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

Construction of a nomogram to guide prophylactic cranial irradiation in extensive‑stage small cell lung cancer

Patients with extensive-stage small cell lung cancer (ES-SCLC) have a high risk of brain metastasis (BM). However, to the best of our knowledge, the risk factors for BM remain unclear. The present study aimed to investigate the risk factors and establish a prediction model for BM in patients with ES-SCLC. A total of 156 patients with ES-SCLC who had no BM and achieved a partial or complete response between January 2020 and March 2023 were included. Patients were randomly divided into training (n=109) and validation (n=47) cohorts. Factors associated with BM were assessed in the training cohort. Univariate and Cox multivariate analyses were performed to evaluate patients with ES-SCLC. Cox multivariate analysis identified oligometastasis [hazard ratio (HR), 0.35; 95% CI, 0.14-0.85; P=0.021], sex (HR, 2.48; 95% CI, 1.05-5.85; P=0.038) and baseline adrenal metastasis (HR, 2.85; 95% CI, 1.54-5.21; P<0.001) as independent risk factors for BM. A nomogram model was constructed to predict intracranial progression-free survival (iPFS). The areas under the receiver operating characteristic curves for the 9-, 12- and 18-month iPFS in the training cohort were 0.77, 0.74 and 0.75, respectively. The nomogram prediction and actual validation cohorts demonstrated good agreement. Among the high-risk factors for BM, the overall survival analysis demonstrated that non-oligometastasis and baseline adrenal metastasis were unfavorable prognostic factors. The present nomogram may aid risk assessment for BM in patients with ES-SCLC and guide prophylactic cranial irradiation.

Efficacy evaluation of prophylactic cranial irradiation for limited stage small‑cell lung cancer in the magnetic resonance imaging era: A meta‑analysis

The role of prophylactic cranial irradiation (PCI) in patients with limited-stage small-cell lung cancer (LS-SCLC) remains controversial in the era of magnetic resonance imaging (MRI). The present study aimed to evaluate the effectiveness of PCI in the treatment of LS-SCLC in the era of MRI. The PubMed, EMBASE and Cochrane Library databases were searched from the time of database creation until May 24, 2023, to identify clinical studies that evaluated the effectiveness of PCI in patients with LS-SCLC in the MRI era. The references of the obtained studies were also reviewed to identify clinical studies that were not discovered in the initial search. All studies were screened in accordance with the inclusion criteria, and the data were extracted and subjected to meta-analysis using STATA17.0. In total, 21 studies were included in the analysis. Notably, 10 studies only used brain MRI at baseline to confirm the absence of brain metastases (BMs; pre-chemoradiotherapy MRI group), 7 studies used brain MRI prior to PCI to confirm the absence of BMs (pre-PCI MRI group) and 4 studies used active surveillance in the form of brain MRI following PCI (MRI surveillance group). The results of the meta-analysis demonstrated that for all included patients, PCI was associated with a significant improvement in overall survival time [OS; hazard ratio (HR), 0.61; confidence interval (CI), 0.53-0.70] and progression-free survival (HR, 0.69; CI, 0.61-0.79), as well as a significant decrease in the rate of BM (HR, 0.59; CI, 0.50-0.70). Subgroup analyses revealed that PCI remained effective in improving OS and reducing the rate of BM in patients with LS-SCLC who did not have BMs confirmed via brain MRI performed at baseline or prior to PCI. However, in the MRI surveillance group, PCI failed to significantly improve the OS (HR, 0.65; CI, 0.41-1.05), despite significantly reducing the BM rate (HR, 0.6; CI, 0.45-0.8) of LS-SCLC. Collectively, the results of the present study demonstrated that PCI remained effective in improving OS and reducing the rate of BM in patients with LS-SCLC who had the absence of BM confirmed via brain MRI at baseline or prior to PCI. Additionally, in patients with LS-SCLC who had undergone active surveillance using brain MRI following PCI, the incidence of BM was reduced, while the OS was not significantly improved. However, additional randomized controlled clinical studies are required to verify these findings.

Analysis of high‑risk factors for brain metastasis and prognosis after prophylactic cranial irradiation in limited‑stage small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive malignancy with a high propensity for brain metastases (BM). Limited-stage SCLC (LS-SCLC) can be effectively treated with chemoradiotherapy and prophylactic cranial irradiation (PCI) to enhance patient outcomes. The aim of the present study was to assess the risk factors and prognostic significance of brain metastases (BM) in patients with limited-stage small cell lung cancer (LS-SCLC) who attained complete remission (CR) or partial remission (PR) following combined chemoradiotherapy and subsequent prophylactic cranial irradiation (PCI). Data for 290 patients diagnosed with LS-SCLC and treated at Chengde Central Hospital and Hebei Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine (Chengde, China), who achieved CR or PR and underwent PCI between 2015 and 2023, were retrospectively analyzed. BM rates and overall survival (OS) were estimated using the Kaplan-Meier method, whilst differences were assessed using the log-rank test. Risk factors affecting BM and OS were assessed using univariate and multivariate Cox regression analyses. The overall incidence of BM after PCI was 16.6% (48/290), with annual rates of 1.4, 6.6 and 12.8% at 1, 2 and 3 years, respectively. Multivariate Cox regression analysis identified an initial tumor size of >5 cm [hazard ratio (HR)=15.031; 95% confidence interval (CI): 5.610-40.270; P<0.001] as a significant independent risk factor for BM following PCI. The median OS was 28.8 months and the 5-year OS rate was 27.9%. The median OS for patients with and without BM at 27.55 and 32.5 months, respectively, and the corresponding 5-year OS rates were 8.3 and 31.8%, respectively (P=0.001). Median OS rates for stages I, II and III were 61.15, 48.5 and 28.4 months, respectively, with 5-year OS rates of 62.5, 47.1 and 21.6%, respectively (P<0.001). Further multivariate Cox regression analysis indicated that BM (HR=1.934; 95% CI: 1.358-2.764; P<0.001) and clinical stage (HR=1.741; 95% CI: 1.102-2.750; P=0.018; P=0.022) were significant independent risk factors associated with patient OS. In conclusion, a tumor size of >5 cm is a significant risk factor for BM following PCI in patients with LS-SCLS achieving CR or PR through radiotherapy and chemotherapy. Furthermore, BM and clinical staging independently influence OS.

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.

The Relationship between Cancer and Dementia: An Updated Review

The risk of cancer and dementia increases with age, raising complex questions about whether it is appropriate to continue cancer treatment in older patients. There is emerging research suggesting the association between cancer and dementia. However, the mechanistic underpinnings are still under investigation. Progress has already been made toward understanding the cognitive effects associated with cancer therapy. Such associations raise awareness about the need to establish better prevention methods and early screening in clinical practice. Additionally, recent studies have suggested possible therapeutic strategies for better preserving cognitive function and reducing the risk for dementia before patients start cancer treatment. We review the current literature and summarize the incidence and mechanisms of cognitive impairment in patients with lung cancer, breast cancer, head and neck cancer, gastric cancer, prostate cancer, colorectal cancer, and brain tumor/brain metastasis following different kinds of therapies. Possible risk factors are suggested to identify the early onset of cognitive changes in cancer patients and provide more insight into the pathophysiological process of dementia.

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.

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.

GOECP/SEOR radiotherapy guidelines for small-cell lung cancer

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

Comparison of treatment strategies for patients with limited-stage small cell lung cancer who received chemotherapy

Background

The standard care for limited-stage small cell lung cancer (SCLC) is unclear. The purpose of this study is to compare the outcome for patients receiving chemotherapy alone, chemotherapy plus surgery (CS), chemotherapy plus radiation (CR), or chemotherapy plus surgery and radiation (CSR) for limited-stage SCLC.

Methods

Patients with T1-4N0-2M0 SCLC who received chemotherapy from 2004 to 2014 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. The overall survival (OS) of these patients, stratified by different stage, was compared in accordance to the method of receiving different treatments using Kaplan-Meier method and Cox regression analysis.

Results

A total of 7,204 patients were included, where 1,347 (18.7%) patients received chemotherapy alone, 296 (4.1%) undergone CS, 5,296 (73.5%) patients were subjected to CR and 267 (3.7%) patients were managed by the three combination of CSR. Chemotherapy alone was associated with the worst survival in comparison to the other two method of combination i.e., chemotherapy with radiation or surgery. When compared with CR, CS had no survival benefit in patients with stage in excess of T1-2N0 disease, but was associated with improved 5-year OS in patients with T1-2N0 disease, which ranged from 29.1% to 54.3% (P<0.001). For patients with T1-2N2 disease who received CSR demonstrated superior OS over those who received CR (P=0.004) or CS (P=0.036). Cox regression analysis showed CS was associated with improved OS when compared with CR in patients with N0 disease (HR, 0.54; 95% CI, 0.43–0.68; P=0.000) and CSR was associated with better OS in comparison with CR in patients with N2 disease (HR, 0.71; 95% CI, 0.55–0.93; P=0.013).

Conclusions

Patients with limited-stage SCLC can benefit from local treatment such as surgery, radiation, and surgery plus radiation. For patients with N0 disease, CS was associated with improved survival in comparison to CR. If N2 was identified after surgery, radiation may be added to improve OS.