Personalized Therapy of Small Cell Lung Cancer

First-Line Treatment for Advanced SCLC: What Is Left Behind and Beyond Chemoimmunotherapy

Small cell lung cancer (SCLC) is still a lethal disease. Three phase III randomized clinical trials (IMpower133, CASPIAN, and KEYNOTE-604) have highlighted the survival gain of adding immune checkpoint inhibitors to first-line standard chemotherapy in advanced SCLC patients. In this review, we discuss the data from the three trials above. Furtherly, we analyze issues that still need to be elucidated, like the role of biomarkers, poor performance status at baseline, the presence of brain metastases, and the platinum compound's choice. Moreover, we depict the future of SCLC first-line therapy management, focusing on new therapeutic strategies currently under investigation.

Emerging drugs for small cell lung cancer: a focused review on immune checkpoint inhibitors

INTRODUCTION

Small cell lung cancer (SCLC) is an aggressive malignancy that accounts for 15% of all lung cancers. It is characterized by initial responsiveness to therapy followed by rapid disease progression that is relatively resistant to further treatment. Recently, the addition of an immune checkpoint inhibitor (ICI) to chemotherapy has improved survival in patients with advanced disease, the first advance in systemic therapy in SCLC in over 30 years.

AREAS COVERED

In this review, we present an overview of SCLC with a focus on the scope of the problem and standard treatment, followed by a critical assessment of scientific rationale for immunotherapy in SCLC and the clinical trials that have been performed with ICIs in SCLC. Finally, we address ongoing hurdles for the development of ICIs in SCLC and potential avenues for further study.

EXPERT OPINION

Despite solid biological rationale, the results of clinical trials of ICIs in SCLC have yielded modest benefits. A small subset of patients does achieve long-term benefit, but further development of ICIs in SCLC will depend on the identification of predictive biomarkers and the design of combination regimens that take advantage of the molecular alterations that drive the immune-avoidance mechanisms and survival of SCLC cells.

Comparative Efficacy and Safety of Nivolumab and Nivolumab Plus Ipilimumab in Advanced Cancer: A Systematic Review and Meta-Analysis

Background

Combination therapy with immune checkpoint inhibitors (ICIs) has been applied in the clinic to achieve synergistic effects and to improve clinical efficacy. Compared with monotherapy, combination therapy has promising efficacy against various advanced cancers. To further verify the effectiveness of combination therapy, we conducted a meta-analysis of the efficacy and safety of nivolumab (NIVO) and NIVO plus ipilimumab (IPI) in advanced cancer.

Methods

Electronic databases (PubMed, EMbase, and The Cochrane Library) were systematically searched for applicable studies published in English between January 1990 and June 2019. Relevant outcomes included objective response rate (ORR), disease control rate (DCR), median progression-free survival (mPFS), median overall survival (mOS), and grade 3–4 adverse events (AEs).

Results

A total of 1,297 patients from six studies were included. Compared with NIVO alone, NIVO + IPI was more efficacious for advanced tumors. Pooled outcome values were: ORR, 1.73 (95% CI: 1.34–2.23); DCR, 1.80 (95% CI: 1.21–2.69); mPFS, 0.22 (95% CI: 0.03–0.41); mOS, 0.03 (95% CI: −0.20–0.26); and grade 3–4 AEs, 3.64 (95% CI: 2.86–4.62).

Conclusion

NIVO + IPI is more effective than NIVO alone for the treatment of advanced cancer and can significantly improve ORR and DCR and prolong mPFS. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to validate the above conclusions.

Efficacy and Safety of Rovalpituzumab Tesirine in Third-Line and Beyond Patients with DLL3-Expressing, Relapsed/Refractory Small-Cell Lung Cancer: Results From the Phase II TRINITY Study

PURPOSE

Although extensive-stage small-cell lung cancer (SCLC) is highly responsive to first-line therapy, virtually all patients develop resistance with short survival. Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate targeting delta-like 3 protein (DLL3). This open-label, single-arm, phase II study (TRINITY) assessed safety and efficacy of Rova-T in patients with DLL3-expressing SCLC in the third-line and beyond (3L+) setting.

PATIENTS AND METHODS

Patients with DLL3-expressing SCLC (determined by mouse antibody immunohistochemistry [IHC] assay), and ≥2 prior regimens, received 0.3 mg/kg Rova-T once every 6 weeks for two cycles. During study, a rabbit antibody IHC assay was developed and used for the final analysis, with DLL3-positive and DLL3-high defined as ≥25% and ≥75% of tumor cells positive for DLL3, respectively. The primary endpoints were objective response rate (ORR) and overall survival (OS).

RESULTS

Among 339 patients enrolled, 261 (77%) had two prior lines of therapy and 78 (23%) had ≥3. DLL3-high and DLL3-positive tumors by rabbit IHC were seen in 238 (70%) and 287 (85%) patients, respectively. The remaining 52 (15%) were DLL3-negative only by rabbit IHC or had missing results. ORR was 12.4%, 14.3%, and 13.2% in all, DLL3-high, and DLL3-positive patients, respectively. Median OS was 5.6 months in all patients and 5.7 months in DLL3-high patients. The most common adverse events (AE) were fatigue, photosensitivity reaction, and pleural effusion. Grade 3-5 AEs were seen in 213 (63%) patients.

CONCLUSIONS

Rova-T is the first targeted agent in SCLC to use DLL3, a novel biomarker. However, results demonstrate modest clinical activity in 3L+ SCLC, with associated toxicities.

Adherence to recommended clinical guidelines in extensive disease small-cell lung cancer across the US, Europe, and Japan

Purpose

This study compared real-world treatment patterns of patients with extensive disease small-cell lung cancer (ED-SCLC) across regions and by platinum resistance/platinum sensitivity (PR/PS) and established if these patterns were in line with published guidelines.

Patients and methods

The data source was the Oncology Monitor, a global database using retrospective medical chart reviews of oncology patients treated with anticancer drugs. All patients diagnosed with ED-SCLC from January 2014 through December 2016 in the US, and in France, Germany, Italy, Spain, and the UK (European Union; EU5), and Japan were included.

Results

Of 5,849 treated patients, 73.4%, 19.8% and 6.8% received first, second, or third/later lines (1L, 2L, 3L) of therapy, respectively. The most frequent 1L treatment, platinum + etoposide, was significantly more common in the US (87.0%) than in the EU5 (82.1%) or Japan (73.3%) (P<0.05). Platinum + irinotecan was a common 1L treatment in Japan (22.7%) but not in the US (2.0%) or EU5 (0.5%, P<0.0001). Topotecan was the most common 2L treatment in the US and EU5, but amrubicin was the most common in Japan. Among PR patients, 27.3%, 10.8%, and 36.4% received a platinum-based 2L therapy in the US, EU5, and Japan, respectively. Among PS patients, approximately half were not re-challenged with a 2L platinum-based therapy across all regions.

Conclusion

In contrast to treatment guidelines, a significant proportion of real-world PR patients were re-challenged with a 2L platinum-based therapy, while conversely, many PS patients did not receive platinum-based therapies in 2L. This study highlights a lack of a consistent paradigm for 2L ED-SCLC treatment, limited therapeutic options, and an unmet need among SCLC patients.

Characteristics and survival difference of clinical tumor size 0 extensive-stage small cell lung cancer with different metastasis pattern

Background

Few studies were focused on the characteristics and survival prognosis of clinical tumor size 0 (cT0) extensive-stage small cell lung cancer (ES-SCLC) patients with distant metastasis.

Methods

The proper patients were screened based on the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2013. Chi-square test was used to analyze the characteristics of cT0 stage. The risk factors on cT0 stage were analyzed by Logistic regression model. The survival difference was compared by the Log rank test. The prognostic factors on survival were analyzed by univariate and multivariate Cox regression model.

Results

Only 1.2% of patients were diagnosed at cT0 stage. Clinical nodal status 0 (cN0) stage, no bone metastasis and no lung metastasis were all risk factors on cT0 stage. The patients at cT0 stage had better cancer specific survival (CSS) benefit (P=0.011). The cT0 stage was also an independent prognostic factor on CSS (P=0.018).

Conclusions

The patients at cT0 stage was a different subgroup compared with the patients at cT1-4 stage for ES-SCLC patients with distant metastasis.

Identification of candidate genes or microRNAs associated with the lymph node metastasis of SCLC

BACKGROUND

Small cell lung cancer (SCLC) is a highly malignant cancer, and over 70% of patients with SCLC present with the metastatic disease. We aimed to explore some novel differentially expressed genes (DEGs) or microRNAs (miRNAs) associated with the lymph node metastasis of SCLC.

METHODS

The DEGs between the metastasis and cancer groups were identified, and GO functional and KEGG pathway enrichment analyses for these DEGs were implemented. Subsequently, the protein-protein interaction network and subnetwork of module were constructed. Then the regulatory networks based on miRNAs, transcription factors (TFs) and target DEGs were constructed. Ultimately, the survival analysis for DEGs was performed to obtain the DEGs related to the survival of SCLC.

RESULTS

Here, 186 upregulated (e.g., GSR, HCP5) and 144 downregulated DEGs (e.g., MET, GRM8, and DACH1) were identified between the SCLC patients with lymph node metastasis and without lymph node metastasis. GRM8 was attracted to the G-protein coupled receptor signaling pathway. Besides, miR-126 was identified in the miRNAs-TFs-target regulatory network. GRM8 and DACH1 were all regulated by miR-126. In particular, GSR and HCP5 were correlated with survival of SCLC patients.

CONCLUSION

MiR-126, DACH1, GRM8, MET, GSR, and HCP5 were implicated in the lymph node metastasis process of SCLC.

Overexpression of 14-3-3ζ in lung tissue predicts an improved outcome in patients with lung adenocarcinoma

One of the factors limiting the survival rate of patients with lung cancer is the high risk for recurrence following surgical resection. Previous studies indicate that 14-3-3ζ is a central cellular hub protein that regulates multiple signaling pathways involved in cancer progression. The present study evaluated the prognostic significance of 14-3-3ζ in patients with lung adenocarcinoma. The expression of 14-3-3ζ and E-cadherin, an important protein involved in the epithelial-mesenchymal transition, was evaluated by immunohistochemistry in lung tumor tissues and adjacent normal lung tissues resected from 123 patients with lung adenocarcinoma. The correlation between the two proteins, their association with clinicopathological features and their prognostic significance were subsequently analyzed. Within these parameters, an overall survival (OS) prediction model was constructed using multivariate Cox proportional hazards regression. The expression of 14-3-3ζ was upregulated in lung adenocarcinoma, in contrast to E-cadherin, which was downregulated in lung adenocarcinoma tissues compared with normal tissues. In addition, the expression of 14-3-3ζ was positively correlated with that of E-cadherin (r=0.256, P=0.012) and differentiation (P<0.001). Increased E-cadherin expression was indicative of smaller tumor size and greater differentiation, and the overexpression of 14-3-3ζ and E-cadherin were associated with longer OS (P=0.010 and P=0.006, respectively). Finally, a multivariate analysis revealed that TNM stage and 14-3-3ζ were independent prognostic indicators (P<0.001 and P=0.026, respectively). 14-3-3ζ may function as a tumor suppressor associated with E-cadherin upregulation and could be used as a prognostic biomarker for resected lung adenocarcinoma. These findings provide a novel insight on potential intervention strategies for patients with lung cancer.

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.

A recurrence-free survivor with chemotherapy-refractory small cell lung cancer after pneumonectomy: A case report and review of the literature

RATIONALE

The optimal therapeutic regimen for chemotherapy-refractory and node-positive small-cell lung cancer (SCLC) is criticizable for the lack of evidence.

PATIENT CONCERNS

A patient with locally advanced SCLC was insensitive to the first-line chemotherapy of etoposide, irinotecan, and cisplatin.

DIAGNOSES

The patient was diagnosed as SCLC with mediastinal lymph node metastasis by pathological staining.

INTERVENTIONS

Salvage pneumonectomy and systematic lymph node dissection combined with oral apatinib and mediastinal radiotherapy were performed for him.

OUTCOMES

The patient survived for more than 2 years without recurrence after the operation and adjuvant therapy.

LESSONS

For patients with chemotherapy-resistant but resectable SCLC, a timely resection combined with postoperative radiotherapy and apatinib might be effective.

A long non-coding RNA HOTTIP expression is associated with disease progression and predicts outcome in small cell lung cancer patients

BACKGROUND

Despite progress in treatment of small cell lung cancer (SCLC), the biology of the tumor still remains poorly understood. Recently, we globally investigated the contributions of lncRNA in SCLC with a special focus on sponge regulatory network. Here we report lncRNA HOTTIP, which is specifically amplified in SCLC, is associated with SCLC proliferation and poor prognosis of patients.

METHODS

RT-qPCR was used to investigate the expression of HOTTIP in SCLC tissues and cell lines. The role of HOTTIP in SCLC cell proliferation was demonstrated by CCK8 assay, colony formation assay, flow cytometry analysis and in vivo SCLC xenograft model in nude mice through HOTTIP loss- and gain-of-function effects. Western blot assay was used to evaluate gene expression in cell lines at protein level. RNA pull-down, Mass spectrometry and RNA binding protein immunoprecipitation (RIP) were performed to confirm the molecular mechanism of HOTTIP involved in SCLC progression.

RESULTS

We found that HOTTIP was overexpressed in SCLC tissues, and its expression was correlated with the clinical stage and the shorter survival time of SCLC patients. Moreover, HOTTIP knockdown could impair cell proliferation, affect the cell cycle and inhibit tumor growth of mice, while HOTTIP overexpression might enhance cell proliferation and cell cycle in vitro and in vivo. Mechanistic investigations showed that HOTTIP functions as an oncogene in SCLC progression by sponging miR-574-5p and affecting the expression of polycomb group protein EZH1.

CONCLUSIONS

Overall, we identified that HOTTIP was involved in SCLC tumorigenesis through the ceRNA network "HOTTIP/miR-574-5p/EZH1". Our findings not only illuminate how HOTTIP confers an oncogenic function in SCLC pathogenesis, but also underscore a novel gene expression governing hallmarks in the disease.

Cisplatin and photodynamic therapy exert synergistic inhibitory effects on small-cell lung cancer cell viability and xenograft tumor growth

Lung cancer is the leading cause of cancer death worldwide. Small-cell lung cancer (SCLC) is an aggressive type of lung cancer that shows an overall 5-year survival rate below 10%. Although chemotherapy using cisplatin has been proven effective in SCLC treatment, conventional dose of cisplatin causes adverse side effects. Photodynamic therapy, a form of non-ionizing radiation therapy, is increasingly used alone or in combination with other therapeutics in cancer treatment. Herein, we aimed to address whether low dose cisplatin combination with PDT can effectively induce SCLC cell death by using in vitro cultured human SCLC NCI-H446 cells and in vivo tumor xenograft model. We found that both cisplatin and PDT showed dose-dependent cytotoxic effects in NCI-H446 cells. Importantly, co-treatment with low dose cisplatin (1 μM) and PDT (1.25 J/cm²) synergistically inhibited cell viability and cell migration. We further showed that the combined therapy induced a higher level of intracellular ROS in cultured NCI-H446 cells. Moreover, the synergistic effect by cisplatin and PDT was recapitulated in tumor xenograft as revealed by a more robust increase in the staining of TUNEL (a marker of cell death) and decrease in tumor volume. Taken together, our findings suggest that low dose cisplatin combination with PDT can be an effective therapeutic modality in the treatment of SCLC patients.

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 antiangiogenic treatment of small-cell lung cancer

Small-cell lung cancer (SCLC), a poorly differentiated neuroendocrine malignancy, has a rapid growth rate, strong aggressiveness, early metastases, and poor prognosis. Angiogenesis greatly contributes to the metastatic process of SCLC, which has a higher vascularization compared with non-small-cell lung cancer (NSCLC). SCLC might constitute an ideal malignancy for assessing new antiangiogenic drugs and therapeutic strategies. Combining bevacizumab with paclitaxel has therapeutic benefits in chemoresistant, relapsed SCLC. The cisplatin–etoposide and bevacizumab combination, as the first-line treatment for extensive-stage SCLC, can improve progression-free survival (PFS), with an acceptable toxicity profile. Ziv-aflibercept combined with topotecan is promising for platinum-refractory SCLC. Chemotherapy combined with thalidomide cannot prolong survival. Maintenance sunitinib of 37.5 mg/day in extensive-stage SCLC patients following induction chemotherapy with platinum/etoposide improves median PFS by 1.6 months. Serum angiopoietin-2 concentrations and vascular endothelial growth factor levels correlate with poor prognosis. Bevacizumab, ziv-aflibercept, and sunitinib are worthy of further evaluation. Thalidomide, sorafenib, pomalidomide, and cediranib may not be suitable for SCLC.

Targeting angiogenesis in small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive and lethal malignancy. Despite high initial response rates to systemic chemotherapy, the disease eventually relapses; further treatment only modestly improves outcomes and overall survival (OS) for patients with extensive stage disease is less than one year. Little progress has been made during the past decades, with no new drugs approved. Consequently, the development of novel strategies is an unmet need. The inhibition of angiogenesis, a defining characteristic of cancer, has demonstrated modest efficacy in several human malignancies, including non-small cell lung cancer (NSCLC). However, results from clinical trials in SCLC have been disappointing, and no anti-angiogenic agent has received regulatory approval due to lack of clinical efficacy. The elucidation of underlying mechanisms responsible for tumor resistance to angiogenic therapy and the simultaneous blockade of multiple elements that play a role in angiogenesis need to be further explored.