Risk factors for brain metastases in completely resected small cell lung cancer: a retrospective study to identify patients most likely to benefit from prophylactic cranial irradiation

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.

The development and validation of a nomogram for predicting brain metastases after chemotherapy and radiotherapy in male small cell lung cancer patients with stage III

OBJECTIVE

The purpose of this research was to develop a model for brain metastasis (BM) in limited-stage small cell lung cancer (LS-SCLC) patients and to help in the early identification of high-risk patients and the selection of individualized therapies.

METHODS

Univariate and multivariate logic regression was applied to identify the independent risk factors of BM. A receiver operating curve (ROC) and nomogram for predicting the incidence of BM were then conducted based on the independent risk factors. The decision curve analysis (DCA) was performed to assess the clinical benefit of prediction model.

RESULTS

Univariate regression analysis showed that the CCRT, RT dose, PNI, LLR, and dNLR were the significant factors for the incidence of BM. Multivariate analysis showed that CCRT, RT dose, and PNI were independent risk factors of BM and were included in the nomogram model. The ROC curves revealed the area under the ROC (AUC) of the model was 0.764 (95% CI, 0.658-0.869), which was much higher than individual variable alone. The calibration curve revealed favorable consistency between the observed probability and predicted probability for BM in LS-SCLC patients. Finally, the DCA demonstrated that the nomogram provides a satisfactory positive net benefit across the majority of threshold probabilities.

CONCLUSIONS

In general, we established and verified a nomogram model that combines clinical variables and nutritional index characteristics to predict the incidence of BM in male SCLC patients with stage III. Since the model has high reliability and clinical applicability, it can provide clinicians with theoretical guidance and treatment strategy making.

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.

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.

Factors Affecting the Risk of Brain Metastasis in Limited-Stage Small Cell Lung Cancer After Prophylactic Cranial Irradiation

Background

Prophylactic cranial irradiation (PCI) can reduce the risk of brain metastases (BM) and improve overall survival (OS) in patients with limited-stage small cell lung cancer (LS-SCLC) after partial or complete response to primary therapy. However, some SCLC patients still develop BM after PCI. This study aimed to evaluate the risk factors of BM in patients with LS-SCLC after PCI and identify characteristics of patients who may not benefit from PCI.

Methods and Materials

We identified 550 patients with LS-SCLC who received chemoradiotherapy at Zhejiang Cancer Hospital between 2002 and 2017. All patients received PCI. Kaplan–Meier analyses and Cox regression analyses were used to identify factors affecting OS and brain metastasis-free survival (BMFS).

Results

For this patient population, the median survival time was 27.9 months, and the 5-year OS rate was 31%. The median survival time was 24.9 months (95% CI: 22.6–27.2 months), and 30.2 months (95% CI: 24.2–36.3 months) in patients with or without BM (P = 0.000). The overall BM rate was 15.6% (86/550). The frequency of BM in patients with pathologic stages I, II, and III were 9.3% (4/43), 13.4% (7/52), and 16.5% (75/455). The patients with tumors ≥5 cm had an increased risk of BM (HR: 1.781, 95% CI: 1.044–3.039, P = 0.034) but not death (HR: 1.126, 95% CI: 0.925–1.663, P = 0.182). The median survival time among patients <60 years was significantly longer than patients ≥60 years (34.9 months vs 24.6 months, P = 0.001); however, the difference in the BM risk between the two groups was not statistically significant.

Conclusion

PCI remains the standard of care for LS-SCLC patients who achieve complete or partial response after completion of chemoradiotherapy. However, patients with tumors ≥5 cm may have a higher risk of developing BM after PCI.

Treatment and Prevention of Brain Metastases in Small Cell Lung Cancer

Central nervous system (CNS) metastasis will develop in 50% of small cell lung cancer (SCLC) patients throughout disease course. Development of CNS metastasis poses a particular treatment dilemma due to the accompanied cognitive changes, poor permeability of the blood-brain barrier to systemic therapy and relatively advanced state of disease. Survival of patients with untreated SCLC brain metastases is generally <3 months with whole brain radiotherapy used as first-line management in most SCLC patients. To prevent development of CNS metastasis prophylactic cranial irradiation (PCI) is recommended in limited stage disease, after response to chemotherapy and radiation, while PCI may be considered in extensive stage disease after favorable response to upfront treatment. Neurocognitive toxicity with whole brain radiotherapy and PCI is a concern and remains difficult to predict. The mechanism of toxicity is likely multifactorial, but a potential mechanism of injury to the hippocampus has led to hippocampal sparing radiation techniques. Treatment of established non-small cell lung cancer CNS metastases has increasingly focused on using stereotactic radiotherapy (SRS) and it is tempting to extrapolate these results to SCLC. In this review, we explore the evidence surrounding the prediction, prevention, detection, and treatment of CNS metastases in SCLC. We further review whether existing evidence supports extrapolating less toxic treatments to SCLC patients with CNS metastases and discuss trials that may shed more light on this question.

A new nomogram and risk classification system for predicting survival in small cell lung cancer patients diagnosed with brain metastasis: a large population-based study

BACKGROUND

The prognosis of patients with small cell lung cancer (SCLC) is poor, most of them are in the extensive stage at the time of diagnosis, and are prone to brain metastasis. In this study, we established a nomogram combined with some clinical parameters to predict the survival of SCLC patients with brain metastasis.

METHODS

The 3522 eligible patients selected from the SEER database between 2010 and 2015 were randomly divided into training cohort and validation cohort. Univariate and multivariate Cox regression analysis were used to evaluate the ability of each parameter to predict OS. The regression coefficients obtained in multivariate analysis were visualized in the form of nomogram, thus a new nomogram and risk classification system were established. The calibration curves were used to verify the model. And ROC curves were used to evaluate the discrimination ability of the newly constructed nomogram. Survival curves were made by Kaplan-Meier method and compared by Log rank test.

RESULTS

Univariate and multivariate analysis showed that age, race, sex, T stage, N stage and marital status were independent prognostic factors and were included in the predictive model. The calibration curves showed that the predicted value of the 1- and 3-year survival rate by the nomogram was in good agreement with the actual observed value of the 1- and 3-year survival rate. And, the ROC curves implied the good discrimination ability of the predictive model. In addition, the results showed that in the total cohort, training cohort, and validation cohort, the prognosis of the low-risk group was better than that of the high-risk group.

CONCLUSIONS

We established a nomogram and a corresponding risk classification system to predict OS in SCLC patients with brain metastasis. This model could help clinicians make clinical decisions and stratify treatment for patients.

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.

Meta-analysis of prophylactic cranial irradiation or not in treatment of extensive-stage small-cell lung cancer: The dilemma remains

PURPOSE

The role of prophylactic cranial irradiation (PCI) in treatment of extensive-stage small-cell lung cancer (SCLC) is controversial. The aim of this study was to systematically evaluate the efficacy and safety of using PCI in the treatment of extensive-stage SCLC. In the present study, we examined whether PCI was essential for the optimal treatment of extensive-disease small-cell lung cancer.

MATERIAL AND METHODS

We searched the PubMed, Embase, Medline, and China National Knowledge Infrastructure databases to identify articles that assessed the efficacy of PCI in treating extensive-stage small-cell lung cancer patients.

RESULTS

We identified 8 studies that involved a total of 982 patients who received PCI (PCI group) and a total of 4509 patients who did not receive PCI (control group). The results showed that PCI significantly improved the 1-year overall survival rate (HR=1.50; 95% CI: 1.23-1.82; I²=67%; P<0.0001) and reduced the incidence of brain metastasis (HR=0.46; 95% CI: 0.37-0.58; I²=6%; P<0.00001).

CONCLUSION

PCI improves the 1-year overall survival rate and reduces the risk of brain metastasis in patients with extensive-stage SCLC.

Prophylactic cranial irradiation is associated with improved survival following resection for limited stage small cell lung cancer

Background

Brain metastases are a major cause of mortality in patients with small cell lung cancer (SCLC). Prophylactic cranial irradiation (PCI) may improve survival among patients that respond to chemotherapy. Less is known about the outcomes of PCI following surgical resection of SCLC. The purpose of this study was to determine if patients who underwent initial surgical resection of SCLC benefit from PCI.

Methods

Adult patients in the National Cancer Database (NCDB) who underwent complete resection for primary, non-metastatic SCLC between 2004 and 2015 were identified. Patients that received preoperative chemotherapy or who did not receive appropriate adjuvant chemotherapy were excluded. Patients were grouped by treatment with or without cranial radiation within 8 months of resection. Survival was estimated using Kaplan-Meier and Cox multivariable analysis, adjusting for patient and tumor characteristics.

Results

A total of 859 patients met inclusion criteria (202 received PCI and 657 did not). Kaplan-Meier analysis demonstrated that patients treated with PCI had significantly improved survival compared to no PCI (5-year survival 59% vs. 50%, logrank P=0.0038). Multivariable cox models confirmed a significantly decreased hazard of death for patients receiving PCI (HR: 0.70, 95% CI: 0.55-0.89, P=0.003). In subset analyses, PCI was associated with significantly improved survival for node positive patients, but not node negative patients.

Conclusions

PCI is associated with increased survival for patients following surgical resection of SCLC. Patients with positive lymph nodes appear to benefit the most, while it remains unclear if patients with negative lymph nodes derive a benefit. Further study is warranted to clarify which subsets of patients should be treated with PCI.

Brain metastases

An estimated 20% of all patients with cancer will develop brain metastases, with the majority of brain metastases occurring in those with lung, breast and colorectal cancers, melanoma or renal cell carcinoma. Brain metastases are thought to occur via seeding of circulating tumour cells into the brain microvasculature; within this unique microenvironment, tumour growth is promoted and the penetration of systemic medical therapies is limited. Development of brain metastases remains a substantial contributor to overall cancer mortality in patients with advanced-stage cancer because prognosis remains poor despite multimodal treatments and advances in systemic therapies, which include a combination of surgery, radiotherapy, chemotherapy, immunotherapy and targeted therapies. Thus, interest abounds in understanding the mechanisms that drive brain metastases so that they can be targeted with preventive therapeutic strategies and in understanding the molecular characteristics of brain metastases relative to the primary tumour so that they can inform targeted therapy selection. Increased molecular understanding of the disease will also drive continued development of novel immunotherapies and targeted therapies that have higher bioavailability beyond the blood-tumour barrier and drive advances in radiotherapies and minimally invasive surgical techniques. As these discoveries and innovations move from the realm of basic science to preclinical and clinical applications, future outcomes for patients with brain metastases are almost certain to improve.

Application of prophylactic cranial irradiation in limited-stage small-cell lung cancer: which patients could benefit?

Aim: To analyze the role of prophylactic cranial irradiation (PCI) on the survival for patients with limited-stage small-cell lung cancer (LS-SCLC). Patients & methods: We screened patients from SEER database. Kaplan–Meier analysis and Cox proportional hazard model were used to evaluate factors influencing survival. Results: LS-SCLC patients who receiving PCI were associated with better overall survival (OS; p < 0.001) and cancer-specific survival (CSS; p < 0.001). Multivariable Cox analysis revealed PCI was an independent prognostic factor for OS (p < 0.001) and CSS (p < 0.001). In subgroup analysis, there were no OS and CSS differences between PCI and no PCI groups in black patients and patient with a tumor size <5 cm (all p > 0.05). Conclusion: PCI remains an effective method for most LS-SCLC patients. However, caution should be taken in recommending PCI for black patients and patients with a tumor size <5 cm. Further clinical trials are necessary to validate our results and identify the most suitable patients for PCI in the modern era.

Efficacy of surgery and prophylactic cranial irradiation in stage II and III small cell lung cancer

Background: The role of surgery for stage II and III small cell lung cancer (SCLC) remains controversial. The use of prophylactic cranial irradiation (PCI) for resected SCLC was limited. This study aimed to assess the efficacy of surgery in patients with stage II and III SCLC, and evaluate the value of PCI on resected disease. Methods: A total of 269 consecutive patients with stage II-IIIA SCLC were retrospectively reviewed from January 2010 to December 2015. Of these, 116 patients received surgical resection, and 153 underwent non-surgical treatment. Resected patients were matched 1:1 with non-surgical patients (n=70 in each group). Results: The median follow-up was 30 months. The 1-, 3- and 5-year overall survival (OS) for matched patients were 80.0%, 44.3% and 31.7% in surgical group, and 80.0%, 24.3% and 20.0% in non-surgical group (P=0.009), respectively. Multivariate analysis in matched patients showed that surgery (HR=0.603, 95%CI: 0.404-0.900) and PCI (HR=0.637, 95%CI: 0.427-0.950) were independent prognostic factors for OS. In subgroup analysis, OS benefit related to surgery was marginal for stage II (P=0.09) and IIIA patients (P=0.061), but was significant for selected stage IIIA patients who received adjuvant chemo-radiation and PCI (P=0.01). PCI was associated with improved OS for non-surgical patients (P=0.036), and stage IIIA of surgical patients (P=0.047). Conclusions: These findings suggest a potential OS benefit of surgery in stages II and IIIA patients, particularly in selected stage IIIA patients who received adjuvant chemo-radiation and PCI. The use of PCI for surgical patients with stage IIIA was associated with improved OS.

Clinical value of carcinoembryonic antigen for predicting the incidence of brain metastases and survival in small cell lung cancer patients treated with prophylactic cranial irradiation

Background

Although the role of prophylactic cranial irradiation (PCI) in the treatment of small cell lung cancer (SCLC) has been confirmed, the occurrence of brain metastases (BM) in patients remains a major problem. We designed this study to evaluate the clinical value of carcinoembryonic antigen (CEA) for predicting the incidence of BM and survival in SCLC patients who received PCI.

Materials and methods

The records of 128 consecutive SCLC patients, who underwent PCI in our institute between 2005 and 2015, were analyzed. The collected data included clinicopathological features and the levels of CEA, neuron-specific enolase (NSE), cytokeratin 19 fragments (CYFRA21-1), and albumin. Kaplan–Meier and Cox regression analyses were used to determine the factors that affect BM and survival in SCLC patients after PCI.

Results

In total, 128 patients were identified, with a median (range) age of 62 (30–83) years. Thirty-two patients developed BM at some time during follow-up. The median levels of CEA, NSE, CYFRA21-1, and albumin were 7.6 ng/mL, 44 ng/mL, 4.6 ng/mL, and 42.1 g/L, respectively. In the multivariate analysis, CEA level (HR: 2.479, 95% CI: 1.101–5.581; P=0.028), advanced clinical stage (HR: 2.929, 95% CI: 1.338–6.413; P=0.007), and NSE level (HR: 3.021, 95% CI: 1.226–7.442; P=0.016) were significantly correlated with BM. CEA (HR: 1.903, 95% CI: 1.133–3.195; P=0.015) and advanced clinical stage (HR: 2.002, 95% CI: 1.227–3.267; P=0.005) were independently associated with worse overall survival in SCLC patients.

Conclusion

CEA is an independent predictive factor for the incidence of BM after PCI in SCLC and can be used as a predictor of BM in SCLC. In addition, a high level of CEA indicates a poor prognosis in SCLC patients after PCI. Prospective randomized clinical studies are required to confirm these findings.

The role of prophylactic cranial irradiation for patients with small-cell lung cancer

Small-cell lung cancer (SCLC) has a particular propensity to metastasize to the brain, affecting ~10% of SCLC patients at diagnosis, but may occur in more than 50% of 2-year survivors. Most cytotoxic drugs have limited ability to cross the blood-brain barrier, and the effectiveness of chemotherapy for brain metastasis is limited. Therefore, prophylactic cranial irradiation (PCI) has been proposed to treat SCLC. A meta-analysis revealed that PCI significantly decreased the risk of brain metastasis and increased the 3-year survival rate; it has been established as a standard therapy for limited-disease SCLC. However, certain aspects of PCI remain unclarified, including the roles in resected SCLC and extensive-disease SCLC, and its neurotoxicities. In addition, information on PCI has been obtained from old clinical trials without the use of new imaging devices, such as magnetic resonance imaging. Evidence from advanced imaging techniques is needed in this era.

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.

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

BACKGROUND AND PURPOSE

The relationship between tumor-node-metastasis (TNM) stage and patterns of failure in limited-stage small cell lung cancer (LS-SCLC) remains unclear. We hypothesized that TNM stage predicts brain metastasis risk, and could inform the use of prophylactic cranial irradiation.

MATERIAL AND METHODS

We reviewed 283 patients with stage I-IIIB SCLC. Competing-risks regression was used to analyze local, distant, and brain failure. Multivariate analysis was used to evaluate the effect of treatment and clinical factors on failure and OS.

RESULTS

Patients with stage I or II SCLC (35% of cohort) had significantly better survival and lower risk of distant and brain metastasis, compared with stage III patients. The 5-year cumulative incidence of brain metastasis for stage I/II and III were 12% and 26%, respectively. Stage had no correlation with local failure. On multivariate analysis, stage was independently prognostic for survival, distant metastasis risk, and brain metastasis risk.

CONCLUSIONS

TNM staging predicts likelihood of distant metastasis, brain metastasis, and survival in LS-SCLC. This supports the routine use of TNM staging in clinical practice. The lower risk of brain metastasis in stage I and II SCLC suggests that prophylactic cranial irradiation could play a more limited role in treatment of early-stage disease.

Prophylactic cranial irradiation for patients with lung cancer

The incidence of brain metastases in patients with lung cancer has increased as a result of improved local and systemic control and better diagnosis from advances in brain imaging. Because brain metastases are responsible for life-threatening symptoms and serious impairment of quality of life, resulting in shortened survival, prophylactic cranial irradiation has been proposed in both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) to try to improve incidence of brain metastasis, survival, and eventually quality of life. Findings from randomised controlled trials and a meta-analysis have shown that prophylactic cranial irradiation not only reduces the incidence of brain metastases in patients with SCLC and with non-metastatic NSCLC, but also improves overall survival in patients with SCLC who respond to first-line treatment. Although prophylactic cranial irradiation is potentially associated with neurocognitive decline, this risk needs to be balanced against the potential benefit in terms of brain metastases incidence and survival. Several strategies to reduce neurotoxicity are being investigated.

Prophylactic cranial irradiation after definitive chemoradiotherapy for limited-stage small cell lung cancer: Do all patients benefit?

PURPOSE

Prophylactic cranial irradiation (PCI) can improve overall survival (OS) and suppress brain metastases (BM) in patients with limited-stage small cell lung cancer (LS-SCLC) after complete response to primary therapy. However, PCI can be toxic. We sought to identify characteristics of patients who may not benefit from PCI.

METHODS

We identified 658 patients who received chemoradiotherapy at MD Anderson in 1986-2012; 364 received PCI and 294 did not. Median follow-up time was 21.2months (range 1.2-240.8months). Cox proportional hazards regression, competing-risk regression, and Kaplan-Meier analyses were used to identify factors influencing OS and BM.

RESULTS

PCI reduced risks of death [HR 0.73, 95% CI 0.61-0.88, P=0.001] and BM [HR 0.54, 95% CI 0.39-0.76, P<0.001]. Having tumors ⩾5cm increased the risk of BM [HR 1.77, 95% CI 1.22-2.55, P=0.002] but not death [HR 1.16, 95% CI 0.96-1.40, P=0.114]. Among patients ⩾70years with ⩾5-cm tumors, PCI did not improve OS [2-year rates 39.4% vs 40.9%, P=0.739].

CONCLUSIONS

PCI remains standard therapy after complete response to chemoradiotherapy for LS-SCLC. However, older patients may be at risk from comorbidity or extracranial disease. Further work is warranted to identify patients who may not benefit from PCI.

Treatment Response and Prophylactic Cranial Irradiation Are Prognostic Factors in a Real-life Limited-disease Small-cell Lung Cancer Patient Cohort Comprehensively Staged With Cranial Magnetic Resonance Imaging

INTRODUCTION

Prophylactic cranial irradiation (PCI) has proven to decrease the incidence of brain metastases (BMs), with a modest improvement in survival.

PATIENTS AND METHODS

The impact of PCI was evaluated in 184 patients treated with chemoradiotherapy. PCI was applied to patients with disease with partial and complete response only when cranial magnetic resonance imaging before and after primary treatment revealed no BMs. Correlation between PCI and overall survival (OS), BM-free survival (BMFS), and time to progression (TTP) was analyzed to describe survival within subgroups.

RESULTS

Concurrent and sequential chemoradiotherapy was applied in 71 patients (39%) and 113 patients (61%), respectively. Seventy-one patients (39%) with partial and complete response were treated with PCI. Metachronous BMs were detected in 16 (23%) of 71 patients in the PCI group compared to 42 (37%) of 113 patients in the non-PCI group. Median BMFS in the PCI group was not reached; it was 23.6 months in the non-PCI group. Median OS and TTP were 26 months (range, 19.4-32.6 months) in the PCI group versus 14 months (range, 11.4-16.6 months) in patients without PCI whose disease responded to therapy versus 9 months in patients with disease that did not respond to therapy (P < .0001), and 27 versus 14.5 months (range, 9.0-19.9 months) versus 8.8 months (range, 7.7-9.9 months) (P < .0001) in the PCI group versus those with response without PCI versus those with nonresponse. The effect of PCI was independent of gender. On multivariate analysis, PCI was a variable correlating with OS (hazard ratio = 1.899; 95% confidence interval, 1.370-2.632; P < .0001) and TTP (hazard ratio = 2.164; 95% confidence interval, 1.371-3.415; P = .001) after adjustment for other prognostic factors.

CONCLUSION

In real-life patients comprehensively staged with cranial magnetic resonance imaging, treatment response and PCI strongly correlated with prolonged OS, TTP, and BMFS.

Prophylactic Cranial Irradiation for Patients with Surgically Resected Small Cell Lung Cancer

INTRODUCTION

Data on prophylactic cranial irradiation (PCI) after complete resection of SCLC are limited. The purpose of this study was to investigate the impact of PCI in this population.

METHODS

We retrospectively identified completely resected SCLC at the Shanghai Chest Hospital between January 2006 and January 2014.

RESULTS

A total of 349 patients (115 patients who received PCI [the PCI-treated cohort] and 234 patients who did not [the non-PCI-treated cohort]) were included in the study. The results demonstrated that the PCI-treated cohort had longer overall survival than the non-PCI-treated cohort among patients with pathologic stage (p-stage) II (hazard ratio [HR] = 0.54, 95% confidence interval [CI]: 0.30-0.99, p = 0.047) and p-stage III (HR = 0.54, 95% CI: 0.34-0.86, p = 0.009) disease. Among patients with p-stage III disease, there was a significantly higher risk for cerebral recurrence from the time of diagnosis in the non-PCI-treated cohort (p = 0.018). With regard to patients with p-stage I disease, neither overall survival benefit (HR = 1.61, 95% CI: 0.68-3.83, p = 0.282) nor risk for cerebral recurrence (p = 0.389) was significant between the PCI-treated and non-PCI-treated cohorts.

CONCLUSIONS

The data presented in the current study support using PCI in patients with p-stage II/III disease but not in patients with p-stage I disease. A relatively lower risk for brain metastases in p-stage I patients might explain the inferior efficacy of PCI in this population.

Treatment outcomes of patients with small cell lung cancer without prophylactic cranial irradiation

BACKGROUND

Prophylactic cranial irradiation (PCI) is indicated for limited disease (LD) in small cell lung cancer (SCLC) patients who achieve a complete or near-complete response; however, it is sometimes not administered because of possible adverse reactions or patient refusal. Here we assessed treatment outcomes among patients with SCLC who were not treated with PCI.

METHODS

The medical records of 60 patients (45 men, 15 women; mean age, 68 years; age range, 51-82 years) with SCLC were retrospectively reviewed. The tumors were staged by TNM classification. Two, 2, 5, 4, 32, and 15 patients had stage IA, IB, IIA, IIB, IIIA, and IIIB tumors, respectively. The patients were treated with thoracic radiotherapy (TRT) and four courses of chemotherapy.

RESULTS

Our subjects had a median survival of 25 months and 2- and 5-year survival rates of 52.6% and 25.3%, respectively. Univariate analysis revealed that the development of brain metastasis, performance status (PS), and T-stage were significant factors correlated with survival rate. Multivariate analysis identified only PS [hazard ratio (HR), 5.845, 95% confidence interval (CI), 2.333-14.63, P=0.002] and brain metastasis as independent prognostic variables (HR, 2.344, 95% CI, 1.071-5.128, P=0.033).

CONCLUSIONS

The results of our study demonstrated that the outcomes of treatment without PCI were improved, as compared with those of previously published data. Our findings may be used as reference data when PCI cannot be performed.

The Role of Radiotherapy in the Treatment of Small-Cell Lung Cancer

OPINION STATEMENT

The standard therapy for limited disease small cell lung cancer (LD-SCLC) is concurrent chemoradiotherapy and prophylactic cranial irradiation (PCI) for those who achieve complete remission (CR) or good partial response (PR) with initial therapy. On the other hand, the standard therapy for extensive disease (ED-SCLC) is chemotherapy only. After the two phase III study conducted by Slotman et al., PCI with/without thoracic radiotherapy (TRT) is also recommended in the treatment of ED-SCLC. However, a Japanese phase III study failed to confirm the benefit of PCI for patients with ED-SCLC. All studies have demonstrated the effectiveness of PCI for preventing brain metastasis, but PCI seems to have a limited influence on OS. In the 2014 edition of the Guidelines for the Treatment of Lung Cancer from the Japan Lung Cancer Society (JLCS), use of PCI for patients with ED-SCLC has been changed from "recommended" to "not recommended". Appropriate selection of patients for PCI with/without TRT is very important. It is hoped that the characteristics of patients for whom PCI with/without TRT should be considered or avoided will be better defined in the future.