Phase III trial of concurrent thoracic radiotherapy with either first- or third-cycle chemotherapy for limited-disease small-cell lung cancer

The Dose/Fractionation Debate in Limited-Stage Small Cell Lung Cancer

To explore the most suitable dosage regimen for limited-stage small cell lung cancer (LS-SCLC) and provide references for clinical selection, strict inclusion criteria were applied, and studies were screened from Pubmed, Embase, and Web of Science. Subsequently, data on two-year overall survival rates and dosage regimens were collected, and scatter plots were constructed to provide a comprehensive perspective. The survival benefits of various dosage regimens were evaluated, and a linear quadratic equation was utilized to fit the relationship between the biologically effective dose (BED10) and the two-year overall survival rate. Among the five randomized controlled trials, the two-year overall survival rate of ConvTRT regimens with BED10 > 60 Gy (rough value) was only at or below the median of all ConvTRT regimens or all included study regimens, indicating that increasing the number and total dose of ConvTRT does not necessarily lead to better prognosis. In the exploration of HypoTRT regimens, there was a linear positive correlation between BED10 and the two-year overall survival rate (p < 0.0001), while the exploration of HyperTRT regimens was relatively limited, with the majority focused on the 45 Gy/30 F regimen. However, the current 45 Gy/30 F regimen is not sufficient to control LS-SCLC, resulting in a high local recurrence rate. High-dose ConvTRT regimens have long treatment durations and may induce tumor regrowth which may cause reduced efficacy. Under reasonable toxicity reactions, HyperTRT or HypoTRT with higher radiotherapy doses is recommended for treating LS-SCLC.

Six versus four or five cycles of first-line etoposide and platinum-based chemotherapy combined with thoracic radiotherapy in patients with limited-stage small-cell lung cancer: A propensity score-matched analysis of a prospective randomized trial

OBJECTIVES

The recommended treatment for limited-stage small-cell lung cancer (LS-SCLC) is a combination of thoracic radiotherapy (TRT) and etoposide plus cisplatin (EP) chemotherapy, typically administered over 4-6 cycles. Nonetheless, the optimal duration of chemotherapy is still not determined. This study aimed to compare the outcomes of patients with LS-SCLC who received either 6 cycles or 4-5 cycles of EP chemotherapy combined with TRT.

MATERIALS AND METHODS

In this retrospective analysis, we utilized data from our prior prospective trial to analyze the outcomes of 265 LS-SCLC patients who received 4-6 courses of EP combined with concurrent accelerated hyperfractionated TRT between 2002 and 2017. Patients were categorized into two groups depending on their number of chemotherapy cycles: 6 or 4-5 cycles. To assess overall survival (OS) and progression-free survival (PFS), we employed the Kaplan-Meier method after conducting propensity score matching (PSM).

RESULTS

Among the 265 LS-SCLC patients, 60 (22.6%) received 6 cycles of EP chemotherapy, while 205 (77.4%) underwent 4-5 cycles. Following PSM (53 patients for each group), the patients in the 6 cycles group exhibited a significant improvement in OS and PFS in comparison to those in the 4-5 cycles group [median OS: 29.8 months (95% confidence interval [CI], 23.6-53.1 months) vs. 22.7 months (95% CI, 20.8-29.1 months), respectively, p = 0.019; median PFS: 17.9 months (95% CI, 13.7-30.5 months) vs. 12.0 months (95% CI, 9.8-14.2 months), respectively, p = 0.006]. The two-year and five-year OS rates were 60.38% and 29.87% in the 6 cycles group, whereas 47.17% and 15.72% in the 4-5 cycles group, respectively.

CONCLUSION

Patients diagnosed with LS-SCLC who were treated with EP regimen chemotherapy combined with TRT exhibited notably enhanced survival when administered 6 cycles of chemotherapy, as compared to those who underwent only 4-5 cycles.

Pulmonary function and toxicities of proton versus photon for limited-stage small cell lung cancer

PURPOSE

We aimed to compare the oncological outcomes and toxicities of definitive proton beam therapy (PBT) and photon beam therapy in patients with limited-stage small cell lung cancer (LS-SCLC).

MATERIALS AND METHODS

We retrospectively reviewed 262 patients with newly diagnosed LS-SCLC who underwent definitive PBT (n = 20; proton group) or photon beam therapy (n = 242; photon group) with concurrent chemotherapy between January 2016 and February 2021 and compared overall survival (OS), progression-free survival (PFS), dose-volume parameters, and toxicities between the groups.

RESULTS

The median follow-up duration was 24.5 months (range, 3.7 to 78.7). Baseline lung function was significantly worse and clinical target volume (CTV) was larger in the proton group (CTV: 296.6 vs. 215.3 mL; p = 0.080). The mean lung V10 was 37.7% ± 16.8% and 51.6% ± 24.5% in the proton and photon groups, respectively (p = 0.002). Two-year OS and PFS rates were 57.2% and 35.7% in the proton group and 65.3% and 40.8% in the photon group, respectively (p = 0.542 and 0.748, respectively). Grade ≥2 radiation pneumonitis and esophagitis occurred in 5 (25.0%) and 7 (35.0%) PBT-treated patients and 66 (27.3%) and 40 (16.5%) photon beam therapy-treated patients, respectively (p = 0.826 and 0.062, respectively).

CONCLUSION

Although the proton group had poorer lung function and a larger CTV than that in the photon group, both groups exhibited comparable treatment outcomes and radiation-related toxicities in LS-SCLC. PBT may be a valuable therapeutic modality in patients with poor pulmonary function or extensive disease burden owing to its lung-sparing ability.

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.

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.

Effect of Segmental Abutting Esophagus-Sparing Technique to Reduce Severe Esophagitis in Limited-Stage Small-Cell Lung Cancer Patients Treated with Concurrent Hypofractionated Thoracic Radiation and Chemotherapy

The aim of the current study is to evaluate the effect of segmental abutting esophagus-sparing (SAES) radiotherapy on reducing severe acute esophagitis in patients with limited-stage small-cell lung cancer treated with concurrent chemoradiotherapy. Thirty patients were enrolled from the experimental arm (45 Gy in 3 Gy daily fractions in 3 weeks) of an ongoing phase III trial (NCT02688036). The whole esophagus was divided into the involved esophagus and the abutting esophagus (AE) according to the distance from the edge of the clinical target volume. All dosimetric parameters were significantly reduced for the whole esophagus and AE. The maximal and mean doses of the esophagus (47.4 ± 1.9 Gy and 13.5 ± 5.8 Gy, respectively) and AE (42.9 ± 2.3 Gy and 8.6 ± 3.6 Gy, respectively) in the SAES plan were significantly lower than those (esophagus 48.0 ± 1.9 Gy and 14.7± 6.1 Gy, AE 45.1 ± 2.4 Gy and 9.8 ± 4.2 Gy, respectively) in the non-SAES plan. With a median follow-up of 12.5 months, only one patient (3.3%) developed grade 3 acute esophagitis, and no grade 4-5 events happened. SAES radiotherapy has significant dosimetric advantages, which are successfully translated into clinical benefits and provide good feasibility for dose escalation to improve local control and prognosis in the future.

PI3K/AKT/mTOR pathway, hypoxia, and glucose metabolism: Potential targets to overcome radioresistance in small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive tumor type for which limited therapeutic progress has been made. Platinum-based chemotherapy with or without thoracic radiotherapy remains the backbone of treatment, but most patients with SCLC acquire therapeutic resistance. Given the need for more effective therapies, better elucidation of the molecular pathogenesis of SCLC is imperative. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is frequently activated in SCLC and strongly associated with resistance to ionizing radiation in many solid tumors. This pathway is an important regulator of cancer cell glucose metabolism, and its activation probably effects radioresistance by influencing bioenergetic processes in SCLC. Glucose metabolism has three main branches-aerobic glycolysis, oxidative phosphorylation, and the pentose phosphate pathway-involved in radioresistance. The interaction between the PI3K/AKT/mTOR pathway and glucose metabolism is largely mediated by hypoxia-inducible factor 1 (HIF-1) signaling. The PI3K/AKT/mTOR pathway also influences glucose metabolism through other mechanisms to participate in radioresistance, including inhibiting the ubiquitination of rate-limiting enzymes of the pentose phosphate pathway. This review summarizes our understanding of links among the PI3K/AKT/mTOR pathway, hypoxia, and glucose metabolism in SCLC radioresistance and highlights promising research directions to promote cancer cell death and improve the clinical outcome of patients with this devastating disease.

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.

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.

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.

Progression-Free Survival and Time to Progression as Potential Surrogate Endpoints for Overall Survival in Chemoradiotherapy Trials in Limited-Stage Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Purpose

To investigate whether progression-free survival (PFS) or time to progression (TTP) could be a valid surrogate endpoint for overall survival (OS) in patients with limited-stage small-cell lung cancer (LS-SCLC) receiving combined chemoradiotherapy.

Methods

Literature searching was performed in PubMed, Embase, and The Cochrane Library up to 2021. Prediction models were firstly established using data from phase III randomized controlled trials (RCTs) and then externally validated in phase II and retrospective studies. Correlation analysis was evaluated by a weighted linear regression model at both trial and arm levels. Cross-validation was performed to assess the consistency and robustness of the established models.

Results

37 studies, including 15 phase III RCTs, 12 phase II studies, and 10 retrospective studies, were selected in the final analysis. In trial-level surrogacy, a very good correlation was observed between hazard ratios (HRs) of PFS/TTP and OS (R2 = 0.783, 95% CI 0.771–0.794). In arm-level surrogacy, very good correlations were also observed between 2-year (R2 = 0.823, 95% CI 0.814–0.832), 3-year (R2 = 0.843, 95% CI 0.833–0.850), 5-year (R2 = 0.852, 95% CI 0.843–0.859) PFS/TTP, and 5-year OS. An excellent correlation was observed between 4-year PFS/TTP and 5-year OS (R2 = 0.906, 95% CI 0.901–0.910). Cross-validation demonstrated reasonable overall consistency. External validation in phase II and retrospective studies showed good agreement (R2, 0.728–0.824).

Conclusions

PFS/TTP was a valid surrogate endpoint for OS in patients with LS-SCLC receiving combined chemoradiotherapy. The finding provides high-level evidence to support PFS/TTP as the primary endpoint in clinical trials so as to speed up introducing novel agents to the treatment of LS-SCLC.

Radiotherapy for primary lung cancer

Herein are presented the recommendations from the Société française de radiothérapie oncologique regarding indications and modalities of lung cancer radiotherapy. The recommendations for delineation of the target volumes and organs at risk are detailed.

Preliminary Safety and Efficacy of Proton Plus Carbon-Ion Radiotherapy With Concurrent Chemotherapy in Limited-Stage Small Cell Lung Cancer

Objectives

This study aimed to investigate the tolerance and effect of proton plus carbon-ion radiotherapy with concurrent chemotherapy in limited-stage small cell lung cancer using the pencil beam scanning technique.

Materials and Methods

From March 2017 to April 2020, 25 patients with limited-stage small cell lung cancer treated with combined proton and carbon-ion radiotherapy were analyzed. The primary lesions and involved lymph nodes were irradiated using 2-4 portals. Proton and sequential carbon-ion beams were delivered with a median dose of 67.1 (range, 63-74.8) GyE as fraction doses of 2.0-2.2 GyE with proton beams in 20-23 fractions and 3.0-3.8 GyE with carbon ions in 5-8 fractions. Chemotherapy was delivered concurrently with radiotherapy in all patients.

Results

At the last follow-up, the 2-year overall and locoregional progression-free survival rates were 81.7% and 66.7%, respectively. Radiochemotherapy was well tolerated, with grade 1, 2, and 3 acute toxicities occurring in 12.0%, 68.0%, and 20.0% of patients, respectively. All grade 3 acute toxicities were hematologically related changes. One patient experienced grade 3 acute non-hematological toxicity in the esophagus, and one other patient had grade 3 bronchial obstruction accompanied by obstructive atelectasis as a late side effect.

Conclusion

Proton plus carbon-ion radiotherapy using pencil beam scanning yielded promising survival rates and tolerability in patients with limited-stage small cell lung cancer. A prospective clinical study is warranted to validate the therapeutic efficacy of particle radiotherapy in combination with chemotherapy in limited-stage small cell lung cancer.

Successful treatment of locally advanced lung cancer using late concurrent chemoradiation therapy administered after immune checkpoint inhibitor plus platinum chemotherapy

Concurrent chemoradiation therapy (CRT) is the standard of care for patients with unresectable stage II/III lung cancer. However, systemic chemotherapy is required for patients who are ineligible for radical radiation therapy. There is little evidence to date for the safety and efficacy of CRT administered after treatment with immune checkpoint inhibitors (ICIs). The cases reported here had inoperable stage III lung cancer (non‐small cell lung cancer and small cell lung cancer) and were ineligible for radical radiation therapy. They were administered ICIs plus chemotherapy and subsequently underwent late concurrent CRT. Because of the remarkable tumor shrinkage achieved by the ICIs plus chemotherapy, adverse events of CRT were tolerable. They were alive without tumor progression as of this report, over 1 year after CRT was terminated. CRT is administered with curative intent, while the intent of immunochemotherapy is palliative. Late concurrent CRT after immunochemotherapy is probably effective and tolerable. After treatment with systemic chemotherapy in patients judged ineligible for radical radiation therapy, radiation therapy should be reconsidered because of its importance once tumor shrinkage has been achieved.

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.

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.

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.

Small-cell lung cancer

Small-cell lung cancer (SCLC) represents about 15% of all lung cancers and is marked by an exceptionally high proliferative rate, strong predilection for early metastasis and poor prognosis. SCLC is strongly associated with exposure to tobacco carcinogens. Most patients have metastatic disease at diagnosis, with only one-third having earlier-stage disease that is amenable to potentially curative multimodality therapy. Genomic profiling of SCLC reveals extensive chromosomal rearrangements and a high mutation burden, almost always including functional inactivation of the tumour suppressor genes TP53 and RB1. Analyses of both human SCLC and murine models have defined subtypes of disease based on the relative expression of dominant transcriptional regulators and have also revealed substantial intratumoural heterogeneity. Aspects of this heterogeneity have been implicated in tumour evolution, metastasis and acquired therapeutic resistance. Although clinical progress in SCLC treatment has been notoriously slow, a better understanding of the biology of disease has uncovered novel vulnerabilities that might be amenable to targeted therapeutic approaches. The recent introduction of immune checkpoint blockade into the treatment of patients with SCLC is offering new hope, with a small subset of patients deriving prolonged benefit. Strategies to direct targeted therapies to those patients who are most likely to respond and to extend the durable benefit of effective antitumour immunity to a greater fraction of patients are urgently needed and are now being actively explored.

Prediction of radiation pneumonitis using dose-volume histogram parameters with high attenuation in two types of cancer: A retrospective study

The constraint values of dose-volume histogram (DVH) parameters for radiation pneumonitis (RP) prediction have not been uniform in previous studies. We compared the differences between conventional DVH parameters and DVH parameters with high attenuation volume (HAV) in CT imaging in both esophageal cancer and lung cancer patients to determine the most suitable DVH parameters in predicting RP onset. Seventy-seven and 72 patients who underwent radiation therapy for lung cancer and esophageal cancer, respectively, were retrospectively assessed. RP was valued according to the Common Terminology Criteria for Adverse Events. We quantified HAV with quantitative computed tomography analysis. We compared conventional DVH parameters and DVH parameters with HAV in both groups of patients. Then, the thresholds of DVH parameters that predicted symptomatic RP and the differences in threshold of DVH parameters between lung cancer and esophageal cancer patient groups were compared. The predictive performance of DVH parameters for symptomatic RP was compared using the area under the receiver operating characteristic curve. Mean lung dose, HAV30% (the proportion of the lung with HAV receiving ≥30 Gy), and HAV20% were the top three parameters in lung cancer, while HAV10%, HAV5%, and V10 (the percentage of lung volume receiving 10 Gy or more) were the top three in esophageal cancer. By comparing the differences in the threshold for parameters predicting RP between the two cancers, we saw that HAV30% retained the same value in both cancers. DVH parameters with HAV showed narrow differences in the threshold between the two cancer patient groups compared to conventional DVH parameters. DVH parameters with HAV may have higher commonality than conventional DVH parameters in both patient groups tested.

Insulinoma-associated Protein 1 (INSM1) Is a Better Marker for the Diagnosis and Prognosis Estimation of Small Cell Lung Carcinoma Than Neuroendocrine Phenotype Markers Such as Chromogranin A, Synaptophysin, and CD56

To diagnose small cell lung carcinoma (SCLC), neuroendocrine (NE) phenotype markers such as chromogranin A, synaptophysin, and CD56 are helpful. However, because they are dispensable, SCLCs occur without apparent NE phenotypes. Insulinoma-associated protein 1 (INSM1) is a transcription factor for NE differentiation and has emerged as a single practical marker for SCLC. Using the surgical samples of 141 pulmonary NE tumors (78 SCLCs, 44 large cell NE carcinomas, and 19 carcinoids), and 246 non-NE carcinomas, we examined the immunohistochemical expression and prognostic relevance of INSM1 in association with NE phenotype markers. We evaluated its sensitivity and specificity for SCLC diagnosis, as well as its usefulness to diagnose SCLC without NE marker expression and to estimate the prognosis. INSM1 was expressed in SCLCs (92%, 72/78), large cell NE carcinomas (68%, 30/44), and carcinoids (95%, 18/19). In addition, among SCLCs with no expression of NE phenotype markers (n=12), 9 (75%) were positive for INSM1. These data suggest the superiority of INSM1 to the phenotype markers. Only 7% of adenocarcinomas (9/134) and 4% of squamous cell carcinomas (4/112) were positive for INSM1. SCLC with low-INSM1 expression (n=28) had a significantly better prognosis (P=0.040) than the high-INSM1 group (n=50). Our study revealed that INSM1 is highly sensitive and specific to detect SCLC and can estimate prognosis. INSM1 will be a promising marker for SCLC.

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.

mRNA Expression of FGFR1 as Potential Marker for Predicting Prognosis of Surgical Resection of Small Cell Lung Cancer may be better than Protein Expression and Gene Amplification

Purpose: Fibroblast growth factor receptor 1 (FGFR1) alterations have been described in many cancers, including lung cancer, but the role has not been elucidated specifically in small cell lung cancer (SCLC). The present study aimed to identify the frequency of FGFR1 alterations among Chinese patients with surgically resected SCLC and the association with the clinicopathological characteristics and the survival were also investigated.

Methods: FGFR1 protein expression, FGFR1 amplification, FGFR1 mutations, and messenger RNA (mRNA) levels, were determined by immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR) and reverse transcription-polymerase chain reaction (RT-PCR), respectively in primary tumors from 33 patients with resected SCLC.

Results: 7/33(21.2%) of the specimens were positive for FGFR1 protein expression. FGFR1 amplification was identified in 4/28 cases (14.3%). If the cut-off value was determined to be 3.5, FGFR1 mRNA positivity was considered in 7/33 cases (21.2%). However, no mutation was detected in the 33 SCLC postoperative tissue specimens. No significant association was observed between FGFR1 protein expression or amplification and clinicalcharacteristics or prognosis. There was a distinct trend for mRNA level and poor prognosis, including recurrence-free survival (RFS) (p = 0.07) and overall survival (OS) (p= 0.08), but they did not reach statistical significance.

Conclusions: As novel FGFR1-targeted therapies are developed, FISH, IHC, especially mRNA were detected, which should be considered as biomarkers of FGFR1 pathway dysregulation in SCLC.

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.

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.

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.

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.

Timing of thoracic radiotherapy is more important than dose intensification in patients with limited-stage small cell lung cancer: a parallel comparison of two prospective studies

PURPOSE

The optimal radiotherapy dose/fraction for limited-stage small cell lung cancer (SCLC) is undefined. Our objectives were to compare efficacy between hyperfractionated thoracic radiotherapy (TRT; 1.5 Gy 2 times per day [bid] in 30 fractions) and hypofractionated TRT (2.5 Gy once per day [qd] in 22 fractions), and to explore prognostic factors influencing the prognosis, such as the timing of TRT.

METHODS

Patients enrolled in two independent prospective studies were combined and analyzed. The primary endpoint was local/regional control (LRC). The prognosis was analyzed using the Cox proportional hazards regression model.

RESULTS

Ninety-two and 96 patients were treated with hyperfractionated TRT and hypofractionated TRT, respectively. The 1‑ and 2‑year LRC rates of the two arms were 82.1 and 60.7%, and 84.9 and 68.8% (P = 0.27), respectively. The median overall survival (OS) times (months) were 28.3 (95% confidence interval, CI 16.4-40.1) and 22.0 (95% CI 16.4-27.5), while the 1‑year, 3‑year, and 5‑year OS rates were 85.2, 40.8, and 27.1%, and 76.9, 34.3, and 26.8% (P = 0.37), respectively. Using a multivariate Cox regression study, time (days) from the initiation of chemotherapy to TRT (TCT) ≤43 was associated with improved LRC (hazard radio, HR 0.39, 95% CI 0.20-0.76; P = 0.005). Time (days) from the start of chemotherapy to the end of TRT (SER) ≤63 (HR 0.50, 95% CI 0.32-0.80; P = 0.003) and prophylactic cranial irradiation (HR 0.43; 95% CI 0.29-0.63; P = 0.000) were favorably related to OS. Grade 2/3 acute radiation esophagitis was observed in 37.0 and 17.7% of patients in the hyperfractionated and hypofractionated arms, respectively (P = 0.003).

CONCLUSION

Both hyperfractionated and hypofractionated TRT schedules achieved good LRC and OS for patients with limited-stage SCLC in this study. Keeping TCT ≤43 and SER ≤63 resulted in a better prognosis. The incidence of acute esophagitis was significantly higher in the hyperfractionated arm.

Final report of a prospective randomized study on thoracic radiotherapy target volume for limited-stage small cell lung cancer with radiation dosimetric analyses

BACKGROUND

The thoracic radiotherapy (TRT) target volume for limited-stage small-cell lung cancer (SCLC) has been controversial for decades. In this report, the final results of a prospective randomized trial on the TRT target volume before and after induction chemotherapy are presented.

METHODS

After 2 cycles of etoposide and cisplatin, patients arm were randomized to receive TRT to the postchemotherapy or prechemotherapy tumor volume in a study arm and a control arm. Involved-field radiotherapy was received in both arms. TRT consisted of 1.5 grays (Gy) twice daily in 30 fractions to up to a total dose of 45 Gy. Lymph node regions were contoured, and intentional and incidental radiation doses were recorded.

RESULTS

The study was halted early because of slow accrual. Between 2002 and 2017, 159 and 150 patients were randomized to the study arm or the control arm, respectively; and 21.4% and 19.1% of patients, respectively, were staged using positron emission tomography/computed tomography (P = .31). With a median follow-up of 54.1 months (range, 19.9-165.0 months) in survivors, the 3-year local/regional progression-free probability was 58.2% and 65.5% in the study and control arms, respectively (P = .44), and the absolute difference was -7.3% (95% CI, -18.2%, 3.7%). In the study and control arms, the median overall survival was 21.9 months and 26.6 months, respectively, and the 5-year overall survival rate was 22.8% and 28.1%, respectively (P = .26). Grade 3 esophagitis was observed in 5.9% of patients in the study arm versus 15.5% of those in the control arm (P = .01). The isolated out-of-field failure rate was 2.6% in the study arm versus 4.1% in the control arm (P = .46), and all such failures were located in the supraclavicular fossa or contralateral hilum. The regions 7, 3P, 4L, 6, 4R, 5, and 2L received incidental radiation doses >30 Gy.

CONCLUSIONS

TRT could be limited to the postchemotherapy tumor volume, and involved-field radiotherapy could be routinely applied for limited-stage SCLC.

Role of prophylactic cranial irradiation for elderly patients with limited-disease small-cell lung cancer: inverse probability of treatment weighting using propensity score

Studies of prophylactic cranial irradiation (PCI) focused on elderly patients with small-cell lung cancer (SCLC) are rarely conducted. We aimed to identify whether there is a survival benefit of prophylactic cranial irradiation (PCI) in elderly patients using a single institution's retrospective data. A total of 234 patients with limited-disease SCLC (LD-SCLC) treated with thoracic chemoradiotherapy were evaluated; of these, 139 patients received PCI. To minimize treatment selection bias, patients were adjusted using the propensity score on factors associated with receipt of PCI. Cox proportional hazard model and Kaplan-Meier analyses were used to identify which subgroup may benefit from PCI. Median follow-up time was 22 months (range 1-150 months). PCI was associated with favorable brain metastasis-free survival, disease-specific survival, and overall survival in the entire population [hazard ratios (HR) 0.588, 95% confidence interval (CI) 0.338-1.024, P = 0.060; HR 0.477, 95% CI 0.331-0.687, P < 0.001; HR 0.543, 95% CI 0.383-0.771, P = 0.001, respectively). However, PCI had no significant relationship with overall survival in patients aged ≥65 years with cT3-4 disease and/or females gender (HR 0.817, 95% CI 0.098-6.849, P = 0.853; HR 1.082, 95% CI 0.114-10.227, P = 0.946, respectively). The benefits and risks of PCI in elderly patients with LD-SCLC need to be scrutinized, especially in those with high T stage tumors and/or females.

The value of prophylactic cranial irradiation in limited-stage small cell lung cancer: should it always be recommended?

Purpose

Prophylactic cranial irradiation (PCI) is a standard treatment for limited-stage small cell lung cancer (LS-SCLC) showing a response to initial treatment, but many patients do not receive PCI due to comorbidities or refusal. This study aims to define the patient group for whom PCI can be omitted with minimal risk.

Materials and Methods

Patients with LS-SCLC who underwent radiotherapy with curative aim at our institution between January 2004 and December 2015 were retrospectively reviewed. Patients who did not receive PCI were evaluated for brain metastasis-free survival (BMFS), progression-free survival (PFS), overall survival (OS), and prognostic factors for survival, and treatment outcomes were compared with a patient cohort who received PCI.

Results

A total of 350 patients achieved a response following thoracic radiotherapy, and 190 of these patients did not receive PCI. Stage I–II and a complete response (CR) to initial therapy were good prognostic factors for BMFS and OS on univariate analysis. Patients with both stage I–II and a CR who declined PCI showed comparable 2-year BMFS to those who received PCI (92% vs. 89%). In patients who achieved CR, PCI did not significantly improve OS or PFS.

Conclusion

There should be less concern about omitting PCI in patients with comorbidities if they have stage I–II or a CR, with brain metastasis control being comparable to those patients who receive PCI.

Determination of Risk Factors Related to Supraclavicular Recurrence for Limited-Stage Small Cell Lung Cancer (SCLC) Patients

BACKGROUND This research aimed to determine high-risk factors of supraclavicular recurrence for limited-stage small cell lung cancer (LS-SCLC) patients to discover a potential subpopulation that can benefit from prophylactic supraclavicular irradiation (PSCI). MATERIAL AND METHODS Between July 2006 and July 2011, LS-SCLC patients without supraclavicular lymph node (SCLN) involvement consecutively treated with concurrent chemo-radiation but without PSCI in the Radiotherapy Department of the Cancer Institute and Hospital of Tianjin Medical University, were retrospectively analyzed. SCLN recurrence rate, overall survival (OS), and distant metastasis-free survival (DMFS) were assessed. Binary logistic regression analysis was conducted to discover the high-risk factors related to the SCLN recurrence. The receiver operating characteristic (ROC) curves were drawn to evaluate logistic regression model prediction performance. RESULTS Eighty-eight LS-SCLC patients were analyzed in this study. During 99 months (ranging from 72 months to 124 months) for survivors, 28 (31.8%) had SCLN recurrence. There were significant differences for median DMFS and OS between LS-SCLC patients with and without SCLN recurrence. The logistic regression model revealed that lymphadenopathy at mediastinal level 2 and level 3 prior to chemotherapy were significantly associated with SCLN recurrence, which was validated by ROC. CONCLUSIONS Lymphadenopathy at mediastinal level 2 and level 3 prior to chemotherapy were the high-risk factors associated with SCLN recurrence for patients with LS-SCLC. Further work is needed to determine whether patients with these factors can benefit from PSCI.

Initial management of small-cell lung cancer (limited- and extensive-stage) and the role of thoracic radiotherapy and first-line chemotherapy: a systematic review

Background

Patients with limited-stage (ls) or extensive-stage (es) small-cell lung cancer (sclc) are commonly given platinum-based chemotherapy as first-line treatment. Standard chemotherapy for patients with ls sclc includes a platinum agent such as cisplatin combined with the non-platinum agent etoposide. The objective of the present systematic review was to investigate the efficacy of adding radiotherapy to chemotherapy in patients with es sclc and to determine the appropriate timing, dose, and schedule of chemotherapy or radiation for patients with sclc.

Methods

The medline and embase databases were searched for randomized controlled trials (rcts) comparing treatment with radiotherapy plus chemotherapy against treatment with chemotherapy alone in patients with es sclc. Identified rcts were also included if they compared various timings, doses, and schedules of treatment for patients with es sclc or ls sclc.

Results

Sixty-four rcts were included. In patients with ls sclc, overall survival was greatest with platinum-etoposide compared with other chemotherapy regimens. In patients with es sclc, overall survival was greatest with chemotherapy containing platinum-irinotecan than with chemotherapy containing platinum-etoposide (hazard ratio: 0.84; 95% confidence interval: 0.74 to 0.95; p = 0.006). The addition of radiation to chemotherapy for patients with es sclc showed mixed results. There was no conclusive evidence that the timing, dose, or schedule of thoracic radiation affected treatment outcomes in sclc.

Conclusions

In patients with ls sclc, cisplatin-etoposide plus radiotherapy should remain the standard therapy. In patients with es sclc, the evidence is insufficient to recommend the addition of radiotherapy to chemotherapy as standard practice to improve overall survival. However, on a case-by-case basis, radiotherapy might be added to reduce local recurrence. The most commonly used chemotherapy is platinum-etoposide; however, platinum-irinotecan can be considered.

Impact of thoracic radiation therapy after chemotherapy on survival in extensive-stage small cell lung cancer: A propensity score-matched analysis

Background

The role of thoracic radiation therapy (TRT) after chemotherapy (CHT) in extensive‐stage small cell lung cancer (ES‐SCLC) has not been well defined. We investigated whether intensity‐modulated radiotherapy (IMRT) improves outcomes in ES‐SCLC after CHT compared to CHT alone.

Methods

A total of 292 patients who reached a complete response (CR), partial response (PR), or stable disease (SD) after CHT were assigned into groups: CHT + TRT and CHT alone. Propensity score matching was used to balance patient groups (n = 72 each).

Results

The five‐year overall survival (OS: 12.3% vs. 3.6%; P < 0.001) and progression‐free survival (PFS: 3.2% vs. 1.7%; P = 0.006) rates were significantly higher in the CHT + TRT group. This data was confirmed in the matched samples (5‐year OS: 10.5% vs. 1.6%, P < 0.001; PFS: 4.3% vs. 0.0%, P = 0.023). The overall (P = 0.002) and locoregional (P < 0.001) recurrence rates in the CHT + TRT group were significantly lower than in the CHT group. Univariate analysis showed that response evaluation after CHT and TRT were significant prognostic factors of OS. Multivariate analyses revealed that N Stage 0–1 (P = 0.02), > 6 cycles of CHT (P = 0.042), CR + PR after CHT (P < 0.001), and TRT (P < 0.001) were independently associated with longer OS compared to CHT alone.

Conclusion

TRT using IMRT is strongly correlated with improved OS and PFS in ES‐SCLC patients reaching CR, PR or SD after CHT. A multicenter, randomized phase III clinical trial is needed to confirm these findings.

A pooled analysis of individual patient data from National Clinical Trials Network clinical trials of concurrent chemoradiotherapy for limited-stage small cell lung cancer in elderly patients versus younger patients

BACKGROUND

Platinum and etoposide with thoracic radiation followed by prophylactic cranial irradiation constitute the standard treatment for limited-stage small cell lung cancer (LS-SCLC). Many patients with LS-SCLC are elderly with comorbidities.

METHODS

Individual patient data were collected from 11 phase 2 or 3 trials for LS-SCLC conducted by the National Clinical Trials Network and activated from 1990 to 2010. The primary endpoint was overall survival (OS); the secondary endpoints were progression-free survival (PFS), the rate of severe adverse events, and off-treatment reasons. The outcomes were compared for patients 70 years old or older (elderly patients) and patients younger than 70 years (younger patients).

RESULTS

Individual patient data from 1049 younger patients (81%) and 254 elderly patients (19%) were analyzed. In the multivariate model, elderly patients, in comparison with younger patients, had worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.18-1.63; median OS for elderly patients, 17.8 months; OS for younger patients, 23.5 months) and worse PFS (HR, 1.19; 95% CI, 1.03-1.39; median PFS for elderly patients, 10.6 months; median PFS for younger patients, 12.3 months). Elderly patients, in comparison with younger patients, experienced more grade 5 adverse events (8% vs 3%; P < .01) and more grade 3 or higher dyspnea (11% vs 7%; P = .03) but less grade 3 or higher esophagitis/dysphagia (14% vs 19%; P = .04) and less grade 3 or higher vomiting (11% vs 17%; P = .01). Elderly patients completed treatment less often, discontinued treatment because of adverse events and patient refusal more frequently, and died during treatment more frequently.

CONCLUSIONS

Elderly patients with LS-SCLC have worse PFS and OS and more difficulty in tolerating therapy. Future trials should incorporate assessments of elderly patients, novel monitoring of adverse events, and more tolerable radiation and systemic therapies.

Barriers to Combined-Modality Therapy for Limited-Stage Small Cell Lung Cancer

Importance

Combined-modality therapy with chemotherapy and radiation therapy plays a crucial role in the upfront treatment of patients with limited-stage small cell lung cancer (SCLC), but there may be barriers to utilization in the United States.

Objective

To estimate utilization rates and factors associated with chemotherapy and radiation therapy delivery for limited-stage SCLC using the National Cancer Database.

Design, Setting, and Participants

Analysis of initial management of all limited-stage SCLC cases from 2004 through 2013 in the National Cancer Database.

Main Outcomes and Measures

Utilization rates of chemotherapy and radiation therapy at time of initial treatment. Multivariable analysis identified independent clinical and socioeconomic factors associated with utilization and overall survival.

Results

A total of 70 247 cases met inclusion criteria (55.3% female; median age, 68 y [range, 19-90 y]). Initial treatment was 55.5% chemotherapy and radiation therapy, 20.5% chemotherapy alone, 3.5% radiation therapy alone, and 20.0% neither (0.5% not reported). Median survival was 18.2 (95% CI, 17.9-18.4), 10.5 (95% CI, 10.3-10.7), 8.3 (95% CI, 7.7-8.8), and 3.7 (95% CI, 3.5-3.8) months, respectively. Being uninsured was associated with a lower likelihood of both chemotherapy (odds ratio [OR], 0.65; 95% CI, 0.56-0.75; P < .001) and radiation therapy (OR, 0.75; 95% CI, 0.67-0.85; P < .001) administration on multivariable analysis. Medicare/Medicaid insurance had no impact on chemotherapy use, whereas Medicaid (OR, 0.79; 95% CI, 0.72-0.87; P < .001) and Medicare (OR, 0.86; 95% CI, 0.82-0.91; P < .001) were independently associated with a lower likelihood of radiation therapy delivery. Lack of health insurance (HR, 1.19; 95% CI, 1.13-1.26; P < .001), Medicaid (HR, 1.27; 95% CI, 1.21-1.32; P < .001), and Medicare (HR, 1.12; 95% CI, 1.09-1.15; P < .001) coverage were independently associated with shorter survival on adjusted analysis, while chemotherapy (HR, 0.55; 95% CI, 0.54-0.57; P < .001) and radiation therapy (HR, 0.62; 95% CI, 0.60-0.63; P < .001) were associated with a survival benefit.

Conclusions and Relevance

Substantial proportions of patients documented in a major US cancer registry did not receive radiation therapy or chemotherapy as part of initial treatment for limited-stage SCLC, which, in turn, was associated with poor survival. Lack of radiation therapy delivery was uniquely associated with government insurance coverage, suggesting a need for targeted access improvement in this population. Additional work will be necessary to conclusively define exact population patterns, specific treatment deficiencies, and causative factors leading to heterogeneous care delivery.

Effects of thoracic radiotherapy timing and duration on progression-free survival in limited-stage small cell lung cancer

Concurrent chemoradiotherapy (CRT) has been recommended and applied widely as the standard treatment for limited‐stage small cell lung cancer (LS‐SCLC). However, controversies remain regarding the optimal timing and treatment duration of thoracic radiotherapy (TRT), and their effects on patient survival. To evaluate prognostic values of TRT timing and duration on progression‐free survival (PFS) in LS‐SCLC and their dependence on TRT fractionation and clinicopathological characteristics, we retrospectively analyzed 197 LS‐SCLC patients receiving CRT from 2000 to 2016 at Sun Yat‐sen University Cancer Center. Based on the optimal cut‐off values of TRT timing and duration generated by Cutoff Finder, patients were divided into early TRT/late TRT group and short TRT/long TRT group respectively. Univariate and multivariate Cox analysis were performed to assess correlations of TRT timing, duration, fractionation, and clinicopathological characteristics with PFS. Univariate analysis revealed that early‐initiated TRT (P = 2.54 × 10⁻⁴) and short TRT (P = .001) significantly correlated with longer PFS. Their PFS benefits persisted in patients receiving hyperfractionated TRT and etoposide‐cisplatin (EP) chemotherapy, but were less prominent in those receiving once‐daily TRT and non‐EP chemotherapy. Multivariate analysis further identified early initiated TRT (P = .004) and short TRT (P = .017) as independent prognostic factors for longer PFS in LS‐SCLC. Our study confirmed that early‐initiated TRT and short TRT had positive prognostic roles in LS‐SCLC, especially in patients receiving hyperfractionated TRT and etoposide‐cisplatin chemotherapy. TRT fractionation was not an independent prognostic factor in LS‐SCLC.

Guideline for the Initial Management of Small Cell Lung Cancer (Limited and Extensive Stage) and the Role of Thoracic Radiotherapy and First-line Chemotherapy

AIMS

We investigated the efficacy of adding radiotherapy to chemotherapy in patients with extensive stage small cell lung cancer (ES-SCLC) and the appropriate timing, dose and schedule of treatment for patients with ES-SCLC or limited stage SCLC (LS-SCLC).

MATERIALS AND METHODS

The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care and by the Lung Cancer Disease Site Group through a systematic review of randomised controlled trials.

KEY RECOMMENDATIONS

In patients with LS-SCLC (stage I, II and III), the addition of thoracic radiotherapy to standard chemotherapy is recommended. However, there is no clear evidence to inform definitive recommendations for optimal timing, sequential versus concurrent therapies and optimal dose or regimen. In patients with LS-SCLC, etoposide-cisplatin is the preferred regimen for adults who are being treated with combined modality therapy with curative intent. In patients with ES-SCLC (stage IV), there is insufficient evidence to recommend the addition of thoracic radiotherapy to standard chemotherapy as a standard practice for survival benefit; however, it could be considered on a case-by-case basis to reduce local recurrence. In patients with ES-SCLC, a platinum agent plus etoposide is the preferred regimen for adult patients who are being treated with combined modality therapy. Cisplatin and irinotecan represents an alternative treatment option to this, but is associated with increased rates of adverse events such as diarrhoea.

Timing of Thoracic Radiation Therapy With Chemotherapy in Limited-stage Small-cell Lung Cancer: Survey of US Radiation Oncologists on Current Practice Patterns

INTRODUCTION

For limited-stage small-cell lung cancer (LS-SCLC), National Comprehensive Cancer Network guidelines recommend that thoracic radiotherapy (TRT) be delivered concurrently with chemotherapy and early in the regimen, with cycle 1 or 2. Evidence is conflicting regarding the benefit of early timing of TRT. A Korean randomized trial did not see a survival difference between early (cycle 1) and late (cycle 3) TRT. Current United States (US) practice patterns are unknown.

MATERIALS AND METHODS

We surveyed US radiation oncologists using an institutional review board-approved online questionnaire. Questions covered treatment recommendations, self-rated knowledge of trials, and demographics.

RESULTS

We received 309 responses from radiation oncologists. Ninety-eight percent recommend concurrent chemoradiotherapy over sequential. Seventy-one percent recommend starting TRT in cycle 1 of chemotherapy, and 25% recommend starting in cycle 2. In actual practice, TRT is started most commonly in cycle 2 (48%) and cycle 1 (44%). One-half of respondents (54%) believe starting in cycle 1 improves survival compared with starting in cycle 3. Knowledge of the Korean trial was associated with flexibility in delaying TRT to cycle 2 or 3 (P = .02). Over one-third (38%) treat based on pre-chemotherapy volume.

CONCLUSION

US radiation oncologists strongly align with National Comprehensive Cancer Network guidelines, which recommend early concurrent chemoradiotherapy. Nearly three-quarters of respondents prefer starting TRT with cycle 1 of chemotherapy. However, knowledge of a trial supporting a later start was associated with flexibility in delaying TRT. Treating based on pre-chemotherapy volume-endorsed by over one-third of respondents-may add unnecessary toxicity. This survey can inform development of future trials.

Effect of sequential chemoradiotherapy in patients with limited-disease small-cell lung cancer who were ineligible for concurrent therapy: a retrospective study at two institutions

Background

The standard treatment for limited-disease small-cell lung cancer (LD-SCLC) is a combination of chemotherapy and concurrent thoracic radiotherapy. In selected cases, sequential radiotherapy is preferred because of the need for a large irradiation field, patient age, comorbidities or performance status. Nevertheless, the efficacy of sequential chemoradiotherapy in patients in whom concurrent chemoradiotherapy is contraindicated is not well known.

Methods

We retrospectively analyzed 286 patients with LD-SCLC at two institutions in Japan between 2000 and 2014. We compared the clinical characteristics and treatment outcomes of patients undergoing sequential radiotherapy with those undergoing concurrent radiotherapy.

Results

One hundred and seventy-five patients received concurrent chemoradiotherapy, 33 received sequential chemoradiotherapy and 46 received chemotherapy only. The median patient age was 64 years (range, 18-82 years) for the concurrent group and 71 years (49-82 years) for the sequential group. Conventional radiotherapy was selected more frequently than accelerated hyperfractionated radiotherapy (27 patients [82%] with conventional radiotherapy, and six patients [18%] with hyperfractionated radiotherapy). The major reasons for the selection of sequential radiotherapy were advanced age (12 patients) and a large irradiation field (11 patients). The median overall survival time was 41.1 months for the sequential group and 38.1 months for the concurrent group. The 5-year survival rates were 36.0% for the sequential group and 41.6% for the concurrent group.

Conclusions

In clinical situation, since the treatment outcomes for patients with sequential radiotherapy were comparable to those receiving concurrent radiotherapy, sequential chemoradiotherapy can be a choice for the treatment of patients who are not candidates for concurrent chemoradiotherapy.

The role of radiation therapy in the management of small cell lung cancer

Small cell lung cancer (SCLC) is a very aggressive form of lung cancer. SCLC treatment requires multidisciplinary management and timely treatment. Radiation therapy is an important part of management of all stages of SCLC, in the curative as well as in the palliative setting. The role of radiation therapy in all stages of SCLC has changed in recent years; this article describes these changes and highlights the role of radiation therapy in the management of SCLC.

Current Treatments for Surgically Resectable, Limited-Stage, and Extensive-Stage Small Cell Lung Cancer

The prevalence of small cell lung cancer (SCLC) has declined in the U.S. as the prevalence of tobacco use has declined. However, a significant number of people in the U.S. are current or former smokers and are at risk of developing SCLC. Routine histological or cytological evaluation can reliably make the diagnosis of SCLC, and immunohistochemistry stains (thyroid transcription factor-1, chromogranin, synaptophysin, and CD56) can be used if there is uncertainty about the diagnosis. Rarely do patients present with SCLC amendable to surgical resection, and evaluation requires a meticulous workup for extra-thoracic metastases and invasive staging of the mediastinum. Resected patients require adjuvant chemotherapy and/or thoracic radiation therapy (TRT), and prophylactic cranial radiation (PCI) should be considered depending on the stage. For limited-stage disease, concurrent platinum-etoposide and TRT followed by PCI is the standard. Thoracic radiation therapy should be started early in treatment, and can be given twice daily to 45 Gy or once daily to 60-70 Gy. For extensive-stage disease, platinum-etoposide remains the standard first-line therapy, and the standard second-line therapy is topotecan. Preliminary studies have demonstrated the activity of immunotherapy, and the response rate is approximately 10-30% with some durable responses observed. Rovalpituzumab tesirine, an antibody drug conjugate, has shown promising activity in patients with high delta-like protein 3 tumor expression (approximately 70% of patients with SCLC). The emergence of these and other promising agents has rekindled interest in drug development in SCLC. Several ongoing trials are investigating novel agents in the first-line, maintenance, and second-line settings.

IMPLICATIONS FOR PRACTICE

This review will provide an update on the standard therapies for surgically resected limited-stage small cell lung cancer and extensive-stage small cell lung cancer that have been investigated in recent clinical trials.

Consolidative thoracic radiotherapy for extensive stage small cell lung cancer

Extensive stage small cell lung cancer (ES-SCLC) represents approximately half of all diagnosed small cell lung cancer worldwide. It is notorious for a high risk of local recurrence although it’s sensitive to chemotherapy. Nearly 90% of intrathoracic failures happen in the first year after diagnosis. The cornerstone of treatment for ES-SCLC is etoposide-platinum based chemotherapy. Consolidative radiotherapy to thorax has diminished the incidence of local relapse, therefore it should be offered to patients with excellent response to induction first-line chemotherapy. This review centers on the clinical evidence for the use of thoracic radiotherapy (TRT) and current modalities of TRT delivery, then tries to determine a feasible way to conduct TRT in a selective group of cases.