterations in TP53-RB1, alterations in PIK3CA and SOX2, and mutations in HIF-1, VEGF and Notch pathways. Large cell neuroendocrine carcinoma (12.7 mutations/Mb) and SCLC (11.9 mutations/Mb) showed higher tumor mutational burdens than TC (2.4 mutations/Mb) and AC (7.1 mutations/Mb). 26.3% of LCNECs and 20.8% of ACs harbored alterations in classical non-small cell lung cancer driver genes. The presence of alterations in the homologous recombination pathway predicted longer progression-free survival in advanced LCNEC patients with systemic therapy (P = .005) and longer overall survival (OS) in SCLC patients with resection (P = .011). The presence of alterations in VEGF (P = .048) and estrogen (P = .018) signaling pathways both correlated with better OS in patients with resected SCLC.

CONCLUSION

We performed a comprehensive genomic investigation on 4 pNET subtypes in the Chinese population. Our data revealed distinctive genomic signatures in subtypes and provided new insights into the prognostic and therapeutic stratification of pNETs.

A phase II, open-label, single-arm trial of carboplatin plus etoposide with bevacizumab and atezolizumab in patients with extended-stage small-cell lung cancer (CeLEBrATE study): background, design and rationale

Based on improved survival from the addition of PD-L1 inhibitors in phase III trials, the combination of immunotherapy and platinum-doublet chemotherapy has become the new standard treatment for extended-stage small-cell lung cancer (ES-SCLC). Furthermore, the antiangiogenetic agent bevacizumab showed a longer progression-free survival by targeting VEGF that has pleiotropic effects, including immunosuppressive ones. We, therefore, hypothesized that targeting angiogenesis would improve the efficacy of chemoimmunotherapy. The CeLEBrATE trial is an open-label, multicenter, phase II study designed to assess the efficacy and safety of the combination of carboplatin and etoposide plus bevacizumab and atezolizumab in treatment-naive patients with ES-SCLC. The primary end point is overall survival rate at 1 year, while secondary end points include overall response rate, progression-free survival and toxicity.

Effectiveness and Safety of Anlotinib Monotherapy for Patients with Extensive-stage Small-Cell Lung Cancer Who Progressed to Chemotherapy: A Real-world Exploratory Study

Background:

Anlotinib demonstrated promising efficacy for patients with extensive-stage small-cell lung cancer (ES-SCLC) in clinical trials. However, the real-world evidence of anlotinib monotherapy in ES-SCLC was still limited currently. Therefore, present study was to investigate the effectiveness and safety of anlotinib for patients with ES-SCLC who progressed to chemotherapy in real-world and the potential biomarker during anlotinib monotherapy.

Methods:

A total of 89 patients with ES-SCLC who failed the previous chemotherapy treatment were recruited. All the patients were administered with anlotinib monotherapy. Demographic data of the patients were collected; effectiveness and safety profile during anlotinib monotherapy were documented through electronic medical record system in the hospital. Progression-free survival (PFS) and overall survival (OS) were presented using Kaplan-Meier survival curves and multivariate analysis was adjusted by Cox regression analysis.

Results:

All the 89 patients with ES-SCLC who progressed to chemotherapy were available for the assessment of effectiveness and safety profile. Best overall response indicated that partial response was observed in 6 patients (6.7%), stable disease was noted in 61 patients (68.5%), and progressive disease was found in 22 patients (24.7%). Therefore, the objective response rate (ORR) and disease control rate (DCR) of the 89 patients with ES-SCLC was 6.7% (95% confidence interval [CI]: 2.5%-14.1%) and 75.3% (95% CI: 65.0%-83.8%), respectively. The prognostic data suggested that the median PFS of the 89 patients was 3.1 months (95% CI: 2.10-4.10), and the median OS was 8.6 months (95% CI: 7.42-9.78). In addition, the most common adverse reactions of the patients who received anlotinib monotherapy were hypertension (34.8%), hand-foot syndrome (30.3%), fatigue (29.2%), loss of appetite (27.0%), and hematological toxicity (21.3%). Association analysis between biomarker (hypertension status) and prognosis indicated that the median PFS of patients with hypertension and patients with non-hypertension was 5.5 and 3.0 months, respectively (χ² = 4.64, P = .031). Furthermore, multivariate Cox analysis for PFS suggested that hypertension status was an independent factor for PFS (hazard ratio [HR] = 0.71, P = .035].

Conclusion:

Anlotinib monotherapy showed encouraging effectiveness and acceptable safety profile for patients with ES-SCLC in real world. Hypertension induced by anlotinib administration might be used as a potential biomarker to predict superior PFS for patients with ES-SCLC.

Optimal regulation of tumour-associated neutrophils in cancer progression

In a tumour microenvironment, tumour-associated neutrophils could display two opposing differential phenotypes: anti-tumour (N1) and pro-tumour (N2) effector cells. Converting N2 to N1 neutrophils provides innovative therapies for cancer treatment. In this study, a mathematical model for N1-N2 dynamics describing the cancer survival and immune inhibition in response to TGF-β and IFN-β is considered. The effects of exogenous intervention of TGF-β inhibitor and IFN-β are examined in order to enhance N1 recruitment to combat tumour progression. Our approach employs optimal control theory to determine drug infusion protocols that could minimize tumour volume with least administration cost possible. Four optimal control scenarios corresponding to different therapeutic strategies are explored, namely, TGF-β inhibitor control only, IFN-β control only, concomitant TGF-β inhibitor and IFN-β controls, and alternating TGF-β inhibitor and IFN-β controls. For each scheme, different initial conditions are varied to depict different pathophysiological condition of a cancer patient, leading to adaptive treatment schedule. TGF-β inhibitor and IFN-β drug dosages, total drug amount, infusion times and relative cost of drug administrations are obtained under various circumstances. The control strategies achieved could guide in designing individualized therapeutic protocols.

Clinical Activity and Safety of Anlotinib Combined with PD-1 Blockades for Patients with Previously Treated Small Cell Lung Cancer

Objective

Anlotinib was the standard monotherapy for patients with previously treated small cell lung cancer (SCLC) in recent years. Programmed cell death protein 1 (PD-1) blockade combined with antiangiogenic targeted drugs have proved to play a synergistic action for cancer treatment clinically. Consequently, the present study was to investigate the efficacy and safety of anlotinib combined with PD-1 blockades for patients with previously treated SCLC.

Methods

A total of 36 patients with SCLC who were treated with at least one previous systemic chemotherapy regimen participated in this study retrospectively. All the patients were administered with anlotinib plus PD-1 blockades therapy. Clinical activity was assessed according to the change of target lesion by imaging evidence and all the subjects were followed up regularly. Safety profiles were collected and documented during the treatment. Univariate analysis was carried out using Log rank test and multivariate analysis was adjusted by Cox regression analysis.

Results

All the 36 patients with previously treated SCLC were able to have their efficacy and safety profile evaluated. The best overall response of the combination regimen showed that complete response was observed in one patient, partial response was noted in 9 patients, stable disease was reported in 19 patients, progressive disease was seen in 7 patients. Therefore, the objective response rate (ORR) of the 36 patients was 27.8% (95% CI: 14.2-45.2%), disease control rate (DCR) was 80.6% (95% CI: 64.0-91.8%). Regarding the prognostic data, the median PFS and OS of the 36 patients was 4.6 months (95% CI: 3.13-6.07) and 9.3 months (95% CI: 3.30-15.30), respectively. The most common treatment-related adverse reactions were hypertension (52.8%), fatigue (47.2%), diarrhea (38.9%), hand and foot reaction (38.9%) and dermal toxicity (33.3%). Furthermore, multivariate Cox regression analysis for PFS indicated that ECOG performance status was an independent factor to predict PFS.

Conclusion

Anlotinib combined with PD-1 blockades regimen preliminarily demonstrated encouraging efficacy and tolerable safety for patients with previously treated SCLC. The conclusion should be validated in prospective clinical trials subsequently.

EGPI-1, a novel eIF4E/eIF4G interaction inhibitor, inhibits lung cancer cell growth and angiogenesis through Ras/MNK/ERK/eIF4E signaling pathway

eIF4E plays an important role in regulating tumor growth and angiogenesis, and eIF4E is highly expressed in a variety of lung cancer cell lines. siRNA eIF4E can significantly inhibit the proliferation of lung cancer cells, indicating that inhibition of eIF4E may become a novel anti-tumor target. In the previous study, we synthesized a series of small molecule compounds with the potential to inhibit eIF4E. Among them, the compound EGPI-1 significantly inhibited the proliferation of a variety of lung cancer cells such as A549, NCI-H460, NCI-H1650 and 95D without inhibiting the proliferation of HUVEC cells. Further studies found that EGPI-1 interfered with the eIF4E/eIF4G interaction and inhibited the phosphorylation of eIF4E in NCI-H460 cells. The results of flow cytometry showed that EGPI-1 induced apoptosis and G0/G1 cycle arrest in NCI-H460 cell. Interestingly, we also found that EGPI-1 induced autophagy and DNA damage in NCI-H460 cells. The mechanism results showed that EGPI-1 inhibited the Ras/MNK/ERK/eIF4E signaling pathway. Moreover, EGPI-1 inhibited tube formation of HUVECs, as well as inhibited the neovascularization of CAM, proving the anti-angiogenesis activity of EGPI-1. The NCI-H460 xenograft studies showed that EGPI-1 inhibited tumor growth and angiogenesis in vivo by regulating Ras/MNK/ERK/eIF4E pathway. Our studies proved that eIF4E was a novel target for regulating tumor growth, and the eIF4E/eIF4G interaction inhibitor EGPI-1 was promising to develop into a novel anti-lung cancer drug.

Recapitulating the Angiogenic Switch in a Hydrogel-Based 3D In Vitro Tumor-Stroma Model

To ensure nutrient and oxygen supply, tumors beyond a size of 1–2 mm³ need a connection to the vascular system. Thus, tumor cells modify physiological tissue homeostasis by secreting inflammatory and angiogenic cytokines. This leads to the activation of the tumor microenvironment and the turning of the angiogenic switch, resulting in tumor vascularization and growth. To inhibit tumor growth by developing efficient anti-angiogenic therapies, an in depth understanding of the molecular mechanism initiating angiogenesis is essential. Yet so far, predominantly 2D cell cultures or animal models have been used to clarify the interactions within the tumor stroma, resulting in poor transferability of the data obtained to the in vivo situation. Consequently, there is an abundant need for complex, humanized, 3D models in vitro. We established a dextran-hydrogel-based 3D organotypic in vitro model containing microtumor spheroids, macrophages, neutrophils, fibroblasts and endothelial cells, allowing for the analysis of tumor–stroma interactions in a controlled and modifiable environment. During the cultivation period of 21 days, the microtumor spheroids in the model grew in size and endothelial cells formed elongated tubular structures resembling capillary vessels, that appeared to extend towards the tumor spheroids. The tubular structures exhibited complex bifurcations and expanded without adding external angiogenic factors such as VEGF to the culture. To allow high-throughput screening of therapeutic candidates, the 3D cell culture model was successfully miniaturized to a 96-well format, while still maintaining the same level of tumor spheroid growth and vascular sprouting. The quantification of VEGF in the conditioned medium of these cultures showed a continuous increase during the cultivation period, suggesting the contribution of endogenous VEGF to the induction of the angiogenic switch and vascular sprouting. Thus, this model is highly suitable as a testing platform for novel anticancer therapeutics targeting the tumor as well as the vascular compartment.

Real-world efficacy and safety of anlotinib as third- or further-line treatment in refractory small cell lung cancer

PURPOSE

As a novel antiangiogenic multi-target tyrosine kinase inhibitor recently approved in China, anlotinib has exhibited promising anticancer efficacy and acceptable safety profile in the salvage treatment of small cell lung cancer (SCLC) in clinical trials. Here we retrospectively investigated the efficacy and safety of anlotinib as third- or further-line treatment in patients with refractory SCLC.

PATIENTS AND METHODS

A total of 40 patients with refractory SCLC treated with anlotinib monotherapy were included in this study. The clinicopathological data, treatment information, survival data and safety data were retrospectively collected. Survival curves were constructed using the Kaplan-Meier method. Univariate analysis was performed by log-rank testing.

RESULTS

Altogether, 40 patients of extensive-stage SCLC or progressive limited-stage SCLC received anlotinib monotherapy as third- or further-line treatment from July 2018 to June 2020. Four patients achieved partial response (PR), 14 patients achieved stable disease (SD), no complete response (CR) was recorded, and 22 patients experienced progressive disease (PD). The disease control rate (DCR) was 45.0%. The median progression-free survival (PFS) was 3.0 months (95% CI 2.241-3.759), and the median overall survival (OS) was 7.8 months (95% CI 3.190-12.410). The common adverse effects (AEs) included hypertension, fatigue, anorexia, cough, rash and nausea. Grade 3 treatment-related AEs occurred in 3 (7.5%) patients. One patient interrupted anlotinib treatment due to repeated grade 1 epistaxis. Univariate analysis revealed that patients without liver metastases, previously treated with radiotherapy or with Eastern Cooperative Oncology Group (ECOG) scores of 0 or 1 had longer OS with anlotinib treatment. Cox regression analysis demonstrated that patients without liver metastases and patients with ECOG score ≤ 1 had longer PFS, while patients without liver metastases had longer OS.

CONCLUSION

Anlotinib is beneficial to refractory SCLC as third- or further-line treatment, especially in patients without liver metastasis and with better physical status. Related adverse effects are tolerable and manageable.

Effectiveness of anlotinib in patients with small-cell lung cancer and pleural effusion: Subgroup analysis from a randomized, multicenter, phase II study

Background

The presence of pleural effusion is an independent predictor for poor survival in patients with small‐cell lung cancer (SCLC). The aim of this study was to assess the efficacy and safety of anlotinib in patients with SCLC and pleural effusion.

Methods

This was a randomized, double‐blind, multicenter, phase II trial. Patients histologically diagnosed with SCLC and pleural effusion and had received at least two lines of chemotherapy were enrolled into the study. The patients received anlotinib 12 mg/day or a placebo.

Results

The overall response rate (ORR) was 3.7% for anlotinib (n = 27) and 0% in the placebo group (n = 15) (p = 1.000). The disease control rate (DCR) of the anlotinib group (63.0%) was higher than that of the placebo group (0%, p < 0.0001). The median progression‐free survival (PFS) increased in the anlotinib group (2.8 months) compared to the placebo group (0.7 months, HR = 0.10, 95% CI: 0.03–0.28, p < 0.001). The median overall survival of the anlotinib group (6.5 months) was higher than that of the placebo group (2.8 months, HR = 0.52, 95% CI: 0.22–1.23, p = 0.1285). The incidence of any grade adverse events was 100% in both groups. The percentage of grade 3–4 adverse events in the anlotinib group was 44.4% (12/27) compared to 40.0% (6/15) in the placebo group. Hypertension (37.0%), fatigue (29.6%), and loss of appetite (29.6%) typically appeared in the anlotinib group.

Conclusions

In this post hoc analysis, anlotinib was associated with improved PFS in patients with SCLC and baseline pleural effusion. However, additional studies with a large sample size are necessary to substantiate the current findings.

Revisiting Lung Cancer Metastasis: Insight From the Functions of Long Non-coding RNAs

Globally, lung cancer is the most common cause of cancer-related deaths. After diagnosis at all stages, <7% of patients survive for 10 years. Thus, diagnosis at later stages and the lack of effective and personalized drugs reflect a significant need to better understand the mechanisms underpinning lung cancer progression. Metastasis should be responsible for the high lethality and recurrence rates seen in lung cancer. Metastasis depends on multiple crucial steps, including epithelial–mesenchymal transition, vascular remodeling, and colonization. Therefore, in-depth investigations of metastatic molecular mechanisms can provide valuable insights for lung cancer treatment. Recently, long noncoding RNAs (lncRNAs) have attracted considerable attention owing to their complex roles in cancer progression. In lung cancer, multiple lncRNAs have been reported to regulate metastasis. In this review, we highlight the major molecular mechanisms underlying lncRNA-mediated regulation of lung cancer metastasis, including (1) lncRNAs acting as competing endogenous RNAs, (2) lncRNAs regulating the transduction of several signal pathways, and (3) lncRNA coordination with enhancer of zeste homolog 2. Thus, lncRNAs appear to execute their functions on lung cancer metastasis by regulating angiogenesis, autophagy, aerobic glycolysis, and immune escape. However, more comprehensive studies are required to characterize these lncRNA regulatory networks in lung cancer metastasis, which can provide promising and innovative novel therapeutic strategies to combat this disease.

Role of microRNAs in regulating cell proliferation, metastasis and chemoresistance and their applications as cancer biomarkers in small cell lung cancer

Small cell lung cancer (SCLC), a smoking-related highly aggressive neuroendocrine cancer, is characterized by rapid cell proliferation, early metastatic dissemination, and early relapse due to chemoresistance to first-line platinum-doublet chemotherapy. Genomically, SCLC tumors show nearly universal loss of TP53 and RB1 tumor suppressor genes, while gene expression signature classifies them into 4 distinct subgroups based on the expression patterns of lineage transcription factors - ASCL1/ASH1, NEUROD1, YAP-1, and POU2F3. Due to the lack of targetable molecular alterations and clinically useful diagnostic, prognostic and predictive biomarker, there is insignificant progress in the therapeutic management of SCLC patients. Numerous studies have shown a significant involvement of non-coding RNAs in the regulation of cell proliferation, invasion and migration, apoptosis, metastasis, and chemoresistance in various human cancers. In this review, we comprehensively discuss the role of microRNAs (miRNAs) in regulating the aforementioned biological process in SCLC. For this, we searched the scientific literature and selected studies that have evaluated the role of miRNAs in the disease pathogenesis or as a cancer biomarker in SCLC. Our review suggests that several miRNAs are involved in the pathogenesis of SCLC mainly by regulating cell proliferation, metastasis, and chemoresistance. Few studies have also demonstrated the clinical utility of miRNAs in monitoring response to chemotherapy as well as in predicting survival outcomes. However, more in-depth mechanistic studies utilizing in vivo models and multicentric studies with larger patient cohorts are needed before the applications of miRNAs as therapeutic targets or as biomarkers are translated from the laboratory into clinics.

Targeting Cytoprotective Autophagy to Enhance Anticancer Therapies

Autophagy is a highly regulated multi-step process that occurs at the basal level in almost all cells. Although the deregulation of the autophagy process has been described in several pathologies, the role of autophagy in cancer as a cytoprotective mechanism is currently well established and supported by experimental and clinical evidence. Our understanding of the molecular mechanism of the autophagy process has largely contributed to defining how we can harness this process to improve the benefit of cancer therapies. While the role of autophagy in tumor resistance to chemotherapy is extensively documented, emerging data point toward autophagy as a mechanism of cancer resistance to radiotherapy, targeted therapy, and immunotherapy. Therefore, manipulating autophagy has emerged as a promising strategy to overcome tumor resistance to various anti-cancer therapies, and autophagy modulators are currently evaluated in combination therapies in several clinical trials. In this review, we will summarize our current knowledge of the impact of genetically and pharmacologically modulating autophagy genes and proteins, involved in the different steps of the autophagy process, on the therapeutic benefit of various cancer therapies. We will also briefly discuss the challenges and limitations to developing potent and selective autophagy inhibitors that could be used in ongoing clinical trials.

PARP Inhibitors in Small-Cell Lung Cancer: Rational Combinations to Improve Responses

Simple Summary

Small-cell lung cancer carries a dismal prognosis with few long-term treatment options. The enzyme poly-(ADP)-ribose polymerase (PARP), which functions to repair DNA breaks, has emerged as a promising therapeutic target, with modest response rates in early clinical trials prompting investigation of predictive biomarkers and therapeutic combinations. This review summarizes the development and testing of PARP inhibitors in small-cell lung cancer with an emphasis on developing treatment combinations. These combinations can be divided into three categories: (1) contributing to DNA damage; (2) inhibiting the DNA damage response; and (3) activating the immune system. An evolving classification of small-cell lung cancer subtypes and gene expression patterns will guide PARP inhibitor biomarker identification to improve treatments for this challenging cancer.

Abstract

Despite recent advances in first-line treatment for small-cell lung cancer (SCLC), durable responses remain rare. The DNA repair enzyme poly-(ADP)-ribose polymerase (PARP) was identified as a therapeutic target in SCLC using unbiased preclinical screens and confirmed in human and mouse models. Early trials of PARP inhibitors, either alone or in combination with chemotherapy, showed promising but limited responses, suggesting that selecting patient subsets and treatment combinations will prove critical to further clinical development. Expression of SLFN11 and other components of the DNA damage response (DDR) pathway appears to select for improved responses. Combining PARP inhibitors with agents that damage DNA and inhibit DDR appears particularly effective in preclinical and early trial data, as well as strategies that enhance antitumor immunity downstream of DNA damage. A robust understanding of the mechanisms of DDR in SCLC, which exhibits intrinsic replication stress, will improve selection of agents and predictive biomarkers. The most effective combinations will target multiple nodes in the DNA damage/DDR/immune activation cascade to minimize toxicity from synthetic lethality.

Influence of VEGFR2 gene polymorphism on the clinical outcomes of apatinib for patients with chemotherapy-refractory extensive-stage SCLC: a real-world retrospective study

PURPOSE

Great individual differences were observed regarding the efficacy of apatinib clinically. The aim of present study was to investigate the influence of vascular endothelial growth factor receptor2 (VEGFR2) gene polymorphism on the clinical outcomes of apatinib for patients with chemotherapy-refractory extensive-stage small cell lung cancer (ES-SCLC).

METHODS

A total of 128 patients with chemotherapy-refractory ES-SCLC who were treated with apatinib at an initial dosage of 250 or 500 mg were included in this study. The change of target lesions was assessed. Overall response rate (ORR) was evaluated. Prognosis was carried out and safety profile was documented. Additionally, peripheral blood and biopsy cancer tissue specimens of the patients with SCLC were collected for the analysis of polymorphism and VEGFR2 gene mRNA expression, respectively. The association between genotype status and baseline characteristics was performed. Univariate analysis of genotype status and prognosis was carried out using Kaplan-Meier survival analysis and multivariate analysis were adjusted by Cox regression analysis.

RESULTS

Efficacy of apatinib included partial response (PR) in 15 patients, stable disease (SD) in 86 patients, progressive disease (PD) in 27 patients. Therefore, ORR of the 128 patients with ES-SCLC was 11.7%, and disease control rate (DCR) was 78.9%. Prognosis suggested that the median progression-free survival (PFS) and overall survival (OS) of the 128 patients with ES-SCLC was 4.2 months and 8.2 months, respectively. The polymorphism analysis focusing on VEGFR2 gene indicated that one single nucleotide polymorphism 889C>T was of clinical significance. Prevalence of 889C>T among the 128 patients with SCLC were as follows: CC genotype 87 cases (68.0%), CT genotype 38 cases (29.7%) and TT genotype 3 cases (2.3%), the minor allele frequency of 889C>T was 0.17, which was in accordance with Hardy-Weinberg Equilibrium (P = 0.628). Patients with CT and TT genotypes were merged in the subsequent analysis. Prognosis analysis exhibited that the median PFS of patients with CT/TT genotype and CC genotype was 3.3 and 5.0 months, respectively (P = 0.02). Furthermore, the median OS of patients was 5.5 and 9.0 months, respectively (P = 0.008). Additionally, multivariate Cox regression analysis of OS demonstrated that CT/TT genotype was an independent factor for OS [Hazard ratio (HR) = 0.64, P = 0.019]. However, the safety profile according to genotype status of 889C>T failed to show significant difference. Interestingly, mRNA expression analysis suggested that the mRNA expression of VEGFR2 in cancer tissues were significantly different according to CC and CT/TT genotypes (P < 0.001).

CONCLUSION

The administration with apatinib for patients with chemotherapy-refractory ES-SCLC was of potential clinical significance. The clinical outcomes of patients with ES-SCLC who were treated with apatinib could be impacted by VEGFR2 889C>T polymorphism through mediating the VEGFR2 mRNA expression.

Vascular co-option and vasculogenic mimicry mediate resistance to antiangiogenic strategies

BACKGROUND

The concept that all the tumors need the formation of new vessels to grow inspired the hypothesis that inhibition of angiogenesis would have led to "cure" cancer. The expectancy that this type of therapy would have avoided the insurgence of resistance was based on the concept that targeting normal vessels, instead of the cancer cells which easily develop new mutations, would have allowed evasion of drug caused selection is, however, more complex as it was made apparent by the discovery of nonangiogenic tumors. At the same time an increasing number of trials with antiangiogenic drugs were coming out as not as successful as expected, mostly because of the appearance of unexpected resistance.

RECENT FINDINGS

Among the several different mechanisms of resistance to antiangiogenic treatment by now described, we review the evidences that vascular co-option and vasculogenic mimicry by nonangiogenic tumors are effectively two of such mechanisms. We focused on reviewing exclusively the study, both clinical and preclinical, that offer a demonstration that vascular co-option and vasculogenic mimicry are effectively two mechanisms of both intrinsic and acquired resistance.

CONCLUSION

The discovery that vascular co-opting and vasculogenic mimicry are two ways of escaping antiangiogenic treatment, prompts the need for a better understanding of this phenomenon in order to improve cancer treatment.

Profilin 2 promotes growth, metastasis, and angiogenesis of small cell lung cancer through cancer-derived exosomes

Small cell lung cancer (SCLC) is highly aggressive and prone to hypervascular metastases. Recently, we found profilin 2 (PFN2) expression in SCLC but not in normal tissues. Furthermore, PFN2 expression had been shown to promote angiogenesis through exosomes. However, it remains unclear whether PFN2 contributes to the progression and metastasis of SCLC through angiogenesis. We report here that overexpression (OE) of PFN2 increased, whereas its knockdown (KD) decreased the proliferation, migration, and invasion of SCLC cell H446. The exosomes from OE-H446 (SCLC-OE-exo) exhibited similar effects on H446 properties. Culturing of endothelial cells (ECs) in SCLC-OE conditioned medium (CM) or SCLC-OE-exo increased the migration and tube formation ability of ECs, whereas SCLC-KD-CM and SCLC-KD-exo had inhibitory effects. Interestingly, both SCLC- and EC-derived exosomes were internalized in H446 more rapidly than in ECs. More importantly, OE-PFN2 dramatically elevated SCLC growth and vasculature formation as well as lung metastasis in tumor xenograft models. Finally, we found that PFN2 activated Smad2/3 in H446 and pERK in ECs, respectively. Taken together, our study revealed the role of PFN2 in SCLC development and metastasis, as well as tumor angiogenesis through exosomes, providing a new molecular target for SCLC treatment.

Mechanisms of resistance to anti-angiogenic treatments

Hailed as the cancer treatment to end all the resistance to treatment, anti-angiogenic therapy turned out to be not quite what was promised. The hope that this therapeutic approach would not have suffered by the phenomenon of resistance was based on the fact that was targeting normal vessels rather than tumour cells prone to mutation and subject to drug induced selection. However, reality turned out to be more complex and since 1997, several mechanisms of resistance have been described to the point that the study of resistance to these drugs is now a very large field. Far from being exhaustive, this paper presents the main mechanisms discovered trough some examples.

The impact of angiogenesis inhibitors on survival of patients with small cell lung cancer

Background

Small cell lung cancer (SCLC) is a highly invasive and lethal neuroendocrine tumor. Antiangiogenic drugs have been reported in the treatment of SCLC. We aimed to provide a comprehensive evaluation of the impact of angiogenic inhibitors on SCLC survival using network meta‐analysis.

Methods

The impact of five angiogenesis inhibitors, that is, vandetanib (Van), bevacizumab (Bev), Rh‐endostatin (End), sunitinib (Sun), and thalidomide (Tha), on progression‐free survival (PFS) and overall survival (OS) was evaluated by conducting a network meta‐analysis. RNA sequencing data were downloaded from publicly available databases.

Results

Nine phase II and III randomized controlled trials (RCTs), that involved 1599 participants, that investigated angiogenesis inhibitors in the treatment of SCLC were included in this meta‐analysis. Sun and Bev achieved better PFS than Tha (Bev VS. Tha, HR = 0.88, 95% CI: 0.79‐0.98, Sun VS. Tha, HR = 0.80, 95% CI: 0.65‐1.00). Moreover, Sun and Bev were superior to placebo in terms of PFS (Bev VS. Placebo, HR = 0.89, 95%CI: 0.81‐0.97, Sun VS. Placebo, HR = 0.81, 95% CI: 0.66‐1.00). Based on this study, we found no significant difference of OS of SCLC. The angiogenesis pathway and expression of target genes were globally deactivated in SCLC tissue.

Conclusion

Results of this network meta‐analysis indicate that the PFS outcome of SCLC with Sun or Bev drugs is superior to that of Tha. The improved therapeutic impact of angiogenesis inhibitors on SCLC needs more evidence, such as long‐term observation in clinical trials, to be validated.

Apatinib for chemotherapy-refractory extensive-stage SCLC: a retrospective study

PURPOSE

There is no standard treatment strategy for patients with extensive-stage small cell lung cancer (SCLC) who have failed two or more prior chemotherapeutic regimens. In this study, we retrospectively evaluated the efficacy and safety of apatinib in patients with extensive-stage SCLC after failure of more than second-line chemotherapy.

METHODS

A study group comprised of 22 patients with extensive-stage SCLC after failure of more than two prior chemotherapeutic regimens was given apatinib orally at an initial dose of 500 mg daily until disease progression or unacceptable toxicity. This study was analyzed according to the National Cancer Institute Common Toxicity Criteria for adverse events (AEs) and Response Evaluation Criteria in Solid Tumors (RECIST) for response assessment.

RESULTS

Between August 30, 2015, and May 26, 2017, 22 patients were enrolled for evaluating the efficacy and safety of apatinib. Among them, 12/22 (54.5%) underwent dose reduction during treatment. Up to July 31, 2018, the median progression-free survival rate was 135.0 days [95% confidence interval (CI) 63.8-206.2]. According to the RECIST criteria, the disease control rate (DCR) was 86.4%, 19/22 [comprised of partial response (PR) 18.2%, 4/22; and stable disease (SD) 68.2%, 15/22 patients]. The most frequent AEs were hand-foot syndrome (45.5%, 10/22), secondary hypertension (45.5%, 10/22) and fatigue (40.9%, 9/22). The primary grade 3 or 4 toxicities were hypertension (22.7%, 5/22), hand-foot syndrome (13.6%, 3/22), and proteinuria (9.1%, 2/22).

CONCLUSIONS

Apatinib exhibits modest activity and acceptable toxicity for patients with heavily pretreated extensive-stage SCLC.

Role of tumor-associated neutrophils in regulation of tumor growth in lung cancer development: A mathematical model

Neutrophils display rapid and potent innate immune responses in various diseases. Tumor-associated neutrophils (TANs) however either induce or overcome immunosuppressive functions of the tumor microenvironment through complex tumor-stroma crosstalk. We developed a mathematical model to address the question of how phenotypic alterations between tumor suppressive N1 TANS, and tumor promoting N2 TANs affect nonlinear tumor growth in a complex tumor microenvironment. The model provides a visual display of the complex behavior of populations of TANs and tumors in response to various TGF-β and IFN-β stimuli. In addition, the effect of anti-tumor drug administration is incorporated in the model in an effort to achieve optimal anti-tumor efficacy. The simulation results from the mathematical model were in good agreement with experimental data. We found that the N2-to-N1 ratio (N21R) index is positively correlated with aggressive tumor growth, suggesting that this may be a good prognostic factor. We also found that the antitumor efficacy increases when the relative ratio (Dap) of delayed apoptotic cell death of N1 and N2 TANs is either very small or relatively large, providing a basis for therapeutically targeting prometastatic N2 TANs.

Autophagy Inhibition Promotes Bevacizumab-induced Apoptosis and Proliferation Inhibition in Colorectal Cancer Cells

Aim: Anti-VEGF therapy plays an important role in the treatment of malignant tumors, especially metastatic malignant tumors. However, resistance and an inefficient response to anti-VEGF therapy exist. The current study aimed to investigate whether autophagy plays a part in the anti-tumor effect of bevacizumab in colorectal cancer cells. Methods: VEGF-A expression was measured by immunohistochemical methods. Cell viability and cell apoptosis were detected using 3-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) and flow cytometry. Autophagy was assessed by a western blot, fluorescence microscopy and transmission electron microscopy. HIF-1α was measured using a western blot. A xenograft tumor model of colorectal cancer was constructed to determine the efficacy of the treatment of bevacizumab and chloroquine. Results: VEGF-A protein was upregulated in colorectal cancer tissue. Anti-VEGF (bevacizumab) inhibited cell viability and induced apoptosis. Moreover, bevacizumab induced autophagy. The inhibition of autophagy by chloroquine or by small interfering RNA promoted bevacizumab-induced apoptosis and proliferation inhibition. Further study showed that bevacizumab treatment significantly augmented HIF-1α. Furthermore, cells pretreated with YC-1, a HIF-1α inhibitor, displayed significantly attenuated bevacizumab-induced autophagy. Finally, a combinatory treatment of bevacizumab and chloroquine synergistically inhibited tumor growth in a xenograft tumor model of colorectal cancer cells. Conclusions: Our results showed that the inhibition of autophagy promoted the anti-tumor effect of bevacizumab and may offer a promising therapeutic strategy for colorectal cancer.

Targeting chaperonin containing TCP1 (CCT) as a molecular therapeutic for small cell lung cancer

Identifying new druggable targets is desired to meet the needs for effective cancer treatments. To this end, we previously reported the efficacy of a therapeutic peptide called CT20p that displays selective cytotoxicity through inhibition of a multi-subunit, protein-folding complex called Chaperonin-Containing TCP-1 (CCT). To investigate the role of CCT in cancer progression, we examined protein levels of CCT subunits in liver, prostate, and lung cancer using human tissue microarrays. We found that these cancers expressed higher levels of CCT2 as compared to normal tissues. Small cell lung cancer (SCLC) stood out as having statistically significant difference in CCT2. Higher levels of CCT2 in tumors from lung cancer patients were also associated with decreased survival. Using SCLC cell lines, we observed detectable amounts of CCT subunits and cells were susceptible to killing by CT20p. Treatment with CT20p, delivered to cells using polymeric nanoparticles, was cytotoxic to all SCLC cell lines, decreasing the levels of CCT client proteins like STAT3. In contrast, treatment with a STAT3 inhibitor was effective in one of the SCLC cell lines. While we found that CCT levels could vary in cell lines, normal tissues had low levels of CCT and minimal toxicity to liver or kidney function was observed in mice treated with CT20p. These results indicate that in SCLC, changes in CCT levels could be used as a biomarker for diagnosis and that targeting CCT for inhibition with CT20p is a promising treatment approach for those cancers such as SCLC that currently lack targeted therapeutics.

Targeted therapy with apatinib in a patient with relapsed small cell lung cancer: A case report and literature review

RATIONALE

Small cell lung cancer (SCLC) is a lethal malignancy. Once relapsed, the disease is irreversible and most of the patients will die of cancer aggravation in 1 to 2 months. In the past several decades, little progress has been made in the systemic treatment of SCLC. Apatinib, as a novel small-molecule tyrosine kinase inhibitor specifically targeting the vascular endothelial growth factor receptor 2 (VEGFR2), has achieved progress in treatment of a variety of cancers. However, there has been no report of the targeted therapy with apatinib in SCLC yet.

PATIENT CONCERNS

A 63-year-old man, an ex-smoker, presented with a slight hoarseness and cough. The patient was admitted to our department with a primary diagnosis of SCLC at an extensive stage (ES-SCLC). After 17 months of successful first-, second-, and third-line chemotherapy, the disease eventually became relapsed. Then, apatinib treatment started promptly on demand by the patient and his family.

INTERVENTION

After presenting an informed consent, the patient received apatinib treatment immediately at a dose of 250 mg/day orally.

OUTCOMES

(1) On the 28th day of apatinib therapy, the symptoms of dyspnea and poor appetite of the patient were notably improved. (2) The CT scan taken on the 70th day showed that the pleural effusion in the left lung almost disappeared. (3) The elevated serum neuron-specific enolase (NSE) level was decreased. The patient died of acute respiratory failure on the 172nd day of apatinib treatment. Importantly, the tumor mass did not enlarge obviously during apatinib treatment.

LESSONS

Here, we presented a case with relapsed SCLC who unexpectedly responded to single-agent apatinib treatment. Therefore, this report will shed light on future studies of targeted therapy with apatinib in SCLC at different stages.

What's new in small cell lung cancer – extensive disease? An overview on advances of systemic treatment in 2016

Systemic therapy options for small cell lung cancer patients with extensive disease remain poor. After an initial response on first-line therapy, virtually all patients develop disease progression. For those who showed an initial response only few therapy options with low response rates are currently available. Until now, many experimental and targeted agents have failed to yield convincing clinical benefits, and new therapy options are clearly warranted for these patients. In this year's oncological congresses, several new therapy strategies, including checkpoint inhibition, showed promising results in ongoing trials. Furthermore, a potential benefit of new agents targeting DLL3, Aurora A kinase and PARP-inhibitor was reported. In this review we summarize new developments and critically highlight the most important and promising data in the relapsed small cell lung cancer disease.

Ovarian function following targeted anti-angiogenic therapy with bevacizumab

Improvements in cancer therapy have enabled further insight into the long-term effects of treatment, including the highly prevalent gonadal failure. The focus of treatment has been shifted to the preservation of fertility, which may be achieved by preventing ovarian toxicity. To this end, new molecular-targeted agents, including monoclonal antibodies, have been developed and used in a standard procedure for managing different cancers. However, the prolonged antitumor activity of these drugs may cause the emergence of new toxic effects. The aim of the present review was to discuss the leading toxic effect of the anti-angiogenic agent bevacizumab on ovarian function in female patients of reproductive age, which may be observed and expected during in clinical practice. The majority of bevacizumab-induced side effects are expected to be transient and eliminated within the anticipated drug clearance time frame; however, fundamental investigations on these effects are required for generating more evidence-based practice guidelines.

Survival changes in patients with small cell lung cancer and disparities between different sexes, socioeconomic statuses and ages

Small cell lung cancer (SCLC), as a proportion, makes up only 15–17% of lung cancer cases. The development of treatments for SCLC has remained stagnant for decades, and SCLC is expected to persist as a threat to human health. To date, no publications based on large populations have been reported. We calculated survival changes in patients with SCLC during each decade between 1983 and 2012 to determine the roles of race, sex, age, and socioeconomic status (SES) on survival rates based on the Surveillance, Epidemiology, and End Results (SEER) registries. In total, 106,296 patients with SCLC were identified, with the overall incidence per 100,000 decreasing each decade from 9.6 to 7.8 to 5.8. The median survival for SCLC remained 7 months, and the 12-month relative survival rates (RSRs) remained relatively stable at 32.9%, 33.2% and 33.2% during each decade. The 5-year RSRs significantly improved from 4.9% to 5.9% to 6.4% during each decade, but remained extremely low. In addition, a narrowing of the survival gaps among SES groups and stable survival gaps between sexes were observed. Although the incidence of SCLC decreased during each decade, the overall survival remained relatively stable, highlighting the urgency of developing novel treatments and the importance of prevention and early detection.

Improvements in Clinical Trials Information Will Improve the Reproductive Health and Fertility of Cancer Patients

There are a number of barriers that result in cancer patients not being referred for oncofertility care, which include knowledge about reproductive risks of antineoplastic agents. Without this information, clinicians do not always make recommendations for oncofertility care. The objective of this study was to describe the level of reproductive information and recommendations that clinicians have available in clinical trial protocols regarding oncofertility management and follow-up, and the information that patients may receive in clinical trials patient information sheets or consent forms. A literature review of the 71 antineoplastic drugs included in the 68 clinical trial protocols showed that 68% of the antineoplastic drugs had gonadotoxic animal data, 32% had gonadotoxic human data, 83% had teratogenic animal data, and 32% had teratogenic human data. When the clinical trial protocols were reviewed, only 22% of the protocols reported the teratogenic risks and 32% of the protocols reported the gonadotoxic risk. Only 56% of phase 3 protocols had gonadotoxic information and 13% of phase 3 protocols had teratogenic information. Nine percent of the protocols provided fertility preservation recommendations and 4% provided reproductive information in the follow-up and survivorship period. Twenty-six percent had a section in the clinical trials protocol, which identified oncofertility information easily. When gonadotoxic and teratogenic effects of treatment were known, they were not consistently included in the clinical trial protocols and the lack of data for new drugs was not reported. Very few protocols gave recommendations for oncofertility management and follow-up following the completion of cancer treatment. The research team proposes a number of recommendations that should be required for clinicians and pharmaceutical companies developing new trials.