Phase II Trial of Temozolomide in Patients with Relapsed Sensitive or Refractory Small Cell Lung Cancer, with Assessment of Methylguanine-DNA Methyltransferase as a Potential Biomarker

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.

Deep analysis of the trials and major challenges in the first-line treatment for patients with extensive-stage small cell lung cancer

The median overall survival (OS) is approximately 10 months when chemotherapy alone is the first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). The approval of the two PD-L1 inhibitors, atezolizumab and durvalumab, marked the beginning of the immunotherapy era for ES-SCLC. Serplulimab, as the first PD-1 inhibitor to achieve success in the first-line treatment of ES-SCLC, has not only demonstrated significant improvements in patient survival outcomes but also ushered in a new era for PD-1 inhibitors in the treatment of ES-SCLC. Recently, antiangiogenic agents with chemo-immunotherapy have achieved breakthroughs in first-line ES-SCLC treatment. Improving the clinical benefits of individualized treatment for patients with ES-SCLC remains challenging. Challenges include identifying biomarkers for targeted therapy, exploring new treatments, developing new medicines, and classifying SCLC molecular subtypes. This review provides an in-depth analysis of research on first-line ES-SCLC treatment. Additionally, it discusses advances in ES-SCLC treatment.

Phase I/II Investigator-Initiated Study of Olaparib and Temozolomide in SCLC: Final Analysis and CNS Outcomes

PURPOSE

Temozolomide plus PARP inhibition has shown promise in small cell lung cancer (SCLC). We previously reported outcomes from the first 50 patients (cohort 1) of a phase I/II trial of olaparib/temozolomide in recurrent SCLC. In this study, we report a final analysis of this trial, including a second cohort with an alternate dosing strategy and an exploratory analysis of central nervous system (CNS)-specific outcomes.

PATIENTS AND METHODS

This was an open-label phase I/II trial testing the combination of olaparib and temozolomide in relapsed SCLC. The primary endpoint was objective response rate (ORR). Secondary endpoints were safety, progression-free survival, and overall survival. We tested escalating doses of olaparib/temozolomide across two cohorts, both of which had temozolomide dosed on days 1 to 7 of each 21-day cycle. In previously published cohort 1, olaparib was dosed on days 1 to 7; in cohort 2, olaparib was dosed continuously.

RESULTS

Sixty-six patients were enrolled across the two cohorts: 50 in cohort 1 and 16 in cohort 2. The confirmed ORR of cohort 1 was 41.7% (20/48 evaluable), and the confirmed ORR of cohort 2 was 7% (1/14 evaluable; closed after dose escalation to enrollment for lack of observed efficacy). Among 15/66 patients (22.7%) with untreated brain metastases at enrollment, the best overall intracranial response was complete response in 6/15 patients, partial response in 4/15 patients, and stable disease in 3/15 patients for a CNS disease control rate of 87% (95% confidence interval, 59.5%-98.3%).

CONCLUSIONS

Olaparib/temozolomide may be effective in relapsed SCLC, especially for patients with CNS disease. Ongoing analyses with regard to optimal dosing schedule will inform potential for future use of this combination in SCLC.

Strategies to Target Chemoradiotherapy Resistance in Small Cell Lung Cancer

Background: Small cell lung cancer (SCLC) is a lethal form of lung cancer with few treatment options and a high rate of relapse. While SCLC is initially sensitive to first-line DNA-damaging chemo- and radiotherapy, relapse disease is almost universally therapy-resistant. As a result, there has been interest in understanding the mechanisms of therapeutic resistance in this disease. Conclusions: Progress has been made in elucidating these mechanisms, particularly as they relate to the DNA damage response and SCLC differentiation and transformation, leading to many clinical trials investigating new therapies and combinations. Yet there remain many gaps in our understanding, such as the effect of epigenetics or the tumor microenvironment on treatment response, and no single mechanism has been found to be ubiquitous, suggesting a significant heterogeneity in the mechanisms of acquired resistance. Nevertheless, the advancement of techniques in the laboratory and the clinic will improve our ability to study this disease, especially in patient populations, and identify methods to surmount therapeutic resistance.

Bi-weekly irinotecan is an effective and convenient regimen in the treatment of relapsed or refractory small cell lung cancer

BACKGROUND

Despite initial dramatic responses, metastatic small cell lung cancer (SCLC) invariably recurs. Irinotecan is one of the active agents for patients with recurrent SCLC. In the second line, weekly or three-weekly irinotecan regimens have been adopted, however, the optimal dose and schedule is not defined. In our institution, we use a bi-weekly regimen of irinotecan. In this study, we aimed to investigate the safety and efficacy of the bi-weekly irinotecan in the second- or third-line treatment of SCLC patients.

METHODS

The study population consisted of advanced stage SCLC patients who were followed at Hacettepe University Cancer Institute between January 2007 and March 2021 and received salvage irinotecan 180 mg/m2 every two weeks, following progression after platinum-etoposide treatment.

RESULTS

One hundred patients were included. At diagnosis, nineteen patients (19%) had limited stage and 81 patients (81%) had extensive stage SCLC. Objective response rates (ORR) were 44.6% and 46.2% for patients who received irinotecan treatment in second line, and in third line, respectively. Seventeen percent of all the patients had grade 3 and above adverse events during irinotecan treatment. In our study, 45.8% of patients were able to complete at least 6 cycles of irinotecan treatment and 69.8% were able to receive at least 3 cycles of irinotecan treatment without any dose interruption or reduction.

CONCLUSIONS

Irinotecan 180 mg/m2 every two weeks appears to be safe and effective in the 2nd- and 3rd-line treatment of advanced stage SCLC. Bi-weekly administration allows G-CSF prophylaxis in between doses, leading to an uninterrupted administration.

Challenges and future perspectives for the use of temozolomide in the treatment of SCLC

Small-cell lung cancer (SCLC), accounting for 10-20 % of all lung tumors, represents the most aggressive high-grade neuroendocrine carcinoma. Most patients are diagnosed with extensive-stage SCLC (ES-SCLC), with brian metastases identified in ∼ 80 % of cases during the disease cours, and the prognosis is dismal, with a 5-year survival rate of less than 5 %. Current available treatments in the second-line setting are limited, and topotecan has long been the only FDA-approved drug in relapsed or refractory ES-SCLC, until the recent approval of lurbinectedin, a selective inhibitor of RNA polymerase II. Temozolomide (TMZ) is an oral alkylating agent, which showed single-agent activity in SCLC, particularly among patients with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. Several studies have revealed the synergistic activity of temozolomide with poly-ADP-ribose polymerase (PARP) inhibitors, that prevent repair of TMZ-induced DNA damage. This review focuses on the rationale for the use of TMZ in ES-SCLC and provides an overview of the main trials that have evaluated and are currently investigating its role, both as a single-agent and in combinations, in relapse or refractory disease.

Phase II study of nab-paclitaxel with gemcitabine for relapsed/refractory small cell lung cancer

Background

Patients with small cell lung cancer (SCLC) often respond to first-line chemoimmunotherapy. However, relapse is inevitable and is associated with a poor prognosis. Treatments for relapsed SCLC, such as lurbinectedin and topotecan, are limited by modest efficacy and significant hematologic adverse events, leaving a need for newer therapeutic agents or regimens. The combination of gemcitabine and nab-paclitaxel is active and safe in other types of malignancies, such as pancreatic cancer.

Patients and methods

We conducted a phase II trial evaluating the efficacy and safety of gemcitabine and nab-paclitaxel in patients with relapsed/refractory SCLC. The primary endpoint was objective response rate (ORR), defined as the proportion of patients with confirmed complete or partial response. Secondary endpoints included time to progression (TTP), progression-free survival (PFS), overall survival (OS), and safety.

Results

Between October 2016 and May 2021, 32 patients were enrolled. Patients were followed for a median of 9.3 months (range 1.8-65.2). Median age was 65 years (range 48-81). Fifty percent of patients were female. Fifty-three percent of patients had platinum-resistant/refractory relapsed SCLC. The ORR was 28.1% (95% confidence interval [CI] 15.5-100%). Median PFS was 2.9 months (95% CI 2.4-3.6), and median OS was 9.3 months (95% CI 5.2-12.4). Seven patients (21.9%) developed grade 3 or 4 neutropenia.

Conclusion

Our study showed that the combination of gemcitabine and nab-paclitaxel led to encouraging outcomes in relapsed/refractory SCLC. Further studies are needed to compare this combination with other treatments used for relapsed SCLC, including lurbinectedin, temozolomide, and topotecan.

Clinical trial registration

https://clinicaltrials.gov/study/NCT02769832?cond=NCT02769832&rank=1, identifier NCT02769832.

Recent advances and future strategies in first-line treatment of ES-SCLC

Recent advancements in treating extensive-stage small-cell lung cancer (ES-SCLC) have been significantly marked by incorporating immune checkpoint inhibitors (ICIs) into platinum-based chemotherapy, leading to modest yet notable improvements in patient outcomes, which become more evident with longer follow-up. However, critical challenges persist, such as identifying effective biomarkers for accurate patient selection or finding more effective drugs. This review delves into the current and evolving treatment landscape for ES-SCLC, focusing on the most promising therapeutic strategies under investigation. We discuss the latest developments in the use of newer ICIs, antiangiogenic agents, PARP inhibitors (PARPi), lurbinectedin, and anti-DLL3 agents, offering insights into potential future directions in the management of this aggressive cancer.

MGMT function determines the differential response of ATR inhibitors with DNA-damaging agents in glioma stem cells for GBM therapy

Background

The most prevalent cancer treatments cause cell death through DNA damage. However, DNA damage response (DDR) repair pathways, initiated by tumor cells, can withstand the effects of anticancer drugs, providing justification for combining DDR inhibitors with DNA-damaging anticancer treatments.

Methods

Cell viability assays were performed with CellTiter-Glo assay. DNA damage was evaluated using Western blotting analysis. RNA-seq and single-cell level expression were used to identify the DDR signatures. In vivo, studies were conducted in mice to determine the effect of ATris on TMZ sensitization.

Results

We found a subpopulation of glioma sphere-forming cells (GSCs) with substantial synergism with temozolomide (TMZ) using a panel of 3 clinical-grade ataxia-telangiectasia- and Rad3-related kinase inhibitors (ATRis), (elimusertib, berzosertib, and ceralasertib). Interestingly, most synergistic cell lines had O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, indicating that ATRi mainly benefits tumors with no MGMT repair. Further, TMZ activated the ATR-checkpoint kinase 1 (Chk1) axis in an MGMT-dependent way. TMZ caused ATR-dependent Chk1 phosphorylation and DNA double-strand breaks as shown by increased γH2AX. Increased DNA damage and decreased Chk1 phosphorylation were observed upon the addition of ATRis to TMZ in MGMT-methylated (MGMT-) GSCs. TMZ also improved sensitivity to ATRis in vivo, as shown by increased mouse survival with the TMZ and ATRi combination treatment.

Conclusions

This research provides a rationale for selectively targeting MGMT-methylated cells using ATRis and TMZ combination. Overall, we believe that MGMT methylation status in GBM could serve as a robust biomarker for patient selection for ATRi combined with TMZ.

Treating patients with platinum-sensitive extensive-stage small-cell lung cancer in a real-world setting

Extensive-stage small-cell lung cancer (ES-SCLC) is an aggressive disease with poor 5-year survival. The first-line standard-of-care for ES-SCLC is platinum plus etoposide, along with 1 of the immune checkpoint inhibitors atezolizumab or durvalumab. Although SCLC first-line therapy often leads to rapid responses, treatment becomes more challenging at progression, particularly for those with a chemotherapy-free interval (CTFI) of ≤6 months. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for SCLC no longer specify treatment recommendations in this setting, but options approved by the US Food and Drug Administration include topotecan and lurbinectedin. Participation in a clinical trial is recommended as an option regardless of CTFI. Other NCCN-recommended regimens are paclitaxel, irinotecan, temozolomide, and cyclophosphamide/doxorubicin/vincristine, among others. Nivolumab and pembrolizumab are options in those not previously treated with a checkpoint inhibitor. For patients with platinum-sensitive SCLC (CTFI >6 months), preferred treatment per the NCCN Guidelines® for SCLC is retreatment with platinum and etoposide, although the use of immune checkpoint inhibitors is discouraged if there is progression on a drug in this class. Further research on immunotherapies and combination regimens is ongoing, and continuing work on the subcharacterization of SCLC may lead to better precision of therapies that promote more durable responses in individual patients with ES-SCLC.

Systemic Therapy for Small-Cell Lung Cancer: ASCO-Ontario Health (Cancer Care Ontario) Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on the management of patients with small-cell lung cancer.

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2022. Outcomes of interest included response rates, overall survival, disease-free survival or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 95 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address systemic therapy options, timing of therapy, treatment in patients who are older or with poor performance status, role of biomarkers, and use of myeloid-supporting agents in patients with small-cell lung cancer.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

Antigen presentation in cancer - mechanisms and clinical implications for immunotherapy

Over the past decade, the emergence of effective immunotherapies has revolutionized the clinical management of many types of cancers. However, long-term durable tumour control is only achieved in a fraction of patients who receive these therapies. Understanding the mechanisms underlying clinical response and resistance to treatment is therefore essential to expanding the level of clinical benefit obtained from immunotherapies. In this Review, we describe the molecular mechanisms of antigen processing and presentation in tumours and their clinical consequences. We examine how various aspects of the antigen-presentation machinery (APM) shape tumour immunity. In particular, we discuss genomic variants in HLA alleles and other APM components, highlighting their influence on the immunopeptidomes of both malignant cells and immune cells. Understanding the APM, how it is regulated and how it changes in tumour cells is crucial for determining which patients will respond to immunotherapy and why some patients develop resistance. We focus on recently discovered molecular and genomic alterations that drive the clinical outcomes of patients receiving immune-checkpoint inhibitors. An improved understanding of how these variables mediate tumour-immune interactions is expected to guide the more precise administration of immunotherapies and reveal potentially promising directions for the development of new immunotherapeutic approaches.

Current Evidence and Future Perspectives about the Role of PARP Inhibitors in the Treatment of Thoracic Cancers

In recent years, poly (ADP-ribose) polymerase (PARP) inhibition has become a promising therapeutic option for several tumors, especially for those harboring a BRCA 1-2 mutation or a deficit in the homologous recombination repair (HRR) pathway. Nevertheless, to date, PARP inhibitors are still not largely used for thoracic malignancies neither as a single agent nor in combination with other treatments. Recently, a deeper understanding of HRR mechanisms, alongside the development of new targeted and immunotherapy agents, particularly against HRR-deficient tumors, traced the path to new treatment strategies for many tumor types including lung cancer and malignant pleural mesothelioma. The aim of this review is to sum up the current knowledge about cancer-DNA damage response pathways inhibition and to update the status of recent clinical trials investigating the use of PARP inhibitors, either as monotherapy or in combination with other agents for the treatment of thoracic malignancies. We will also briefly discuss available evidence on Poly(ADP-Ribose) Glycohydrolase (PARG) inhibitors, a novel promising therapeutic option in oncology.

Canadian Consensus Recommendations on the Management of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive, neuroendocrine tumour with high relapse rates, and significant morbidity and mortality. Apart from advances in radiation therapy, progress in the systemic treatment of SCLC had been stagnant for over three decades despite multiple attempts to develop alternative therapeutic options that could improve responses and survival. Recent promising developments in first-line and subsequent therapeutic approaches prompted a Canadian Expert Panel to convene to review evidence, discuss practice patterns, and reach a consensus on the treatment of extensive-stage SCLC (ES-SCLC). The literature search included guidelines, systematic reviews, and randomized controlled trials. Regular meetings were held from September 2022 to March 2023 to discuss the available evidence to propose and agree upon specific recommendations. The panel addressed biomarkers and histological features that distinguish SCLC from non-SCLC and other neuroendocrine tumours. Evidence for initial and subsequent systemic therapies was reviewed with consideration for patient performance status, comorbidities, and the involvement and function of other organs. The resulting consensus recommendations herein will help clarify evidence-based management of ES-SCLC in routine practice, help clinician decision-making, and facilitate the best patient outcomes.

Efficacy and safety of nab-paclitaxel or combined nab-paclitaxel and immune checkpoint inhibitors in relapsed small-cell lung cancer

Background

Most patients with small-cell lung cancer (SCLC) experience disease progression after first-line chemotherapy. Notably, nab-paclitaxel monotherapy has antitumor activity in relapsed SCLC.

Objective

This study evaluated the efficacy and safety of combined of nab-paclitaxel and immune checkpoint inhibitors (ICIs) in relapsed SCLC.

Design

We retrospectively analyzed patients with relapsed SCLC who received nab-paclitaxel or combined nab-paclitaxel and ICIs (anti-programmed death-1, PD-1 or anti-programmed cell death 1 ligand, PD-L1) between February 2017 and September 2021.

Methods

Efficacy and safety data were collected from electronic health records. Progression-free survival (PFS) and overall survival (OS) were assessed using the Kaplan-Meier method and a standard log-rank test.

Results

We included 56 patients with relapsed SCLC, of which 29 received nab-paclitaxel alone (Group A), and 27 received combined nab-paclitaxel and ICIs (Group B). Baseline characteristics were similar between the two groups. Group B had a numerically higher objective response rate than Group A (40.7% versus 17.2%; p = 0.052). However, combined nab-paclitaxel and ICIs failed to demonstrate survival superiority over nab-paclitaxel monotherapy [median PFS: 3.2 months versus 2.8 months (p = 0.5225); median OS: 11.0 months versus 9.3 months (p = 0.7298)]. The safety profiles of Groups A and B were both tolerable.

Conclusion

This study indicated that compared with nab-paclitaxel monotherapy, combined nab-paclitaxel and ICIs failed to improve survival in relapsed SCLC.

Emerging Strategies for the Treatment of Small Cell Lung Cancer: A Review

Importance

Small cell lung cancer (SCLC) is an aggressive disease that is characterized by rapid growth and the early development of metastases. Patients typically respond to initial chemotherapy but quickly experience relapse, resulting in a poor long-term outcome. Therapeutic innovations that substantially improve survival have historically been limited, and reliable, predictive biomarkers are lacking.

Observations

This review examines the biologic characteristics of SCLC, the current treatment landscape, and ongoing efforts to identify novel therapeutic targets. Ongoing research has advanced the understanding of molecular categories and the immunologic microenvironment of SCLC, which in turn has helped improve disease classification and staging. Recently, immunotherapy-based regimens have become available for the management of SCLC, with 2 programmed cell death 1 ligand 1 inhibitors approved in combination with chemotherapy for first-line treatment of extensive-stage disease. For second-line treatment, a novel alkylating agent, lurbinectedin, which inhibits oncogenic transcription, has been approved for use in patients with metastatic SCLC. Furthermore, a wide variety of therapies and innovative combination regimens are being continuously evaluated. Potential therapeutic strategies, including aurora kinase A inhibitors, polyadenosine diphosphate-ribose polymerase inhibitors, ataxia telangiectasia and Rad3-related inhibitors, cyclin-dependent kinase 7 inhibitors, delta-like protein 3 agents, antiganglioside agents, CD47 inhibitors, and lysine-specific histone demethylase 1a inhibitors, are also being examined.

Conclusions and Relevance

Therapeutic optimization of SCLC remains a challenge, but recent trial results and drug approvals are encouraging. Advances in research have revealed critical information regarding biologic characteristics of the disease, which may lead to the identification of vulnerabilities and the development of new therapies. Further research focused on identifying biomarkers and evaluating innovative therapies will be paramount to improving treatment outcomes for patients with SCLC.

Targeting the DNA Damage Response Machinery for Lung Cancer Treatment

Lung cancer is considered the most commonly diagnosed cancer and one of the leading causes of death globally. Despite the responses from small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) patients to conventional chemo- and radiotherapies, the current outcomes are not satisfactory. Recently, novel advances in DNA sequencing technologies have started to take off which have provided promising tools for studying different tumors for systematic mutation discovery. To date, a limited number of DDR inhibition trials have been conducted for the treatment of SCLC and NSCLC patients. However, strategies to test different DDR inhibitor combinations or to target multiple pathways are yet to be explored. With the various biomarkers that have either been recently discovered or are the subject of ongoing investigations, it is hoped that future trials would be designed to allow for studying targeted treatments in a biomarker-enriched population, which is defensible for the improvement of prognosis for SCLC and NSCLC patients. This review article sheds light on the different DNA repair pathways and some of the inhibitors targeting the proteins involved in the DNA damage response (DDR) machinery, such as ataxia telangiectasia and Rad3-related protein (ATR), DNA-dependent protein kinase (DNA-PK), and poly-ADP-ribose polymerase (PARP). In addition, the current status of DDR inhibitors in clinical settings and future perspectives are discussed.

Targeting the epigenetic processes to enhance antitumor immunity in small cell lung cancer

Dysregulation of the epigenetic processes, such as DNA methylation, histone modifications, and modulation of chromatin states, drives aberrant transcription that promotes initiation and progression of small cell lung cancer (SCLC). Accumulating evidence has proven crucial roles of epigenetic machinery in modulating immune cell functions and antitumor immune response. Epigenetics-targeting drugs such as DNA methyltransferase inhibitors, histone deacetylase inhibitors, and histone methyltransferase inhibitors involved in preclinical and clinical trials may trigger antitumor immunity. Herein, we summarize the impact of epigenetic processes on tumor immunogenicity and antitumor immune cell functions in SCLC. Furthermore, we review current clinical trials of epigenetic therapy against SCLC and the mechanisms of epigenetic inhibitors to boost antitumor immunity. Eventually, we discuss the opportunities of developing therapeutic regimens combining epigenetic agents with immunotherapy for SCLC.

Survival Benefit of Adjuvant Chemotherapy in Pulmonary Carcinoid Tumors

Pulmonary carcinoid tumors are a rare subtype of neuroendocrine cell tumor found in approximately 1–2% of lung cancers. Management is primarily through surgical resection, with limited benefit of adjuvant therapy in the clinical setting. Genomic profiling is in the nascent stages to molecularly classify these tumors, but there are promising insights for future targeted therapy. A total of 80 abstracts were analyzed for further review with 11 included in our final analysis. Only 4 of the 11 reviewed in depth provided statistical analysis. We evaluated PFS, OS, 1- and 5-year survival as mentioned in the studies. Nodal and KI67 status were also analyzed. Based on the current literature, there is no definitive evidence that adjuvant chemotherapy after resection confers a survival benefit in typical or atypical carcinoids.

Arginine Deprivation in SCLC: Mechanisms and Perspectives for Therapy

Arginine deprivation has gained increasing traction as a novel and safe antimetabolite strategy for the treatment of several hard-to-treat cancers characterised by a critical dependency on arginine. Small cell lung cancer (SCLC) displays marked arginine auxotrophy due to inactivation of the rate-limiting enzyme argininosuccinate synthetase 1 (ASS1), and as a consequence may be targeted with pegylated arginine deiminase or ADI-PEG20 (pegargiminase) and human recombinant pegylated arginases (rhArgPEG, BCT-100 and pegzilarginase). Although preclinical studies reveal that ASS1-deficient SCLC cell lines are highly sensitive to arginine-degrading enzymes, there is a clear disconnect with the clinic with minimal activity seen to date that may be due in part to patient selection. Recent studies have explored resistance mechanisms to arginine depletion focusing on tumor adaptation, such as ASS1 re-expression and autophagy, stromal cell inputs including macrophage infiltration, and tumor heterogeneity. Here, we explore how arginine deprivation may be combined strategically with novel agents to improve SCLC management by modulating resistance and increasing the efficacy of existing agents. Moreover, recent work has identified an intriguing role for targeting arginine in combination with PD-1/PD-L1 immune checkpoint inhibitors and clinical trials are in progress. Thus, future studies of arginine-depleting agents with chemoimmunotherapy, the current standard of care for SCLC, may lead to enhanced disease control and much needed improvements in long-term survival for patients.

Novel therapeutic combinations with PARP inhibitors for small cell lung cancer: A bench-to-bedside review

Small cell lung cancer (SCLC) is treated as a monolithic disease despite the evident intra- and intertumoral heterogeneity. Non-specific DNA-damaging agents have remained the first-line treatment for decades. Recently, emerging transcriptomic and genomic profiling of SCLC tumors identified distinct SCLC subtypes and vulnerabilities towards targeted therapeutics, including inhibitors of the nuclear enzyme poly (ADP-ribose) polymerase (PARPi). SCLC cell lines and tumors exhibited an elevated level of PARP1 protein and mRNA compared to healthy lung tissues and other subtypes of lung tumors. Notable responses to PARPi were also observed in preclinical SCLC models. Clinically, PARPi monotherapy exerted variable benefits for SCLC patients. To date, research is being vigorously conducted to examine predictive biomarkers of PARPi response and various PARPi combination strategies to maximize the clinical utility of PARPi. This narrative review summarizes existing preclinical evidence supporting PARPi monotherapy, combination therapy, and respective translation to the clinic. Specifically, we covered the combination of PARPi with DNA-damaging chemotherapy (cisplatin, etoposide, temozolomide), thoracic radiotherapy, immunotherapy (immune checkpoint inhibitors), and many other novel therapeutic agents that target DNA damage response, tumor microenvironment, epigenetic modulation, angiogenesis, the ubiquitin-proteasome system, or autophagy. Putative biomarkers, such as SLFN11 expression, MGMT methylation, E2F1 expression, and platinum sensitivity, which may be predictive of response to distinct therapeutic combinations, were also discussed. The future of SCLC treatment is undergoing rapid change with a focus on tailored and personalized treatment strategies. Further development of cancer therapy with PARPi will immensely benefit at least a subset of biomarker-defined SCLC patients.

New perspectives in the management of small cell lung cancer

The treatment of small cell lung cancer (SCLC) is a challenge for all specialists involved. New treatments have been added to the therapeutic armamentarium in recent months, but efforts must continue to improve both survival and quality of life. Advances in surgery and radiotherapy have resulted in prolonged survival times and fewer complications, while more careful patient selection has led to increased staging accuracy. Developments in the field of systemic therapy have resulted in changes to clinical guidelines and the management of patients with advanced disease, mainly with the introduction of immunotherapy. In this article, we describe recent improvements in the management of patients with SCLC, review current treatments, and discuss future lines of research.

Are anaplastic lymphoma kinase (ALK) and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation driver biomarkers of pulmonary neuroendocrine tumors (NETs) and carcinomas (NECs)?

Background: Novel targets in neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) are needed to improve outcome. The presence of O6-Methylguanine-DNA methyltransferase (MGMT) promoter methylation in NETs and NECs may act as a predictive marker for response on treatment with temozolomide. As anaplastic lymphoma kinase (ALK) plays an important role in the nervous system we hypothesized that ALK rearrangement can act as a biomarker in patients with NETs and NECs.

Materials and Methods: We performed a retrospective analysis to establish the frequency of MGMT promoter methylation and ALK expression in tissue samples of patients with NETs and NECs.

Results: 21% (14/67) of patients tested positive for MGMT promoter methylation. MGMT promoter methylation was present in 33% (3/9) patients with typical carcinoid, in 22% (2/9) patients with atypical carcinoid, in 22% (8/37) patients with small cell lung cancer and in 8% (1/12) patient with large cell neuroendocrine carcinoma. ALK- expression was present in 14% (10 of 70 patients). In all of these patients, no ALK-rearrangement nor ALK-mutation was revealed.

Conclusions: Routine testing of NET and NEC samples for an ALK rearrangement is not recommended as ALK-expression is not associated with an ALK-rearrangement. Routine testing of NET and NEC samples for MGMT will detect a promoter hypermethylation in a sizable minority of patients who are eligible for a targeted treatment with temozolomide.

Extensive-Stage Small-Cell Lung Cancer: First-Line and Second-Line Treatment Options

Extensive-stage small-cell lung cancer is a therapeutically challenging disease. After more than two decades without clinical progress, the addition of programmed cell death protein 1 axis blockade to platinum-based chemotherapy has demonstrated sustained overall survival benefit and represents the current standard of care in the first-line setting. Despite this benefit, resistance emerges relatively rapidly in virtually all patients. Although newer treatments are being incorporated in the relapse setting, marked therapeutic resistance is typically observed in patients with relapsed small-cell lung cancer (SCLC), underscoring the need of developing more effective therapies in this setting. Notably, recent progress in the understanding of the molecular biology of SCLC might bring possibilities toward molecularly informed therapeutic strategies for patients with SCLC, which could have a significant impact for improving outcomes in this disease. Here, we review current treatment options and recent progress made in the first-line and relapsed SCLC, including the role of biomarkers and new evolving therapeutic strategies.

Therapeutic Modalities in Small Cell Lung Cancer: a paradigm shift after decades of quiescence

INTRODUCTION

Small cell lung cancer (SCLC) is known to be the most aggressive of all thoracic malignancies, notoriously known for its very poor prognosis. Platinum based chemotherapy has been the standard of care for decades. Despite years of research, no treatment novelties with significant impact on survival have been achieved until recently. The last few years have witnessed light at the end of the tunnel with immunotherapy proving to improve survival. Nevertheless, responses were not homogeneous in all subgroups, and finding who would best benefit from treatment remains unanswered. Multiple limitations exist, and the quest for optimal biomarkers seemed unfruitful until the discovery of different SCLC phenotypes.

AREAS COVERED

In this review, the authors briefly discuss SCLC phenotypes and biomarker assays. Then, the authors continue with the main trials of SCLC treatment using chemotherapy, immunotherapy and targeted treatment in the front-line or subsequent line settings.

EXPERT OPINION

Research has been extensively implemented to better understand the biology of SCLC, and test for the optimal use of immunotherapy in patients with SCLC, as well as to enhance responses via possible combinations. Targeted mechanisms of action have also been attempted; yet no solid proof of efficacy has been established.

Poly(ADP-Ribose) Polymerase Inhibition in Small Cell Lung Cancer: A Review

ABSTRACT

Small cell lung cancer (SCLC) is a highly aggressive neuroendocrine malignancy with high and rapid relapse rates and poor outcomes. Treatment for SCLC has historically been limited by the lack of targetable driver genomic lesions, however recent developments in the underpinnings of genomic instability in SCLC and understanding of its transcriptional subtypes have led to increased interest in the use of poly(ADP-ribose) polymerase (PARP) inhibitors as a rationale therapy. Poly(ADP-ribose) polymerase inhibitors, historically designed to target BRCA1/2-mutated malignancies, capitalize on synthetic lethality in homologous recombination-deficient tumors. In this review, we outline the mechanistic rationale for the use of PARP inhibitors in treating SCLC and detail key clinical trials investigating their use in combination with chemotherapy and immunotherapy. We describe developments in the understanding of biomarkers for sensitivity to therapy and highlight further investigational directions for the use of PARP inhibitors in treating SCLC.

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Management of brain metastases in lung cancer: evolving roles for radiation and systemic treatment in the era of targeted and immune therapies

Brain metastases are a common occurrence in both non-small cell and small cell lung cancer with the potential to affect quality of life and prognosis. Due to concerns about the accessibility of the central nervous system by systemic chemotherapy agents, the management of brain metastases has historically relied on local therapies including surgery and radiation. However, novel targeted and immune therapies that improve overall outcomes in lung cancer have demonstrated effective intracranial activity. As a result, the management of brain metastases in lung cancer has evolved, with both local and systemic therapies now playing an important role. Factors such as tumor histology (non-small versus small cell), oncogenic driver mutations, and symptom burden from intracranial disease impact treatment decisions. Here, we review the current management of brain metastases in lung cancer, highlighting the roles of stereotactic radiosurgery and novel systemic therapies as well as the ongoing questions that remain under investigation.

Recent developments in the treatment of small cell lung cancer

Small cell lung cancer (SCLC) comprises about 15% of all lung cancers. It is an aggressive disease, with early metastasis and a poor prognosis. Until recently, SCLC treatment remained relatively unchanged, with chemotherapy remaining the cornerstone of treatment. In this overview we will highlight the recent advances in the field of staging, surgery, radiotherapy and systemic treatment. Nevertheless, the prognosis remains dismal and there is a pressing need for new treatment options. We describe the progress that has been made in systemic treatment by repurposing existing drugs and the addition of targeted treatment. In recent years, immunotherapy entered the clinic with high expectations of its role in the treatment of SCLC. Unravelling of the genomic sequence revealed new possible targets that may act as biomarkers in future treatment of patients with SCLC. Hopefully, in the near future, we will be able to identify patients who may benefit from targeted therapy or immunotherapy to improve prognoses.

Current Strategies for Extensive Stage Small Cell Lung Cancer Beyond First-line Therapy

Extensive stage small cell lung cancer carries extremely poor prognosis and adding immune checkpoint inhibitor to platinum etoposide combination in first line only improved outcomes modestly. Once disease recurs, treatment response is only transient in nature. Various strategies that are being explored include dual checkpoint blockade, BiTE and CAR-T cell approaches. Immune checkpoint inhibitors are being combined with PARP inhibitors. Other approaches currently being investigated include liposomal irinotecan and combining known active agents for SCLC in relapsed setting such as newly approved lurbinectedin with doxorubicin, paclitaxel, irinotecan or topotecan with ATR inhibitor (Berzosertib). Temozolomide has also been tested in combination with a Parp inhibitor. New antibody or small molecule drug conjugates are being actively investigated, so is a biomarker based approach. Better understanding of small cell lung cancer disease biology via high through-put genomic, proteomic and methylation profiling offer glimpse of hope in our efforts to contain this deadly disease. A table of representative molecular targets under investigation is provided in the end.

Repositioning PARP inhibitors in the treatment of thoracic malignancies

The evaluation of the homologous recombination repair (HRR) status is emerging as a predictive tumor agnostic biomarker for poly (ADP-ribose) polymerase (PARP) inhibition across different tumor types and testing for HRR-signature is currently a developing area with promising therapeutic implications. Treatment with PARP inhibitors (PARPi) either as single agent or in combination with chemotherapy have shown so far limited activity in patients with thoracic malignancies. A deeper understanding of the biological background underlying HRR-deficient tumors, along with the recent advent of new effective targeted and immunotherapeutic agents, prompted the design of a new generation of clinical trials investigating novel PARPi-combinations in patients with lung cancer as well as malignant pleural mesothelioma. In this review we briefly summarize the biological basis of the DNA damage response pathway inhibition and provide an updated and detailed overview of clinical trials testing different PARPi-combinations strategies in patients with thoracic malignancies.

An overview of lurbinectedin as a new second-line treatment option for small cell lung cancer

Small cell lung cancer (SCLC) is a highly proliferative, aggressive form of lung cancer that carries a poor prognosis. Recent approvals with new therapeutic options represent the first in more than a decade for SCLC. Lurbinectedin, a newly approved second-line option, is a synthetic alkaloid that covalently binds DNA, generating double-strand breaks, and disrupts DNA-protein interactions and RNA transcription. Lurbinectedin may also modulate the tumor microenvironment by inducing apoptosis of peripheral blood monocytes and tumor associated macrophages, decreasing expression of the inflammatory chemokine (C-C motif) ligand 2 (CCL2) and reducing tumor angiogenesis. A single-arm, open-label, basket trial included 105 patients with SCLC that had received one prior line of therapy. Patients received lurbinectedin 3.2 mg/m² as an intravenous infusion every 3 weeks, resulting in a response rate of 35.2% and a disease control rate of 68.6%. The response rate was 45% among those with >90 days chemotherapy free interval (CTFI) and 22% in the resistant group (CTFI < 90 days). The median overall survival was 9.3 months. Myelosuppression is the most frequent clinically significant adverse event, particularly neutropenia; however, neutropenic fever occurred in only 5% of those in the SCLC cohort of the basket trial. Nausea and fatigue were also noted. The side effect profile compares favorably to topotecan, while a direct comparison of tolerability can be made between lurbinectedin versus topotecan or pegylated-liposomal doxorubicin from CORAIL, a randomized study for platinum-resistant/refractory ovarian cancer. A press release has reported the ongoing clinical trial for SCLC including combination lurbinectedin and doxorubicin versus topotecan or cyclophosphamide, doxorubicin, and vinblastine to be negative. The details may provide more insight at publication, and future trials will be important to further define the clinical utility of lurbinectedin. Lurbinectedin represents a new option in second-line SCLC.

An updated analysis of the epidemiologic trends of neuroendocrine tumors in Taiwan

The incidence of neuroendocrine tumors (NETs) has been increasing in recent decades. Previously, we reported the incidence and survival of NETs in Taiwan by analyzing the 1996–2008 data from the Taiwan Cancer Registry. Here we performed an updated analysis on the incidence and survival of NETs in Taiwan from 1996 to 2015. The incidence of NETs was 0.244 per 100,000 in 1996 and increased to 3.162 per 100,000 in 2015. The most common site of NETs was rectum (29.65%), followed by lung/bronchus (17.22%), and pancreas (10.71%). The 5- and 10-year overall survival rates of all NETs were 54.6% and 45.3%, respectively. Female and younger NETs patients had a better survival. The survival of all NETs diagnosed between 2010 and 2015 was better than those diagnosed between 2004 and 2009. Among the common sites of NETs, an improved survival of pancreatic NETs diagnosed between 2010 and 2015 compared to those diagnosed between 2004 and 2009 was observed. Overall, the incidence of NETs in Taiwan has continued to increase. The survival of pancreatic NET has shown a recent improvement. The development of novel therapeutic agents has the potential to improve the prognosis of NETs of other sites in the near future.

Temozolomide: An Updated Overview of Resistance Mechanisms, Nanotechnology Advances and Clinical Applications

Temozolomide (TMZ), an oral alkylating prodrug which delivers a methyl group to purine bases of DNA (O6-guanine; N7-guanine and N3-adenine), is frequently used together with radiotherapy as part of the first-line treatment of high-grade gliomas. The main advantages are its high oral bioavailability (almost 100% although the concentration found in the cerebrospinal fluid was approximately 20% of the plasma concentration of TMZ), its lipophilic properties, and small size that confer the ability to cross the blood-brain barrier. Furthermore, this agent has demonstrated activity not only in brain tumors but also in a variety of solid tumors. However, conventional therapy using surgery, radiation, and TMZ in glioblastoma results in a median patient survival of 14.6 months. Treatment failure has been associated with tumor drug resistance. This phenomenon has been linked to the expression of O6-methylguanine-DNA methyltransferase, but the mismatch repair system and the presence of cancer stem-like cells in tumors have also been related to TMZ resistance. The understanding of these mechanisms is essential for the development of new therapeutic strategies in the clinical use of TMZ, including the use of nanomaterial delivery systems and the association with other chemotherapy agents. The aim of this review is to summarize the resistance mechanisms of TMZ and the current advances to improve its clinical use.

Novel Cytotoxic Chemotherapies in Small Cell Lung Carcinoma

Small cell lung cancer (SCLC) is one of the deadliest thoracic neoplasms, in part due to its fast doubling time and early metastatic spread. Historically, cytotoxic chemotherapy consisting of platinum-etoposide or anthracycline-based regimens has demonstrated a high response rate, but early chemoresistance leads to a poor prognosis in advanced SCLC. Only a fraction of patients with limited-disease can be cured by chemo-radiotherapy. Given the disappointing survival rates in advanced SCLC, new cytotoxic agents are eagerly awaited. Unfortunately, few novel chemotherapy drugs have been developed in the latest decades. This review describes the results and potential application in the clinical practice of novel chemotherapy agents for SCLC.

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

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.

Metastasis to the Central Nervous System

PURPOSE OF REVIEW

Management of metastasis to the central nervous system (CNS) has evolved, and molecular characterization of metastatic disease is now routinely done. Targeted therapies, once few in number with limited penetration into the CNS, have multiplied in number and increased in CNS coverage. This article addresses recent advances in the evaluation and clinical management of patients with CNS metastasis.

RECENT FINDINGS

Metastasis of cancer to the CNS can be diagnosed and characterized with novel techniques, including molecular analyses of the spinal fluid, so-called liquid biopsies. Resected parenchymal CNS metastases are now routinely subjected to genomic sequencing. For patients with CNS metastases displaying targetable mutations, a wide variety of treatment options are available, including deferral of radiation therapy in favor of a trial of an orally bioavailable targeted therapy or immunotherapy. For patients without a molecularly targetable lesion, local treatment in the form of radiation therapy, now most often stereotactic radiosurgery, is supplanting untargeted whole-brain radiation therapy.

SUMMARY

Technologic advances in diagnosis and management have resulted in new diagnostic and therapeutic approaches to patients with metastasis to the CNS, with resulting improvements in progression-free and overall survival.

Systemic therapy options following first-line chemoimmunotherapy in small-cell lung cancer

Nearly all patients with extensive-stage small-cell lung cancer (ES-SCLC) relapse following first-line etoposide plus platinum (EP) with or without immune checkpoint inhibition. Topotecan and amrubicin are chemotherapies approved for these patients. The toxicities of these chemotherapies are significant and survival when treated with these regimens is minimal. The programmed death-1 (PD-1) inhibitors nivolumab and pembrolizumab are unlikely to be effective for patients who develop progressive disease on first-line chemoimmunotherapy. Newer systemic therapies (e.g., lurbinectedin and temozolomide plus poly-ADP ribose polymerase inhibition) have demonstrated greater response rates than topotecan, amrubicin or PD-1 inhibitors. The data on these newer systemic therapies and other agents that may soon enter clinic are reviewed in this manuscript. Additionally, some of the key questions arising following clinical trials of these newer agents are highlighted.

Epigenetic landscape of small cell lung cancer: small image of a giant recalcitrant disease

Small cell lung cancer (SCLC) is a particular subtype of lung cancer with high mortality. Recent advances in understanding SCLC genomics and breakthroughs of immunotherapy have substantially expanded existing knowledge and treatment modalities. However, challenges associated with SCLC remain enigmatic and elusive. Most of the conventional drug discovery approaches targeting altered signaling pathways in SCLC end up in the 'grave-yard of drug discovery', which mandates exploring novel approaches beyond inhibiting cell signaling pathways. Epigenetic modifications have long been documented as the key contributors to the tumorigenesis of almost all types of cancer, including SCLC. The last decade witnessed an exponential increase in our understanding of epigenetic modifications for SCLC. The present review highlights the central role of epigenetic regulations in acquiring neoplastic phenotype, metastasis, aggressiveness, resistance to chemotherapy, and immunotherapeutic approaches of SCLC. Different types of epigenetic modifications (DNA/histone methylation or acetylation) that can serve as predictive biomarkers for prognostication, treatment stratification, neuroendocrine lineage determination, and development of potential SCLC therapies are also discussed. We also review the utility of epigenetic targets/epidrugs in combination with first-line chemotherapy and immunotherapy that are currently under investigation in preclinical and clinical studies. Altogether, the information presents the inclusive landscape of SCLC epigenetics and epidrugs that will help to improve SCLC outcomes.

Comparative effectiveness of nivolumab versus standard of care for third-line patients with small-cell lung cancer

Aim: To estimate the comparative effectiveness of nivolumab versus standard of care (SOC) in terms of overall survival (OS) for small-cell lung cancer patients treated with two prior lines of chemotherapy, in other words, third line in the USA. Materials & methods: Data were from CheckMate 032, a single-arm trial of nivolumab, and real-world electronic patient records. Comparisons of OS were conducted using three different methods to adjust for differences (regression, weighting and doubly robust) between the populations. Results: Nivolumab was associated with longer survival compared with SOC (hazard ratio for OS: 0.58-0.70) across all methods for adjustment. Conclusion: Nivolumab was more efficacious in terms of OS as third-line treatment for small-cell lung cancer compared with current SOC in the USA.

Small Cell Lung Cancer from Traditional to Innovative Therapeutics: Building a Comprehensive Network to Optimize Clinical and Translational Research

Small cell lung cancer (SCLC) is an aggressive, complex disease with a distinct biology that contributes to its poor prognosis. Management of SCLC is still widely limited to chemotherapy and radiation therapy, and research recruitment still poses a considerable challenge. Here, we review the current standard of care for SCLC and advances made in utilizing immunotherapy. We also highlight research in the development of targeted therapies and emphasize the importance of a team-based approach to make clinical advances. Building an integrative network between an academic site and community practice sites optimizes biomarker and drug target discovery for managing and treating a difficult disease like SCLC.

Pamiparib is a potent and selective PARP inhibitor with unique potential for the treatment of brain tumor

Pamiparib, an investigational Poly (ADP-ribose) polymerase (PARP) inhibitor in clinical development, demonstrates excellent selectivity for both PARP1 and PARP2, and superb anti-proliferation activities in tumor cell lines with BRCA1/2 mutations or HR pathway deficiency (HRD). Pamiparib has good bioavailability and is 16-fold more potent than olaparib in an efficacy study using BRCA1 mutated MDA-MB-436 breast cancer xenograft model. Pamiparib also shows strong anti-tumor synergy with temozolomide (TMZ), a DNA alkylating agent used to treat brain tumors. Compared to other PARP inhibitors, pamiparib demonstrated improved penetration across the blood brain barrier (BBB) in mice. Oral administration of pamiparib at a dose as low as 3 mg/kg is sufficient to abrogate PARylation in brain tumor tissues. In SCLC-derived, TMZ-resistant H209 intracranial xenograft model, combination of pamiparib with TMZ overcomes its resistance and shows significant tumor inhibitory effects and prolonged life span. Our data suggests that combination of pamiparib with TMZ has unique potential for treatment of brain tumors. Currently, the combination therapy of pamiparib with TMZ is evaluated in clinical trial [NCT03150862].

Targeted Therapies and Biomarkers in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an aggressive malignancy characterized by rapid growth, early metastasis, and acquired therapeutic resistance. A majority of patients with SCLC have extensive-stage (ES) disease, defined as the presence of metastatic disease outside the hemithorax at first diagnosis. SCLC has been considered “a graveyard for drug development,” with chemotherapy remaining the standard treatment for first- and second-line management until quite recently. In contrast to NSCLC, identifying therapeutic targets in SCLC has been challenging, partly because driver mutations are primarily loss of function, involving the tumor suppressor genes RB1 and TP53 or currently untargetable (e.g., amplification of MYC family members). Recent gene expression profiling of SCLC cells lines, patient samples and representative murine models, have led to a proposed delineation of four major subtypes for SCLC distinguished by differential expression of four key transcriptional regulators (ASCL1, NEUROD1, POU2F3, and YAP1). Our understanding of the biology of SCLC has indeed significantly improved recently due to the continued efforts of the dedicated investigators in this field, but the therapeutic options remain dismal. While recent results from immunotherapy trials are encouraging, most patients demonstrate either primary or rapid acquired resistance to current regimens, highlighting the clear need to improve the effectiveness and expand the scope of current therapeutic strategies. In this opinion article, we will discuss recent developments in the treatment of SCLC, focused on current understanding of the signaling pathways, the role of immunotherapy and targeted therapy, and emerging biomarkers of response to therapy in SCLC.

Oral Chemotherapy for Treatment of Lung Cancer

The global COVID-19 pandemic has disrupted healthcare delivery, particularly for patients with advanced lung cancer. While certain aspects of care can be safely omitted or delayed, systemic therapy plays an important role in survival and quality of life for patients with advanced lung cancer; limiting access to systemic therapy will compromise cancer-related outcomes. This can be at odds with strategies to mitigate risk of COVID-19 exposure, which include reducing hospital and clinic visits. One important strategy is implementation of oral cancer therapies. Many standard regimens require intravenous infusions but there are specific circumstances where an oral agent could be an acceptable alternative. Integrating oral therapeutics can permit patients to receive effective systemic treatment without the exposure risks associated with frequent infusions. Here, we review currently available oral cytotoxic agents with a potential role in the treatment of lung cancer.

Prognostic value of tumor cavitation in extensive-stage small-cell lung cancer patients treated with anlotinib

PURPOSE

Anlotinib is a novel multi-target tyrosine kinase inhibitor (TKI) for tumor angiogenesis and tumor cell proliferation. The efficacy of anlotinib as a third-line or beyond therapy for SCLC was confirmed in the ALTER1202 trial. For lung cancer patients treated with antiangiogenesis agents, the phenomenon of cavitation is commonly seen in the lung target lesions. The impact of tumor cavitation on survival in lung cancer patients treated with vascular-targeted therapy remains controversial. Our retrospective study was to investigate the prognostic value of tumor cavitation in extensive-stage SCLC patients treated with anlotinib.

METHODS

A total of 73 extensive-stage SCLC patients confirmed by histopathology from January 2018 to January 2019 were retrospectively analyzed. All patients received anlotinib therapy at Shanghai Chest Hospital. We defined tumor cavitation of the lung target lesions as that part of solid component was changed to air-filled area according to chest CT. Progression-free survival (PFS) was calculated from the beginning of anlotinib therapy to the disease progression or the last follow-up visit.

RESULTS

Eleven (15.0%) patients had tumor cavitation during anlotinib therapy. The ORR of the 73 patients was 15.1%. Multivariate logistic regression analysis showed that tumor cavitation during anlotinib therapy was not associated with gender (P = 0.630), age (P = 0.190), smoking status (P = 0.165), anatomy type (P = 0.641), and the line of anlotinib therapy (P = 0.302). The median PFS of all patients was 2.6 months (95%CI 2.1-3.2). According to the univariate analysis, the median PFS in patients with and without tumor cavitation was 5.0 months and 2.2 months, respectively, and the difference was statistically significant (P = 0.041). According to the multivariate analysis, tumor cavitation was an independent factor for PFS after adjusting gender, age, smoking status, anatomy type, the line of anlotinib therapy, tumor cavitation, and response to anlotinib (adjusted HR 0.316, 95%CI 0.142-0.702; P = 0.005).

CONCLUSIONS

In 73 extensive-stage SCLC patients treated with anlotinib, no demographic/clinical characteristic was related to tumor cavitation, and tumor cavitation was an independent factor in predicting better PFS.