Comprehensive Analysis of Lung Adenocarcinoma and Brain Metastasis through Integrated Single-Cell Transcriptomics

Lung adenocarcinoma (LUAD) is a highly prevalent and lethal form of lung cancer, comprising approximately half of all cases. It is often diagnosed at advanced stages with brain metastasis (BM), resulting in high mortality rates. Current BM management involves complex interventions and conventional therapies that offer limited survival benefits with neurotoxic side effects. The tumor microenvironment (TME) is a complex system where cancer cells interact with various elements, significantly influencing tumor behavior. Immunotherapies, particularly immune checkpoint inhibitors, target the TME for cancer treatment. Despite their effectiveness, it is crucial to understand metastatic lung cancer and the specific characteristics of the TME, including cell-cell communication mechanisms, to refine treatments. Herein, we investigated the tumor microenvironment of brain metastasis from lung adenocarcinoma (LUAD-BM) and primary tumors across various stages (I, II, III, and IV) using single-cell RNA sequencing (scRNA-seq) from publicly available datasets. Our analysis included exploring the immune and non-immune cell composition and the expression profiles and functions of cell type-specific genes, and investigating the interactions between different cells within the TME. Our results showed that T cells constitute the majority of immune cells present in primary tumors, whereas microglia represent the most dominant immune cell type in BM. Interestingly, microglia exhibit a significant increase in the COX pathway. Moreover, we have shown that microglia primarily interact with oligodendrocytes and endothelial cells. One significant interaction was identified between DLL4 and NOTCH4, which demonstrated a relevant association between endothelial cells and microglia and between microglia and oligodendrocytes. Finally, we observed that several genes within the HLA complex are suppressed in BM tissue. Our study reveals the complex molecular and cellular dynamics of BM-LUAD, providing a path for improved patient outcomes with personalized treatments and immunotherapies.

The Impact of Time Interval on Prognosis in Patients with Non-Small Cell Lung Cancer Brain Metastases After Metastases Surgery

BACKGROUND

Non-small cell lung cancer (NSCLC) is a prominent malignancy often linked to the development of brain metastases (BM), which commonly appear at diverse time intervals (TI) following the lung cancer diagnosis. This study endeavors to determine the prognostic significance of the time interval in patients with NSCLC who undergo BM surgery. Through this investigation, we aim to improve our understanding of the factors impacting the prognosis of BM cases originating from NSCLC.

METHODS

We analyzed data from 74 patients (2011-2021) who underwent BM surgery at our institution. The relationship between various clinical, radiological, and histopathological factors, as well as TI and overall survival (OS), was examined.

RESULTS

The median TI from initial NSCLC diagnosis to BM surgery was 19 months (range: 9-36 months). Notably, a shorter TI of less than 23 months was found to be independently associated with postoperative survival (adjusted odds ratio [aOR] 2.87, 95% confidence interval [CI] 1.03-8.02, P = 0.045). Additionally, a shorter TI was independently correlated with the absence of adjuvant chemotherapy for NSCLC (aOR 0.25, 95% CI 0.07-0.83, P = 0.023) and lack of targeted therapy (aOR 0.02, 95% CI 0.00-0.16, P < 0.001). Late-onset BM (TI ≥ 36 months) was observed in 15 cases (20.3%), in this subgroup, patients aged 60 years or older at the time of lung cancer diagnosis exhibited a significant independent correlation with late-onset BM (aOR 7.24, 95% CI 1.59-32.95, P = 0.011). NSCLC patients who underwent adjuvant chemotherapy displayed a notable correlation with late-onset BM (aOR 6.46, 95% CI 1.52-27.43, P = 0.011), while those who received targeted therapy also exhibited an independent association (aOR 2.27, 95% CI 1.70-3.03, P < 0.001).

CONCLUSIONS

Multiple factors contribute to the variability in the onset interval of BM subsequent to NSCLC diagnosis. The occurrence of BM within TI < 23 months following the initial diagnosis of NSCLC was demonstrated as an independent factor associated with an unfavorable prognosis following BM surgery. Furthermore, patients with NSCLC who did not receive adjuvant chemotherapy and lacked targeted therapy were shown to have an elevated likelihood of developing BM after a long progression-free survival.

A "Seed-and-Soil" Radiomics Model Predicts Brain Metastasis Development in Lung Cancer: Implications for Risk-Stratified Prophylactic Cranial Irradiation

Introduction: Brain is a major site of metastasis for lung cancer, and effective therapy for developed brain metastasis (BM) is limited. Prophylactic cranial irradiation (PCI) has been shown to reduce BM rate and improve survival in small cell lung cancer, but this result was not replicated in unselected non-small cell lung cancer (NSCLC) and had the risk of inducing neurocognitive dysfunctions. We aimed to develop a radiomics BM prediction model for BM risk stratification in NSCLC patients. Methods: 256 NSCLC patients with no BM at baseline brain magnetic resonance imaging (MRI) were selected; 128 patients developed BM within three years after diagnosis and 128 remained BM-free. For radiomics analysis, both the BM and non-BM groups were randomly distributed into training and testing datasets at an 70%:30% ratio. Both brain MRI (representing the soil) and chest computed tomography (CT, representing the seed) radiomic features were extracted to develop the BM prediction models. We first developed the radiomic models using the training dataset (89 non-BM and 90 BM cases) and subsequently validated the models in the testing dataset (39 non-BM and 38 BM cases). A radiomics BM score (RadBM score) was generated, and BM-free survival were compared between RadBM score-high and RadBM score-low groups. Results: The radiomics model developed from baseline brain MRI features alone can predict BM development in NSCLC patients. A fusion model integrating brain MRI features with primary tumor CT features (seed-and-soil model) provided synergetic effect and was more efficient in predicting BM (areas under the receiver operating characteristic curve 0.84 (95% confidence interval: 0.80−0.89) and 0.80 (95% confidence interval: 0.71−0.88) in the training and testing datasets, respectively). BM-free survival was significantly shorter in the RadBM score-high group versus the RadBM score-low group (Log-rank, p < 0.001). Hazard ratios for BM were 1.056 (95% confidence interval: 1.044−1.068) per 0.01 increment in RadBM score. Cumulative BM rates at three years were 75.8% and 24.2% for the RadBM score-high and RadBM score-low groups, respectively. Only 1.2% (7/565) of the BM lesions were located within the hippocampal avoidance region. Conclusion: The results demonstrated that intrinsic features of a non-metastatic brain exert a significant impact on BM development, which is first-in-class in metastasis prediction studies. A radiomics BM prediction model utilizing both primary tumor and pre-metastatic brain features might provide a useful tool for individualized PCI administration in NSCLC patients more prone to develop BM.

Bevacizumab's association with a decreased risk of brain metastases in ECOG-ACRIN E1505, a phase III randomized trial of adjuvant chemotherapy with or without bevacizumab in surgically-resected NSCLC

Introduction

ECOG-ACRIN E1505 was a phase 3 randomized trial of adjuvant chemotherapy with or without bevacizumab for patients with stages IB (>4 cm) to IIIA NSCLC. We sought to estimate the incidence and risk factors for brain recurrence as compared with extracranial recurrences (ECRs).

Methods

ECOG-ACRIN E1505 noted that bevacizumab failed to improve overall survival (OS) (OS hazard ratio [HR] = 0.99 [0·82–1·19], p = 0.90) or recurrence-free survival when added to chemotherapy in the adjuvant setting. The cumulative incidence of brain/ECR was estimated after adjusting for recurrence at other sites and death as competing events. A multivariable regression model was fitted using competing risk analysis to evaluate the effect of covariates on brain recurrence incidence.

Results

Median follow-up was 50.4 months. Among the 1501 patients enrolled, 472 developed ECR. There were 122 patients who had recurrence in the brain with or without simultaneous ECR as the first recurrence site (all-brain recurrences [ABRs]), and 84 of those with ABRs had recurrence in the brain only (isolated-brain recurrence [IBR]). The incidence of ABR, IBR, and ECR at 6 years was 9.9%, 5.9%, and 38.8%, respectively. Chemotherapy plus bevacizumab was associated with a decreased incidence of ABR (HR = 0.64, p = 0.02) and IBR (HR = 0.62, p = 0.032), but there was no significant trend for an OS decrement in the bevacizumab arm versus the control arm for both ABR and IBR. Median survivals associated with IBR, ABR, and ECR were 9.5, 9.5, and 14.1 months, respectively. Nonsquamous histology (HR = 1.87, p = 0.003) was also associated with ABR. ECR was associated with nonsquamous NSCLC histology (HR = 1.79, p < 0.01) and stage/N2 involvement (HR = 1.13/1.37, both p < 0.01).

Conclusions

The addition of bevacizumab to chemotherapy was associated with reduction in brain recurrences, but not ECR. Brain metastases whether isolated or not are associated with a lower median survival than ECR and unlike ECR are not associated with traditional staging variables.

VEGF and Immune Checkpoint Inhibition for Prevention of Brain Metastases: Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

We conducted a systematic review and meta-analysis to investigate the role of vascular endothelial growth factor (VEGF) inhibitors and immune checkpoint inhibitors (ICIs) in preventing the development of brain metastases (BMs).

METHODS

We searched MEDLINE, Embase, Cochrane Database, and Google Scholar between January 1, 2000, and June 1, 2020. Included studies were randomized controlled trials (RCTs) of adults with systemic cancer that reported the incidence of BMs treated with and without VEGF inhibitors, as well as observational studies of adults with systemic cancer that reported the incidence of BMs treated with and without ICIs (no RCTs addressed the ICI question). Pooled relative risks (RR) were computed with a binary random-effects model.

RESULTS

A search for VEGF and incidence of new BMs revealed 7 studies (6,212 patients with breast, colon, and non-small-cell lung cancer). Meta-analysis showed a lower incidence of new BMs compared to control (RR 0.71, 95% confidence interval [CI] 0.56-0.89, p = 0.003). A search for ICIs and incidence of new BMs yielded 8 studies (732 patients with non-small-cell lung cancer or metastatic melanoma) in which ICIs were used as an adjunct to radiosurgery. Meta-analysis showed a lower incidence of out-of-treatment-field BMs with ICIs compared to controls at 1 year (RR 0.65, 95% CI 0.49-0.88, p = 0.005). The overall Grading of Recommendations, Assessment, Development and Evaluations score for the evidence evaluating the role of bevacizumab and ICIs was high and moderate, respectively.

DISCUSSION

VEGF and ICIs may have a role in prophylaxis against BM in patients with solid tumors.

Estimating Survival in Patients with Non-Small-Cell Lung Cancer and Brain Metastases: A Verification of the Graded Prognostic Assessment for Lung Cancer Using Molecular Markers (Lung-molGPA)

Purpose

A new tool based on clinical characteristics and molecular factors (Lung-molGPA) was developed to predict the survival of patients with non-small-cell lung cancer but was has not been validated. This study aims to validate the feasibility of the Lung-molGPA in NSCLC.

Patients and Methods

Patients diagnosed NSCLC between Feb 2012 and July 2018 were retrospectively reviewed and scored using the Lung-molGPA tool to compare clinical outcomes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by Cox regression analyses.

Results

A total of 618 patients (524 adenocarcinoma [ADC], 94 non-adenocarcinoma [non-ADC]) were collected. For all patients, the median survival time (MST) was 33.0 months (33.6 and 28 months in the ADC and non-ADC groups, respectively; p = 0.21). In the ADC group, the MST for patients with a Lung-molGPA score of 3.5 to 4 was more than 4 years, while the MST was only 25 months in patients scoring 0-1, 30.0 months in patients scoring 1.5-2, and 35.0 months for scores of 2.5-3 (p = 0.048). For the non-ADC group, the MST for scores 0-1, 1.5-2, 2.5-3, and 3.5-4 were 12.0, 20.2, 29.0, and 33.0 months, respectively (p = 0.017).

Conclusion

Our findings provided evidence validating the Lung-molGPA score as a useful tool to determine treatment strategies and to predict prognosis. The model is still exploratory and needs to be evaluated further in combination with additional prognostic markers.

[Surgical Treatment of Lung Cancer: How Has the Introduction of the 8th Edition of the TNM Classification Affected Guideline-Based Therapy?]

STUDY AIM

The 8th edition of the TNM classification combined with the latest update of the S3-guideline (by AWMF/Scientific Medical Societies in Germany) on prevention, diagnosis, therapy and follow-up of lung cancer led to several changes in staging and treatment of lung cancer. The aim of this study was to identify differences in the distribution of patients due to changes from the 7th to the 8th edition that affected staging. The influence on surgical therapy will be discussed by using the recommendations of the latest S3 guideline.

METHODS

Prospective analysis of all primary cases at two thoracic surgical centres in the year 2016 and follow-up in March 2019. Comparison of the 7th edition of tumour classification for lung cancer with the 8th edition, focused on changes in tumour staging and its effects on the appropriate surgical therapy according to the latest S3 guideline.

RESULTS

A total of 432 primary cases comprised the study population. According to the 8th edition, 82 patients (7th edition: n = 85) in stage I, 43 (n = 49) patients in stage II, 100 (n = 91) patients in stage III and 207 (n = 207) patients are assigned to stage IV. 81 changes (18.7%) were detected (77 upgrades vs. 4 downgrades). 63 patients (14.6%) exhibited a different graduation within the stages. 18 patients (4.1%) were classified in different tumour stages. As a result, fewer patients (n = 12; 2.8%) should have surgery according to the latest S3 guidelines. 290 patients (67.1%) were classified to new subgroups (IA1-3, IIIC and IVA/B). Two-year survival was significantly higher in IVA (25.2%) vs. IVB (13.0%) patients (p < 0.05).

CONCLUSION

The 8th edition of the TNM-classification affords a higher level of differentiation. In this study, the new TNM classification led to a shift in the distribution, with a tendency to increase the tumour stage. This is mainly caused by changes in the T-descriptor and stage grouping. As a result, fewer patients in stage I - IIIA should have surgery according to the latest S3 guidelines. A significantly higher two-year survival rate was detected in stage IVA (M1a and M1b) compared to IVB and justifies the new differentiation due to the metastatic pattern.

Brain Metastases as a First Site of Recurrence in Patients Receiving Chemotherapy with Controlled Systemic Cancer: a Critical but Under-Recognized Clinical Scenario

PURPOSE OF REVIEW

As the treatment of many malignancies has improved, brain metastases (BM) have been observed as a site of the first recurrence in patients with controlled systemic cancers. This suggests that while the administered chemotherapy is effective against systemic cancer, drug concentrations in the central nervous system (CNS) are likely too low to be effective. These findings are in accord with data suggesting that more than 98% of FDA-approved drugs on the market today are unable to cross the blood-brain barrier (BBB).

RECENT FINDINGS

This retrospective literature review was conducted to estimate the proportion of patients with non-small lung cancer, breast cancer, and melanoma who develop BM as their initial site of recurrence while their systemic cancers are well controlled. Of 267 studies screened, 12 studies fit criteria for inclusion. These 12 studies reported on 923 patients. According to compiled data across these studies, 16% of patients on chemotherapy with stable or responding systemic cancer developed isolated BM as their initial site of relapse. These findings strongly suggest that while chemotherapy controlled systemic cancer, drug concentrations within the CNS were low enough to allow disease progression. Ultimately, reducing the incidence of BM in these patients will require novel therapeutic approaches that facilitate drug entry through an intact BBB early in their treatment.

Natural history, clinical course and predictors of interval time from initial diagnosis to development of subsequent NSCLC brain metastases

PURPOSE

Non-small cell lung cancer (NSCLC) brain metastases are associated with substantial morbidity and mortality. During recent years, accompanying dramatic improvements in systemic disease control, NSCLC brain metastases have emerged as an increasingly relevant clinical problem. However, optimal surveillance practices remain poorly defined. This purpose of this study was to further characterize the natural history, clinical course and risk factors associated with earlier development of subsequent NSCLC brain metastases to better inform clinical practice and help guide survivorship care.

METHODS

We retrospectively reviewed all institutional NSCLC brain metastasis cases treated with radiotherapy between 1997 and 2015. Exclusion criteria included presence of brain metastases at initial NSCLC diagnosis and incomplete staging information. Interval time to brain metastases and subsequent survival were characterized using Kaplan-Meier and multivariate Cox regression analyses.

RESULTS

Among 105 patients within this cohort, median interval time to development of brain metastases was 16 months. Median interval times were 29, 19, 16 and 13 months for Stage I-IV patients, respectively (P = 0.016). Additional independent predictors for earlier development of NSCLC brain metastases included non-adenocarcinomatous histopathology (HR 3.036, P < 0.001), no prior surgical resection (HR 1.609, P = 0.036) and no prior systemic therapy (HR 3.560, P = 0.004). Median survival following intracranial progression was 16 months. Delayed development of brain metastases was associated with better prognosis (HR 0.970, P < 0.001) but not survival following intracranial disease onset.

CONCLUSIONS

Collectively, our results provide valuable insights into the natural history of NSCLC brain metastases. NSCLC stage, histology, prior surgical resection and prior systemic therapy emerged as independent predictors for interval time to brain metastases.

Prevention of Brain Metastases

The incidence of brain metastases is projected to rise because survival rates of lung cancer, breast cancer, and melanoma continue to improve (1). The brain is being identified as a sanctuary site for harboring metastases despite excellent control of extracranial disease. This is thought to occur because the drug therapies that control extracranial disease have limited central nervous system (CNS) penetration. The development of brain metastases is a devastating diagnosis affecting both quality of life (QOL) and survival. Symptoms after diagnosis can include headache, nausea, vomiting, seizure, neurocognitive decline, and focal neurologic deficit. Some of these symptoms can be irreversible even after successful treatment of intracranial disease. Treatment of brain metastases often necessitates surgery and radiation. There have been some reports of systemic therapies offering an intracranial response however long-term data is lacking. These treatments for CNS metastases can also lead to neurocognitive sequelae impacting quality of life. Therefore, preventing disease from spreading to the brain is a topic that has generated much interest in oncology. Prophylactic cranial Irradiation (PCI) has been used in leukemia, small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC). While showing effectiveness in preventing intracranial disease development, its carries with it side effects of neurocognitive decline that can affect QOL. There are Clinical trials exploring novel delivery of PCI and concurrent neuroprotective drug therapy to try to mitigate these neurocognitive sequelae. These will be important trials to complete, as PCI has shown promise in controlling disease and prolonging survival in select patient populations. There are also drug therapies that have shown efficacy in preventing CNS metastases development. This review will explore the current therapies available to prevent CNS metastases.

Potential Molecular Signatures Predictive of Lung Cancer Brain Metastasis

Brain metastases are the most common tumors of the central nervous system (CNS). Incidence rates vary according to primary tumor origin, whereas the majority of the cerebral metastases arise from primary tumors in the lung (40-50%). Brain metastases from lung cancer can occur concurrently or within months after lung cancer diagnosis. Survival rates after lung cancer brain metastasis diagnosis remain poor, to an utmost of 10 months. Therefore, prevention of brain metastasis is a critical concern in order to improve survival among cancer patients. Although several studies have been made in order to disclose the genetic and molecular mechanisms associated with CNS metastasis, the precise mechanisms that govern the CNS metastasis from lung cancer are yet to be clarified. The ability to forecast, which patients have a higher risk of brain metastasis occurrence, would aid cancer management approaches to diminish or prevent the development of brain metastasis and improve the clinical outcome for such patients. In this work, we revise genetic and molecular targets suitable for prediction of lung cancer CNS disease.

Risk factors and treatments for brain metastasis in patients with adenocarcinoma of the lung: a retrospective analysis of 373 patients

Background

Risk factors and treatments for brain metastasis (BM) in patients with adenocarcinoma have not been fully profiled in previous studies because of the enrolment of patients with tumours of mixed histology. Thus, we specifically addressed the issue in patients with adenocarcinoma.

Methods

Clinical data for 373 patients with pathologically confirmed adenocarcinoma were studied retrospectively. Factors including age (≤60 vs. > 60), gender (male vs. female), stage at diagnosis, T status (T1–2 vs. T3–4), N status (N0–1 vs. N2–3), epidermal growth factor receptor (EGFR) mutation status (wild-type vs. mutant) and smoking status (never vs. current) were analyzed.

Results

In multivariate analysis, age (P = 0.006) and N status (P = 0.041) were independent risk factors for BM. In patients with BM, adding systemic therapy to local therapy improved median post-brain-metastasis survival (mPBMS) (P = 0.02). However, if stratification was conducted according to the recursive partitioning analysis (RPA) classification or graded prognostic assessment (GPA) scoring, only patients in RPA class II (P = 0.020) or with GPA score 1.5-2.5 (P = 0.032) could benefit from local plus systemic therapy. Those who received both pemetrexed and tyrosine kinase inhibitors (TKIs) as systemic therapies had a longer mPBMS than those who received TKIs alone, regardless of whether local therapy was applied. In patients with EGFR-sensitive mutations, TKIs therapy led to a longer mPBMS than conventional chemotherapy (P = 0.002).

Conclusions

Adenocarcinoma patients who were younger than 60 years of age and those with N2–3 disease have a significantly higher risk of BM. The addition of systemic therapy to local therapy can significantly prolong mPBMS, but the survival benefit confined in certain populations. Patients with opportunity to receive both pemetrexed and TKIs had the longest mPBMS.

Prophylactic Cranial Irradiation in Patients With Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We systematically reviewed the literature for trials addressing the efficacy of prophylactic cranial irradiation (PCI) in patients with non-small-cell lung cancer (NSCLC) treated with a curative intent.

METHODS

Randomized controlled trials (RCT) comparing PCI to no PCI in patients with NSCLC treated with a curative intent were eligible for inclusion. We searched EMBASE, MEDLINE, PubMed, and CENTRAL between 1946 and July 2016. We also received continual search alerts from PubMed through September 2017. Search terms included "non-small-cell lung carcinoma," "cranial irradiation," and "randomized controlled trials." We conducted meta-analyses using random-effects models for relative measures of treatment effect for the incidence of brain metastasis, overall survival (OS), and disease-free survival (DFS). We used Parmar's methodology to derive hazard ratios (HR) when not explicitly stated in RCTs. We narratively synthesized data for the impact of PCI on quality of life (QoL) and neurocognitive function (NCF). We assessed the quality of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation methodology.

RESULTS

Out of 3,548 citations captured by the search strategy, we retained 8 papers and 1 abstract, reporting on 6 eligible trials. Patients who received PCI had a significant reduction in the risk of developing brain metastases as compared with patients who did not [relative risk (RR) = 0.37; 95% confidence interval (CI): 0.26-0.52; moderate quality evidence]. However, there was no OS benefit (HR = 1.08, 95% CI: 0.90-1.31; moderate quality evidence). Sensitivity analysis excluding older studies did not show substantively different findings. DFS was reported in the two most recent trials that included only stage III patients. There was significant improvement in DFS with PCI (HR = 0.67; 95% CI: 0.46-0.98; high quality evidence). Two studies that reported on QoL reported no statistically significant differences. There was no significant difference in NCF decline in the only study that reported on this outcome, except in immediate and delayed recall, as assessed by the Hopkins Verbal Learning Test.

CONCLUSION

There is moderate quality evidence that the use of PCI in patients with NSCLC decreases the risk of brain metastases, but does not provide an OS benefit. However, data limited to stage III patients suggests that PCI improves DFS, with no effect on QoL.

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.

Incorporating Erlotinib or Irinotecan Plus Cisplatin into Chemoradiotherapy for Stage III Non-small Cell Lung Cancer According to EGFR Mutation Status

Purpose

Concurrent chemoradiotherapy (CCRT) is the standard care for stage III non-small cell lung cancer (NSCLC) patients; however, a more effective regimen is needed to improve the outcome by better controlling occult metastases. We conducted two parallel randomized phase II studies to incorporate erlotinib or irinotecan-cisplatin (IP) into CCRT for stage III NSCLC depending on epidermal growth factor receptor (EGFR) mutation status.

Materials and Methods

Patients with EGFR-mutant tumors were randomized to receive three cycles of erlotinib first and then either CCRT with erlotinib followed by erlotinib (arm A) or CCRT with IP only (arm B). Patients with EGFR unknown or wild-type tumors were randomized to receive either three cycles of IP before (arm C) or after CCRT with IP (arm D).

Results

Seventy-three patients were screened and the study was closed early because of slow accrual after 59 patients were randomized. Overall, there were seven patients in arm A, five in arm B, 22 in arm C, and 25 in arm D. The response rate was 71.4% and 80.0% for arm A and B, and 70.0% and 73.9% for arm C and D. The median overall survival (OS) was 39.3 months versus 31.2 months for arm A and B (p=0.442), and 16.3 months versus 25.3 months for arm C and D (p=0.050). Patients with sensitive EGFR mutations had significantly longer OS than EGFR-wild patients (74.8 months vs. 25.3 months, p=0.034). There were no unexpected toxicities.

Conclusion

Combined-modality treatment by molecular diagnostics is feasible in stage III NSCLC. EGFR-mutant patients appear to be a distinct subset with longer survival.

Analysis of the benefit of sequential cranial radiotherapy in patients with EGFR mutant non-small cell lung cancer and brain metastasis

Although cranial radiotherapy is considered the standard treatment for brain metastasis (BM), EGFR tyrosine kinase inhibitors (TKIs) have shown promising activity in EGFR mutant non-small cell lung cancer (NSCLC) patients with BM. However, the efficacy of sequential cranial radiotherapy in patients with EGFR mutant NSCLC who are treated with EGFR TKIs remains to be determined. Patients with NSCLC who harbored an EGFR mutation and whose BM had been treated with EGFR TKIs were retrospectively reviewed. The clinical outcomes of patients treated with EGFR TKIs alone and those treated with cranial radiotherapy followed by EGFR TKIs (additive therapy) were compared. Of the 573 patients with NSCLC with BM who harbored an EGFR mutation and had received EGFR TKIs, 121 (21.1 %) had BM at the time of initial diagnosis. Fifty-nine (49 %) patients were treated with additive therapy, whereas 62 (51 %) patients were treated only with EGFR TKIs. No significant differences were observed between the additive therapy group and the EGFR TKI alone group regarding intracranial progression-free survival (PFS) (16.6 vs 21.0 months, p = 0.492) or extracranial PFS (12.9 vs 15.0 months, p = 0.770). The 3-year survival rates were similar in both groups (71.9 vs 68.2 %, p = 0.675). Additive therapy consisting of cranial radiotherapy followed by EGFR TKI treatment did not improve OS or intracranial PFS compared with EGFR TKI treatment alone in EGFR mutant NSCLC patients with BM. Further prospective studies are needed to determine the precise benefits of sequential cranial radiotherapy in EGFR mutant NSCLC treated with EGFR TKIs.

Prophylactic cranial irradiation: recent outcomes and innovations

Brain metastases represent a frequent problem in several malignancies. They can shorten survival while causing significant morbidity and impairment in the patient's quality of life. Prophylactic cranial irradiation (PCI) has become an integral part of the standard of care in small cell lung cancer (SCLC), yet its role in other malignancies remains the subject of significant discussion. Its role has been extensively investigated in non-small cell lung cancer and less so for breast cancer and other malignancies. Improvements in medical care as well as in whole brain radiotherapy (WBRT) techniques may improve the risk-benefit ratio of this therapy so as to expand its role in cancer care. The use of memantine in WBRT patients as well as the use of hippocampal avoidance techniques are of particular interest in this effort. Herein, we review the history of PCI, its current use, and areas of investigation in the application of PCI.

A nomogram to predict brain metastasis as the first relapse in curatively resected non-small cell lung cancer patients

OBJECTIVES

Development of brain metastasis results in a significant reduction in overall survival. However, there is no an effective tool to predict brain metastasis in non-small cell lung cancer (NSCLC) patients. We conducted this study to develop a feasible nomogram that can predict metastasis to the brain as the first relapse site in patients with curatively resected NSCLC.

MATERIAL AND METHODS

A retrospective review of NSCLC patients who had received curative surgery at National Cancer Center (Goyang, South Korea) between 2001 and 2008 was performed. We chose metastasis to the brain as the first relapse site after curative surgery as the primary endpoint of the study. A nomogram was modeled using logistic regression.

RESULTS

Among 1218 patients, brain metastasis as the first relapse developed in 87 patients (7.14%) during the median follow-up of 43.6 months. Occurrence rates of brain metastasis were higher in patients with adenocarcinoma or those with a high pT and pN stage. Younger age appeared to be associated with brain metastasis, but this result was not statistically significant. The final prediction model included histology, smoking status, pT stage, and the interaction between adenocarcinoma and pN stage. The model showed fairly good discriminatory ability with a C-statistic of 69.3% and 69.8% for predicting brain metastasis within 2 years and 5 years, respectively. Internal validation using 2000 bootstrap samples resulted in C-statistics of 67.0% and 67.4% which still indicated good discriminatory performances.

CONCLUSION

The nomogram presented here provides the individual risk estimate of developing metastasis to the brain as the first relapse site in patients with NSCLC who have undergone curative surgery. Surveillance programs or preventive treatment strategies for brain metastasis could be established based on this nomogram.

Overexpression of adenylate cyclase-associated protein 1 may predict brain metastasis in non-small cell lung cancer

This study was designed to establish a biomarker risk model for predicting brain metastasis (BM) in non-small cell lung cancer (NSCLC). The model comprises 120 cases of NSCLC that were treated and followed up for 4 years. The patients were divided into the BM (n=50) and non-BM (other visceral metastasis and those without recurrence) (n=70) groups. Immunohistochemical and western blot analyses were performed in metastatic tissues of NSCLC. Multivariate regression analysis was performed to correlate the immunoreactive cyclase-associated protein 1 (CAP1) signal with BM. Survival analyses were performed by using the Kaplan-Meier method. CAP1 protein content and immunoreactivity were significantly increased in BM specimens compared to other-metastatic specimens. The survival analysis revealed that CAP1 overexpression was significantly associated with survival (P<0.05). The ROC test suggested that the area under the curve was 73.33% (P<0.001; 95% CI, 63.5-83.2%). When P=0.466, the sensitivity and specificity reached 79.5 and 67.1%, respectively. These findings suggested that CAP1 is involved in the BM of NSCLC, and that elevated levels of CAP1 expression may indicate a poor prognosis for patients with BM. The CAP1 molecular model may be useful in the prediction of the risk of BM in NSCLC.

Prophylactic cranial irradiation may impose a detrimental effect on overall survival of patients with nonsmall cell lung cancer: a systematic review and meta-analysis

PURPOSE

To determine the role of brain metastases (BM) and overall survival (OS) in patients with non-small cell lung cancer (NSCLC) by performing a meta-analysis of the RCTs (randomized controlled clinical trials) and non-RCTs (non-randomized controlled clinical trials) published in the literature.

METHODS

A meta-analysis was performed using trials identified through PubMed, EMBASE and Cochrane databases. Two investigators independently assessed the quality of the trials and extracted data. The outcomes included BM, OS, median survival (MS), response rate (RR), Hazard ratios (HRs) and odds ratios (ORs), and their 95% confidence intervals (CIs) were pooled using ReMan software.

RESULTS

Twelve trials (6 RCTs and 6 non-RCTs) involving 1,718 NSCLC patients met the inclusion criteria. They were grouped on the basis of study design for separate Meta-analyses. The results showed that prophylactic cranial irradiation (PCI) reduced the risk of BM as compared with non-PCI in NSCLC patients (OR = 0.30, 95% [CI]: 0.21-0.43, p<0.00001). However, HRs for OS favored non-PCI (HR = 1.19, 95% [CI]: 1.06-1.33, p = 0.004), without evidence of heterogeneity between the studies.

CONCLUSION

Our results suggest that although PCI decreased the risk of BM, it may impose a detrimental effect on OS of NSCLC patients.

Risk factors for brain metastases in locally advanced non-small cell lung cancer with definitive chest radiation

PURPOSE

We intended to identify risk factors that affect brain metastases (BM) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving definitive radiation therapy, which may guide the choice of selective prevention strategies.

METHODS AND MATERIALS

The characteristics of 346 patients with stage III NSCLC treated with thoracic radiation therapy from January 2008 to December 2010 in our institution were retrospectively reviewed. BM rates were analyzed by the Kaplan-Meier method. Multivariate Cox regression analysis was performed to determine independent risk factors for BM.

RESULTS

The median follow-up time was 48.3 months in surviving patients. A total of 74 patients (21.4%) experienced BM at the time of analysis, and for 40 (11.7%) of them, the brain was the first site of failure. The 1-year and 3-year brain metastasis rates were 15% and 28.1%, respectively. In univariate analysis, female sex, age ≤60 years, non-squamous cell carcinoma, T3-4, N3, >3 areas of lymph node metastasis, high lactate dehydrogenase and serum levels of tumor markers (CEA, NSE, CA125) before treatment were significantly associated with BM (P<.05). In multivariate analysis, age ≤60 years (P=.004, hazard ratio [HR] = 0.491), non-squamous cell carcinoma (P=.000, HR=3.726), NSE >18 ng/mL (P=.008, HR=1.968) and CA125 ≥ 35 U/mL (P=.002, HR=2.129) were independent risk factors for BM. For patients with 0, 1, 2, and 3 to 4 risk factors, the 3-year BM rates were 7.3%, 18.9%, 35.8%, and 70.3%, respectively (P<.001).

CONCLUSIONS

Age ≤60 years, non-squamous cell carcinoma, serum NSE >18 ng/mL, and CA125 ≥ 35 U/mL were independent risk factors for brain metastasis. The possibilities of selectively using prophylactic cranial irradiation in higher-risk patients with LA-NSCLC should be further explored in the future.

TGFβ1 Polymorphisms Predict Distant Metastasis-Free Survival in Patients with Inoperable Non-Small-Cell Lung Cancer after Definitive Radiotherapy

Purpose

Transforming growth factor (TGF) -β1 signaling is involved in cancer-cell metastasis. We investigated whether single nucleotide polymorphisms (SNPs) at TGFβ1 were associated with overall survival (OS) and distant metastasis-free survival (DMFS) in patients with non-small cell lung cancer (NSCLC) treated with definitive radiotherapy, with or without chemotherapy.

Methods

We genotyped TGFβ1 SNPs at rs1800469 (C–509T), rs1800471 (G915C), and rs1982073 (T+29C) by polymerase chain reaction-restriction fragment length polymorphism in blood samples from 205 NSCLC patients who had had definitive radiotherapy at one institution in November 1998–January 2005. We also tested whether the TGF-β1 rs1982073 (T+29C) SNP affected the migration and invasion of A549 and PC9 lung cancer cells.

Results

Median follow-up time for all patients was 17 months (range, 1–97 months; 39 months for patients alive at the time of analysis). Multivariate analysis showed that the TGFβ1 rs1800469 CT/CC genotype was associated with poor OS (hazard ratio [HR] = 1.463 [95% confidence interval {CI} = 1.012–2.114], P = 0.043) and shorter DMFS (HR = 1.601 [95% CI = 1.042–2.459], P = 0.032) and that the TGFβ1 rs1982073 CT/CC genotype predicted poor DMFS (HR = 1.589 [95% CI = 1.009–2.502], P = 0.046) and poor brain MFS (HR = 2.567 [95% CI = 1.155–5.702], P = 0.021) after adjustment for age, sex, race, performance status, smoking status, tumor histology and volume, stage, receipt of concurrent radiochemotherapy, number of chemotherapy cycles, and radiation dose. Transfection with TGFβ1+29C (vs. +29T) stimulated the migration and invasion of A549 and PC9 cells, suggesting that TGFβ1+29C may be linked with increased metastatic potential.

Conclusions

TGFβ1 genotypes at rs1800469 and rs1982073 could be useful for predicting DMFS among patients with NSCLC treated with definitive radiation therapy. These findings require validation in larger prospective trials and thorough mechanistic studies.

Prophylactic cranial irradiation in small cell lung cancer: a single institution experience

BACKGROUND

Prophylactic cranial irradiation (PCI) is used to prevent the development of brain metastases in small cell lung carcinoma. PCI confers an overall survival (OS) benefit in both limited and extensive stage disease.

AIMS

We analyze the incidence of symptomatic brain metastases, progression-free survival (PFS) and OS in a cohort of patients who received PCI, in a 5-year period.

METHODS

A retrospective review of all patients who had received PCI between 2006 and 2011 at the Whitfield Clinic was completed. Patient- and disease-related characteristics, the number of patients who developed brain metastases, PFS and OS data were collected.

RESULTS

24 patients were identified. 14 (58.3 %) patients were male, 10 (41.7 %) were female, with a mean age of 62.5 years (range 31-78). All patients were smokers. 12 (50 %) patients had limited stage small cell lung cancer (SCLC), 12 (50 %) had extensive stage disease. 2 (8.2 %) patients developed brain metastases post PCI (p = 0.478.) The median PFS for limited stage SCLC was 13 months (range 3-20) and 10 months (range 5-18) for extensive stage SCLC. Median OS was 15 months (range 4-29) in limited stage SCLC, and 11 months (range 5-29) in extensive stage SCLC.

CONCLUSIONS

Our study demonstrated a low incidence of symptomatic brain metastases and favourable median PFS and OS in the patients that received PCI, when compared to published phase III data.

Implications for preserving neural stem cells in whole brain radiotherapy and prophylactic cranial irradiation: a review of 2270 metastases in 488 patients

This study delineated the incidence of metastatic involvement of neural stem cell (NSC) regions and further aimed to explore the feasibility of selectively sparing the NSC compartments during whole brain radiotherapy (WBRT) and prophylactic cranial irradiation (PCI). A total of 2270 intracranial metastases in 488 patients were identified. Lesions were classified according to locations, including lesions in the NSC compartments (subventricular zone, SVZ, or hippocampus) and those in the rest of the brain/brainstem. The incidence of involvement of NSC regions was compared between oligometastatic patients (those with 1-4 lesions) and non-oligometastatic patients (those with 5 or more lesions) using a chi-square test. The volume of the NSC regions accounted for 2.23% of the whole brain, and the overall rate of metastatic lesions in NSC regions was 1.1% in 2270 metastases (25/2270), and 4.7% in 488 patients (23/488). Of the NSC region metastases, 7 (0.3%) involved the hippocampus and 18 (0.8%) occurred in the SVZ. Among the 7 hippocampal metastases identified in this study, 1/7 (14.3%) were found in oligometastatic patients, while 6/7 (85.7%) metastases were in non-oligometastatic patients. For metastases in the SVZ, all lesions occurred in non-oligometastatic patients with none in oligometastatic patients. Metastatic involvement of the NSC compartments was significantly lower in oligometastatic patients (0.15%, 1/670) than in non-oligometastatic patients (1.5%, 24/1600) (P < 0.001). Our retrospective review of 2270 metastases in 488 patients is that the volume of the compartments of NSC regions was 2.23% relative to the whole brain, but the incidence of involvement of the NSC compartments was 1.1%, and the vast majority of NSC lesions were found in non-oligometastatic patients. We believe our data supports selective reduction of doses for these aforementioned structures, when treating oligometastatic patients with WBRT and locally advanced-stage small-cell lung cancer patients with PCI.

Risk factors of brain metastases in completely resected pathological stage IIIA-N2 non-small cell lung cancer

Background

Brain metastases (BM) is one of the most common failures of locally advanced non-small cell lung cancer (LA-NSCLC) after combined-modality therapy. The outcome of trials on prophylactic cranial irradiation (PCI) has prompted us to identify the highest-risk subset most likely to benefit from PCI. Focusing on patients with completely resected pathological stage IIIA-N2 (pIIIA-N2) NSCLC, we aimed to assess risk factors of BM and to define the highest-risk subset.

Methods

Between 2003 and 2005, the records of 217 consecutive patients with pIIIA-N2 NSCLC in our institution were reviewed. The cumulative incidence of BM was estimated using the Kaplan–Meier method, and differences between the groups were analyzed using log-rank test. Multivariate Cox regression analysis was applied to assess risk factors of BM.

Results

Fifty-three (24.4 %) patients developed BM at some point during their clinical course. On multivariate analysis, non-squamous cell cancer (relative risk [RR]: 4.13, 95 % CI: 1.86–9.19; P = 0.001) and the ratio of metastatic to examined nodes or lymph node ratio (LNR) ≥ 30 % (RR: 3.33, 95 % CI: 1.79–6.18; P = 0.000) were found to be associated with an increased risk of BM. In patients with non-squamous cell cancer and LNR ≥ 30 %, the 5-year actuarial risk of BM was 57.3 %.

Conclusions

In NSCLC, patients with completely resected pIIIA-N2 non-squamous cell cancer and LNR ≥ 30 % are at the highest risk for BM, and are most likely to benefit from PCI. Further studies are warranted to investigate the effect of PCI on this subset of patients.

Radiation therapy in the prevention of brain metastases

Over 150,000 cancer patients will be diagnosed with brain metastases this year alone. Survival for those diagnosed with brain metastases remains poor despite multimodality management with surgery, chemotherapy, and radiation. Preventative strategies to mitigate brain metastases have met with mixed results. In leukemia and small cell lung cancer there are defined roles for preventative radiation to be delivered, which can result in improved local control and survival. There is a less defined role for preventative radiation in locally advanced non-small cell lung cancer and budding interest for radiation prevention in breast cancer. The potential impact preventative cranial irradiation may have on neurocognitive function and quality of life needs to be considered prior to its administration.

Treatment of brain metastasis from lung cancer

Brain metastases are not only the most common intracranial neoplasm in adults but also very prevalent in patients with lung cancer. Patients have been grouped into different classes based on the presence of prognostic factors such as control of the primary tumor, functional performance status, age, and number of brain metastases. Patients with good prognosis may benefit from more aggressive treatment because of the potential for prolonged survival for some of them. In this review, we will comprehensively discuss the therapeutic options for treating brain metastases, which arise mostly from a lung cancer primary. In particular, we will focus on the patient selection for combined modality treatment of brain metastases, such as surgical resection or stereotactic radiosurgery (SRS) combined with whole brain irradiation; the use of radiosensitizers; and the neurocognitive deficits after whole brain irradiation with or without SRS. The benefit of prophylactic cranial irradiation (PCI) and its potentially associated neuro-toxicity for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) are also discussed, along with the combined treatment of intrathoracic primary disease and solitary brain metastasis. The roles of SRS to the surgical bed, fractionated stereotactic radiotherapy, WBRT with an integrated boost to the gross brain metastases, as well as combining WBRT with epidermal growth factor receptor (EGFR) inhibitors, are explored as well.

Phase III trial of prophylactic cranial irradiation compared with observation in patients with locally advanced non-small-cell lung cancer: neurocognitive and quality-of-life analysis

PURPOSE

There are scant data regarding the effects of prophylactic cranial irradiation (PCI) on neurocognitive function (NCF) and quality of life (QOL). Radiation Therapy Oncology Group trial 0214 showed no overall survival (OS) benefit for PCI in stage III non-small-cell lung cancer (NSCLC) at 1 year. However, there was a significant decrease in brain metastases (BM). This analysis focuses on the impact of PCI on NCF and QOL.

PATIENTS AND METHODS

Patients with stage III NSCLC who completed definitive therapy without progression were randomly assigned to PCI or observation. NCF was assessed with Mini-Mental Status Examination (MMSE), Activities of Daily Living Scale (ADLS), and Hopkins Verbal Learning Test (HVLT). QOL was assessed with the European Organisation for Research and Treatment of Cancer (EORTC) core tool (QOL Questionnaire-QLQC30) and brain module (QLQBN20).

RESULTS

There were no statistically significant differences at 1 year between the two arms in any component of the EORTC-QLQC30 or QLQBN20 (P > .05), although a trend for greater decline in patient-reported cognitive functioning with PCI was noted. There were no significant differences in MMSE (P = .60) or ADLS (P = .88). However, for HVLT, there was greater decline in immediate recall (P = .03) and delayed recall (P = .008) in the PCI arm at 1 year.

CONCLUSION

PCI in stage III NSCLC significantly decreases the risk of BM without improving 1-year OS. There were no significant differences in global cognitive function (MMSE) or QOL after PCI, but there was a significant decline in memory (HVLT) at 1 year. This study provides prospective data regarding the relative risks and benefits of PCI in this setting and the need to use sensitive cognitive assessments.

Phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non-small-cell lung cancer: primary analysis of radiation therapy oncology group study RTOG 0214

PURPOSE

This study was conducted to determine if prophylactic cranial irradiation (PCI) improves survival in locally advanced non-small-cell lung cancer (LA-NSCLC).

PATIENTS AND METHODS

Patients with stage III NSCLC without disease progression after treatment with surgery and/or radiation therapy (RT) with or without chemotherapy were eligible. Participants were stratified by stage (IIIA v IIIB), histology (nonsquamous v squamous), and therapy (surgery v none) and were randomly assigned to PCI or observation. PCI was delivered to 30 Gy in 15 fractions. The primary end point of the study was overall survival (OS). Secondary end points were disease-free survival (DFS), neurocognitive function (NCF), and quality of life. Kaplan-Meier and log-rank analyses were used for OS and DFS. The incidence of brain metastasis (BM) was evaluated with the logistic regression model.

RESULTS

Overall, 356 patients were accrued of the targeted 1,058. The study was closed early because of slow accrual; 340 of the 356 patients were eligible. The 1-year OS (P = .86; 75.6% v 76.9% for PCI v observation) and 1-year DFS (P = .11; 56.4% v 51.2% for PCI v observation) were not significantly different. The hazard ratio for observation versus PCI was 1.03 (95% CI, 0.77 to 1.36). The 1-year rates of BM were significantly different (P = .004; 7.7% v 18.0% for PCI v observation). Patients in the observation arm were 2.52 times more likely to develop BM than those in the PCI arm (unadjusted odds ratio, 2.52; 95% CI, 1.32 to 4.80).

CONCLUSION

In patients with stage III disease without progression of disease after therapy, PCI decreased the rate of BM but did not improve OS or DFS.

Prophylactic cranial irradiation in lung cancer

As multi-modality treatments are now able to ensure better local control and a lower rate of extra cranial metastases, brain relapse has become a major concern in lung cancer. As survival is poor after development of brain metastases in spite of specific treatment, prophylactic cranial irradiation (PCI) has been introduced in the 70's. PCI has been evaluated in randomized trials in both small-cell (SCLC) and non-small-cell (NSCLC) lung cancers to reduce the incidence of brain metastases and possibly increase survival. PCI reduces significantly the BM rate in both limited disease (LD) and extensive disease (ED) SCLC and in non-metastatic NSCLC. Considering SCLC, PCI significantly improves overall survival in LD (from 15% to 20% at 3 years) and ED (from 13% to 27% at 1 year) in patients who respond to first-line treatment; it should thus be part of the standard treatment in all responders in ED and in good responders in LD. No dose-effect relationship for PCI was demonstrated in LD SCLC patients so that the recommended dose is 25Gy in 10 fractions. In NSCLC, even if the risk of brain dissemination is lower than in SCLC, it has become a challenging issue. Studies have identified subgroups at higher risk of brain failure. There are more local treatment possibilities for NSCLC patients with BM, but most of them will eventually recur so that PCI should be reconsidered. Few randomized trials have been performed and they were not able to show an effect on survival as they were underpowered. New trials are needed.

Posterior fossa metastasis in lung cancer patients with vertigo

This study investigated whether vertiginous attacks indicate a high probability for posterior fossa metastasis in lung cancer patients. Twenty-five lung cancer patients having vertiginous episodes were enrolled in this study. All patients underwent a battery of audiovestibular function testing and MR imaging study. Ten (40%) of 25 lung cancer patients with vertigo were proven to have posterior fossa metastasis (PM1 group), while the other 15 patients had no posterior fossa metastasis (PM0 group). Of the PM1 group, all were adenocarcinoma with the women predominant (80%). Seven (70%) and two (13%) patients of PM1 and PM0 groups had other (bone, liver) systemic metastases before the vertigo episodes, respectively, exhibiting significant difference between them. However, no statistical differences existed in the audiovestibular function testing between the two groups. In contrast with 58% of PM0 group, none of the patients in PM1 group survived for > 3 years after the vertiginous attacks. The mean interval from vertiginous episode to death was 16 months (range 5-27). In conclusion, vertiginous attack in a lung cancer patient having other systemic metastases indicates a high probability of posterior fossa metastasis.

Growth rate of newly developed metastatic brain tumors after thoracotomy in patients with non-small cell lung cancer

Among 1372 lung cancer patients without brain metastasis that underwent resection of lung cancer at our center from 2001 to 2007, brain metastases developed in 72 patients (5.2%) during their hospital course. We hypothesized that there were micro-metastases in the brain at the time of lung surgery in these patients, even though there were no detectable brain metastases on the MRI. The purpose of this study was to evaluate the growth rates of metastatic brain tumors in this unique subset of patients, and to compare the findings with our previous study that calculated the growth rate of brain metastases during chemotherapy. Among 72 patients, 23 with cystic or hemorrhagic metastases were excluded. Seventy-six metastatic brain tumors in 49 patients were reviewed. Twenty-five patients underwent adjuvant or neoadjuvant chemotherapy; however, for the rest of the patients, chemotherapy was not added after lung cancer surgery. The tumor volume was determined using V-works software (v. 4.0) (Cybermed, Seoul, Korea) and T1 gadolinium enhanced MR images. The overall median tumor growth rate was 11.7 mm³/day (interquartile range, 4.9-26.8). There were no statistically significant differences in the tumor growth among the lung cancer stages and the growth rate was similar regardless of the use of chemotherapy. The growth rate reported in this study shows consistency with that of our previous report (12.1 mm³/day). These findings may help optimize patient management during follow up.

Prophylactic cranial irradiation in locally advanced non-small cell lung cancer: outcome of recursive partitioning analysis group 1 patients

BACKGROUND

Prophylactic cranial irradiation (PCI) has been demonstrated to reduce or delay the incidence of brain metastases (BM) in locally advanced non-small cell lung carcinoma (LA-NSCLC) patients with various prognostic groups. With this current cohort we planned to evaluate the potential usefulness of prophylactic cranial irradiation (PCI) specifically in recursive partitioning analysis (RPA) Group 1, which is the most favorable group of LA-NSCLC patients.

METHODS

Between March 2007 and February 2008, 62 patients in RPA group 1 were treated with sequential chemoradiotherapy and PCI for stage IIIB NSCLC. The induction chemotherapy consisted of 3 courses of cisplatin (80 mg/m2) and docetaxel (80 mg/m2); each course was given every 21 days. Thoracic radiotherapy (TRT) was given at a dose of 60 Gy using 3-D conformal planning. All patients received a total dose of 30 Gy PCI (2 Gy/fr, 5 days a week), beginning on the first day of the TRT. Then, all patients received 3 further courses of the same chemotherapy protocol.

RESULTS

Six (9.7%) patients developed brain metastases during their clinical course. Only one (2%) patient developed brain metastasis as the site of first treatment failure. Median brain metastasis-free survival, overall survival, and progression free survival were 16.6, 16.7, and 13.0 months, respectively. By univariate analysis, rates of BM were significantly higher in patients younger than 60 years of age (p = 0.03). Multivariate analysis showed no significant difference in BM-free survival according to gender, age, histology, and initial T- and N-stage.

CONCLUSION

The current finding of almost equal bone metastasis free survival and overall survival in patients with LA-NSCLC in RPA group 1 suggests a longer survival for patients who receive PCI, and thereby have a reduced risk of BM.