Impact of thoracic radiotherapy timing in limited-stage small-cell lung cancer: usefulness of the individual patient data meta-analysis

Molecular mechanism of radiation tolerance in lung adenocarcinoma cells using single-cell RNA sequencing

The efficacy of radiotherapy, a cornerstone in the treatment of lung adenocarcinoma (LUAD), is profoundly undermined by radiotolerance. This resistance not only poses a significant clinical challenge but also compromises patient survival rates. Therefore, it is important to explore this mechanism for the treatment of LUAD. Multiple public databases were used for single-cell RNA sequencing (scRNA-seq) data. We filtered, normalized and downscaled scRNA-seq data based on the Seurat package to obtain different cell subpopulations. Subsequently, the ssGSEA algorithm was used to assess the enrichment scores of the different cell subpopulations, and thus screen the cell subpopulations that are most relevant to radiotherapy tolerance based on the Pearson method. Finally, pseudotime analysis was performed, and a preliminary exploration of gene mutations in different cell subpopulations was performed. We identified HIST1H1D+ A549 and PIF1+ A549 as the cell subpopulations related to radiotolerance. The expression levels of cell cycle-related genes and pathway enrichment scores of these two cell subpopulations increased gradually with the extension of radiation treatment time. Finally, we found that the proportion of TP53 mutations in patients who had received radiotherapy was significantly higher than that in patients who had not received radiotherapy. We identified two cellular subpopulations associated with radiotherapy tolerance, which may shed light on the molecular mechanisms of radiotherapy tolerance in LUAD and provide new clinical perspectives.

Hyperfractionated Accelerated Radiotherapy Versus Stereotactic Body Radiotherapy in the Treatment of Limited-Stage Small Cell Lung Cancer: A Matched-Pair Analysis

BACKGROUND

Concurrent chemoradiotherapy based on hyperfractionated accelerated radiotherapy (HART) is the first-line recommended regimen for the treatment of small-cell lung cancer (SCLC). However, Stereotactic Body Radiotherapy (SBRT) is also regarded as an effective treatment for limited-stage (LS) SCLC, and the efficacy and safety of HART versus SBRT stay controversial.

METHODS

In this study, 188 LS-SCLC patients were retrospectively divided into two groups receiving chemotherapy combined with either HART or SBRT. In HART group, patients received 4500 cGy in 30 fractions, administered twice daily for 3 weeks. Whereas in the SBRT group, a total radiation dose of 4000-4500 cGy was delivered in 10 fractions over 2 weeks. Thirty-three pairs of patients were finally included for next analysis.

RESULTS

The estimated objective response rates were 63.6 % (21/33) and 78.8 % (26/33) in HART group and SBRT group, respectively (P = 0.269). Furthermore, there was no significant difference between HART and SBRT groups in overall survival (26 months vs. 29 months, P = 0.362) and progression free survival (11 months vs. 15 months, P = 0.223). As for the adverse events, toxicity of both groups is similar and slight that no grade 4 event was observed. Grade 3 pneumonitis cases were all occurred in the HART group (9.1%, 3/33, P = 0.238), and grade 3 esophagitis cases were all occurred in the SBRT group (6.1%, 2/33, P = 0.492).

CONCLUSION

Compared with HART, SBRT could be another effective treatment with satisfactory safety for the concurrent chemoradiotherapy in patients with LS-SCLC.

Coronavirus disease 2019 and lung cancer: where are we?

Oncology patients are more susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to hospital contact and an immunological system that can be compromised by antineoplastic therapy and supportive treatments. Certain similarities have been described in the physiopathology of coronavirus disease 2019 (COVID-19) and lung cancer (LC) that may explain the higher probability of these patients of developing a more serious disease with more frequent hospitalizations and even death, especially with the addition of smoking, cardiovascular and respiratory comorbidities, old age and corticosteroids use. Pre-existing lesions and cancer therapies change the normal architecture of the lungs, so diagnostic scales such as COVID-19 Reporting and Data System (CO-RADS) are of vital importance for a correct diagnosis and patient homogenization, with a high inter-observer correlation. Moreover, anticancer treatments have required an adaptation to reduce the number of visits to the hospital [hypofractionated radiotherapy (RT), larger intervals between chemotherapy cycles, delay in follow-up tests, among others]. In a way, this has also caused a delay in the diagnosis of new cancers. On the other hand, vaccination has had a positive impact on the mortality of these patients, who maintain a similar seroprevalence to the rest of the population, with a similar impact in mortality.

Trends in the epidemiology of small-cell lung cancer: a Dutch nationwide population-based study over 1989-2020

INTRODUCTION

This study describes the evolving characteristics of patients with small-cell lung cancer (SCLC) from 1989 to 2020 in the Netherlands to analyse how the population of patients with SCLC has changed in the last decades, hypothesising that this might explain the little progress made in SCLC.

METHODS

Patients with SCLC diagnosed from 1989 to 2020 were selected from the Dutch cancer registry. Incidence, patient and disease characteristics, treatments, and overall survival (OS) were analysed. Joinpoint analyses were used to test annual percentage changes for statistical significance.

RESULTS

A total of 52,527 patients were diagnosed with SCLC. The absolute numbers of patients with SCLC remained equal over the years; however, the incidence rates decreased from 15.01 to 8.93 per 100,000 person-years. The proportion of women increased from 22% to 50%, and those aged ≥75 years increased from 20% to 25%. The latter coincided with a higher proportion receiving only the best supportive care (BSC) over the years (18-24%). The use of surgery in stage I increased from 2% to 37%. The proportion of patients diagnosed with stage IV increased from 46% to 70% due to better staging. The OS improved for all stages, with a 2-year OS rate for stage IV doubling from 3% to 6%.

CONCLUSION

The incidence of SCLC has significantly decreased over the last 30 years, with an increasing proportion of elderly and women. The male-female ratio became similar, and the OS improved. As a consequence of more elderly and probably more vulnerable patients, more patients received only the BSC.

SEOM-GECP Clinical guidelines for diagnosis, treatment and follow-up of small-cell lung cancer (SCLC) (2022)

Small-cell lung cancer (SCLC) is a highly aggressive malignancy comprising approximately 15% of lung cancers. Only one-third of patients are diagnosed at limited-stage (LS). Surgical resection can be curative in early stages, followed by platinum-etoposide adjuvant therapy, although only a minority of patients with SCLC qualify for surgery. Concurrent chemo-radiotherapy is the standard of care for LS-SCLC that is not surgically resectable, followed by prophylactic cranial irradiation (PCI) for patients without progression. For extensive-stage (ES)-SCLC, a combination of platinum and etoposide has historically been a mainstay of treatment. Recently, the efficacy of programmed death-ligand 1 inhibitors combined with chemotherapy has become the new front-line standard of care for ES-SCLC. Emerging knowledge regarding SCLC biology, including genomic characterization and molecular subtyping, and new treatment approaches will potentially lead to advances in SCLC patient care.

No survival benefit with early incorporation of thoracic radiotherapy using daily fractionation in patients with limited-stage small cell lung cancer undergoing chemoradiotherapy in the modern era: A systematic review and meta-analysis

BACKGROUND

When concurrent chemoradiotherapy (CCRT) is administered for limited-stage small cell lung cancer (LS-SCLC), the early incorporation of thoracic radiotherapy (TRT) is generally recommended. However, it is controversial if this approach is really beneficial with most commonly used daily fractionated TRT in the modern era.

METHODS

A systematic literature search was performed using several databases following the PRISMA guidelines from Jan 2000 to Nov 2022. We excluded twice-daily TRT-based studies. The hazard ratio (HR) for survival following late TRT as a primary effect size was pooled from comparisons within individual studies according to the timing of daily fractionated TRT (early vs. late).

RESULTS

A total of 10 studies including 10,164 analyzable patients met all inclusion criteria. 'Early' timing usually referred to TRT within 1-2 cycles of concurrent chemotherapy. The pooled results demonstrated that the risk of death was not significantly increased following late TRT compared with early TRT (HR 1.01, 95% CI 0.84-1.20, p = 0.94). All sensitivity analysis and planned subgroup analyses showed similar results. In comparison with early TRT, late TRT did not significantly increase the risk of progression (HR 0.94, 95% CI 0.80-1.11, p = 0.48). Furthermore, late TRT was beneficial in alleviating grade 3 or higher esophagitis (OR 0.42, p = 0.01), but no significant differences was found in pneumonitis (OR 0.62, p = 0.38), and neutropenia (OR 0.57, p = 0.11). No evidence of publication bias was found.

CONCLUSIONS

This is the first meta-analysis to support the late incorporation of TRT in managing patients with LS-SCLC undergoing daily fractionated CCRT in the modern era. This approach may not compromise survival and can prevent severe acute toxicities. Further prospective studies of the daily fractionated TRT timing are warranted.

Radiotherapy Fraction in Limited-Stage Small Cell Lung Cancer in the Modern Era: A Systematic Review and Meta-Analysis of 8006 Reconstructed Individual Patient Data

The optimal thoracic radiotherapy (TRT) dose and fractionation for limited-stage small cell lung cancer (LS-SCLC) using modern techniques remain unclear. We conducted systematic review and meta-analyses of the efficacy and safety differences between definitive hypofractionated TRT (HypoTRT), conventional TRT (ConvTRT) and hyperfractionated TRT (HyperTRT), especially in the modern era. Eligible randomized controlled trials (RCTs), real-world cohorts, and single-arm trials published between 1990 and 2021 were identified. Two meta-analyses of overall survival (OS) were conducted: (i) a random-effects meta-analysis based on reconstructed individual-patient data (IPD) of all studies; and (ii) a Bayesian network meta-analysis based on study-level aggregated data (AD) of RCTs. The incidences of severe radiation-related toxicities were compared using the random-effects meta-regression model. Overall, 53 of the 30,031 publications met the inclusion criteria, and a total of 8006 IPD were reconstructed. After adjusting for key treatment variables and stratification by study type, there were no significant differences in the OS rates between the altered fractionation regimens (HypoTRT vs. HyperTRT, aHR [adjusted HR] = 1.05, 95% CI 0.93-1.19; ConvTRT vs. HyperTRT, aHR = 1.00, 95% CI 0·90-1.11; HypoTRT vs. ConvTRT, aHR = 1.05, 95% CI 0.91-1.20). In the modern era, the survival outcomes of all three schedules, while remaining comparable, have improved significantly. Results of the AD-based network meta-analysis were consistent with those of IPD analysis, and HypoTRT was ranked as the best regimen (SUCRA = 81%). There were no significant differences in toxicities between groups when using modern radiation techniques. In the modern era, no significant differences in OS or severe radiation-related toxicities were observed between altered schedules in LS-SCLC. HypoTRT may be associated with moderate and non-significant OS improvements, which should be further confirmed in prospective randomized phase III trials.

Prognostic ability of lung immune prognostic index in limited-stage small cell lung cancer

BACKGROUND

Lung immune prognostic index (LIPI) is a prognostic marker of extensive-stage small cell lung cancer (ES-SCLC) patients received immunotherapy or chemotherapy. However, its ability in limited-stage SCLC (LS-SCLC) should be evaluated extensively.

METHODS

We retrospectively enrolled 497 patients diagnosed as LS-SCLC between 2015 and 2018, and clinical data included pretreatment lactate dehydrogenase (LDH), white blood cell count, and absolute neutrophil count levels were collected. According to the LIPI scores, the patients were stratified into low-risk (0 points) and high-risk (1-2 points). The correlations between LIPI and overall survival (OS) or progression-free survival (PFS) were analyzed by the Cox regression. Additionally, the propensity score matching (PSM) and inverse probability of treatment weight (IPTW) methods were used to reduce the selection and confounding bias. A nomogram was constructed using on multivariable Cox model.

RESULTS

Two hundred fifty and 247 patients were in the LIPI high-risk group and low-risk group, and their median OS was 14.67 months (95% CI: 12.30-16.85) and 20.53 months (95% CI: 17.67-23.39), respectively. In the statistical analysis, High-risk LIPI was significantly against worse OS (HR = 1.377, 95%CI:1.114-1.702) and poor PFS (HR = 1.338, 95%CI:1.1-1.626), and the result was similar after matching and compensating with the PSM or IPTW method. A novel nomogram based on LIPI has a decent level of predictive power.

CONCLUSION

LIPI stratification was a significant factor against OS or PFS of LS-SCLC patients.

Survey of treatment and care practices in small-cell lung cancer among German radiation oncologists

Background

The management of small-cell lung cancer shows differences, particularly with regard to the use of radio- (RT), chemo-, and immunotherapy. We performed a survey among German radiation oncologists to assess the management of small-cell lung cancer (SCLC).

Methods

A 34-question online survey was created and sent out by e‑mail to radiation oncologists throughout Germany. The survey period extended from August 2020 to January 2021. The questions addressed indications for RT, planning techniques, dosing/fractionation, target volume definition for consolidative thoracic irradiation, and the use of prophylactic cranial irradiation (PCI). At the same time, we surveyed the use of atezolizumab. The survey addressed the treatment practice for limited-stage SCLC (LS-SCLC) and extensive-stage SCLC (ES-SCLC).

Results

We received 74 responses. In LS-SCLC, treatment is planned predominantly based on diagnostic information from computed tomography (CT) of the thorax/abdomen/pelvis (88%), PET-CT (86%), and pulmonary function testing (88%). In LS-SCLC, 99% of respondents perform radiation concurrently with chemotherapy, preferably starting with cycle one or two (71%) of chemotherapy. The most common dose and fractionation schedule was 60–66 Gy in 30–33 fractions (once daily: 62% of all respondents). In ES-SCLC, 30 Gy in 10 fractions (once daily: 33% of all respondents) was the most commonly used regimen in consolidative thoracic irradiation. Only 25% use chemosensitization with RT. The inclusion criteria for PCI were similar for limited and extensive disease, with Karnofsky index (78% and 75%) being the most important decision factor. Respondents use a schedule of 30 Gy in 15 fractions most frequently in both stages (68% limited stage [LS], 60% extensive stage [ES]). Immunotherapy was used regularly or occasionally in LS-SCLC by 45% of respondents, with reduced lung function (37%), cardiac comorbidities (30%), and hepatic insufficiency (30%) being the most commonly mentioned exclusion criteria for this form of therapy. In ES-SCLC, atezolizumab use was reported in 78% of all questionnaires. Half of the respondents (49%) administer it simultaneously with cranial irradiation.

Conclusion

Our survey showed variability in the management of SCLC. Results from future studies might help to clarify open questions regarding the optimal treatment paradigms. In addition, new treatment modalities, such as immunotherapy, might change practices in the near future.

An Overview of the Role of Radiotherapy in the Treatment of Small Cell Lung Cancer - A Mainstay of Treatment or a Modality in Decline?

AIMS

Small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. Chemotherapy, immunotherapy and radiotherapy all play important roles in the management of SCLC. The aim of this study was to provide a comprehensive overview of the role and evidence of radiotherapy in the cure and palliation of SCLC.

MATERIALS AND METHODS

The search strategy included a search of the PubMed database, hand searches, reference lists of relevant review articles and relevant published abstracts.

CLINICALTRIALS

gov was also queried for relevant trials.

RESULTS

Thoracic radiotherapy improves overall survival in limited stage SCLC, but the timing and dose remain controversial. The role of thoracic radiotherapy in extensive stage SCLC with immunotherapy is the subject of several ongoing trials. Current evidence supports the use of prophylactic cranial irradiation (PCI) for limited stage SCLC but the evidence is equivocal in extensive stage SCLC. Whole brain radiotherapy is well established for the treatment of brain metastases but evidence is rapidly accumulating for the use of stereotactic radiosurgery. Further studies will define the role of PCI, whole brain radiotherapy and hippocampal avoidant PCI in the immunotherapy era.

CONCLUSION

Radiotherapy is an essential component in the multimodality management of SCLC. Technological advances have allowed safer delivery of radiotherapy with reduced toxicities. Discussion at multidisciplinary team meetings is important to ensure radiotherapy is considered and offered in appropriate patients.

Once daily (OD) versus twice-daily (BID) chemoradiation for limited stage small cell lung cancer (LS-SCLC): A meta-analysis of randomized clinical trials

OBJECTIVES

Assess Once daily (OD) chemoradiation effectiveness for LS-SCLC compared with twice daily (BID) chemoradiation.

METHODS AND MATERIALS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline, eligible randomized clinical trials (RCT) comparing OD and BID were identified on electronic databases. A meta-analysis was performed to compare overall survival (OS), progression-free survival (PFS), and toxicity. A metaregression analysis was conducted to explore the influence of fractionation, biological effective dose (BED), the proportion of patients treated with prophylactic cranial irradiation (PCI), elective nodal irradiation (ENI), and the start of radiotherapy (week 1 or week 4).

RESULTS

Five RCTs with a total of 1941 patients (OD vs. BID) were included. The relative risk (RR) for OS and PFS was 0.97 (CI95% 0.8-1.1, p = 0.731) and 0.90 (CI95% 0.7-1.1, p = 0.20) at 3-years. In the metaregression analysis, hypofractionated radiotherapy schedules were associated with an improvement in overall survival (p = 0.03). The start of radiotherapy (W1 or W4), BED, and ENI had no significant effect on OS and PFS. The complete response rate partial response and overall response rate for BID vs OD were 40% vs. 33% (p = 0.97), 50% vs. 57% (p = 0.94), and 89% vs. 93% (p = 0.99). The rate of completed planned RT 96% vs. 94% (p = 0.66), and the % of ≥4 chemotherapy cycles received 74% vs. 74% (p = 0.99), did not differ between OD and BID. The local and distant failure rates were not significantly different between OD and BID 40% vs. 33% (p = 0.88) and 36% vs. 36% (p = 0.99). No difference in grade 2 or grade 3 pneumonitis and esophagitis was observed among the groups (p = NS).

CONCLUSION

For LS-SCLC, OD conventional chemoradiation results in similar outcomes to BID chemoradiation. In contrast, hypofractionated radiotherapy was associated with a better OS and PFS than BID. Additional randomized phase III trials exploring hypofractionation with systemic therapy are warranted to validate our findings.

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.

Radiotherapy for small cell lung cancer in current clinical practice guidelines

Several guidelines including radiotherapy recommendations exist worldwide for the treatment of small cell lung cancer (SCLC). To evaluate the differences in radiotherapy recommendations we conducted a systematic review. PubMed and the sites of medical societies were searched for SCLC guidelines published in either English, Chinese, or Dutch. This was limited to January 2018 till February 2021 to only include up-to-date recommendations. Data was extracted and compared regarding the guideline's development method and radiotherapy recommendations. Eleven guidelines were identified (PubMed n=4, societies n=7) from Spain (n=1), Canada (n=1), America (n=3), United Kingdom (n=1), the Netherlands (n=1), and China (n=3), respectively. Nine guidelines assessed the strength of evidence (SOE) and specified the strength of recommendation (SOR), although methods were different. The major radiotherapy recommendations are similar although differences exist in thoracic radiotherapy (TRT) dose, time, and volume. Controversial areas are TRT in resected stage I-IIA (pN1), prophylactic cranial irradiation (PCI) in resected as well as unresected stage I-IIA, stereotactic body radiation therapy (SBRT) in unresected stage I-IIA, PCI time, and PCI versus magnetic resonance imaging (MRI) surveillance in stage IV. The existence of several overlapping guidelines for SCLC treatment indicates that guideline development is (unnecessarily) repeated by different organizations or societies. Improvement could be made by better international collaboration to avoid duplicating unnecessary work, which would spare a lot of time and resources. Efforts should be made to work together on controversial or unknown fields.

Practice Patterns of Treatment Strategy of Limited-Stage Small-Cell Lung Cancer: Survey of Chinese Oncologists

Background

Thoracic radiotherapy (TRT) with concurrent chemotherapy is the standard treatment of limited-stage small-cell lung cancer (LS-SCLC). However, there is still a controversy surrounding the treatment strategy especially optimal dosing and fractionation schedule. Current practice patterns among Chinese oncologists are unknown.

Materials and Methods

We surveyed 212 Chinese oncologists using a questionnaire including 50 questions designed by experienced oncologists. Questions covered demographic data, treatment recommendations, and self-assessed knowledge of guidelines or key clinical trials for SCLC. The chi-square test and Fisher's exact test were utilized to describe the result of the study.

Results

The response rate was 97% (207/212). Of all the respondents, 69% preferred TRT QD, 29% preferred BID, and 2% chose HFRT. For those who prefer TRT QD, 72% preferred a total dose of 60 Gy, followed by 15% opting for 66 Gy, 12% for <60 Gy, and 1% for 70 Gy. Of those who prefer BID, 79% preferred a total dose of 45 Gy, with 4% choosing 30 Gy, 8% choosing 50 Gy, 7% choosing 54 Gy, and 2% choosing >54 Gy. Regarding PCI, 82% of participants believed that PCI should be performed when treatment is completed and 13% believed that PCI should begin immediately after concurrent chemoradiotherapy. As for other therapies, 26% of participants choose concurrent anti-angiogenic therapy during SCLC treatment, and 49% recommended small-molecule TKI as the main anti-angiogenic therapy.

Conclusion

Substantial variation exists in how Chinese oncologists approach TRT dosing and fractionation for LS-SCLC. Almost 70% of respondents reported administering TRT QD more often in daily work. The most common doses were 60 Gy QD and 45 Gy BID.

Comparative effectiveness and toxicity of radiotherapy regimens in limited stage small cell lung cancer: A network meta-analysis

PURPOSE

The aim of this Network Meta-analysis was to compare the current radiotherapy regimens of limited-stage small cell lung cancer (LS-SCLC), in terms of overall survival (OS), progression-free survival (PFS), and the incidence of acute radioactive esophagitis and radioactive pneumonia.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were comprehensively searched until January 2022. The studies were included, comparing radiotherapy regimens in LS-SCLC patients. We compared hypofractionated radiotherapy (HypoTRT), hyperfractionated radiotherapy (HyperTRT), and conventionally fractionated radiotherapy (ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy)).

RESULTS

There was similar efficacy among the contemporary radiotherapy regimens for PFS of LS-SCLC. HypoTRT and HyperTRT significantly improved the OS of LS-SCLC compared with ConvTRT1 (<60 Gy), while not improving the OS of LS-SCLC compared with ConvTRT2 (≥60 Gy). There was no significant difference between HypoTRT and HyperTRT, between ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy), respectively. HyperTRT developed the highest odds of acute radioactive esophagitis compared to ConvTRT1(<60 Gy) and ConvTRT2(≥60 Gy). There was no significant difference in the incidence of acute radioactive esophagitis between HypoTRT and HyperTRT, ConvTRT1(<60 Gy), ConvTRT2(≥60 Gy), respectively and between ConvTRT1 and ConvTRT2. There was no statistically significant difference among radiotherapy regimens for the incidence of acute radioactive pneumonia.

CONCLUSION

The current radiotherapy regimens are similar in efficacy and toxicity for LS-SCLC, except for ConvTRT1(<60 Gy). Given the lower costs and convenient logistics management of HypoTRT comparatively, it is an acceptable alternative for LS-SCLC.

Optimal timing of thoracic irradiation for limited stage small cell lung cancer: Current evidence and future prospects

Lung cancer is a global health concern as the leading cause of cancer related mortality worldwide. Small cell lung cancer (SCLC) poses a formidable challenge to the treating physicians with the worst prognosis among all lung cancers. However, limited stage SCLC (LS-SCLC) has a relatively better outcome with multimodality management. Efforts have been focused on optimal integration of treatment modalities to achieve an improved therapeutic ratio for patients with LS-SCLC. While chemotherapy and thoracic radiation therapy (TRT) are primary components of initial management for LS-SCLC, there is no consensus on optimal timing of TRT. Within this context, we herein provide a concise overview of current evidence and future prospects regarding the optimal timing of thoracic irradiation for LS-SCLC in light of the literature.

Radiation and Systemic Therapy for Limited-Stage Small-Cell Lung Cancer

Progress in the overall treatment of small-cell lung cancer (SCLC) has moved at a slower pace than non-small-cell lung cancer. In fact, the standard treatment regimen for limited stage SCLC has not appreciably shifted in more than 20 years, consisting of four to six cycles of cisplatin and etoposide chemotherapy concurrent with thoracic radiotherapy (TRT) followed by prophylactic cranial irradiation (PCI) for responsive disease. Nevertheless, long-term outcomes have improved with median survival approaching 25-30 months, and approximately one third of patients now survive 5 years. This is likely attributable in part to improvements in staging, including use of brain magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography imaging, advances in radiation treatment planning, and supportive care. The CONVERT and CALGB 30610 phase III trials failed to demonstrate a survival advantage for high-dose, once-daily TRT compared with standard 45 Gy twice-daily TRT, although high-dose, once-daily TRT remains common in practice. A phase III comparison of high-dose 60 Gy twice-daily TRT versus 45 Gy twice-daily TRT aims to confirm the provocative outcomes reported with 60 Gy twice daily in the phase II setting. Efforts over time have shifted from intensifying PCI, to attempting to reduce treatment-related neurotoxicity, to more recently questioning whether careful magnetic resonance imaging surveillance may obviate the routine need for PCI. The addition of immunotherapy has resulted in mixed success in extensive-stage SCLC with modest benefit observed with programmed death-ligand 1 inhibitors, and several ongoing trials assess programmed death-ligand 1 inhibition concurrent or adjuvant to chemoradiotherapy in limited-stage SCLC. Major advances in future treatment will likely depend on a better understanding and exploiting of molecular characteristics of SCLC with increasing personalization of therapy.

A wake-up call for cancer DNA damage: the role of Schlafen 11 (SLFN11) across multiple cancers

DNA-damaging agents exploit increased genomic instability, a hallmark of cancer. Recently, inhibitors targeting the DNA damage response (DDR) pathways, such as PARP inhibitors, have also shown promising therapeutic potential. However, not all tumors respond well to these treatments, suggesting additional determinants of response are required. Schlafen 11 (SLFN11), a putative DNA/RNA helicase that induces irreversible replication block, is emerging as an important regulator of cellular response to DNA damage. Preclinical and emerging clinical trial data suggest that SLFN11 is a predictive biomarker of response to a wide range of therapeutics that cause DNA damage including platinum salts and topoisomerase I/II inhibitors, as well as PARP inhibitors, which has raised exciting possibilities for its clinical application. In this article, we review the function, prevalence, and clinical testing of SLFN11 in tumor biopsy samples and circulating tumor cells. We discuss mounting evidence of SLFN11 as a key predictive biomarker for a wide range of cancer therapeutics and as a prognostic marker across several cancer types. Furthermore, we discuss emerging areas of investigation such as epigenetic reactivation of SLFN11 and its role in activating immune response. We then provide perspectives on open questions and future directions in studying this important biomarker.

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.

Somatic copy number alterations are predictive of progression-free survival in patients with lung adenocarcinoma undergoing radiotherapy

OBJECTIVE

Lung cancer is the most common cause of cancer-related deaths worldwide. Somatic copy number alterations (SCNAs) have been used to predict responses to therapies in many cancers, including lung cancer. However, little is known about whether they are predictive of radiotherapy outcomes. We aimed to understand the prognostic value and biological functions of SCNAs.

METHODS

We analyzed the correlation between SCNAs and clinical outcomes in The Cancer Genome Atlas data for 486 patients with non-small cell lung cancer who received radiotherapy. Gene set enrichment analyses were performed to investigate the potential mechanisms underlying the roles of SCNAs in the radiotherapy response. Our results were validated in 20 patients with lung adenocarcinoma (LUAD) receiving radiotherapy.

RESULTS

SCNAs were a better predictor of progression-free survival (PFS) in LUAD (P = 0.024) than in lung squamous carcinoma (P = 0.18) in patients treated with radiotherapy. Univariate and multivariate regression analyses revealed the superiority of SCNAs in predicting PFS in patients with LUAD. Patients with stage I cancer and low SCNA levels had longer PFS than those with high SCNA levels (P = 0.022). Our prognostic nomogram also showed that combining SCNAs and tumor/node/metastasis provided a better model for predicting long-term PFS. Additionally, high SCNA may activate the cell cycle pathway and induce tumorigenesis.

CONCLUSIONS

SCNAs may be used to predict PFS in patients with early-stage LUAD with radiotherapy, in combination with TNM, with the aim of predicting long-term PFS. Therefore, SCNAs are a novel predictive biomarker for radiotherapy in patients with LUAD.

A Comparison of Hypofractionated and Twice-Daily Thoracic Irradiation in Limited-Stage Small-Cell Lung Cancer: An Overlap-Weighted Analysis

Despite evidence for the superiority of twice-daily (BID) radiotherapy schedules, their utilization in practice remains logistically challenging. Hypofractionation (HFRT) is a commonly implemented alternative. We aim to compare the outcomes and toxicities in limited-stage small-cell lung cancer (LS-SCLC) patients treated with hypofractionated versus BID schedules. A bi-institutional retrospective cohort review was conducted of LS-SCLC patients treated with BID (45 Gy/30 fractions) or HFRT (40 Gy/15 fractions) schedules from 2007 to 2019. Overlap weighting using propensity scores was performed to balance observed covariates between the two radiotherapy schedule groups. Effect estimates of radiotherapy schedule on overall survival (OS), locoregional recurrence (LRR) risk, thoracic response, any ≥grade 3 (including lung, and esophageal) toxicity were determined using multivariable regression modelling. A total of 173 patients were included in the overlap-weighted analysis, with 110 patients having received BID treatment, and 63 treated by HFRT. The median follow-up was 20.4 months. Multivariable regression modelling did not reveal any significant differences in OS (hazard ratio [HR] 1.67, p = 0.38), LRR risk (HR 1.48, p = 0.38), thoracic response (odds ratio [OR] 0.23, p = 0.21), any ≥grade 3+ toxicity (OR 1.67, p = 0.33), ≥grade 3 pneumonitis (OR 1.14, p = 0.84), or ≥grade 3 esophagitis (OR 1.41, p = 0.62). HFRT, in comparison to BID radiotherapy schedules, does not appear to result in significantly different survival, locoregional control, or toxicity outcomes.

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.

Moderately Hypofractionated Once-Daily Compared With Twice-Daily Thoracic Radiation Therapy Concurrently With Etoposide and Cisplatin in Limited-Stage Small Cell Lung Cancer: A Multicenter, Phase II, Randomized Trial

PURPOSE

Chemotherapy and concurrent thoracic radiation therapy (CCTRT) followed by prophylactic cranial irradiation (PCI) is the standard of care for limited-stage small cell lung cancer (LS-SCLC). We aimed to compare the efficacy and toxicity of moderately hypofractionated once-daily CCTRT with that of a standard twice-daily regimen.

METHODS AND MATERIALS

This multicenter, phase 2, randomized study enrolled patients aged 18 to 75 years old who had pathologically confirmed LS-SCLC and an Eastern Cooperative Oncology Group performance status of 0 to 1. Eligible patients received 4 to 6 cycles of etoposide-cisplatin chemotherapy and were randomized to receive twice-daily CCTRT at 45 Gray (Gy) in 30 fractions or once-daily CCTRT at 65 Gy in 26 fractions, commencing with cycles 1 to 3 of chemotherapy. PCI was given to good responders. The primary endpoint was progression-free survival (PFS).

RESULTS

The analyses included 182 patients, with 94 in the twice-daily group and 88 in the once-daily group. CCTRT started with cycle 3 of chemotherapy for most patients (80.2%). At a median follow-up of 24.3 months, the median PFS was 13.4 months (95% confidence interval [CI], 10.8-16.0) in the twice-daily group versus 17.2 months (95% CI, 11.8-22.6) in the once-daily group (P = .031), with 2-year PFS rates of 28.4% (95% CI, 18.2-38.6) and 42.3% (95% CI, 31.1-53.5), respectively. The estimated overall survival was 33.6 months in the twice-daily group versus 39.3 months in the once-daily group (P = .137). The median locoregional PFS was 23.9 months in the twice-daily group and was not reached in the once-daily group (P = .017). The incidences of most toxicities were similar in both groups, except for a higher incidence of ≥grade 3 acute lymphopenia in the once-daily group (71.7% vs 40.2% in the twice-daily group; P < .001). There was no difference in the incidences of ≥grade 3 esophagitis (17.4% vs 15.3%, respectively), pneumonitis (3.3% vs 2.4%, respectively) or treatment-related death (2.2% vs 1.2%, respectively) between the once-daily and twice-daily groups.

CONCLUSIONS

Moderately hypofractionated, once-daily CCTRT showed improved PFS and similar toxicities compared with twice-daily CCTRT in LS-SCLC. This regimen should be evaluated for comparison in a phase 3 randomized trial.

Development and validation of a nomogram for assessing survival in extensive-stage small-cell lung cancer patients with superior vena cava syndrome referred for thoracic radiotherapy: a comparison of upfront vs. consolidative approaches

PURPOSE

This study sought to design and validate a nomogram capable of predicting outcomes in extensive-stage small-cell lung cancer (ES-SCLC) patients with superior vena cava syndrome (SVCS) based upon the timing of their radiotherapy treatment.

METHODS

We retrospectively analyzed data from 175 ES-SCLC patients with SCVS, comparing outcomes between those that underwent upfront thoracic radiotherapy (initial radiotherapy with simultaneous chemotherapy) and those that underwent consolidative thoracic radiotherapy (following 4-6 cycles of chemotherapy). Significant predictors of patient outcomes were identified using a Cox proportional hazard model and were used to construct our nomogram. This model was subsequently validated using receiver operating characteristic (ROC) curves, concordance index (C-index) values, and a risk classification system in order to evaluate its discriminative and predictive accuracy.

RESULTS

The overall survival (OS) of ES-SCLC patients with SVCS that underwent chemotherapy (CT), consolidative thoracic radiotherapy (cc-TRT), and upfront thoracic radiotherapy (cu-TRT) was 8.2, 11.7, and 14.9 months, respectively (p < 0.001), with respective progression-free survival (PFS) durations of 3.3, 5.0, and 7.3 months (p < 0.001). A multivariate regression analysis revealed age, gender, ECOG performance status, sites of tumor metastasis, and treatment approach to all be independent predictors of survival outcomes. A nomogram was therefore developed incorporating these factors. C‑index values upon internal and external validation of this nomogram were 0.7625 and 0.7959, respectively, and ROC and calibration curves revealed this model to be accurate and consistent.

CONCLUSIONS

We found that upfront thoracic radiotherapy in combination with chemotherapy may be associated with a positive impact on outcomes in ES-SCLC patients with SVCS.

Efficacy of concurrent chemoradiotherapy for patients with limited-disease small-cell lung cancer: a retrospective, nationwide, population-based cohort study

Background

Small-cell lung cancer (SCLC) is a highly proliferative, rapidly growing tumor with a poor prognosis, even in cases of limited disease (LD). Timely and accurate high-intensity therapy is necessary. For concurrent chemoradiotherapy (CCRT), etoposide/platinum (EP)-based regimens are recommended, although irinotecan/platinum (IP)-based regimens are also effective with radiotherapy. This large-scale, retrospective, nationwide cohort study aimed to analyze the efficacy of CCRT in patients with LD-SCLC.

Methods

Population data registered between January 2008 and December 2018 was extracted from the Health Insurance Review and Assessment Service of Korea database. Survival outcomes of 4446 LD-SCLC patients who received CCRT were analyzed.

Results

Patients who received EP-CCRT (n = 4187) showed better time to first subsequent therapy (TFST: 11.2 months) and overall survival (OS: 22.2 months) than those who received IP-CCRT (n = 259; TFST: 9.6 months, P = 0.0477; OS: 16.4 months, P <  0.0001). When CCRT failed, dual-agent chemotherapy (n = 925; OS: 9.1 months) provided a better survival benefit than single-agent chemotherapy (n = 815; OS: 7.5 months). IP-based chemotherapy resulted in better OS (9.6 months) than EP-based chemotherapy (7.1 months, P = 0.017) in platinum-resistant relapsed patients; the opposite was observed for platinum-sensitive relapsed patients (OS: EP, 17.2 months; IP, 6.6 months; P <  0.0001). Poisson regression analysis demonstrated that age, EP-CCRT, and hypercholesterolemia retained significant associations with OS after adjustment for all variables.

Conclusion

In the Korean population, the effects of EP-CCRT on OS and TFST are significantly more favorable than those of IP-CCRT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08082-2.

GOECP/SEOR radiotherapy guidelines for small-cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 20% of all lung cancers. The main treatment is chemotherapy (Ch). However, the addition of radiotherapy significantly improves overall survival (OS) in patients with non-metastatic SCLC and in those with metastatic SCLC who respond to Ch. Prophylactic cranial irradiation reduces the risk of brain metastases and improves OS in both metastatic and non-metastatic patients. The 5-year OS rate in patients with limited-stage disease (non-metastatic) is slightly higher than 30%, but less than 5% in patients with extensive-stage disease (metastatic). The present clinical guidelines were developed by Spanish radiation oncologists on behalf of the Oncologic Group for the Study of Lung Cancer/Spanish Society of Radiation Oncology to provide a current review of the diagnosis, planning, and treatment of SCLC. These guidelines emphasise treatment fields, radiation techniques, fractionation, concomitant treatment, and the optimal timing of Ch and radiotherapy. Finally, we discuss the main indications for reirradiation in local recurrence.

Prophylactic cranial irradiation in patients with small cell lung cancer in The Netherlands: A population-based study

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Prophylactic cranial irradiation (PCI) use declined in The Netherlands.

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Independent predictors for prescription of PCI were identified.

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An alarming increase of practice variation was observed.

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Alternative MRI surveillance is not strictly adhered to.

Introduction

Controversy has arisen regarding the benefit of prophylactic cranial irradiation (PCI) in patients with small cell lung cancer (SCLC), particularly since the 2017 Takahashi trial publication that supports MRI surveillance in extensive-stage (ES-)SCLC. The primary aim of this study was to assess trends and determinants in PCI use over the years 2010–2018. A secondary aim was to determine contemporary practice considerations among radiation oncologists (ROs).

Methods

A nationwide population-based cohort study was conducted using the Netherlands Cancer Registry data on all newly diagnosed SCLC patients (2010–2018). The change in PCI frequency over the years and determinants for PCI were analyzed using logistic regression models. Second, an online survey was performed among Dutch lung cancer ROs in 2020.

Results

Among 10,264 eligible patients, 4,894 (47%) received PCI. Compared to 2010–2014, PCI use significantly decreased in 2017–2018 in ES-SCLC (OR 0.68, 95%CI 0.60–0.77) and LS-SCLC (OR 0.56, 95%CI 0.47–0.67). Incidence year, age, performance status, and thoracic radiotherapy were independent determinants for PCI. Among 41 survey participants, PCI was recommended always/sometimes/never by 22%/71%/7% in ES-SCLC and 54%/44%/2% in LS-SCLC. For ES-SCLC and LS-SCLC, 63% and 25% of ROs, respectively, confirmed influence of the Takahashi trial on PCI recommendations. Denial of such influence was associated with insufficient institutional MRI capacity.

Conclusions

A significant declining trend of PCI use in both ES-SCLC and LS-SCLC was observed in The Netherlands since 2017. The Takahashi trial seems an explanation for this trend even in LS-SCLC, with differential influence of the trial depending on institutional MRI capacity. An alarming increase in practice variation regarding PCI was found which stresses the importance of ongoing trials.

New Therapies and Biomarkers: Are We Ready for Personalized Treatment in Small Cell Lung Cancer?

Small cell lung cancer (SCLC) is an aggressive form of lung cancer with a 5-year survival rate of less than 7%. In contrast to non-small cell lung cancer, SCLC has long been treated as a homogeneous disease without personalized treatment options. In recent years, the incorporation of immunotherapy into the treatment paradigm has brought moderate benefit to patients with SCLC; however, more effective therapies are urgently needed. In this article, we describe the current treatment standards and emerging therapeutic approaches for the treatment of SCLC. We also discuss promising biomarkers in SCLC and the recently discovered four subtypes of SCLC, each with its unique therapeutic vulnerability. Lastly, we discuss the advances in radiation therapy for the treatment of SCLC.

Impact of proton radiotherapy on treatment timing in pediatric and adult patients with CNS tumors

BACKGROUND

Despite putative benefits associated with proton radiotherapy in the setting of CNS tumors, numerous barriers limit treatment accessibility. Given these challenges, we explored the association of proton use with variations in treatment timing.

METHODS

Pediatric and adult patients with histologically confirmed CNS tumors were identified from the National Cancer Database (2004-2015). Univariable and multivariable regression models were constructed to assess factors impacting radiation timing. Multivariable Cox regression was used to evaluate the effect of treatment delay on survival.

RESULTS

A total of 76 157 patients received photon or proton radiotherapy. Compared to photons, time to proton administration was longer in multiple pediatric (embryonal, ependymal, nonependymal glial, and other) and adult (ependymal, nonependymal glial, meningeal, other) tumor histologies. On adjusted analysis, proton radiotherapy was associated with longer delays in radiotherapy administration in pediatric embryonal tumors (+3.00 weeks, P = .024) and in all adult tumors (embryonal [+1.36 weeks, P = .018], ependymal [+3.15 weeks, P < .001], germ cell [+2.65 weeks, P = .024], glial [+2.15 weeks, P < .001], meningeal [+5.05 weeks, P < .001], and other [+3.06 weeks, P < .001]). In patients with high-risk tumors receiving protons, delays in adjuvant radiotherapy were independently associated with poorer survival (continuous [weeks], adjusted hazard ratio = 1.09, 95% CI = 1.02-1.16).

CONCLUSIONS

Proton radiotherapy is associated with later radiation initiation in pediatric and adult patients with CNS tumors. In patients with high-risk CNS malignancies receiving protons, delayed adjuvant radiotherapy is associated with poorer survival. Further studies are needed to understand this discrepancy to maximize the potential of proton radiotherapy for CNS malignancies.

European Cancer Organisation Essential Requirements for Quality Cancer Care (ERQCC): Lung cancer

European Cancer Organisation Essential Requirements for Quality Cancer Care (ERQCC) are written by experts representing all disciplines involved in cancer care in Europe. They give patients, health professionals, managers and policymakers a guide to essential care throughout the patient journey. Lung cancer is the leading cause of cancer mortality and has a wide variation in treatment and outcomes in Europe. It is a major healthcare burden and has complex diagnosis and treatment challenges. Care must only be carried out in lung cancer units or centres that have a core multidisciplinary team (MDT) and an extended team of health professionals detailed here. Such units are far from universal in European countries. To meet European aspirations for comprehensive cancer control, healthcare organisations must consider the requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis, to treatment, to survivorship.

Current and future strategies in radiotherapy for small-cell lung cancer

Small-cell lung cancer (SCLC) accounts for 13% of all lung tumors. The standard treatment in patients with limited-stage (LS) disease is thoracic radiotherapy (TRT) combined with chemotherapy. In extensive-stage (ES) SCLC, the importance of consolidation TRT in patients with a good treatment response has become increasingly recognized. In both LS and ES disease, prophylactic cranial irradiation is recommended in patients who respond to treatment. New therapeutic approaches such as immunotherapy are being increasingly incorporated into the treatment of SCLC, although more slowly than in non-small cell lung cancer. Diverse radiation dose and fractionation schemes, administered in varying combinations with these new drugs, are being investigated. In the present article, we review and update the role of radiotherapy in the treatment of SCLC. We also discuss the main clinical trials currently underway to identify future trends.

RELEVANCE FOR PATIENTS

Radiotherapy is a critical component of multimodality treatment of SCLC. This article can help physicians to improve medical knowledge and find better ways to treat their SCLC patients.

GOECP/SEOR clinical recommendations for lung cancer radiotherapy during the COVID-19 pandemic

The coronavirus disease 2019 crisis has had a major and highly complex impact on the clinical practice of radiation oncology worldwide. Spain is one of the countries hardest hit by the virus, with devastating consequences. There is an urgent need to share experiences and offer guidance on decision-making with regard to the indications and standards for radiation therapy in the treatment of lung cancer. In the present article, the Oncological Group for the Study of Lung Cancer of the Spanish Society of Radiation Oncology reviews the literature and establishes a series of consensus-based recommendations for the treatment of patients with lung cancer in different clinical scenarios during the present pandemic.

Bracing for impact with new 4R's in the COVID-19 pandemic - A provincial thoracic radiation oncology consensus

As COVID-19 pandemic continues to explode, cancer centers worldwide are trying to adapt and are struggling with this constantly changing scenario. Intending to ensure patient safety and deliver quality care, we sought consensus on the preferred thoracic radiation regimen in a Canadian province with 4 new R's of COVID era.

Consolidation radiotherapy for patients with extended disease small cell lung cancer in a single tertiary institution: impact of dose and perspectives in the era of immunotherapy

Background Consolidation radiotherapy (cRT) in extended disease small cell lung cancer (ED-SCLC) showed improved 2-year overall survival in patients who responded to chemotherapy (ChT) in CREST trial, however results of two meta - analysis were contradictive. Recently, immunotherapy was introduced to the treatment of ED-SCLC, making the role of cRT even more unclear. The aim of our study was to access if consolidation thoracic irradiation improves survival of ED-SCLC patients treated in a routine clinical practice and to study the impact of cRT dose on survival. We also discuss the future role of cRT in the era of immunotherapy. Patients and methods We retrospectively reviewed 704 consecutive medical records of patients with small cell lung cancer treated at the Institute of Oncology Ljubljana from January 2010 to December 2014 with median follow up of 65 months. We analyzed median overall survival (mOS) of patients with ED-SCLC treated with ChT only and those treated with ChT and cRT. We also compared mOS of patients treated with different consolidation doses and performed univariate and multivariate analysis of prognostic factors. Results Out of 412 patients with ED-SCLC, ChT with cRT was delivered to 74 patients and ChT only to 113 patients. Patients with cRT had significantly longer mOS compared to patients with ChT only, 11.1 months (CI 10.1-12.0) vs. 7.6 months (CI 6.9-8.5, p < 0.001) and longer 1-year OS (44% vs. 23%, p = 0.0025), while the difference in 2-year OS was not significantly different (10% vs. 5%, p = 0.19). The cRT dose was not uniform. Higher dose with 45 Gy (in 18 fractions) resulted in better mOS compared to lower doses 30-36 Gy (in 10-12 fractions), 17.2 months vs. 10.3 months (p = 0.03) and statistically significant difference was also seen for 1-year OS (68% vs. 30%, p = 0.01) but non significant for 2-year OS (18% vs. 5%, p = 0.11). Conclusions Consolidation RT improved mOS and 1-year OS in ED-SCLC as compared to ChT alone. Higher dose of cRT resulted in better mOS and 1-year OS compared to lower dose. Consolidation RT, higher number of ChT cycles and prophylactic cranial irradiation (PCI) were independent prognostic factors for better survival in our analysis. For patients who received cRT, only higher doses and PCI had impact on survival regardless of number of ChT cycles received. Role of cRT in the era of immunotherapy is unknown and should be exploited in further trials.

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.

Twice-daily vs higher-dose once-daily thoracic radiotherapy for limited-disease small-cell lung cancer: A PRISMA-compliant meta-analysis

INTRODUCTION

The optimal dose and fractionation of thoracic radiotherapy (RT) for limited-disease small-cell lung cancer (LD-SCLC) remain controversial. This meta-analysis was performed to compare the efficacy and RT toxicity between twice-daily thoracic RT (45 Gy with 1.5 Gy twice daily) and higher-dose once-daily RT (60-72 Gy with 1.8 Gy/2 Gy once daily) administered with chemotherapy in LD-SCLC patients.

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library were searched up to March 19, 2020 for studies that compared twice-daily thoracic RT (45 Gy with 1.5 Gy twice daily over 3 weeks) with higher-dose once-daily RT (60-72 Gy with 1.8 Gy/2 Gy once daily over 6-8 weeks) in LD-SCLC patients.

RESULTS

Five studies involving 13,726 patients were included in this analysis. Compared with the once-daily thoracic RT group, the 1-year overall survival (OS) rate (P < .001), the 2-year OS rate (P < .001), the 5-year OS rate (P < .001), the mOS (P < .001), and the 1-year LRFS rate (P = .048) were significantly improved in the twice-daily RT group. The toxic effects of RT (esophagitis: P = .293; pneumonitis: P = .103) were similar in both groups.

CONCLUSION

Compared with the higher-dose once-daily regimen, the twice-daily thoracic radiotherapy regimen improved efficacy but did not increase RT toxicity in LD-SCLC patients.

Thoracic Radiation Therapy During Coronavirus Disease 2019: Provisional Guidelines from a Comprehensive Cancer Center within a Pandemic Epicenter

Coronavirus disease 2019 is an unprecedented pandemic with significant and evolving impact on the practice of radiation oncology. Radiation oncology departments must anticipate and account for coronavirus disease 2019 exposure risk for both patients and staff. The potential for severe radiation therapy resource constraints, particularly due to staff illness, must also be considered. Here we present provisional guidelines for thoracic radiation therapy adopted at our facility, a high-volume cancer center located in a United States pandemic epicenter. Generally, these guidelines reflect the principle that where evidence-supported hypofractionated schedules with comparable efficacy and toxicity exist, the shortest such schedules should be employed. In addition, we discuss potential adaptations in the prioritization and timing of radiation therapy for thoracic malignancies under these circumstances.

Concurrent or Sequential Chemoradiotherapy after 3-4 Cycles Induction Chemotherapy for LS-SCLC with Bulky Tumor

The current study was to compare the efficacy and safety between concurrent and sequential chemoradiotherapy after 3-4 cycles of induction chemotherapy for limited-stage small-cell lung cancer (LS-SCLC) with bulky tumor. From July 2012 to September 2015, a total of 68 patients with stage IIIA and IIIB SCLC who had completed 3-4 cycles of etoposide plus cisplatin/carboplatin and achieved clinical complete response (cCR) or clinical partial response (cPR) were randomized into the two groups equally. The concurrent group received radiotherapy combined with oral etoposide and cisplatin and the sequential group received sequential chemoradiotherapy. Thoracic radiotherapy was performed using intensity-modulated radiation therapy (IMRT) with 95% PTV 60Gy/30 times. After completing chemoradiotherapy, patients received prophylactic cranial irradiation. The primary endpoint was progression-free survival (PFS), and secondary endpoints included overall survival (OS) and toxicity. The median follow-up time was 63.3 months (95% confidence interval [CI], 50.8-75.8). Better PFS and OS were observed in concurrent group (median PFS, 26.0 months [95% CI, 9.0-43.0] versus 13.1 months [95%CI, 9.7-16.6], p=0.023; median OS, 35.0 months [95% CI, 25.4-44.6] versus 22.0 months [95% CI, 17.0-27.1], p=0.015). There was no significant difference in the incidence of radiation esophagitis and radiation pneumonitis between the two groups (p=0.795, p=0.525). This study demonstrated that after the completion of 3-4 cycles of chemotherapy with a remission, concurrent chemoradiotherapy with oral etoposide and cisplatin improved survival compared with sequential chemoradiotherapy in LS-SCLC with bulky tumor. ClinicalTrials.gov Identifier: NCT01745445.

Radiotherapy treatment for lung cancer: Current status and future directions

Radiotherapy is an important modality used for the treatment of lung cancer. Seventy-seven percent of all patients with lung cancer have an evidence-based indication for radiotherapy, although it is often underutilized. Radiotherapy can be used as curative or palliative treatment across all stages of disease. Technological advances have allowed better radiotherapy targeting of tumours and reduced incidental irradiation of surrounding normal tissues. This has expanded the indications for radiotherapy in lung cancer and improved outcomes both in terms of increasing survival and reducing toxicity. This review examines the current role of radiotherapy in lung cancer, discusses the evidence behind this and identifies future directions in the radiotherapy treatment of lung cancer.

Optimizing lung cancer radiation treatment worldwide in COVID-19 outbreak

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Lung Cancer patients are at high risk for COVID-19 infection.

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All steps should be taken to protect patients and the healthcare workforce.

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Shortened RT overall treatment time is an important consideration during the COVID-19 pandemic.

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Twelve recommendations in the use of RT are proposed by an international panel.

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The proposed recommendations require urgent consideration during this pandemic.

COVID-19 has spread around the planet, sending billions of people into lockdown as health services struggle to cope. Meanwhile in Asia, where the disease began, the spread continues, in China it seems for now to have passed its peak. Italy, Spain, France, UK, and the US have been the countries more affected in terms of deaths. The coronavirus is more dangerous to the elderly and those with certain pre-existing medical conditions which is precisely the profile of lung cancer patients. Essential cancer services should be delivered but all steps should be taken to protect patients and the health workforce from infection with COVID-19. This presents a major challenge to radiotherapy (RT) departments worldwide. An international panel with expertise in the management of lung cancer in high-volume comprehensive centres has come together to share its experience on COVID-19 preparedness to deliver optimal care in such exceptional circumstances. A comprehensive systematic review of the literature through a PubMed search was undertaken. Twelve recommendations including, among others, the consideration of shorter courses, delays, and the omission of RT for lung cancer are proposed by the panel. In summary, we recommend the screening of every single person accessing the treatment room, the consideration of hypofractionation and to delay postoperative RT for non-small cell lung cancer, to avoid twice-daily treatments and delay or deliver prophylactic cranial irradiation during radio(chemo)therapy for limited-stage small cell lung cancer, review image guided RT images for suspicious image findings, and the use of single-fraction RT for the palliative treatment of stage IV lung cancer patients. Given that lung cancer is one of the most common and severe pathologies in radiation oncology departments, the following recommendations require particularly urgent consideration. The decision-making paths strongly depend on locally available resources, and a tailored approach should be used to attend lung cancer patients during this pandemic.

Once daily versus twice-daily radiotherapy in the management of limited disease small cell lung cancer - Decision criteria in routine practise

BACKGROUND

In limited disease small cell lung cancer (LD-SCLC), the CONVERT trial has not demonstrated superiority of once-daily (QD) radiotherapy (66 Gy) over twice-daily (BID) radiotherapy (45 Gy). We explored the factors influencing the selection between QD and BID regimens.

METHODS

Thirteen experienced European thoracic radiation oncologists as selected by the European Society for Therapeutic Radiation Oncology (ESTRO) were asked to describe their strategies in the management of LD-SCLC. Treatment strategies were subsequently converted into decision trees and analysed for agreement and discrepancies.

RESULTS

Logistic reasons, patients' performance status and radiotherapy dose constraints were the three major decision criteria used by most experts in decision making. The use of QD and BID regimens was balanced among European experts, but there was a trend towards the BID regimen for fit patients able to travel twice a day to the radiotherapy site.

CONCLUSION

BID and QD radiotherapy are both accepted regimens among experts and the decision is influenced by pragmatic factors such as availability of transportation.

Radiation Therapy for Small Cell Lung Cancer: An ASTRO Clinical Practice Guideline

PURPOSE

Several sentinel phase III randomized trials have recently been published challenging traditional radiation therapy (RT) practices for small cell lung cancer (SCLC). This American Society for Radiation Oncology guideline reviews the evidence for thoracic RT and prophylactic cranial irradiation (PCI) for both limited-stage (LS) and extensive-stage (ES) SCLC.

METHODS

The American Society for Radiation Oncology convened a task force to address 4 key questions focused on indications, dose fractionation, techniques and timing of thoracic RT for LS-SCLC, the role of stereotactic body radiation therapy (SBRT) compared with conventional RT in stage I or II node negative SCLC, PCI for LS-SCLC and ES-SCLC, and thoracic consolidation for ES-SCLC. Recommendations were based on a systematic literature review and created using a consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

The task force strongly recommends definitive thoracic RT administered once or twice daily early in the course of treatment for LS-SCLC. Adjuvant RT is conditionally recommended in surgically resected patients with positive margins or nodal metastases. Involved field RT delivered using conformal advanced treatment modalities to postchemotherapy volumes is also strongly recommended. For patients with stage I or II node negative disease, SBRT or conventional fractionation is strongly recommended, and chemotherapy should be delivered before or after SBRT. In LS-SCLC, PCI is strongly recommended for stage II or III patients who responded to chemoradiation, conditionally not recommended for stage I patients, and should be a shared decision for patients at higher risk of neurocognitive toxicities. In ES-SCLC, radiation oncologist consultation for consideration of PCI versus magnetic resonance surveillance is strongly recommended. Lastly, the use of thoracic RT is strongly recommended in select patients with ES-SCLC after chemotherapy treatment, including a conditional recommendation in those responding to chemotherapy and immunotherapy.

CONCLUSIONS

RT plays a vital role in both LS-SCLC and ES-SCLC. These guidelines inform best clinical practices for local therapy in SCLC.

SEOM clinical guidelines for the treatment of small-cell lung cancer (SCLC) (2019)

Small-cell lung cancer (SCLC) accounts for 15% of lung cancers. Only one-third of patients are diagnosed at limited stage. The median survival remains to be around 15–20 months without significative changes in the strategies of treatment for many years. In stage I and IIA, the standard treatment is the surgery followed by adjuvant therapy with platinum–etoposide. In stage IIB–IIIC, the recommended treatment is early concurrent chemotherapy with platinum–etoposide plus thoracic radiotherapy followed by prophylactic cranial irradiation in patients without progression. However, in the extensive stage, significant advances have been observed adding immunotherapy to platinum–etoposide chemotherapy to obtain a significant increase in overall survival, constituting the new recommended standard of care. In the second-line treatment, topotecan remains as the standard treatment. Reinduction with platinum–etoposide is the recommended regimen in patients with sensitive relapse (≥ 3 months) and new drugs such as lurbinectedin and immunotherapy are new treatment options. New biomarkers and new clinical trials designed according to the new classification of SCLC subtypes defined by distinct gene expression profiles are necessary.

A systematic review of survival following anti-cancer treatment for small cell lung cancer

OBJECTIVES

We conducted a systematic review and meta-analysis of survival following treatment recommended by the European Society of Medical Oncology for SCLC in order to determine a benchmark for novel therapies to be compared with.

MATERIALS AND METHODS

Randomized controlled trials and observational studies reporting overall survival following chemotherapy for SCLC were included. We calculated survival at 30 and 90-days along with 1-year, 2-year and median.

RESULTS

We identified 160 for inclusion. There were minimal 30-day deaths. Survival was 99 % (95 %CI 98.0-99.0 %, I²33.9 %, n = 77) and 90 % (95 %CI 89.0-92.0 %, I²79.5 %, n = 73) at 90 days for limited (LD-SCLC) and extensive stage (ED-SCLC) respectively. The median survival for LD-SCLC was 18.1 months (95 %CI 17.0-19.1 %, I²77.3 %, n = 110) and early thoracic radiotherapy (thoracic radiotherapy 18.4 months (95 %CI 17.3-19.5, I²78.4 %, n = 100)) vs no radiotherapy 11.7 months (95 %CI 9.1-14.3, n = 10), prophylactic cranial irradiation (PCI 19.7 months vs No PCI 13.0 months (95 %CI 18.5-21.0, I²75.7 %, n = 78 and 95 %CI 10.5-16.6, I²81.1 %, n = 15 respectively)) and better performance status (PS0-1 22.5 months vs PS0-4 15.3 months (95 %CI 18.7-26.1, I²72.4 %, n = 11 and 95 %CI 11.5-19.1 I²77.9 %, n = 13)) augmented this. For ED-SCLC the median survival was 9.6 months (95 %CI 8.9-10.3 %, I²95.2 %, n = 103) and this improved when irinotecan + cisplatin was used, however studies that used this combination were mostly conducted in Asian populations where survival was better. Survival was not improved with the addition of thoracic radiotherapy or PCI. Survival for both stages of cancer was better in modern studies and Asian cohorts. It was poorer for studies administering carboplatin + etoposide but this regimen was used in studies that had fewer patient selection criteria.

CONCLUSION

Early thoracic radiotherapy and PCI should be offered to people with LD-SCLC in accordance with guideline recommendations. The benefit of the aforementioned therapies to treat ED-SCLC and the use of chemotherapy in people with poor PS is less clear.

Treatment time to the end of thoracic radiotherapy has more predictive power for survival than radiation dose intensity in patients with limited-stage small-cell lung cancer receiving concurrent chemoradiation of more than 45 Gy

The optimal protocol for thoracic radiotherapy (TRT) in combination with chemotherapy in patients with limited-stage small-cell lung cancer (LS-SCLC) remains elusive. The present study aimed to evaluate radiation parameters in association with survival outcomes. A total of 101 patients with LS-SCLC who completed TRT at ≥45 Gy and concurrent chemotherapy were retrospectively reviewed. The median dose and duration of TRT were 50 Gy and 38 days, respectively. The median duration from the start of either therapy to the end of TRT (SER) was 60 days. The median survival for all patients was 26.9 months. The 3-year local control (LC), progression-free survival (PFS) and overall survival (OS) rates were 52.0, 29.5 and 37.6%, respectively, and the 5-year LC, PFS and OS rates were 50.1, 28.3 and 26.7%, respectively. Univariate analysis revealed that patient age, tumor stage, timing and dose of TRT, SER, prophylactic cranial irradiation (PCI), and tumor response were significantly associated with treatment outcomes. Multivariate analysis revealed that stage was the only significant prognostic factor for LC (P=0.011), PFS (P<0.001) and OS (P<0.001). Tumor response (P=0.014), PCI (P=0.007) and SER (P=0.005) were significant predictors of OS. OS was improved in patients who achieved complete response, and their SER was ≤70 days (P<0.001). Short treatment duration (SER ≤70 days) was a significant predictor of OS in patients with LS-SCLC who completed planned TRT at ≥45 Gy with concurrent chemoradiotherapy.