Patterns of failure in limited-stage small cell lung cancer: Implications of TNM stage for prophylactic cranial irradiation

Construction of brain metastasis prediction model in limited stage small cell lung cancer patients without prophylactic cranial irradiation

INTRODUCTION

Small cell lung cancer (SCLC) is a highly aggressive lung cancer variant known for its elevated risk of brain metastases (BM). While earlier meta-analyses supported the use of prophylactic cranial irradiation (PCI) to reduce BM incidence and enhance overall survival, modern MRI capabilities raise questions about PCI's universal benefit for limited-stage SCLC (LS-SCLC) patients. As a response, we have created a predictive model for BM, aiming to identify low-risk individuals who may not require PCI.

METHODS

A total of 194 LS-SCLC patients without PCI treated between 2009 and 2021 were included. We conducted both univariate and multivariate analyses to pinpoint the factors associated with the development of BM. A nomogram for predicting the 2- and 3-year probabilities of BM was then constructed.

RESULTS

Univariate and multivariate analyses revealed several significant independent risk factors for the development of BM. These factors include TNM stage, the number of chemotherapy (ChT) cycles, Ki-67 expression level, pretreatment serum lactate dehydrogenase (LDH) levels, and haemoglobin (HGB) levels. These findings underscore their respective roles as independent predictors of BM. Based on the results of the final multivariable analysis, a nomogram model was created. In the training cohort, the nomogram yielded an area under the receiver operating characteristic curve (AUC) of 0.870 at 2 years and 0.828 at 3 years. In the validation cohort, the AUC values were 0.897 at 2 years and 0.789 at 3 years. The calibration curve demonstrated good agreement between the predicted and observed probabilities of BM.

CONCLUSIONS

A novel nomogram has been developed to forecast the likelihood of BM in patients diagnosed with LS-SCLC. This tool holds the potential to assist healthcare professionals in formulating more informed and tailored treatment plans.

Survival of small-cell lung cancer patients after surgery: A single-center retrospective cohort study

This study summarized and analyzed the clinical characteristics and prognosis of small-cell lung cancer (SCLC) patients after surgical treatment. The clinical data of 130 patients (99 males and 31 females) with SCLC treated by surgery and confirmed by postoperative pathological examination at Peking Union Medical College Hospital from April 2004 to April 2019 were retrospectively analyzed. Clinical characteristics, surgery, pathological stage, and perioperative treatment were summarized. Kaplan-Meier survival curve and Cox regression analysis were performed. Pathological examination revealed that 36 (27.69%) patients had stage I SCLC, 22 (16.92%) patients had stage II SCLC, 65 (50.00%) patients had stage III SCLC, and 7 (5.39%) patients had stage IV SCLC. The overall median survival time was 50 months (95% confidence interval, 10.8-89.2 months). The median survival time of stage I, II, III and IV SCLC patients was 148, 42, 32, and 10 months, respectively. In patients who underwent surgical treatment, postoperative adjuvant therapy and tumor stage were independent prognostic factors for survival (p < 0.05).Lobectomy and lymph nodes resection combined with adjuvant therapy were cautiously recommended for stage I-IIIa SCLC patients.

Clinical value of combined serum CA125, NSE and 24-hour urine VMA for the prediction of recurrence in children with neuroblastoma

BACKGROUND

In this study, we intend to retrospectively analyze the clinical data of postoperative neuroblastoma children, including the results of follow-up examinations and laboratory tests, to explore the clinical value of combined serum Carbohydrate antigen 125 (CA125), neuron-specific enolase (NSE) and 24-hour urine vanillylmandelic acid (VMA) levels at baseline for the prediction of recurrence in children with neuroblastoma.

METHODS

265 children with neuroblastoma were successfully followed up, including 163 cases without recurrence (non-recurrence group) and 102 cases with recurrence (recurrence group). The levels of 24-hour urine VMA were determined using spectrophotometric methods. Additionally, the serum levels of CA125 and NSE were measured using electrochemiluminescence immunoassay.

RESULTS

The serum CA125, NSE and 24-hour urine VMA levels were significantly higher in the recurrence group than in the non-recurrence group. It demonstrated a significant positive correlation between the levels of serum CA125, NSE, and 24-hour urine VMA in all children with neuroblastoma. All children in stage IV of neuroblastoma had the highest level of serum CA125, NSE and 24-hour urine VMA and vice versa. The combined CA125, NSE and VMA had significantly better sensitivity and specificity than an individual marker.

CONCLUSIONS

Combined serum CA125, NSE and 24-hour urine VMA had the potential to predict neuroblastoma recurrence more effectively.

Efficacy of Prophylactic Cranial Irradiation According to the Risk of Extracranial Recurrence in Limited-Stage Small Cell Lung Cancer

PURPOSE

We aimed to evaluate the effectiveness of prophylactic cranial irradiation (PCI) for "early brain metastasis", which occurs before extracranial recurrence (ECR), and "late brain metastasis", which occurs after ECR, in limited-stage small cell lung cancer (LS-SCLC).

Materials and Methods

We retrospectively analyzed 271 LS-SCLC patients who underwent definitive chemoradiation. All patients were initially staged with brain magnetic resonance imaging and positron emission tomography. Intracranial recurrence (ICR), ECR, progression-free rate (PFR), and overall survival (OS) were analyzed as clinical endpoints. The competing risk of the first recurrence with ICR (ICRfirst) was evaluated. Significantly associated variables in multivariate analysis of ECR were considered as ECR risk factors. Patients were stratified according to the number of ECR risk factors.

RESULTS

The application of PCI was associated with higher PFR (p=0.008) and OS (p=0.045). However, PCI was not associated with any of the clinical endpoints in multivariate analysis. The competing risk of ICRfirst was significantly decreased with the application of PCI (hazard ratio, 0.476; 95% confidence interval, 0.243 to 0.931; p=0.030). Stage III disease, sequential, and stable disease after thoracic radiation were selected as ECR risk factors. For patients without these risk factors, the application of PCI was significantly associated with increased OS (p=0.048) and a decreased risk of ICRfirst (p=0.026).

CONCLUSION

PCI may play a role in preventing early brain metastasis rather than late brain metastasis after ECR, suggesting that only patients with a low risk of ECR may currently benefit from PCI.

Activities against Lung Cancer of Biosynthesized Silver Nanoparticles: A Review

Nanomedicine is an interdisciplinary field where nanostructured objects are applied to treat or diagnose disease. Nanoparticles (NPs) are a special class of materials at nanometric scale that can be prepared from lipids, polymers, or noble metals through bottom-up approaches. Biological synthesis is a reliable, sustainable, and non-toxic bottom-up method that uses phytochemicals, microorganisms, and enzymes to induce the reduction of metal ions into NPs. Silver (Ag) NPs exhibit potent therapeutic properties that can be exploited to overcome the limitations of current treatment modalities for human health issues such as lung cancer (LC). Here, we review the preparation of AgNPs using biological synthesis and their application against LC using in vitro and in vivo models. An overview of the staging, diagnosis, genetic mutations, and treatment of LC, as well as its main subtypes, is presented. A summary of the reaction mechanisms of AgNPs using microbial cell cultures, plant extracts, phytochemicals, and amino acids is included. The use of capping agents in the biosynthesis of AgNPs with anticancer activity is also detailed. The history and biological activities of metal-based nanostructures synthesized with gold, copper, palladium, and platinum are considered. The possible anticancer mechanisms of AgNPs against LC models are covered. Our perspective about the future of AgNPs in LC treatment and nanomedicine is added.

Construction of Brain Metastasis Prediction Model and Optimization of Prophylactic Cranial Irradiation Selection for Limited-Stage Small-Cell Lung Cancer

Prophylactic cranial irradiation (PCI), as an essential part of the treatment of limited-stage small-cell lung cancer (LS-SCLC), inevitably leads to neurotoxicity. This study aimed to construct a brain metastasis prediction model and identify low-risk patients to avoid PCI; 236 patients with LS-SCLC were retrospectively analyzed and divided into PCI (63 cases) and non-PCI groups (173 cases). The nomogram was developed based on variables determined by univariate and multivariate analyses in the non-PCI group. According to the cutoff nomogram score, all patients were divided into high- and low-risk cohorts. A log-rank test was used to compare the incidence of brain metastasis between patients with and without PCI in the low-risk and high-risk groups, respectively. The nomogram included five variables: chemotherapy cycles (ChT cycles), time to radiotherapy (RT), lactate dehydrogenase (LDH), pro-gastrin-releasing peptide precursor (ProGRP), and lymphocytes−monocytes ratio (LMR). The area under the receiver operating characteristics (AUC) of the nomogram was 0.763 and 0.782 at 1 year, and 0.759 and 0.732 at 2 years in the training and validation cohorts, respectively. Based on the nomogram, patients were divided into high- and low-risk groups with a cutoff value of 165. In the high-risk cohort, the incidence of brain metastasis in the non-PCI group was significantly higher than in the PCI group (p < 0.001), but there was no difference in the low-risk cohort (p = 0.160). Propensity score-matching (PSM) analysis showed similar results; the proposed nomogram showed reliable performance in assessing the individualized brain metastasis risk and has the potential to become a clinical tool to individualize PCI treatment for LS-SCLC.

Usefulness of pro-gastrin-releasing peptide as a predictor of the incidence of brain metastasis and effect of prophylactic cranial irradiation in patients with limited-stage small-cell lung cancer

Prophylactic cranial irradiation (PCI) is recommended for patients with limited-stage small-cell lung cancer (LS-SCLC) who respond well to initial treatment. However, PCI is often omitted because of its potential neurotoxicity in the era of modern diagnostic imaging devices. In the present study, we aimed to investigate the risk factors for brain metastasis (BM) in patients eligible for PCI and who may benefit more from it. Patients with LS-SCLC who responded well to definitive thoracic chemoradiotherapy were included in the present study. Competing risk regression was used to identify factors associated with BM, and the Kaplan-Meier method was used to assess overall survival (OS). Between 2004 and 2017, 62 patients were eligible for PCI and were analyzed. Of these, 38 (61.3%) underwent PCI. Overall, 17 patients (27.4%) developed BM, with a 2-year cumulative incidence of 22.8%. Multivariate analysis (MVA) revealed that pretreatment elevated pro-gastrin-releasing peptide (ProGRP) levels were associated with an increased risk for BM (HR, 7.96, P = 0.0091). PCI tended to reduce the risk of BM (HR, 0.33; P = 0.051). The use of PCI was associated with improved OS in patients with ProGRP levels > 410 pg/mL (P = 0.008), but not in those with ProGRP ≤ 410 pg/mL (P = 0.9). Pretreatment ProGRP levels may be useful in predicting the development of BM in patients with LS-SCLC who achieved a good response to initial therapy and to determine which patients should undergo PCI.

Risk Factors for Brain Metastases in Patients With Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

The use of prophylactic cranial irradiation (PCI) for small cell lung cancer (SCLC) patients is controversial. Risk factors for brain metastasis (BM) development are largely lacking, hampering personalized treatment strategies. This study aimed to identify the possible risk factors for BM in SCLC.We systematically searched the Pubmed database (1 January 1995 to 18 January 2021) according to the PRISMA guidelines. Eligibility criteria: studies reporting detailed BM data with an adequate sample size (randomized clinical trials [RCTs]: N ≥50; non-RCTs: N ≥100) in patients with SCLC. We summarized the reported risk factors and performed meta-analysis to estimate the pooled hazard ratios (HR) if enough qualified data (i.e., two or more studies; the same study type; the same analysis method; and HRs retrievable) were available. In total, 61/536 records were eligible (18 RCTs and 39 non-RCTs comprising 13,188 patients), in which 57 factors were reported. Ten factors qualified BM data for meta-analysis: Limited stage disease (LD) (HR = 0.34, 95% CI: 0.17–0.67; P = 0.002) and older age (≥65) (HR = 0.70, 95% CI: 0.54–0.92; P = 0.01) were associated with less BM; A higher T stage (≥T3) (HR = 1.72, 95% CI: 1.16–2.56; P = 0.007) was a significant risk factor for BM. Male sex (HR = 1.24, 95% CI: 0.99–1.54; P = 0.06) tended to be a risk factor, and better PS (0–1) (HR = 0.66, 95% CI: 0.42–1.02; P = 0.06) tended to have less BM. Smoking, thoracic radiotherapy dose were not significant (P >0.05). PCI significantly decreased BM (P <0.001), but did not improve OS in ED-SCLC (P = 0.81). A higher PCI dose did not improve OS (P = 0.11). The impact on BM was conflicting between Cox regression data (HR = 0.59, 95% CI: 0.26–1.31; P = 0.20) and competing risk regression data (HR = 0.74, 95% CI: 0.55–0.99; P = 0.04). Compared to M0–M1a, M1b was a risk factor for OS (P = 0.01) in ED-SCLC, but not for BM (P = 0.19). As regular brain imaging is rarely performed, high-quality data is lacking. Other factors such as N-stage and blood biomarkers had no qualified data to perform meta-analysis. In conclusion, younger age, higher T stage, and ED are risk factors for BM, suggesting that PCI should be especially discussed in such cases. Individual patient data (IPD) meta-analysis and well-designed RCTs are needed to better identify more risk factors and further confirm our findings. Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021228391, identifier CRD42021228391.

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.

The overall survival impact of prophylactic cranial irradiation in limited-stage small-cell lung cancer: a systematic review and meta-analysis

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PCI for LS-SCLC patients has become more controversial.

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Literature search on PCI impact on overall survival in LS-SCLC yielded 28 studies.

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Meta-analysis of adjusted HRs revealed pooled HR of 0.62 (95% CI: 0.57–0.69).

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Findings support PCI in current practice while awaiting prospective trial results.

Background

Prophylactic cranial irradiation (PCI) for limited-stage small-cell lung cancer (LS-SCLC) patients has become more controversial. Since the publication of the systematic review by Aupérin et al. in 1999, no randomized controlled trials regarding PCI in LS-SCLC have been completed. The aim of this study was to systematically review and meta-analyze the effect of PCI on overall survival (OS) in patients with LS-SCLC.

Methods

A systematic search was conducted in the databases of MEDLINE (PubMed), Embase and the Cochrane library. Only studies that reported an adjusted hazard ratio (aHR), indicating the effect of PCI versus no PCI on OS (adjusted for confounders) in patients with LS-SCLC were included for critical appraisal and meta-analysis. A pooled aHR estimate was calculated using a random-effects model.

Results

Pooling of 28 retrospective studies including a total of 18,575 patients demonstrated a significant beneficial effect of PCI versus no PCI on OS with a pooled aHR of 0.62 (95% CI: 0.57–0.69). Substantial heterogeneity of reported aHRs among studies was observed (I² = 65.9%). Subgroup analyses revealed that this heterogeneity could partly be explained by study sample size. The pooled aHR among 7 versus 21 studies with a sample size of > 300 versus ≤ 300 patients was 0.79 (95% CI: 0.64–0.97) versus 0.56 (95% CI: 0.46–0.69; p < 0.001), respectively.

Conclusions

This meta-analysis demonstrates a significant beneficial effect of PCI on OS in patients with LS-SCLC. Larger studies reported a milder beneficial effect, possibly due to a decreased risk of model overfitting. Serious risk of selection and confounding bias were of concern due to the lack of prospective trials. These results support the role of PCI in standard clinical practice in patients with LS-SCLC while awaiting results of prospective trials on alternative strategies.

Limited-Stage Small-Cell Lung Cancer: Current Progress and the Next Frontier

Limited-stage (LS) small-cell lung cancer (SCLC) is defined as disease confined to a tolerable radiation portal without extrathoracic metastases. Despite clinical research over two decades, the prognosis of LS-SCLC patients remains poor. The current standard of care for LS-SCLC patients is concurrent platinum-based chemotherapy with thoracic radiotherapy (RT). Widespread heterogeneity on the optimal radiation dose and fractionation regimen among physicians highlights the logistical challenges of administering BID regimens. Prophylactic cranial irradiation (PCI) is recommended to patients following a good initial response to chemoradiation due to improved overall survival from historical trials and the propensity for LS-SCLC to recur with brain metastases. However, PCI utilization is being debated due to the greater availability of magnetic resonance imaging (MRI) and data in extensive-stage SCLC regarding close MRI surveillance in lieu of PCI while spurring novel RT techniques, such as hippocampal-avoidance PCI. Additionally, novel treatment combinations incorporating targeted small molecule therapies and immunotherapies with or following radiation for LS-SCLC have seen recent interest and some concepts are being investigated in clinical trials. Here, we review the landscape of progress, limitations, and challenges for LS-SCLC including current standard of care, novel radiation techniques, and the integration of novel therapeutic strategies for LS-SCLC.

Values of serum CA125, NSE and 24-hour urine VMA in diagnosis and prediction of treatment of paediatric neuroblastoma

BACKGROUND

Paediatric neuroblastoma is a relatively common type of malignant tumour originating from neural crest tissues. Early diagnosis and the performance of specific therapeutic strategies can increase the survival rate and improve the prognosis of children with neuroblastoma.

METHODS

A total of 86 children with neuroblastoma were recruited in this research, and 50 healthy children aged 1-12 years were also selected as controls. Twenty-four-hour urine vanillylmandelic acid (VMA) was evaluated by high-performance liquid chromatography. Serum carbohydrate antigen 125 CA125 and neuron-specific enolase (NSE) levels were evaluated by electrochemiluminescence in Cobas E411 autoanalyser.

RESULTS

The serum CA125, NSE and 24-hour urine VMA levels of children with stage III-IVs neuroblastoma were significantly higher than those of children with clinical stages I-II; the serum CA125, NSE and 24-hour urine VMA levels of children in the effective treatment group were significantly lower than those in the treatment-ineffective group. The serum CA125 generated sensitivity and specificity of 71.88% and 59.26%, combined with an AUC (area under the curve) of 0.7049. The serum NSE generated sensitivity and specificity of 68.75% and 81.48%, combined with an AUC of 0.7407. The 24-hour urine VMA generated sensitivity and specificity of 90.63% and 59.26%, combined with an AUC of 0.7986.

CONCLUSION

In conclusion, serum CA125, NSE and 24-hour urine VMA levels before treatment could assess the condition of children with neuroblastoma and predict the effect of treatment.

Limited-stage small cell lung cancer: Outcomes associated with prophylactic cranial irradiation over a 20-year period at the Princess Margaret Cancer Centre

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Prophylactic cranial irradiation (PCI) was more commonly used in younger patients.

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PCI utilization rates did not change throughout our 20-year institutional experience.

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PCI was associated with improved OS and lower brain metastasis risk, independent of MRI follow-up or era of treatment.

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For LS-SCLC patients with good thoracic response, PCI remains the standard-of-care.

Background & purpose

Prophylactic cranial irradiation (PCI) is recommended for limited-stage small-cell lung cancer (LS-SCLC) patients with good response to concurrent chemoradiation. We report our institution’s 20-year experience with this patient population and associated clinical outcomes.

Materials & methods

A retrospective cohort of consecutive LS-SCLC patients treated with curative intent chemoradiation at our institution (1997–2018) was reviewed. Overall survival (OS) was calculated using the Kaplan-Meier method, and significant covariates determined by the Cox proportional hazards model. Covariates predictive of PCI were determined using Fisher's exact test and the Mann-Whitney test. Brain failure risk (BFR) was calculated using the cumulative incidence method treating death as a competing event. Treatment cohorts (historic vs. contemporary) were stratified by the median year of diagnosis (2005).

Results

A total of 369 patients with LS-SCLC were identified, of which 278 patients were notionally PCI eligible. PCI was given to 196 patients (71%). Younger age was associated with PCI utilization (p < 0.001). PCI utilization rates did not change between the historic and contemporary treatment era (p = 0.11), whereas magnetic resonance imaging (MRI) use at baseline and follow-up became more prevalent in the contemporary era (p = <0.001). On multivariable analysis, PCI utilization was associated with improved OS (HR 1.88, 95% CI 1.32–2.69) and decreased BFR (HR 4.66, 95% CI 2.58–8.40). Patients who had MRI follow-up had a higher incidence of BFR (HR 0.35, 95% CI 0.18–0.66) in multivariable analyses.

Conclusions

For LS-SCLC patients at our institution, PCI is more frequently utilized in younger patients, and the utilization rate did not change significantly over the past 20 years. PCI was independently associated with improved OS and lower BFR. Omission of PCI in LS-SCLC patients should not be routinely practiced in the absence of further prospective data.

Prophylactic cranial irradiation confers favourable prognosis for patients with limited-stage small cell lung cancer in the era of MRI: A propensity score-matched analysis

INTRODUCTION

Prophylactic cranial irradiation (PCI) is recommended for patients with limited-stage small cell lung cancer (LS-SCLC) who achieve good response after chemoradiotherapy. But PCI is neurotoxic. Magnetic resonance imaging (MRI) is the standard tool for evaluating brain metastasis (BM). This study was to retrospectively analyse the necessity of PCI in the era of MRI in LS-SCLC.

METHODS

From July 2013 to June 2017, 190 patients with LS-SCLC who were treated with definitive chemoradiotherapy were included and analysed in this study. They were divided into the PCI group and non-PCI group. Propensity score matching (PSM) analysis was used to balance the variable differences. The Kaplan-Meier method was applied to estimate survival with log-rank test to ascertain significance between different groups.

RESULTS

Seventy-seven patients (40.5%) received PCI after chemoradiotherapy. After adjustment for propensity scores, 69 pairs of patients were matched between two groups. After PSM, the 1-year and 3-year OS rates were 96.9% and 48.5% in PCI group versus 89.9% and 25.0% in non-PCI group (HR: 0.419, 95% CI: 0.251-0.701, P = 0.001). The 1-year and 3-year BMFS in PCI group were 96.8% and 67.5% versus 62.3% and 37.9% in non-PCI group (HR: 0.247, 95% CI: 0.132-0.460, P < 0.001).

CONCLUSION

For patients showing no BM on MRI after definitive CRT, PCI confers less BM and better OS in LS-SCLC.

Downregulation of lncRNA XR_429159.1 Linked to Brain Metastasis in Patients With Limited-Stage Small-Cell Lung Cancer

Purpose: The purpose of this study was to identify aberrant long non-coding RNAs (lncRNAs) and explore the predictive value of lncRNA expression patterns on the risk of brain metastases (BMs) in patients with limited-stage small-cell lung cancer (SCLC). Patients and Methods: We executed an array of lncRNA and mRNA chip assays to examine the expression in peripheral blood mononuclear cells obtained from SCLC patients with BMs and compared the expression patterns against those from patients without BMs to identify lncRNAs associated with BMs. Validation was performed against clinical data to further confirm the relationship between lncRNAs and BM. Kaplan-Meier analysis was applied to estimate the cumulative incidence of BMs, and differences between the groups were analyzed using the log-rank test. Results: The expression of 67 lncRNAs (27 upregulated and 40 downregulated) and 47 mRNAs (20 upregulated and 27 downregulated) was significantly different between the BM and non-BM groups (fold change ≥ 2.0, p-value ≤ 0.05), based on the lncRNA and mRNA chip assays. Four lncRNAs were verified by quantitative real-time polymerase chain reaction (qRT-PCR) to confirm the accuracy of the microarray data, and the results of 11 patient pairs (11 patients with BM and 11 patients without BM) revealed that low LncRNA XR_429159.1 expression was a high-risk factor for BM. Further clinical data showed that the incidence of BM among 25 patients with low-level LncRNA XR_429159.1 expression was 31% at 1 year, compared with 14.3% among the 18 patients with high-level LncRNA XR_429159.1 expression (p = 0.035). Conclusion: Our present study identified the low-level expression of lncRNA XR_429159.1 as a high-risk factor among BM in patients with limited-stage SCLC. LncRNA XR_429159.1 is a critical molecule that regulates SCLC metastasis, involved in the neuroepithelial transforming gene 1 (NET1) pathway, and serum levels of this lncRNA are significantly associated with the risk of BM.

The current role of surgery and SBRT in early stage of small cell lung cancer

BACKGROUND

Early stage small cell lung cancer (T1-2N0M0SCLC) represents 7% of all SCLC. The standard treatment in patients with intrathoracic SCLC disease is the use of concurrent chemoradiotherapy (CRT). Nowadays, the recommended management of this highly selected group is surgical resection due to favorable survival outcomes. For medically inoperable patients or those who refuse surgery, there is an increasing interest in evaluating the role of Stereotactic Body Radiotherapy (SBRT) for T1-2N0SCLC, transferring the favorable experience obtained on inoperable NSCLC (Non-Small-cell Lung Cancer). In the era of multimodality treatment, adjuvant systemic therapy plays an important role even in the management of early SCLC, increasing the disease-free survival (DFS) and Overall Survival (OS). The benefit of Prophylactic Cranial Irradiation (PCI), that currently has a Category I recommendation for localized stage SLCL, remains controversial in this selected subgroup of patients due to the lower risk of brain metastasis.

AIM

This review summarizes the most relevant data on the local management of T1-2N0M0SCLC (surgery and radiotherapy), and evaluates the relevance of adjuvant treatment.

RELEVANCE FOR PATIENTS

Provides a critical evaluation of best current clinical management options for T1-2N0M0 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.

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.

Prophylactic Cranial Irradiation for Small-Cell Lung Cancer: Time for a Reassessment

Prophylactic cranial irradiation (PCI) has been an accepted part of the management of both limited and small-cell lung cancer; however, the data that support its use in limited-stage disease is based on an analysis of trials done before currently accepted approaches to staging (i.e., brain MRI and/or PET scanning) were available. For extensive disease, data are available from two randomized studies that are in direct conflict. This article explores the basic rationale for PCI and the evidence indicating that it is time to readdress the question of its routine use.

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.

Identification of a 5-Gene Signature Predicting Progression and Prognosis of Clear Cell Renal Cell Carcinoma

Background

Although the mortality rates of clear cell renal cell carcinoma (ccRCC) have decreased in recent years, the clinical outcome remains highly dependent on the individual patient. Therefore, identifying novel biomarkers for ccRCC patients is crucial.

Material/Methods

In this study, we obtained RNA sequencing data and clinical information from the TCGA database. Subsequently, we performed integrated bioinformatic analysis that includes differently expressed genes analysis, gene ontology and KEGG pathway analysis, protein-protein interaction analysis, and survival analysis. Moreover, univariate and multivariate Cox proportional hazards regression models were constructed.

Results

As a result, we identified a total of 263 dysregulated genes that may participate in the metastasis of ccRCC, and established a predictive signature relying on the expression of OTX1, MATN4, PI3, ERVV-2, and NFE4, which could serve as significant progressive and prognostic biomarkers for ccRCC.

Conclusions

We identified differentially expressed genes that may be involved in the metastasis of ccRCC. Moreover, a predictive signature based on the expression of OTX1, MATN4, PI3, ERVV-2, and NFE4 could be an independent prognostic factor for ccRCC.

Prophylactic cranial irradiation in small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The efficacy of prophylactic cranial irradiation (PCI) in treating patients with small cell lung cancer (SCLC) has not been clear, and recent randomized studies have demonstrated conflicting results from previously published findings. The purpose of this study was to reevaluate the efficacy of PCI in patients with SCLC and to assess factors associated with its efficacy.

METHODS

We conducted a quantitative meta-analysis to explore the efficacy of PCI in patients with SCLC. A literature search was performed using EMBASE, MEDLINE, Cochrane and ClinicalTrials.gov databases. We pooled the data and compared overall survival (OS) and brain metastasis (BM) between patients treated with PCI (PCI group) and patients without PCI treatment (observation group).

RESULTS

Of the 1074 studies identified in our analysis, we selected seven studies including 2114 patients for the current meta-analysis. Our results showed that the PCI group showed decreased BM (HR = 0.45, 95% CI: 0.38-0.55, P < 0.001) and prolonged OS (HR = 0.81, 95% CI: 0.67-0.99, P < 0.001). However, in terms of OS, the pooled analysis showed a high heterogeneity (I² = 74.1%, P = 0.001). In subgroup analyses of OS, we found that the heterogeneity mainly came from patients with brain imaging after initial chemoradiotherapy (HR = 0.94, 95% CI: 0.74-1.18, P = 0.59).

CONCLUSIONS

The results of this study showed that PCI has a significant effect on decreasing BM but little benefit in prolonging OS when brain imaging was introduced to confirm lack of BM after initial chemoradiotherapy and before irradiation.

Is prophylactic cranial irradiation necessary in individuals suffering from surgically resected pT1-2N0M0 small cell lung cancer?

Adjuvant chemotherapeutics and prophylactic cranial irradiation (PCI) are both recommended in the National Comprehensive Cancer Network (NCCN) guidelines for treating individuals suffering from surgically resected pT1-2N0M0 small cell lung cancer (SCLC). Whether adjuvant chemotherapy combined with PCI is superior to adjuvant chemotherapy alone in these patients is largely unknown. PCI may therefore be with uncertain effects in surgically resected pT1-2N0M0 SCLC.

Extracranial metastatic burden in extensive-stage small cell lung cancer: implications for prophylactic cranial irradiation

Background

Patients with extensive-stage small cell lung cancer (ES-SCLC) often develop brain metastases. There is significant controversy regarding the benefit of prophylactic cranial irradiation (PCI) for patients with ES-SCLC. Our objective is to identify ES-SCLC patients who might be most likely to benefit from PCI.

Methods

We retrospectively reviewed 173 patients with ES-SCLC treated between 2010-2015. Of these, 117 patients were initially diagnosed without brain metastases and received systemic chemotherapy. Following exclusion of patients who received PCI and less than 2 cycles of platinum doublet therapy, 93 patients remained. Patient records were reviewed for clinical and radiographic features previously identified as relevant risk factors. Primary outcome was brain metastasis-free survival (BMFS). Kaplan-Meier analysis, log-rank tests and Cox multivariate models were used to compare outcomes.

Results

Median follow-up was 10.7 months (range, 3-58 months). Thirty-eight (40.9%) patients developed brain metastases. Three or more metastatic sites was associated with inferior BMFS on univariable (1-year estimate 43.8% vs. 61.3%; P=0.020) and multivariable (MVA) analysis [hazard ratio (HR) 2.33, 95% CI: 1.08-5.01; P=0.03).

Conclusions

Our results suggest that extracranial metastatic burden is associated with an increased risk for brain metastases in patients with ES-SCLC. As there is no clear standard regarding delivery of PCI in this patient population, utilizing the number of metastatic disease sites as a clinical indicator may help to improve selection of patients who benefit from PCI.

The role of prophylactic cranial irradiation in surgically resected combined small cell lung cancer: a retrospective study

Background

Combined small cell lung cancer (C-SCLC) is defined as small cell lung cancer (SCLC) combined with any of non-small cell lung cancer (NSCLC) histological types, such as large cell carcinoma, squamous cell carcinoma, or adenocarcinoma. Since C-SCLC is an increasingly recognized subtype of small cell carcinoma, we conducted a retrospective study in our institution to explore the value of prophylactic cranial irradiation (PCI) in patients with C-SCLC treated by surgery.

Methods

Between 2005 and 2014, the records of all consecutive patients with pathologically diagnosed C-SCLC after surgery in our institution were reviewed. Overall survival (OS), disease-free survival (DFS), and brain metastasis free survival (BMFS) were estimated by Kaplan-Meier method. Survival differences were evaluated by log-rank test, while multivariate analysis was performed by a Cox proportional hazards model.

Results

Of the total 91 patients included in this analysis, 11 patients (12.1%) were in PCI group and 80 (87.9%) in non-PCI group. The 5-year cumulative incidence of brain metastasis in the whole group was 22.2% (26.3% in non-PCI group vs. 0% in PCI group), and 5-year OS rate was 44.1%. Patients treated with PCI had significantly longer OS (P=0.011) and DFS (P=0.013), also had the trend to live a longer BMFS with marginal significance (P=0.092) than non-PCI-treated patients. The multivariate analysis showed that PCI [hazard ratio (HR) =0.102, P=0.024] was one of independent prognostic factors of the OS in surgery-treated C-SCLC patients.

Conclusions

C-SCLC patients have a relative high risk of developing brain metastases based on our study. These data showed that PCI could improve OS and DFS, as well as tend to decrease brain metastases in surgically resected C-SCLC. However, whether PCI could be part of comprehensive treatment modalities in C-SCLC should be assessed in prospective studies.

The Road Less Traveled: Should We Omit Prophylactic Cranial Irradiation for Patients With Small Cell Lung Cancer?

New randomized data from Japan have raised questions regarding the use of prophylactic cranial irradiation for patients with extensive-stage small-cell lung cancer but without detectable brain metastases on magnetic resonance imaging. In the present focused review, we examine the general role of prophylactic cranial irradiation in the management of small-cell lung cancer and present relevant controversies from both sides of the discussion. Future directions for clinical investigation and research are also highlighted. Strategies for neurocognitive protection, including memantine use and hippocampal sparing using modulated radiotherapy techniques, are also presented.

The optimal treatment approaches for stage I small cell lung cancer

Although small cell lung cancer (SCLC) represents less than one-sixth of all lung cancer cases, it is an aggressive disease with a high metastatic potential to various sites including the brain. Most landmark trials assessing individual therapy benefits for SCLC dichotomized patients as having either limited or extensive disease. Over the last decade, however, there has been a clear shift towards categorizing and analyzing survival patterns using a more thorough staging system that accounts for tumor size and the degree of nodal or metastatic disease burden. For the 5% of patients who present with clinical stage I (cT1-2aN0M0) SCLC, extrapolating treatment recommendations from a rather heterogeneous population that constitutes limited disease SCLC remains controversial and has led to numerous investigations of alternative therapies such as stereotactic body radiation therapy (SBRT) for the management of this highly select group of patients. Given the changing landscape of multimodal therapy, this review will summarize relevant data pertaining to and outline optimal treatment algorithms for stage I SCLC, with a particular focus on SBRT as a primary mode of local therapy.

Prophylactic cranial irradiation in resected small cell lung cancer: A systematic review with meta-analysis

Background: The use of PCI in early operable patients with small cell lung cancer (SCLC) is still controversial. Therefore, we conducted a systematic review with meta-analysis to investigate the effects of PCI in resected SCLC patients.

Methods: Relevant studies were identified from PubMed and EMBASE databases, the pooled hazard risks were obtained by the random-effects model. We also analyzed the brain metastasis (BM) risk in p-stage I patients without PCI.

Results: Five retrospective studies were identified and a total of 1691 patients were included in our analysis, 315 of them received PCI. For all the resected patients, PCI was associated with improved overall survival (HR: 0.52, 95% CI: 0.33-0.82), and reduced brain metastasis risk (RR: 0.50, 95%CI: 0.32-0.78). However, with regard to p-stage I patients, no survival benefit was brought by PCI (HR: 0.87, 95% CI: 0.34-2.24). Moreover, the pooled analysis of 7 studies found that the 5-year brain metastasis risk was relatively low (12%, 95% CI: 8%-17%) for p-stage I patients without PCI.

Conclusions: PCI might be associated with a favorable survival advantage and reduced BM risk in complete resected SCLC patients, except for p-stage I patients.

Fasting, Fats, and Physics: Combining Ketogenic and Radiation Therapy against Cancer

Radiotherapy (RT) is a mainstay in the treatment of solid tumors and works by physicochemical reactions inducing oxidative stress in cells. Because in practice the efficacy of RT is limited by its toxicity to normal tissues, any strategy that selectively increases the radiosensitivity of tumor cells or boosts the radioresistance of normal cells is a valuable adjunct to RT. In this review, I summarize preclinical and clinical data supporting the hypothesis that ketogenic therapy through fasting and/or ketogenic diets can be utilized as such an adjunct in order to improve the outcome after RT, in terms of both higher tumor control and lower normal-tissue complication probability. The first effect relates to the metabolic shift from glycolysis towards mitochondrial metabolism, which selectively increases reactive oxygen species (ROS) production and impairs adenoside triphosphate (ATP) production in tumor cells. The second effect is based on the differential stress resistance phenomenon describing the reprogramming of normal cells, but not tumor cells, from proliferation towards maintenance and stress resistance when glucose and growth factor levels are decreased and ketone body levels are elevated. Underlying both effects are metabolic differences between normal and tumor cells. Ketogenic therapy is a non-toxic and cost-effective complementary treatment option that exploits these differences and deserves further clinical investigation.