Phase I Trial of Pembrolizumab and Radiation Therapy after Induction Chemotherapy for Extensive-Stage Small Cell Lung Cancer

Adebrelimab plus chemotherapy and sequential thoracic radiotherapy as first-line therapy for extensive-stage small-cell lung cancer (ES-SCLC): a phase II trial

Background

This phase II prospective trial aimed to investigate the efficacy and safety of adebrelimab (PD-L1 antibody) plus first-line chemotherapy followed by sequential thoracic radiotherapy (TRT) combined with adebrelimab in extensive-stage small-cell lung cancer (ES-SCLC). Biomarkers associated with potential therapeutic effects were also explored.

Methods

Patients with previously untreated ES-SCLC were enrolled at Shandong Cancer Hospital and Institute (Jinan, China). Patients received 4-6 cycles of adebrelimab (20 mg/kg, D1, Q3W) combined with EP/EC (etoposide, 100 mg/m2, D1-3, Q3W and cisplatin, 75 mg/m2, D1, Q3W or carboplatin, AUC = 5, D1, Q3W). Then patients with response sequentially underwent consolidative TRT (≥30 Gy in 10 fractions or ≥50 Gy in 25 fractions, involved-field irradiation), and maintenance adebrelimab until disease progression or intolerable adverse events (AEs). The primary endpoint was overall survival (OS). Genomic and circulating tumour DNA (ctDNA) profiling were also analyzed with tumour tissues and peripheral blood. This trial was registered with ClinicalTrials.gov, NCT04562337.

Findings

From October 2020 to April 2023, 67 patients diagnosed with ES-SCLC were enrolled and received at least one dose of study treatment. All patients were included in the efficacy and safety analyses. 45 patients received sequential TRT as planned. The median OS and progression-free survival (PFS) was 21.4 months (95% CI: 17.2-not reached months) and 10.1 months (95% CI: 6.9-15.5 months), respectively. The confirmed objective response rate was 71.6% (48/67, 95% CI: 59.3-82.0%) and disease control rate was 89.6% (60/67, 95% CI: 79.7-95.7%). There were no treatment-related deaths. The most common grade 3 or higher treatment-related adverse events (TRAEs) were hematological toxicities. The incidence of any grade and G3+ pneumonitis was 25% (17/67) and 6% (4/67), respectively. No unexpected adverse events were observed. Patients without co-mutations of TP53/RB1 in both tissue and peripheral blood displayed longer PFS (tissue, P = 0.071; ctDNA, P = 0.060) and OS (tissue, P = 0.032; ctDNA, P = 0.031).

Interpretation

Adebrelimab plus chemotherapy and sequential TRT as first-line therapy for ES-SCLC showed promising efficacy and acceptable safety.

Funding

This study was funded by the National Natural Science Foundation of China (82172865), Jiangsu Hengrui Pharmaceuticals Co., Ltd. and Amoy Diagnostics Co., Ltd.

Impact of thoracic radiotherapy on first-line treatment outcomes in ES-SCLC patients

BACKGROUND

The therapeutic advantage of thoracic radiotherapy (tRT) as an adjunct to first-line immunotherapy and chemotherapy in patients with extensive-stage small cell lung cancer (ES-SCLC) remains unclear. We sought to elucidate this in a retrospective cohort study comparing the effectiveness and safety of tRT in combination with first-line immunotherapy and chemotherapy.

METHODS

Our retrospective study included patients with ES-SCLC, treated at the West China Hospital between January 2019 and December 2022. They received first-line immunotherapy and chemotherapy and were categorized into two cohorts based on the administration of tRT. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Cox regression analysis was utilized to identify potential independent predictors of prognosis and to compare the treatment outcomes across various patient subgroups. Treatment-related toxicities across both cohorts were compared using the Chi-squared test.

RESULTS

A total of 99patients were eligible for the study, out of which 55 received tRT. The medianduration of follow-up was 39 months. Remarkably, patients who received tRTdemonstrated superior OS and PFS in comparison to those who did not (P < 0.05). Subgroup analysis further confirmed these findings. Multivariate analysisidentified treatment group and liver metastasis as independent prognosticfactors (P < 0.05). The incidence of grade 3-4 adverse events showed nostatistically significant difference between the two cohorts.

CONCLUSIONS

Thus, weconfirmed that the addition of tRT to the conventional regimen of first-linechemotherapy and immunotherapy yields better survival outcomes without asignificant increase in toxicity.

Immunotherapy for small cell lung cancer: the current state and future trajectories

Small cell lung cancer (SCLC) constitutes approximately 10% to 15% of all lung cancer diagnoses and represents a pressing global public health challenge due to its high mortality rates. The efficacy of conventional treatments for SCLC is suboptimal, characterized by limited anti-tumoral effects and frequent relapses. In this context, emerging research has pivoted towards immunotherapy combined with chemotherapy, a rapidly advancing field that has shown promise in ameliorating the clinical outcomes of SCLC patients. Through originally developed for non-small cell lung cancer (NSCLC), these therapies have extended new treatment avenues for SCLC. Currently, a nexus of emerging hot-spot treatments has demonstrated significant therapeutic efficacy. Based on the amalgamation of chemotherapy and immunotherapy, and the development of new immunotherapy agents, the treatment of SCLC has seen the hoping future. Progress has been achieved in enhancing the tumor immune microenvironment through the concomitant use of chemotherapy, immunotherapy, and tyrosine kinase inhibitors (TKI), as evinced by emerging clinical trial data. Moreover, a tripartite approach involving immunotherapy, targeted therapy, and chemotherapy appears auspicious for future clinical applications. Overcoming resistance to post-immunotherapy regimens remains an urgent area of exploration. Finally, bispecific antibodies, adoptive cell transfer (ACT), oncolytic virus, monotherapy, including Delta-like ligand 3 (DLL3) and T cell immunoreceptor with Ig and ITIM domains (TIGIT), as well as precision medicine, may present a prospective route towards achieving curative outcomes in SCLC. This review aims to synthesize extant literature and highlight future directions in SCLC treatment, acknowledging the persistent challenges in the field. Furthermore, the continual development of novel therapeutic agents and technologies renders the future of SCLC treatment increasingly optimistic.

M, Gross CP, Slotman BJ, Chiang AC, Park HS. Differential Effect of Consolidative Thoracic Radiation Therapy in Extensive-Stage Small Cell Lung Cancer Based on Sex

Purpose

The landmark randomized trial on chest irradiation in extensive disease small cell lung cancer (CREST) demonstrated that consolidative thoracic radiation therapy (cTRT) improved overall (OS) and progression-free survival (PFS) after initial chemotherapy (chemo) in extensive-stage small cell lung cancer, with potentially increased benefit in women compared with men. It is unknown whether similar findings would apply after chemoimmunotherapy became the standard first-line treatment. In this analysis, we report national practice patterns and survival outcomes of cTRT according to patient sex.

Methods and Materials

We included patients from de-identified electronic health record-derived database diagnosed with stage IV small cell lung cancer (2014-2021) who completed 4 to 6 cycles of first-line systemic therapy (platinum-doublet chemotherapy or chemoimmunotherapy). We evaluated OS and PFS using multivariable Cox proportional hazards regression with receipt of cTRT as an independent variable and stratified by sex. As a sensitivity analysis, we weighted the models by the inverse probability of receiving cTRT.

Results

A total of 1227 patients were included (850 chemotherapy, 377 chemoimmunotherapy). There were no statistically significant differences in baseline characteristics between patients who did and did not receive cTRT. Among women, cTRT was associated with superior OS (adjusted hazard ratio [HR], 0.67; 95% CI, 0.52-0.87) and PFS (HR, 0.63; 95% CI, 0.49-0.82) compared with those not receiving cTRT. Conversely, no OS or PFS benefit with cTRT was observed in men (OS HR, 1.03; 95% CI, 0.80-1.31; PFS HR, 1.12; 95% CI, 0.85-1.47). Findings were similar in weighted analyses.

Conclusions

The survival efficacy of cTRT may be moderated by sex, with female patients appearing more likely to benefit than male patients. These findings reflect sex-based survival trends with similar effect sizes to those observed in the CREST trial. Although the underpinnings of this association need to be elucidated, stratification by sex should be considered for randomized-controlled trials studying cTRT in extensive-stage small cell lung cancer.

Efficacy and safety of thoracic radiotherapy in extensive-stage small-cell lung cancer patients receiving first-line immunotherapy plus chemotherapy: a propensity score matched multicentre retrospective analysis

BACKGROUND

Platinum-etoposide chemotherapy combined with immune checkpoint inhibitors (ICIs) has been recommended as the first-line standard treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, the effect of thoracic radiotherapy (TRT) on these patients is still unknown. This study aimed to evaluate the efficacy and safety of TRT for ES-SCLC patients who responded to first-line ICIs and chemotherapy (CHT).

METHODS

Patients who received 4 to 6 cycles of ICIs and CHT as first-line therapy at three hospitals between 2018 and 2022 were included in the analysis. All patients were divided into two groups based on whether they received TRT as first-line treatment, and propensity score matching (PSM) was performed to ensure that the characteristics of two groups were well-balanced. The primary endpoints were overall survival (OS) and progression-free survival (PFS), and the secondary endpoint was toxic effects.

RESULTS

A total of 276 patients were included, and the median follow-up time was 22.3 (range, 4.0-53.73) months. After PSM, 197 patients were further analysed, and 99 of whom received TRT. The baseline characteristics were well-balanced between patients in the TRT and non-TRT groups. There were significant differences in PFS between the TRT and non-TRT groups, with the median PFS of 10.76 and 7.63 months, respectively (P = 0.014). Significantly improved OS was observed in the TRT group (21.67 vs. 16.6 months, P = 0.009). In addition, the use of TRT was an independent prognostic factor for PFS and OS of ES-SCLC patients receiving ICIs plus CHT. In terms of safety, no significant increase of any grades adverse event (AE) (P = 0.874) and G3-4 AE (P = 0.909) was observed for patients receiving TRT. Radiation esophagitis, gastrointestinal and hematologic toxicities were the most common AEs in TRT group, which were tolerable. And high-dose radiotherapy was associated with higher incidence of pneumonitis.

CONCLUSION

Addition of TRT showed significant survival benefits and well tolerability in ES-SCLC patients receiving platinum-etoposide CHT and ICIs, which could be a feasible first-line treatment strategy for ES-SCLC patients.

Radiotherapy in the management of synchronous metastatic lung cancer

Metastatic lung cancer classically portends a poor prognosis. The management of metastatic lung cancer has dramatically changed with the emergence of immune checkpoint inhibitors, targeted therapy and due to a better understanding of the oligometastatic process. In metastatic lung cancers, radiation therapy which was only used with palliative intent for decades, represents today a promising way to treat primary and oligometastatic sites with a curative intent. Herein we present through a literature review the role of radiotherapy in the management of synchronous metastatic lung cancers.

Consolidative thoracic radiation therapy for extensive-stage small cell lung cancer in the era of first-line chemoimmunotherapy: preclinical data and a retrospective study in Southern Italy

Background

Consolidative thoracic radiotherapy (TRT) has been commonly used in the management of extensive-stage small cell lung cancer (ES-SCLC). Nevertheless, phase III trials exploring first-line chemoimmunotherapy have excluded this treatment approach. However, there is a strong biological rationale to support the use of radiotherapy (RT) as a boost to sustain anti-tumor immune responses. Currently, the benefit of TRT after chemoimmunotherapy remains unclear. The present report describes the real-world experiences of 120 patients with ES-SCLC treated with different chemoimmunotherapy combinations. Preclinical data supporting the hypothesis of anti-tumor immune responses induced by RT are also presented.

Methods

A total of 120 ES-SCLC patients treated with chemoimmunotherapy since 2019 in the South of Italy were retrospectively analyzed. None of the patients included in the analysis experienced disease progression after undergoing first-line chemoimmunotherapy. Of these, 59 patients underwent TRT after a multidisciplinary decision by the treatment team. Patient characteristics, chemoimmunotherapy schedule, and timing of TRT onset were assessed. Safety served as the primary endpoint, while efficacy measured in terms of overall survival (OS) and progression-free survival (PFS) was used as the secondary endpoint. Immune pathway activation induced by RT in SCLC cells was explored to investigate the biological rationale for combining RT and immunotherapy.

Results

Preclinical data supported the activation of innate immune pathways, including the STimulator of INterferon pathway (STING), gamma-interferon-inducible protein (IFI-16), and mitochondrial antiviral-signaling protein (MAVS) related to DNA and RNA release. Clinical data showed that TRT was associated with a good safety profile. Of the 59 patients treated with TRT, only 10% experienced radiation toxicity, while no ≥ G3 radiation-induced adverse events occurred. The median time for TRT onset after cycles of chemoimmunotherapy was 62 days. Total radiation dose and fraction dose of TRT include from 30 Gy in 10 fractions, up to definitive dose in selected patients. Consolidative TRT was associated with a significantly longer PFS than systemic therapy alone (one-year PFS of 61% vs. 31%, p<0.001), with a trend toward improved OS (one-year OS of 80% vs. 61%, p=0.027).

Conclusion

Multi-center data from establishments in the South of Italy provide a general confidence in using TRT as a consolidative strategy after chemoimmunotherapy. Considering the limits of a restrospective analysis, these preliminary results support the feasibility of the approach and encourage a prospective evaluation.

Chemoimmunotherapy combined with consolidative thoracic radiotherapy for extensive-stage small cell lung cancer: A systematic review and meta-analysis

INTRODUCTION

This study aimed to evaluate the efficacy and safety of chemoimmunotherapy combined with consolidative thoracic radiation therapy (cTRT) in patients with extensive-stage small cell lung cancer (ES-SCLC).

METHODS

A meta-analysis was conducted. PubMed, Embase, Web of Science, and the Cochrane Library were searched. The study was registered in PROSPERO (registration no. CRD42023410344).

RESULTS

A total of 4677 studies were initially screened and 15 studies encompassing a total of 1033 patients were included. Chemoimmunotherapy combined with cTRT significantly improved survival (HR = 0.52, 95 % CI: 0.39, 0.68) with favorable 6-month (0.89, 95 % CI: 0.77, 1.00) and 1-year (0.77, 95 % CI: 0.72, 0.82) OS, without affecting ≥3 grade TRAEs (RR = 1.29, 95 % CI: 0.85, 1.98). Pooled 6-month and 1-year PFS were 0.67 (95 % CI: 0.47, 0.86) and 0.38 (95 % CI: 0.22, 0.55), respectively. Incidence of ≥3 grade TRAEs was 0.24 (95 % CI: 0.08, 0.39) and radiation pneumonitis was 0.03 (95 % CI: 0.01, 0.06).

CONCLUSIONS

Chemoimmunotherapy combined with cTRT improves survival and shows favorable outcomes in ES-SCLC patients, with manageable adverse events. Further research with larger samples is needed to confirm these findings.

Efficacy and safety of thoracic radiotherapy for extensive stage small cell lung cancer after immunotherapy in real world

The immunotherapy combined chemotherapy has been the standard treatment strategy for extensive-stage small lung cancer (ES-SCLC). The CREST trial reported consolidative thoracic radiotherapy (cTRT) improved overall survival (OS) for ES-SCLC with intrathoracic residual after chemotherapy. In this study, patients with ES-SCLC who received immunotherapy were assigned to receive either TRT or no TRT. TRT significantly improved progression-free survival (PFS), local recurrence-free survival (LRFS) and OS with well tolerated toxicity. Further sub-cohort analysis, TRT significantly improved LRFS in patients with oligo-metastasis and without liver metastasis.

Challenges in synergizing radiotherapy with immunotherapy to unlock the abscopal effect in metastatic NSCLC: A systematic review

BACKGROUND

With the recent success of immunotherapy, there is a growing interest in combining radiation with immunotherapy to boost abscopal response rates. Several challenges exist in determining how to synergize these two modalities in the treatment of metastatic NSCLC.

METHODS

References for this review were identified through searches of MEDLINE/PubMed and Clinicaltrials.gov databases with the search terms "abscopal", "radiation OR radiotherapy," "NSCLC", and "lung" on the index date of July 2022 from 2000-2022. This systematic review focuses primarily on clinical papers.

DISCUSSION

Early work combining radiotherapy with immunotherapy show promise in unlocking the abscopal effect. Preliminary evidence suggests that radiotherapy regimens with <5 fractions and smaller fields may be superior to regimens with 15 fractions and larger fields. There does not appear to be enough evidence to draw conclusions about the optimal timing of radiotherapy in relation to immunotherapy or the optimal anatomical location of radiation to induce the abscopal effect. Several studies suggest selecting patients with a higher absolute lymphocyte count (ALC) and lower neutrophil-to-lymphocyte ratio (NLR) may help to further boost abscopal response rates. Furthermore, selecting tumors with programmed death ligand-1 (PD-L1) expression, mismatch repair deficiency, and higher tumor mutational burden may similarly achieve this goal. Lastly, additional work is needed to minimize and predict for severe toxicity associated with combination therapy.

Radiotherapy for extensive-stage small-cell lung cancer in the immunotherapy era

Currently, chemoimmunotherapy is the first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, only 0.8%-2.5% of the patients presented complete response after chemoimmunotherapy. Considering that ES-SCLC is highly sensitive to radiotherapy, the addition of radiotherapy after first-line treatment for ES-SCLC could further improve local control, which may be beneficial for patients' survival. Prior studies have shown that consolidative thoracic radiotherapy (cTRT) can decrease disease progression and improve overall survival in patients with ES-SCLC who respond well to chemotherapy. However, the efficacy and safety of cTRT in the immunotherapy era remain unclear owing to a lack of prospective studies. Prophylactic cranial irradiation (PCI) has been shown to decrease brain metastasis (BM) and prolong survival in patients with limited-stage SCLC in previous reports. However, according to current guidelines, PCI is not commonly recommended for ES-SCLC. Immunotherapy has the potential to reduce the incidence of BM. Whether PCI can be replaced with regular magnetic resonance imaging surveillance for ES-SCLC in the era of immunotherapy remains controversial. Whole brain radiation therapy (WBRT) is the standard treatment for BM in SCLC patients. Stereotactic radiosurgery (SRS) has shown promise in the treatment of limited BM. Considering the potential of immunotherapy to decrease BM, it is controversial whether SRS can replace WBRT for limited BM in the immunotherapy era. Additionally, with the addition of immunotherapy, the role of palliative radiotherapy may be weakened in patients with asymptomatic metastatic lesions. However, it is still indispensable and urgent for patients with obvious symptoms of metastatic disease, such as spinal cord compression, superior vena cava syndrome, lobar obstruction, and weight-bearing metastases, which may critically damage the quality of life and prognosis. To improve the outcome of ES-SCLC, we discuss the feasibility of radiotherapy, including cTRT, PCI, WBRT/SRS, and palliative radiotherapy with immunotherapy based on existing evidence, which may offer specific prospects for further randomized trials and clinical applications.

The role of thoracic consolidative radiotherapy in the setting of immunotherapy in extensive stage small cell lung cancer

The improvement in treatment strategies and outcomes in small cell lung cancer (SCLC) has lagged behind other cancers. The addition of immune checkpoint inhibitors (ICIs), durvalumab and atezolizumab, to the platinum-based chemotherapy in frontline setting has improved the survival in extensive stage SCLC, (ES-SCLC), albeit modestly, and is now the new standard of care. Prior to advent of immunotherapy into the therapeutic armamentarium in ES-SCLC, consolidative thoracic radiotherapy (TRT) was associated with improved thoracic control and survival outcomes. In the era of ICIs, the role of TRT is not well defined, chiefly because TRT was not incorporated in any immunotherapy trials, secondly due to concerns regarding the increased risks of pneumonitis, and finally uncertain magnitude of benefit with this combined approach. In principle, radiation can increase in the immunogenicity of tumor and hence the activity of immune checkpoint blockade, thereby increasing efficacy both locally and distantly. Such an approach has been promising in non-small cell lung cancer with ICIs improving outcomes after concurrent chemoradiation, but remains unanswered in ES-SCLC. It is, thus, possible that the modest improvement in survival by addition of ICIs to chemotherapy in ES-SCLC can be further improved by the incorporation of consolidative TRT in selected patients. Several early phase trials and retrospective studies have suggested that such an approach may be feasible and safe. Prospective trials are ongoing to answer whether adding radiation therapy to chemoimmunotherapy will improve outcomes in ES-SCLC.

Quad-shot-immunotherapy: quad-shot radiotherapy with pembrolizumab for advanced/recurrent head and neck cancer

Effective treatments for advanced/recurrent head and neck squamous-cell carcinoma are limited. For cases not curable by conventional local therapies, the immune checkpoint inhibitor pembrolizumab shows modest response rates. Quad-shot, a hypofractionated palliative radiotherapy regimen (14.8 Gy in four twice-daily fractions), can provide symptomatic relief, contributes to local control and may potentiate the effects of immune checkpoint inhibitors. In this study, 15 patients with advanced/recurrent head and neck squamous-cell carcinoma will be treated with pembrolizumab combined with up to three administrations of quad-shot before cycles four, eight and 13. Outcomes include disease response, survival and treatment toxicity. Correlative multiomics analysis of blood and saliva will identify molecular biomarkers of response to immune checkpoint inhibitor and the immune-related impact of quad-shot. Clinical trial registration: This study (WFBCCC 60320) is registered on NCT04454489 (ClinicalTrials.gov).

Efficacy and safety of first-line immunotherapy plus chemotherapy in treating patients with extensive-stage small cell lung cancer: a Bayesian network meta-analysis

Background

Despite numerous immunotherapy and chemotherapy regimens available for patients with extensive-stage small cell lung cancer (ES-SCLC), it remains unclear which regimen is the most effective and safest; relative studies comparing such regimens are scarce.

Objective

The aim of this study was to investigate the efficacy and safety of first-line immunotherapy combinations with chemotherapy for patients with extensive-stage small cell lung cancer. In addition, for the first time, comparisons among the first-line systemic regimens on OS and PFS in ES-SCLC by each time node were made.

Methods

Databases including PubMed, Embase, Cochrane Library, Scopus, Google Scholars, and ClinicalTrials.gov, and major international conferences were searched for randomized controlled trials (RCTs) regarding comparing immunotherapy combinations with chemotherapy as first-line treatments for patients with advanced ES-SCLC from inception to 1 November. Hazard ratios (HRs) and odds ratios (ORs) were generated for dichotomous variants by RStudio 4.2.1. The outcomes comprised overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events of grade 3 or higher (Grade ≥ 3 AEs).

Results

Eventually, a total of nine RCTs reporting 4,352 individuals with nine regimens were enrolled. The regimens were ipilimumabnu (Ipi), atezolizumab (Atez), durvalumab plus tremelimumab (Durv-Trem), durvalumab (Durv), pembrolizumab (Pemb), adebrelimab (Adeb), serplulimab (Serp), atezolizumab plus tiragolumab (Atez-Tira), and nivolumab (Nivo). With regard to OS, serplulimab (HR = 0.63, 95% CI: 0.49 to 0.81) was found to yield the best OS benefit when compared with chemotherapy. Meanwhile, serplulimab had the highest probability (46.11%) for better OS. Furthermore, compared with chemotherapy, serplulimab significantly increased the OS rate from the 6th to the 21st month. With regard to PFS, serplulimab (HR = 0.47, 95% CI: 0.38 to 0.59) was found to yield the best PFS benefit when compared with chemotherapy. Simultaneously, serplulimab had the highest probability (94.48%) for better PFS. Serplulimab was also a long-lasting first-line regimen in both OS and PFS from a longitudinal perspective. In addition, there was no significant difference among the various treatment options for ORR and grade ≥3 AEs.

Conclusion

Considering OS, PFS, ORR, and safety profiles, serplulimab with chemotherapy should be recommended as the best therapy for patients with ES-SCLC. Certainly, more head-to-head studies are needed to confirm these findings.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022373291.

Tackling the current dilemma of immunotherapy in extensive-stage small cell lung cancer: A promising strategy of combining with radiotherapy

Progress in the treatment of small cell lung cancer (SCLC) has been modest over the past decades until the advent of immune checkpoint inhibitors, which have redefined the standard first-line treatment for extensive-stage SCLC (ES-SCLC). However, despite the positive results of several clinical trials, the limited survival benefit achieved suggests that the priming and sustaining of immunotherapeutic efficacy are poor and further investigation is urgently needed. In this review, we aim to summarize the potential mechanisms underlying the limited efficacy of immunotherapy and intrinsic resistance in ES-SCLC, including impaired antigen presentation and limited T cell infiltration. Moreover, to tackle the current dilemma, given the synergistic effects of radiotherapy on immunotherapy, especially the unique advantages of low-dose radiotherapy (LDRT), such as less immunosuppression and lower radiation toxicity, we propose radiotherapy as a booster to enhance the immunotherapeutic efficacy by overcoming the poor priming effect. Recent clinical trials, including ours, have also focused on adding radiotherapy, including LDRT, to first-line treatment of ES-SCLC. Additionally, we also suggest combination strategies to sustain the immunostimulatory effect of radiotherapy, as well as the cancer-immunity cycle, and further improve survival outcomes.

Role of consolidative thoracic radiation in extensive-stage small-cell lung cancer with first-line chemoimmunotherapy: a retrospective study from a single cancer center

OBJECTIVE

To investigate the role of consolidative thoracic radiation (TRT) in extensive-stage small-cell lung cancer (ES-SCLC) receiving first-line chemo-immunotherapy followed by immunotherapy maintenance.

PATIENTS AND METHODS

Outcomes of patients without disease progression after first-line chemotherapy were retrospectively reviewed (January 2020 to December 2021). Based on TRT or not, patients were allocated to TRT group or non-TRT group. Progression-free survival (PFS), overall survival (OS) and local-recurrence free survival (LRFS) were calculated by the Kaplan-Meier method and compared by log-rank test.

RESULTS

Of 100 patients, 47 received TRT and 53 non-TRT. The median follow-up was 20.3 months. The median PFS and OS in TRT were 9.1 months and 21.8 months, versus 8.8 months (p = 0.93) and 24.3 months (p = 0.63), respectively, in non-TRT. The median LRFS time in TRT was not reached, but significantly longer than 10.8 months in non-TRT (HR = 0.27, p < 0.01). Second-line chemotherapy significantly prolonged survival compared to that with chemo-free patients (mOS: 24.5 vs. 21.4 months, p = 0.026). The subgroup analysis showed a trend of patients with brain metastases benefit from TRT (21.8 versus 13.7 months, HR 0.61, p = 0.38) while liver metastases did not. Of 47 patients with TRT, only 10.6% of patients experienced grade 3 radiation-induced pneumonitis, while no grade 4 or 5 adverse events occurred.

CONCLUSION

Consolidative TRT in the period of immunotherapy maintenance followed first-line chemo-immunotherapy did not prolong OS and PFS but associated with improved LRFS in ES-SCLC.

Combining radiation therapy with immune checkpoint blockade for the treatment of small cell lung cancer

The addition of immune checkpoint blockade (ICB) therapy to standard chemotherapy has been shown to improve survival in patients with metastatic small cell lung cancer. However, the benefit is modest and there remains an unmet need for novel therapeutic approaches to enhance the effectiveness of immunotherapy in this disease, both in the early and late stages. Ionizing radiation, which is a standard treatment for small cell lung cancer, is known to trigger immunogenic cell death in tumor cells, making it an attractive partner for ICB therapies in multiple solid tumor types. However, the optimal radiation dosage and fractionation scheme, target sites for radiation, and sequencing of radiation in relation to ICB treatment are still unclear. In this review we discuss the molecular biology underlying radiation-induced tumor immunity as well as pre-clinical and clinical studies combining radiation with ICB treatments, with a focus on translational and clinical trials in small cell lung cancer.

First-line atezolizumab/durvalumab plus platinum-etoposide combined with radiotherapy in extensive-stage small-cell lung cancer

BACKGROUND

Immunotherapy has made significant advances in the treatment of extensive-stage small-cell lung cancer (ES-SCLC), but data in combination with radiotherapy are scarce. This study aims to assess the safety and efficacy of chemoimmunotherapy combined with thoracic radiotherapy in patients with ES-SCLC.

METHODS

This single-center retrospective study analyzed patients with ES-SCLC who received standard platinum-etoposide chemotherapy combined with atezolizumab or durvalumab immunotherapy as induction treatment, followed by consolidative thoracic radiotherapy (CTRT) before disease progression in the first-line setting. Adverse events during radiotherapy with or without maintenance immunotherapy and survival outcomes were assessed.

RESULTS

Between December 2019 and November 2021, 36 patients with ES-SCLC were identified to have received such treatment modality at one hospital. The number of metastatic sites at diagnosis was 1-4. The biological effective dose of CTRT ranged from 52 to 113 Gy. Only two patients (6%) developed grade 3 toxic effect of thrombocytopenia, but none experienced grade 4 or 5 toxicity. Four patients developed immune-related pneumonitis during the induction treatment period but successfully completed later CTRT. The rate of radiation-related pneumonitis was 8% with grades 1-2 and well tolerated. The median progression-free survival (PFS) was 12.8 months, but the median overall survival (OS) was not determined. The estimated 1-year OS was 80.2% and 1-year PFS was 53.4%.

CONCLUSIONS

Immunotherapy combined with CTRT for ES-SCLC is safe and has ample survival benefit.

Progress in the clinical application of immune checkpoint inhibitors in small cell lung cancer

Small cell lung cancer (SCLC) is a refractory cancer with poor prognosis due to its aggressive malignancy and high rates of metastasis, recurrence and drug resistance. These characteristics have also greatly impeded the identification of new treatment methods and drugs. The traditional model of SCLC treatment that has been reliant on platinum combined with etoposide for decades has been superseded by the emergence of immune checkpoint inhibitors (ICIs), which have shown significant therapeutic effects and broad application prospects as a monotherapy. This has led to the evaluation of ICIs with different mechanisms of action and their use in combination with radiotherapy or a variety of molecular targeted drugs to achieve synergy, complementary advantages, and reduce adverse reactions. Here, we review the progress in the use of ICIs as a monotherapy or in combination therapy for SCLC and consider the current limitations of these approaches as well as prospects for future developments.

Use of radiation therapy among patients with Extensive-stage Small-cell lung cancer receiving Immunotherapy: Canadian consensus recommendations

OBJECTIVES

Thoracic radiation therapy (TRT) and prophylactic cranial irradiation (PCI) are commonly used in the management of extensive-stage small-cell lung cancer (ES-SCLC); however, Phase III trials of first-line immunotherapy often excluded these options. Guidance is needed regarding appropriate use of TRT, PCI, and magnetic resonance imaging (MRI) surveillance while new data are awaited.

MATERIALS AND METHODS

In two web-based meetings, a pan-Canadian expert working group of five radiation oncologists and four medical oncologists addressed eight clinical questions regarding use of radiation therapy (RT) and MRI surveillance among patients with ES-SCLC receiving immunotherapy. A targeted literature review was conducted using PubMed and conference proceedings to identify recent (January 2019-April 2022) publications in this setting. Fifteen recommendations were developed; online voting was conducted to gauge agreement with each recommendation.

RESULTS

After considering recently available evidence across lung cancer populations and clinical experience, the experts recommended that all patients with a response to chemo-immunotherapy, good performance status (PS), and limited metastases be considered for consolidation TRT (e.g., 30 Gy in 10 fractions). When considered appropriate after multidisciplinary team discussion, TRT can be initiated during maintenance immunotherapy. All patients who respond to concurrent chemo-immunotherapy should undergo restaging with brain MRI to guide decision-making regarding PCI versus MRI surveillance alone. MRI surveillance should be conducted for two years after response to initial therapy. PCI (e.g., 25 Gy in 10 fractions or 20 Gy in 5 fractions) can be considered for patients without central nervous system involvement who have a response to chemo-immunotherapy and good PS. Concurrent treatment with PCI and immunotherapy or with TRT, PCI, and immunotherapy is appropriate after completion of initial therapy. All recommendations were agreed upon unanimously.

CONCLUSIONS

These consensus recommendations provide practical guidance regarding appropriate use of RT and immunotherapy in ES-SCLC while awaiting new clinical trial data.

Real-world evaluation of atezolizumab and etoposide-carboplatin as a first-line treatment for extensive-stage small cell lung cancer

BACKGROUND/AIMS

Despite the obvious benefits of adding immune checkpoint inhibitors to platinum-etoposide chemotherapy in patients with extensive-stage small-cell lung cancer (ES-SCLC), real-world data remain scarce.

METHODS

This retrospective study included 89 patients with ES-SCLC treated with platinum-etoposide chemotherapy alone (chemo-only group; n = 48) or in combination with atezolizumab (atezolizumab group; n = 41) and compared the survival outcomes between these two groups.

RESULTS

Overall survival (OS) was significantly longer in the atezolizumab group than in the chemo-only group (15.2 months vs. 8.5 months; p = 0.047), whereas the median progression-free survival was almost the same (5.1 months vs. 5.0 months) in both groups (p = 0.754). Subsequent multivariate analysis revealed that thoracic radiation (hazard ratio [HR], 0.223; 95% confidence interval [CI], 0.092-0.537; p = 0.001) and atezolizumab administration (HR, 0.350; 95% CI, 0.184-0.668; p = 0.001) were favorable prognostic factors for OS. In the thoracic radiation subgroup, patients who received atezolizumab demonstrated favorable survival outcomes and no grade 3-4 adverse events (AEs).

CONCLUSION

The addition of atezolizumab to platinum-etoposide resulted in favorable outcomes in this real-world study. Thoracic radiation was associated with improved OS and acceptable AE risk in combination with immunotherapy in patients with ES-SCLC.

Safety and potential increased risk of toxicity of radiotherapy combined immunotherapy strategy

Accumulating interest has emerged in exploring the toxicity profiles of the combination strategy of radiotherapy (RT) and immune checkpoint inhibitors (ICIs). Much remains unknown regarding safety and the potential increased risk of toxicity of a combined treatment. ICI prolongs survival but can induce immune-related adverse events as well. To increase awareness of adverse effect and support immediate and successful management, we go over the literature on the safety of RT combined immunotherapy strategy. Representative evidence relevant to RT combined with ICI in the brain, lung, head and neck, and pelvic malignance was reviewed respectively. Given radiation doses and fractionation, the irradiated volume, the timing of RT, and ICI would significantly affect the safety and efficiency of ICI+RT combination therapy, and no consensus had been reached about how to arrange RT delivery in the combined contexture, we went over the available literature and tried to address these challenges including the timing of RT, optimal dose and fractionations, RT target and target volume, and potential biomarkers to predict toxicity. We found even though RT+ICI combination therapy might augment toxicities, the majority of patients experienced grade 4 or 5 AE are relatively rare and no significant difference could be found between combination group and monotherapy group. Sometimes the acute toxicity with ICI is much less predictable and often life threatening and in some can give rise to permanent effects. Clinicians across disciplines should be aware of these uncommon lethal complications induced by ICI+RT. Early recognition is the key to successful treatment, reversibility of organ dysfunction, and in some cases even prevention of fatal outcome. If recognized early, managed properly, and no fatal AE occurs, the development of irAE indicates a good prognosis. It should be noted that nothing is known about potential late effects because very few studies have 5-year follow-up. The nature of irAE is the attack of activated immune cells on normal tissues. The nature of RT-induced AE is the DNA damage on normal tissue, which is related with the dose delivered and volume irradiated and the tolerance of surrounding normal tissues. The immune-modulating effect of SBRT may augment the damage on normal tissues. To maximize the antitumor immune response, 8-12 Gy/fraction is preferred when conducting RT. The available clinical evidence suggest RT of this dose/fractionated strategy combined with ICI have a tolerable AE profile, which need further validation by more clinical trials in the future. The combination strategy of RT with anti-PD1/PDL1 anti-body is supposed to be concurrent or RT followed by anti-PD1/PDL1 antibody. Although RT and ipilimumab combination sequence is controversial, ipilimumab prior to or concurrent with RT might be proper, which need more clinical validation. Under the concept of immunological dose painting, SBRT work as a trigger of immune response. It has been observed that SBRT of partially radiated tumors combined with ICI could induce similar tumor control compared with total tumor irradiation. The side effects of RT may be mitigated potentially due to the reduction of irradiated volume. The antitumor efficiency and safety profile of immunological RT dose painting+ICI deserve further investigation. Clinical predictive factors for irAE risk remain unclear, and more investigation deserves to be conducted about the irAE prediction.

Thoracic Radiotherapy in Extensive Disease Small Cell Lung Cancer: Multicenter Prospective Observational TRENDS Study

(1) Introduction: Small cell lung cancer (SCLC) is an aggressive tumor type, accounting for about 15% of all lung cancers. Radiotherapy (RT) plays a fundamental role in both early and advanced stages. Currently, in advanced disease, the use of consolidative chest RT should be recommended for patients with good response to platinum-based first-line chemotherapy, but its use has not yet been standardized. The present prospective study aims to evaluate the pattern of care of consolidative chest RT in patients with advanced stage SCLC, and its effectiveness in terms of disease control and tolerability. (2) Materials and methods: This study was a multicenter prospective observational trial, proposed and conducted within the AIRO lung study group to evaluate the pattern of care of consolidative chest RT after first-line chemotherapy in patients with advanced SCLC. The patient and tumor characteristics, doses, fractionation and volumes of thoracic RT and prophylactic cranial irradiation (PCI), as well as the thoracic and extrathoracic response to the treatment, toxicity and clinical outcomes, were collected and analyzed. (3) Results: From January 2017 to December 2019, sixty-four patients were enrolled. Median follow-up was 33 months. The median age was 68 years (range 42-81); 38 patients (59%) were male and 26 (41%) female. Carboplatin + etoposide for 6 cycles was the most commonly used first-line therapeutic scheme (42%). With regard to consolidative chest RT, 56% of patients (35) received 30 Gy in 10 factions and 16 patients (26%) received 45 Gy in 15 sessions. The modulated intensity technique was used in 84.5% of cases, and post-chemotherapy macroscopic residual disease was the target volume in 87.5% of patients. Forty-four patients (69%) also underwent PCI. At the last follow-up, over 60% of patients did not experience chest disease progression, while 67% showed extrathoracic progression. At the first radiological evaluation after RT, complete response and stable disease were recorded in 6% and 46% of the cases, respectively. Two patients had a long-term complete response to the combined treatment. The brain was the first site of extrathoracic progression in 28%. 1y and 2y OS and PFS were 67%, 19%, 28% and 6%, respectively. Consolidative chest RT was well-tolerated in the majority of patients; it was interrupted in three cases (due to G2 pulmonary toxicity, disease progression and clinical decay, respectively). Only 1 patient developed G3 asthenia. (4) Conclusions: Consolidative chest RT has been shown to be useful in reducing the risk of thoracic disease progression and is absolutely well-tolerated in patients with advanced stage SCLC with good response after first-line chemotherapy. Among the Italian centers that participated in this study, there is still variability in the choice of fractionation and target volumes, although the guidelines contain clear recommendations. The aim of future research should be to clarify the role and modalities of chest RT in the era of immunotherapy in advanced-stage SCLC.

Global research landscape and trends of lung cancer immunotherapy: A bibliometric analysis

​Background

Immunotherapy for lung cancer has been a hot research area for years. This bibliometric analysis aims to present the research trends on lung cancer immunotherapy.

Method

On 1 July, 2022, the authors identified 2,941 papers on lung cancer immunotherapy by the Web of Science and extracted their general information and the total number of citations. A bibliometric analysis was carried out to present the research landscape, demonstrate the research trends, and determine the most cited papers (top papers) as well as major journals on lung cancer immunotherapy. After that, recent research hotspots were analyzed based on the latest publications in major journals.

Results

These 2,941 papers were cited a total of 122,467 times. "Nivolumab vs. docetaxel in advanced non-squamous non-small-cell lung cancer" published in 2015 by Borghaei H et al. was the most cited paper (5,854 citations). Among the journals, New England Journal of Medicine was most influential. Corresponding authors represented China took part in most articles (904) and papers with corresponding authors from the USA were most cited (139.46 citations per paper). Since 2015, anti-PD-(L)1 has become the hottest research area.

Conclusions

This bibliometric analysis comprehensively and quantitatively presents the research trends and hotspots based on thousands of publications, and further suggests future research directions. Moreover, the results can benefit researchers to select journals and find potential collaborators. This study can help researchers get a comprehensive impression of the research landscape, historical development, and recent hotspots in lung cancer immunotherapy and provide inspiration for further research.

Research landscape and trends of lung cancer radiotherapy: A bibliometric analysis

Background

radiotherapy is one of the major treatments for lung cancer and has been a hot research area for years. This bibliometric analysis aims to present the research trends on lung cancer radiotherapy.

Method

On August 31, 2022, the authors identified 9868 articles on lung cancer radiotherapy by the Web of Science (Science Citation Indexing Expanded database) and extracted their general information and the total number of citations. A bibliometric analysis was carried out to present the research landscape, demonstrate the research trends, and determine the most cited papers (top-papers) as well as top-journals on lung cancer radiotherapy. After that, the authors analyzed the recent research hotspots based on the latest publications in top-journals.

Results

These 9868 papers were cited a total of 268,068 times. “Durvalumab after chemoradiotherapy in stage III non–small-cell lung cancer” published in 2017 by Antonia et al.was the most cited article (2110 citations). Among the journals, New England Journal of Medicine was most influential. Moreover, J. Clin. Oncol. and Int. J. Radiat. Oncol. Biol. Phys. was both influential and productive. Corresponding authors represented the USA (2610 articles) and China mainland (2060 articles) took part in most publications and articles with corresponding authors from Netherlands were most cited (46.12 citations per paper). Chemoradiotherapy was the hottest research area, and stereotactic body radiotherapy has become a research hotspot since 2006. Radiotherapy plus immunotherapy has been highly focused since 2019.

Conclusions

This bibliometric analysis comprehensively and quantitatively presents the research trends and hotspots based on 9868 relevant articles, and further suggests future research directions. The researchers can benefit in selecting journals and in finding potential collaborators. This study can help researchers gain a comprehensive picture of the research landscape, historical development, and recent hotspots in lung cancer radiotherapy and can provide inspiration for future research.

Dissecting Immunotherapy Strategies for Small Cell Lung Cancer: Antibodies, Ionizing Radiation and CAR-T

Small cell lung cancer (SCLC) is a highly aggressive malignancy that accounts for about 14% of all lung cancers. Platinum-based chemotherapy has been the only available treatment for a long time, until the introduction of immune checkpoint inhibitors (ICIs) recently changed first-line standard of care and shed light on the pivotal role of the immune system. Despite improved survival in a subset of patients, a lot of them still do not benefit from first-line chemo-immunotherapy, and several studies are investigating whether different combination strategies (with both systemic and local treatments, such as radiotherapy) may improve patient outcomes. Moreover, research of biomarkers that may be used to predict patients' outcomes is ongoing. In addition to ICIs, immunotherapy offers other different strategies, including naked monoclonal antibodies targeting tumor associated antigens, conjugated antibody, bispecific antibodies and cellular therapies. In this review, we summarize the main evidence available about the use of immunotherapy in SCLC, the rationale behind combination strategies and the studies that are currently ongoing in this setting, in order to give the reader a clear and complete view of this rapidly expanding topic.

[Clinical Progress in the Immunotherapy of Small Cell Lung Cancer]

Small cell lung cancer is a kind of malignant tumor with strong invasiveness and poor prognosis, and the classic therapeutic modality of the disease remains multidisciplinary and comprehensive treatment. Treatment options for small cell lung cancer have been stalled for a long time, and new opportunities have emerged in recent years due to the development and initial experience of immunotherapeutic drugs. Clinical trials of some selected immune checkpoint inhibitors have confirmed the efficacy and safety in small cell lung cancer. Based on the results of phase III clinical trials (Impower133 and CASPIAN), Atezolizumab or Durvalumab in combination with chemotherapy has been approved by the U.S. Food and Drug Administration for the first-line treatment of extensive-stage small cell lung cancer. Clinical trials involving immune checkpoint inhibitors are being actively carried out and provide different perspectives for the management of small cell lung cancer. This article aimed to review the clinical progress in immunotherapy of small cell lung cancer.
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Radiation therapy for extensive-stage small-cell lung cancer in the era of immunotherapy

Unlike non-small-cell lung cancer (NSCLC), the progression of small-cell lung cancer (SCLC) is slow. Extensive-stage SCLC (ES-SCLC) is a serious threat to human health, with a 5-year survival rate of <7%. Chemotherapy has been the first-line treatment for the past 30 years. The anti-PD-L1 checkpoint blockades durvalumab and atezolizumab have greatly prolonged overall survival and have become the standard first-line therapy for ES-SCLC since the CASPIAN and IMpower133 trials. In the era of chemotherapy, radiation therapy (RT), including thoracic radiation therapy (TRT) and brain radiation therapy (BRT), has shown clinical effects in randomized and retrospective studies on ES-SCLC. RT-immunotherapy has shown exciting synergistic effects in NSCLC. For ES-SCLC, the clinical effects of combining TRT/BRT with immunotherapy have not yet been systematically explored. In this review, we found that studies on RT-immunotherapy in ES-SCLC are relatively few and limited to early phase studies focusing on toxicity. The efficacy and safety profiles of early phase studies encourage prospective clinical trials. In this review, we discuss the best population, optimum TRT dose, proper TRT time, and strategies for reducing radiation-induced neurotoxicity. Furthermore, we suggest that biomarkers and patient performance status should be fully assessed before RT-immunotherapy treatment. Prospective trials are needed to provide more evidence for RT-immunotherapy applications in ES-SCLC.

Multidisciplinary Treatment of Non-Spine Bone Metastases: Results of a Modified Delphi Consensus Process

•

Evidence is emerging for new paradigms in the management of non-spine bone metastases.

•

Consensus was feasible amongst physicians in both academic and community-based practice settings.

•

Topics deemed of highest importance for consensus included referral for surgical stabilization and approach to peri-operative radiation, preferred radiation fractionation and appropriate use of stereotactic techniques, and clinical scenarios classified as potentially “complex” warranting multidisciplinary discussion.

Purpose

Methods and Materials

Results

Conclusions

Facile synthesis of near-infrared responsive on-demand oxygen releasing nanoplatform for precise MRI-guided theranostics of hypoxia-induced tumor chemoresistance and metastasis in triple negative breast cancer

BACKGROUND

Hypoxia is an important factor that contributes to chemoresistance and metastasis in triple negative breast cancer (TNBC), and alleviating hypoxia microenvironment can enhance the anti-tumor efficacy and also inhibit tumor invasion.

METHODS

A near-infrared (NIR) responsive on-demand oxygen releasing nanoplatform (O2-PPSiI) was successfully synthesized by a two-stage self-assembly process to overcome the hypoxia-induced tumor chemoresistance and metastasis. We embedded drug-loaded poly (lactic-co-glycolic acid) cores into an ultrathin silica shell attached with paramagnetic Gd-DTPA to develop a Magnetic Resonance Imaging (MRI)-guided NIR-responsive on-demand drug releasing nanosystem, where indocyanine green was used as a photothermal converter to trigger the oxygen and drug release under NIR irradiation.

RESULTS

The near-infrared responsive on-demand oxygen releasing nanoplatform O2-PPSiI was chemically synthesized in this study by a two-stage self-assembly process, which could deliver oxygen and release it under NIR irradiation to relieve hypoxia, improving the therapeutic effect of chemotherapy and suppressed tumor metastasis. This smart design achieves the following advantages: (i) the O2 in this nanosystem can be precisely released by an NIR-responsive silica shell rupture; (ii) the dynamic biodistribution process of O2-PPSiI was monitored in real-time and quantitatively analyzed via sensitive MR imaging of the tumor; (iii) O2-PPSiI could alleviate tumor hypoxia by releasing O2 within the tumor upon NIR laser excitation; (iv) The migration and invasion abilities of the TNBC tumor were weakened by inhibiting the process of EMT as a result of the synergistic therapy of NIR-triggered O2-PPSiI.

CONCLUSIONS

Our work proposes a smart tactic guided by MRI and presents a valid approach for the reasonable design of NIR-responsive on-demand drug-releasing nanomedicine systems for precise theranostics in TNBC.

Treatment of small cell lung cancer: recent advances

PURPOSE OF REVIEW

In this article, we aimed to summarize the recent progress being made in treatment of small cell lung cancer (SCLC).

RECENT FINDINGS

SCLC is characterized by strong invasiveness, easy recurrence and early metastasis. In recent years, the emergence of immune checkpoint inhibitors (ICIs) therapy has broken the deadlock in the treatment field of SCLC. Combination strategies, such as the addition of ICIs to chemotherapy and radiotherapy, are actively underway. Some of these strategies have yielded significant survival benefits and tolerable adverse events, whereas several of them have failed with no significant improvement. In addition, the new classification of SCLC based on genomic analysis has deepened the understanding of SCLC and suggested new therapeutic directions. Similarly, the discovery of some new therapeutic targets, such as DDL3, CDK7 and PARP, also brings new hope for improving the survival of patients with SCLC.

SUMMARY

In this article, we will review the recent advances of therapeutic regimen for patients with SCLC. Following the revolutionary success of adding ICIs to chemotherapy, more varieties of combination strategies have been explored in recent trials. In addition, therapeutic drug research and efficacy evaluation against for new targets are under investigation. Altogether, progress on genomic analysis, investigation of biological pathways and treatment regimen combination are providing renewed hope for patients with SCLC.

The benefits and risks of pembrolizumab in combination with chemotherapy as first-line therapy in small-cell lung cancer: a single-arm meta-analysis of noncomparative clinical studies and randomized control trials

BACKGROUND

Although pembrolizumab has shown clinical benefit in patients with small-cell lung cancer (SCLC), its actual efficacy in combination with a conventional chemotherapy drug has not been determined. We performed this study to discern the efficacy and risk of pembrolizumab in combination with chemotherapy as first-line therapy in SCLC patients.

METHODS

We systematically searched the PubMed, ScienceDirect, Cochrane Library, Scopus, Ovid MEDLINE, Embase, Web of Science, and Google Scholar databases for relevant studies. The main outcomes were overall survival (OS) and progression-free survival (PFS).

RESULTS

We identified 2980 articles and included 6 studies (5 were noncomparative open-label studies and 1 was a randomized controlled trial [RCT]) involving 396 patients in our meta-analysis. The pooled median OS (mOS) was 9.6 months (95% CI, 8.0-11.2), and the pooled median PFS (mPFS) was 4.2 months (95% CI, 2.2-6.1). The 1-year overall survival rate (OSR-1y) and 6-month progression-free survival rate (PFSR-6m) were 45.1% (95% CI, 33-57.2%) and 41.6% (95% CI, 24.3-59%), respectively. The objective response rate (ORR) was 38.8% (95% CI, 11.9-65.67%), disease control rate (DCR) was 69.30% (95% CI, 51.6-87.0%), complete response (CR) was 2.20% (95% CI, 0.8-3.7%), partial response (PR) was 34.70% (95% CI, 7.8-61.5%), and stable disease (SD) was 20.90% (95% CI, 9.1-32.6%). The grade 3-4 adverse effect (AE) rate was 20.88% (95% CI, 1.22-54.85%). The most common AEs were neutropenia (90.16%), anemia (53.21%), dysphagia (41.96%), platelet count decrease (34.87%), and esophagitis (32.89%); severe AEs included neutropenia, respiratory failure, pneumonitis, acute coronary syndrome, and colitis/intestinal ischemia.

CONCLUSIONS

The combination of pembrolizumab with conventional chemotherapy is an effective therapeutic schedule with acceptable and manageable efficacy and toxicity in patients with SCLC. More high-quality and well-designed RCTs with large sample sizes are warranted to further validate our findings.

Evidence to Date: Evaluating Pembrolizumab in the Treatment of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive subtype of lung cancer characterized by a rapid initial response and early development of resistance to systemic therapy and radiation. The management of SCLC significantly changed for the first time in decades with the introduction of immune checkpoint inhibitors. Pembrolizumab, a humanized IgG4 isotype antibody, targets the programmed cell death protein 1 (PD-1) pathway to restore anti-tumor immunity. Prospective trials of pembrolizumab in patients with previously treated SCLC showed significant durability of responses. These results led to the U.S. Food and Drug Administration (FDA) granting pembrolizumab accelerated approval as second- or third-line monotherapy for patients with extensive-stage (ES) SCLC. In a recent clinical trial that included patients with previously untreated ES-SCLC, pembrolizumab in combination with platinum/etoposide met its progression-free survival endpoint, but overall survival (OS) did not cross the threshold for superiority. With the therapeutic landscape for SCLC rapidly evolving, we review prior experience and future directions of pembrolizumab in ES-SCLC.

High-dose irradiation in combination with non-ablative low-dose radiation to treat metastatic disease after progression on immunotherapy: Results of a phase II trial

AIM

To report early findings from a phase II trial of high-dose radiotherapy (HD-RT) with or without low-dose RT (LD-RT) for metastatic cancer.

METHODS

Eligible patients had metastatic disease that progressed on immunotherapy within 6 months. Patients were given either HD-RT (20-70 Gy total; 3-12.5 Gy/f), or HD-RT + LD-RT (0.5-2 Gy/f up to 1-10 Gy total) to separate lesions, with continued immunotherapy. Radiographic response was assessed per RECIST 1.1 and Immune-Related Response Criteria (irRC). Primary endpoints: (1) 4-month disease control (DCR, complete/partial response [CR/PR] or stable disease [SD]) or an overall response (ORR, CR/PR) at any point in ≥10% of patients, per RECIST 1.1; (2) dose-limiting toxicity within 3 months not exceeding 30%. Secondary endpoint was lesion-specific response.

RESULTS

Seventy-four patients (NSCLC, n = 38; melanoma n = 21) were analyzed (39 HD-RT and 35 HD-RT + LD-RT). The median follow-up time was 13.6 months. The primary endpoint was met for 72 evaluable patients, with a 4-month DCR of 42% (47% [16/34] vs. 37% [14/38] in HD-RT + LD-RT vs. HD-RT, P = 0.38), and 19% ORR at any time (26% [9/34] vs. 13% [5/38] in HD-RT + LD-RT vs. HD-RT, P = 0.27). Three patients had toxicity ≥grade 3. LD-RT lesion response (53%) was improved compared to nonirradiated lesions in HD-RT + LD-RT (23%, P = 0.002) and HD-RT (11%, P < 0.001). T- and NK cell infiltration was enhanced in lesions treated with LD-RT.

CONCLUSIONS

HD-RT plus LD-RT safely improved lesion-specific response in patients with immune resistant solid tumors by promoting infiltration of effector immune cells into the tumor microenvironment.

Immunotherapy in small cell lung cancer: one step at a time: a narrative review

Chemotherapy with or without radiotherapy has been the standard of care for many years for patients with small cell lung cancer (SCLC). Despite exceptionally high responses (up to 80%) with chemotherapy, the majority of patients relapse rapidly within weeks to months after treatment completion. Therefore, new and better treatment options are necessary. Recently, synergistic activity has been reported for the addition of immune checkpoint inhibitors (ICI) to standard platinum-based chemotherapy in the therapeutic strategy of advanced SCLC. For the first time after several decades, a significant survival improvement was achieved for this population. However, the overwhelming majority of patients do not respond to ICI, or relapse rapidly. There is need for better knowledge about the biology, histopathologic features, and molecular pathways of SCLC. This can probably help to identify the optimal predictive biomarkers, which are warranted to develop an individual therapeutic strategy including the rational use of a combination of immunotherapeutic agents. Here, we provide an overview of the rationale for and clinical results of the completed and ongoing trials using different strategies of immunotherapy in SCLC. In addition, opportunities for further improvement of therapies will be discussed, including the addition of radiotherapy, co-stimulatory antibodies, and other immune modifying agents.

Thoracic radiotherapy in small cell lung cancer-a narrative review

Small-cell lung cancer (SCLC) represents 10–15% of all lung cancers and has a poor prognosis. Thoracic radiotherapy plays a central role in current SCLC management. Concurrent chemoradiotherapy (CTRT) is the standard of care for localised disease (stage I−III, limited-stage, LS). Definitive thoracic radiotherapy may be offered in metastatic patients (stage IV, extensive stage, ES-SCLC) after chemotherapy. For LS-SCLC, the gold standard is early accelerated hyperfractionated twice-daily CTRT (4 cycles of cisplatin etoposide, starting with the first or second chemotherapy cycle). Modern radiation techniques should be used with involved-field radiotherapy based on baseline CT and PET/CT scans. In ES-SCLC, thoracic radiotherapy should be discussed in cases of initial bulky mediastinal disease/residual thoracic disease not progressing after induction chemotherapy. This strategy was however not assessed in recent trials establishing chemo-immunotherapy as the standard first line treatment in ES-SCLC. Future developments include technical radiotherapy advances and the incorporation of new drugs. Thoracic irradiation is delivered more precisely given technical developments (IMRT, image-guided radiotherapy, stereotactic radiotherapy), reducing the risks of severe adverse events. Stereotactic ablative radiotherapy may be discussed in rare early stage (T1 to 2, N0) inoperable patients. A number of current clinical trials are investigating immunoradiotherapy. In this review, we highlight the current role of thoracic radiotherapy and describe ongoing research in the integration of biological surrogate markers, advanced radiotherapy technologies and novel drugs in SCLC patients.

Immune Check Point Inhibitors and Immune-Related Adverse Events in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a malignant solid tumor. In recent years, although immune check point inhibitors (ICIs) have achieved important advances in the treatment of SCLC, immune-related adverse events (irAEs) have occurred at the same time during the therapeutic period. Some irAEs lead to dose reduction or treatment rejection. The immune microenvironment of SCLC is complicated, therefore, understanding irAEs associated with ICIs is of great importance and necessity for the clinical management of SCLC. However, the lack of comprehensive understanding of irAEs in patients with SCLC remains remarkable. This review aims to provide an up-to-date overview of ICIs and their associated irAEs in patients with SCLC based on present clinical data.

Small cell lung cancer: a slightly less orphan disease after immunotherapy

Small cell lung cancer (SCLC) is an aggressive malignancy accounting for 15% of all diagnosed cases of lung cancer. After >15 years without any clinically relevant therapeutic advances, extensive-disease SCLC has become the second thoracic malignancy for which immune checkpoint inhibitors (ICIs) have shifted the treatment paradigm to improve overall survival. Today, atezolizumab or durvalumab in combination with platinum-etoposide chemotherapy is considered the new standard of care in the first-line setting in SCLC. However, the magnitude of benefit with this immune-chemotherapy strategy in SCLC is more modest than that observed in metastatic non-small-cell lung cancer patients. The immunosuppressive phenotype of SCLC plays an important role in hampering ICI efficacy and may explain the differences in outcomes between these two types of lung cancer. In this review, we provide a summary of recent therapeutic advances in SCLC in light of ICIs, as well as current challenges of this strategy in patients who are elderly, have poor performance status or brain metastases. We also address future perspectives of immunotherapeutic strategies currently in clinical development for these patients.

Clinical outcomes of extensive-stage small cell lung cancer patients treated with thoracic radiotherapy at different times and fractionations

Objective

The purpose of this study was to assess whether thoracic radiotherapy (TRT) combined with chemotherapy (CHT) showed promising anti-tumour activity in extensive-stage small cell lung cancer (ES-SCLC), to explore practice patterns for the radiation time and dose/fractionation and to identify prognostic factors for patients who would benefit from CHT/TRT.

Methods

A total of 492 ES-SCLC patients were included from January 2010 to March 2019, 244 of whom received CHT/TRT. Propensity score matching was performed to minimize bias between the CHT/TRT and CHT-alone groups. Patients in the CHT/TRT group were categorized into four subgroups based on the number of induction CHT cycles. For effective dose fractionation calculations, we introduced the time-adjusted biological effective dose (tBED). Categorical variables were analysed with chi-square tests and Fisher’s exact tests. Kaplan–Meier curves were generated to estimate survival rates using the R-project. Multivariate prognostic analysis was performed with Cox proportional hazards models.

Results

Patients who received CHT/TRT experienced improved overall survival (OS) (18.1 vs 10.8 months), progression-free survival (PFS) (9.3 vs 6.0 months) and local recurrence-free survival (LRFS) (12.0 vs 6.6 months) before matching, with similar results after matching. In the CHT/TRT group, the median LRFS times for the groups based on the radiation time were 12.7, 12.0, 12.0, and 9.0 months, respectively. Early TRT had a tendency to prolong PFS (median 10.6 vs 9.8 vs 9.0 vs 7.7 months, respectively, p = 0.091) but not OS (median 17.6 vs 19.5 vs 17.2 vs 19.0 months, respectively, p = 0.622). Notably, patients who received TRT within 6 cycles of CHT experienced prolonged LRFS (p = 0.001). Regarding the radiation dose, patients in the high-dose group (tBED > 50 Gy) who achieved complete response and partial response (CR and PR) to systemic therapy had relatively short OS (median 27.1 vs 22.7, p = 0.026) and PFS (median 11.4 vs 11.2, p = 0.032), but the abovementioned results were not obtained after the exclusion of patients who received hyperfractionated radiotherapy (all p > 0.05).

Conclusion

CHT/TRT could improve survival for ES-SCLC patients. TRT performed within 6 cycles of CHT and hyperfractionated radiotherapy (45 Gy in 30 fractions) may be a feasible treatment scheme for ES-SCLC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01773-x.

Use of Multi-Site Radiation Therapy for Systemic Disease Control

Metastatic cancer is a heterogeneous entity, some of which could benefit from local consolidative radiation therapy (RT). Although randomized evidence is growing in support of using RT for oligometastatic disease, a highly active area of investigation relates to whether RT could benefit patients with polymetastatic disease. This article highlights the preclinical and clinical rationale for using RT for polymetastatic disease, proposes an exploratory framework for selecting patients best suited for these types of treatments, and briefly reviews potential challenges. The goal of this hypothesis-generating review is to address personalized multimodality systemic treatment for patients with metastatic cancer. The rationale for using high-dose RT is primarily for local control and immune activation in either oligometastatic or polymetastatic disease. However, the primary application of low-dose RT is to activate distinct antitumor immune pathways and modulate the tumor stroma in efforts to better facilitate T cell infiltration. We explore clinical cases involving high- and low-dose RT to demonstrate the potential efficacy of such treatment. We then group patients by extent of disease burden to implement high- and/or low-dose RT. Patients with low-volume disease may receive high-dose RT to all sites as part of an oligometastatic paradigm. Subjects with high-volume disease (for whom standard of care remains palliative RT only) could be treated with a combination of high-dose RT to a few sites for immune activation, while receiving low-dose RT to several remaining lesions to enhance systemic responses from high-dose RT and immunotherapy. We further discuss how emerging but speculative concepts such as immune function may be integrated into this approach and examine therapies currently under investigation that may help address immune deficiencies. The review concludes by addressing challenges in using RT for polymetastatic disease, such as concerns about treatment planning workflows, treatment times, dose constraints for multiple-isocenter treatments, and economic considerations.

Durvalumab and tremelimumab with or without stereotactic body radiation therapy in relapsed small cell lung cancer: a randomized phase II study

Background

Immune checkpoint blockade (ICB) targeting programmed cell death protein 1 and cytotoxic T lymphocyte-associated protein 4 has achieved modest clinical activity as salvage therapy in relapsed small cell lung cancer (SCLC). We conducted this signal-finding study to assess the efficacy of ICB with or without radiation in relapsed SCLC.

Methods

Patients with relapsed SCLC and ≤2 previous lines of therapy were randomized to (1) arm A: durvalumab (D) 1500 mg/tremelimumab (T) 75 mg (intravenously every 4 weeks without stereotactic body radiation therapy (SBRT)) or (2) arm B: immune-sensitizing SBRT to one selected tumor site (9 Gy × 3 fractions) followed by D/T. Treatment continued until progression or a maximum of 12 months. The co-primary endpoints of the study were overall response rate (ORR) and progression-free survival (PFS). We evaluated circulating lymphocyte repertoire in serial peripheral blood samples and tumor infiltrating lymphocytes (TILs) from on-treatment biopsies as pharmacodynamic markers.

Results

Eighteen patients were randomized to arms A and B (n=9 each): median age 70 years; 41.2% women. The median PFS and ORR were 2.1 months and 0% in arm A and 3.3 months and 28.6% in arm B. The median overall survival (OS) was 2.8 months in arm A and 5.7 months in arm B (p=0.3772). Pooled efficacy of D/T±SBRT in 15 Response evaluation criteria in solid tumors (RECIST) evaluable patients across both arms showed the best ORR in terms of partial response in 13.3%, stable disease in 26.6% and progressive disease in 60.0%; the overall median PFS and OS were 2.76 and 3.9 months. The most common adverse events were grade 1 fatigue (66%) and grade 1 elevated amylase (56%) in arm A, and grade 1 fatigue (56%) and pain (44%) in arm B. There was a significant increase in activated CD8(+)ICOS+ T cells (p=0.048) and a reduction in naïve T cells (p=0.0454) in peripheral blood following treatment, along with a significant amount of activated CD8+ICOS+ T cells in TILs from responders.

Conclusions

The D/T combination with and without SBRT was safe but did not show sufficient efficacy signal in relapsed SCLC. Changes in peripheral blood lymphocyte and TILs were consistent with an immunologic response.

Trial registration number NCT02701400.

American Radium Society Appropriate Use Criteria on Radiation Therapy for Extensive-Stage SCLC

INTRODUCTION

The standard-of-care therapy for extensive-stage SCLC has recently changed with the results of two large randomized trials revealing improved survival with the addition of immunotherapy to first-line platinum or etoposide chemotherapy. This has led to a lack of clarity around the role of consolidative thoracic radiation and prophylactic cranial irradiation in the setting of chemoimmunotherapy.

METHODS

The American Radium Society Appropriate Use Criteria are evidence-based guidelines for specific clinical conditions that are reviewed by a multidisciplinary expert panel. The guidelines include a review and analysis of current evidence with the application of consensus methodology (modified Delphi) to rate the appropriateness of treatments recommended by the panel for extensive-stage SCLC.

RESULTS

Current evidence supports either prophylactic cranial irradiation or surveillance with magnetic resonance imaging every 3 months for patients without evidence of brain metastases. Patients with brain metastases should receive whole-brain radiation with a recommended dose of 30 Gy in 10 fractions. Consolidative thoracic radiation can be considered in selected cases with the recommended dose ranging from 30 to 54 Gy; this recommendation was driven by expert opinion owing to the limited strength of evidence, as clinical trials addressing this question remain ongoing.

CONCLUSIONS

Radiation therapy remains an integral component in the treatment paradigm for ES-SCLC.

Efficacy and Safety of First-Line Immunotherapy in Combination with Chemotherapy for Patients with Extensive-Stage Small Cell Lung Cancer: A Systematic Review and Network Meta-Analysis

Background

The prognosis of patients with extensive-stage small cell lung cancer (SCLC) is poor. Adding an immune checkpoint inhibitor (ICI) to chemotherapy may exert a synergistic effect and improve survival outcomes. However, for treatment-naive extensive-stage SCLC patients, the efficacy of immunotherapy in combination with cytotoxic chemotherapy remains controversial.

Objective

To evaluate the benefits and risks of the combination of immunotherapy and chemotherapy and to assess the comparative effectiveness of different first-line treatment strategies for extensive-stage SCLC.

Methods

PubMed, Web of Science, EMBASE, and Cochrane Library were searched for randomized clinical trials studying different immunotherapeutics for patients with previously untreated extensive-stage SCLC up to Feb 16, 2020. The primary outcomes were overall survival (OS) and progression-free survival (PFS), and the secondary outcomes were objective response rate (ORR), disease control rate (DCR), and adverse events.

Results

We identified 141 published records, and 4 studies (comprising 2202 patients) were included in the analysis. Immunotherapy (including ipilimumab, atezolizumab, and durvalumab) plus chemotherapy was associated with better OS (hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.75-0.93; risk ratio (RR) 0.90, 95% CI 0.81-1.00) and PFS (HR: 0.81, 95% CI 0.74-0.88; RR 0.96, 95% CI 0.93-0.99) than placebo plus chemotherapy. The addition of immunotherapy to chemotherapy showed similar improvement in ORR, DCR, and adverse events versus placebo plus chemotherapy. On the surface under the cumulative ranking (SUCRA) analysis, the anti-PD-L1 agent, atezolizumab, had the highest likelihood of achieving improved OS (93.4%) and PFS (95.0%).

Conclusion

In the first-line setting, combining immunotherapy with chemotherapy is better than standard chemotherapy in terms of OS and PFS. Across the eligible studies, PD-L1 inhibitors might be preferred. Further explorations of more ICIs in the first-line treatment for extensive-stage SCLC patients should be needed.

Prospective Single-Arm Phase 1 and 2 Study: Ipilimumab and Nivolumab With Thoracic Radiation Therapy After Platinum Chemotherapy in Extensive-Stage Small Cell Lung Cancer

PURPOSE

Consolidative thoracic radiation therapy (TRT) has been shown to improve outcomes for patients with extensive stage small cell lung cancer. We hypothesized that the addition of ipilimumab (IPI) and nivolumab (NIVO) after TRT would improve outcomes for patients with extensive stage small cell lung cancer.

METHODS AND MATERIALS

Eligibility required stable disease or better after platinum doublet chemotherapy. Study therapy included consolidative TRT to 30 Gy in 10 fractions, targeting residual primary tumor and initially involved regional lymph nodes. Two weeks after TRT, patients received concurrent IPI (3 mg/kg) and NIVO (1 mg/kg) every 3 weeks for 4 doses followed by NIVO monotherapy (480 mg) every 4 weeks until progression or up to 1 year.

RESULTS

The study enrolled 21 patients, with 6-month progression-free survival (PFS) of 24% (90% confidence interval [CI], 11%-40%) and a median PFS of 4.5 months (95% CI, 2.7%-4.6%). The 12-month overall survival (OS) was 48% (95% CI, 29%-64%) with a median OS of 11.7 months (95% CI, 4.7%-16.0%). Fifty-two percent of patients had ≥1 possibly related grade 3 to 4 immune-related adverse event. Grade 3 pulmonary and gastrointestinal immune-related adverse events were recorded in 19% and 24% of patients, respectively. Exploratory analysis showed increased cytotoxic T cell (CD3+CD8+) tumor infiltration was associated with favorable PFS (P = .01) and OS (P = .02). Reduction in peripheral blood CD3+CD8+ from baseline to after first dose of IPI/NIVO was associated with improved PFS (P = .02) and OS (P = .02).

CONCLUSIONS

Consolidative IPI and NIVO after platinum-based chemotherapy and TRT demonstrated a toxicity profile consistent with the known adverse events attributable to IPI and NIVO. Although the study regimen did not significantly improve PFS, the OS was higher than historic expectations. CD3+CD8+ tumor infiltration and migration may identify patients most likely to have improved outcomes in small cell lung cancer.

Immunoradiotherapy as An Effective Therapeutic Strategy in Lung Cancer: From Palliative Care to Curative Intent

Lung cancer is one of the main causes of cancer-related mortality worldwide. Over the years, different therapeutic modalities have been adopted depending on tumor stage and patient characteristics, such as surgery, radiotherapy (RT), and chemotherapy. Recently, with the development of immune-checkpoint inhibitors (ICI), the treatment of metastatic and locally advanced non-small cell lung cancer (NSCLC) has experienced a revolution that has resulted in a significant improvement in overall survival with an enhanced toxicity profile. Despite this paradigm shift, most patients present some kind of resistance to ICI. In this setting, current research is shifting towards the integration of multiple therapies, with RT and ICI being one of the most promising based on the potential immunostimulatory synergy of this combination. This review gives an overview of the evolution and current state of the combination of RT and ICI and provides evidence-based data that can improve patient selection. The combination in lung cancer is a safe therapeutic approach that improves local control and progression-free survival, and it has the potential to unleash abscopal responses. Additionally, this treatment strategy seems to be able to re-sensitize select patients that have reached a state of resistance to ICI, further enabling the continuation of systemic therapy.

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.

Current Management and Progress in Radiotherapy for Small Cell Lung Cancer

Radiotherapy (RT) and chemotherapy continue to be widely utilized in small cell lung cancer (SCLC) management. In most limited stage (LS)-SCLC cases, the standard initial therapy remains concurrent chemoradiotherapy (CRT), typically with an etoposide and platinum-based regimen. Hyperfractionated twice daily (BID) RT remains the standard of care, though conventional daily (QD) RT is now a viable alternative supported by randomized evidence. In LS-SCLC patients who experienced good response to CRT, prophylactic cranial irradiation (PCI) remains the standard of care. Brain imaging, ideally with MRI, should be performed prior to PCI to screen for clinically apparent brain metastases that may require a higher dose of cranial irradiation. Platinum doublet chemotherapy alone is the historic standard initial therapy in extensive stage (ES)-SCLC. Addition of immunotherapy such as atezolizumab and durvalumab to chemotherapy is now recommended after their benefits were demonstrated in recent trials. In patients with response to chemotherapy, consolidation thoracic RT and PCI could be considered, though with caveats. Emergence of hippocampal avoidance cranial irradiation and SRS in SCLC patients may supplant whole cranial irradiation as future standards of care. Incorporation of novel systemic therapies such as immunotherapies has changed the treatment paradigm and overall outlook of patients with SCLC. This narrative review summarizes the current state, ongoing trials, and future directions of radiotherapy in management of SCLC.