Prophylactic cranial irradiation for patients with small-cell lung cancer in complete remission

Prophylactic Cranial Irradiation Versus Surveillance: Physician Bias and Patient-centered Decision-making

An original work in this month's issue of Clinical Lung Cancer highlights the role of physician bias in the decision to recommend prophylactic cranial irradiation (PCI) to patients with small-cell lung cancer, and presents a patient decision aid to facilitate discussion. After decades of clinical trials, we've learned that PCI can significantly decrease the risk of brain metastases and possibly improve survival. However, PCI is also associated with negative impacts on cognition and quality of life. At present, there is no consensus on how to balance these risks and benefits. Understanding and exploring these issues in a structured fashion offers an opportunity to return decision-making to patients, incorporating their values and priorities.

The role of radiation therapy in the treatment of metastatic cancer

Radiation therapy continues to play an important role in the management of cancer. In this review, we discuss the use of radiation therapy to target and control micrometastatic disease (adjuvant use of radiation), or using stereotactic radiation therapy to address small volumes of gross disease, such as oligometastases, and finally the use of radiation therapy in the era of immunotherapy. Radiation therapy is commonly used to treat nodal basins suspected of harboring microscopic disease. More recently, computer and technical innovations have allowed radiation oncologists to treat small volumes of gross disease within the brain and also in the body with great success, adding to the cancer armamentarium. This modality of cancer treatment that began shortly after the discovery of X-rays by William Roentgen continues to evolve and finds new clinical applications which minimize toxicity while increasing effectiveness. The newly discovered interactions of high dose/fraction radiation (stereotactic radiosurgery) with immune check point inhibitors in melanoma is the latest example of how synergism can be achieved between two different modalities thus increasing the therapeutic ratio to control metastatic cancer.

Effect of Prophylactic Cranial Irradiation on Overall Survival in Metastatic Small-Cell Lung Cancer: A Propensity Score-Matched Analysis

INTRODUCTION

Patients with small-cell lung cancer (SCLC) have a high incidence of occult brain metastases and are often treated with prophylactic cranial irradiation (PCI). Despite a small survival advantage in some studies, the role of PCI in extensive stage SCLC remains controversial. We used the National Cancer Database to assess survival of patients with metastatic SCLC treated with PCI.

PATIENTS AND METHODS

Metastatic SCLC patients without brain metastases were identified. To minimize treatment selection bias, patients with an overall survival (OS) < 6 months were excluded. Cox regression identified variables associated with OS. Patients were propensity score-matched on factors associated with receipt of PCI or OS. The effect of PCI on OS was examined using Kaplan-Meier estimates.

RESULTS

In the overall cohort (n = 4257), treatment with PCI (n = 473) was associated with improved survival (hazard ratio, 0.66; 95% confidence interval, 0.60-0.74; P < .0001). Comparisons of propensity score-matched cohorts revealed a significant survival benefit for patients who received PCI in median OS (13.9 vs. 11.1 months; P < .0001), as well as 1- and 2-year OS (61.2% vs. 44.0% and 19.8% vs. 11.5%, respectively; P < .0001). This survival benefit persisted even after excluding patients who survived < 9 months (median: 15.3 vs. 12.9 months; P < .0001). In multivariable analysis, predictors of receipt of PCI were Caucasian race, younger age, and lower Charlson-Deyo score.

CONCLUSION

Using a modern population-based data set, we showed that metastatic SCLC patients treated with PCI have significantly improved OS. This large retrospective study helps address the conflicting prospective data.

High-dose Chemotherapy in Small Cell Lung Cancer

Improvements in small cell lung cancer (SCLC) therapy with conventional doses of drugs with or without radiotherapy have been poor, and the 5-year survival is discouraging. Since SCLC is highly sensitive to radiotherapy and chemotherapy, some studies have tried to improve survival by increasing the dose of the drugs. Within conventional ranges, dose intensity can be increased with the support of hematopoietic growth factors (G/GM-CSF) and/or shortening treatment intervals (eg weekly regimens). However, dose intensity could be increased by only 20-30% and a survival advantage was not definitively obtained. Given its high chemosensitivity already two decades ago, SCLC was one of the first malignancies deemed suitable for maximizing dose and dose intensity with the support of autologous bone marrow transplantation (ABMT). On the whole, results were disappointing and the procedure was nearly abandoned. Nowadays, some interest is emerging again due to the improvements in supportive care such as the availability of hematopoietic growth factors and the peripheral blood progenitor cells (PBPC).

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.

Efficacy of prophylactic cranial irradiation in patients with limited-disease small-cell lung cancer who were confirmed to have no brain metastasis via magnetic resonance imaging after initial chemoradiotherapy

Background

Prophylactic cranial irradiation (PCI) is recommended for patients with limited-disease small-cell lung cancer (LD-SCLC) who achieved good response to definitive chemoradiotherapy. However, most clinical studies lacked brain imaging scans before PCI. Our study aimed to investigate whether PCI has a survival benefit in patients who have no brain metastases (BM) confirmed via magnetic resonance imaging (MRI) before PCI.

Results

Eighty patients were included in this study. Sixty patients received PCI (PCI group) and 20 patients did not (non-PCI group). OS was not significantly different between the two groups. The median OS time was 4.3 years (95% CI: 2.6 years–8.6 years) in the PCI group and was not reached (NR) (95% CI: 1.9 years–NR) in the non-PCI group (p = 0.542). Moreover, no differences were observed in the 3-year rates of PFS (46.2% and 44.4%, p = 0.720) and cumulative incidence of BM (24.0% vs. 27%, p = 0.404).

Conclusions

Our result suggests that PCI may not have a survival benefit in patients with LD-SCLC confirmed to have no BM after initial therapy, even if patients achieve a good response to definitive chemoradiotherapy.

Patients and Methods

We retrospectively evaluated patients with LD-SCLC who were confirmed to have no BM via MRI after initial chemoradiotherapy at the Shizuoka Cancer Center between September 2002 and August 2015. The overall survival (OS), progression-free survival (PFS), and cumulative incidence of BM were estimated using the Kaplan–Meier method between patients who received PCI and those who did not. Propensity score matching was used to balance baseline characteristics.

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

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

The Role of Prophylactic Cranial Irradiation in Patients With Extensive Stage Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

The role of prophylactic cranial irradiation (PCI) is controversial in patients with extensive stage small cell lung cancer. The aim of this study was to determine the impact of PCI in these patients.

METHODS

We performed a systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A systematic literature search was conducted in MEDLINE, EMBASE, and the Cochrane Central Register. The primary outcome was overall survival (OS).

RESULTS

We identified five studies comprising 984 patients, of whom 448 received PCI and 536 did not receive PCI. In pooled estimates, PCI did not statistically improve OS compared with controls (hazard ratio [HR] = 0.82; 95% confidence interval [CI]: 0.60-1.11; I² = 77%; p = 0.19). However, the PCI group had a significant advantage in 1-year survival compared to the no-PCI group (37.1% versus 27.1%; risk ratio = 0.87; 95% CI: 0.80-0.95; I² = 47%; p = 0.002), and the pooled estimates indicated that progression-free survival and the risk of brain metastasis were associated with significant benefit in the PCI group (HR = 0.83; 95% CI: 0.70-0.98; I² = 22%; p = 0.03; and HR = 0.34; 95% CI: 0.23-0.50; I² = 0%; p < 0.001, respectively).

CONCLUSIONS

Our findings suggest that PCI in patients with extensive stage small cell lung cancer may lead to a significant benefit in 1-year survival, progression-free survival, and the risk of brain metastasis, despite the lack of a significant advantage in OS.

WITHDRAWN: Cranial irradiation for preventing brain metastases of small cell lung cancer in patients in complete remission

BACKGROUND

Prophylactic cranial irradiation halves the rate of brain metastases in patients with small cell lung cancer. Individual randomized trials conducted on patients in complete remission were unable to clarify whether this treatment improves survival.

OBJECTIVES

This study aims to test whether prophylactic cranial irradiation prolongs survival of patients with small cell lung cancer in complete remission.

SEARCH METHODS

Published and unpublished trials were eligible. Electronic databases (Medline, Cancerlit, Excerpta Medica, Biosis from 1965 to 1998), reference lists of trial publications, review articles and relevant books were used to identify potentially eligible trials. The search was also guided by discussions with investigators and experts, and the examination of meeting proceedings and of the Physician Data Query clinical trial registry.

SELECTION CRITERIA

Randomized trials comparing prophylactic cranial irradiation with no prophylactic cranial irradiation in patients with small cell lung cancer in complete remission.

DATA COLLECTION AND ANALYSIS

Meta-analysis based on updated individual data. The main endpoint was survival.

MAIN RESULTS

Seven trials with a total of 987 participants were included. The relative risk of death in the treatment group compared to the control group was 0.84 (95% confidence interval=0.73 to 0.97, P=0.01), corresponding to a 5.4 percent increase in the 3-year survival rate (from 15.3 percent in the control group to 20.7 percent in the treatment group). Prophylactic cranial irradiation also increased disease-free survival (relative risk=0.75, 95% confidence interval=0.65 to 0.86, P<0.001) and decreased the risk of brain metastases (relative risk=0.46, 95% confidence interval=0.38 to 0.57, P<0.001). Increasing doses of irradiation decreased the risk of brain metastases when four groups (8 Gy, 24-25 Gy, 30 Gy, 36-40 Gy) were analyzed [trend test, P=0.02], but the effect on survival did not differ significantly according to the dose. We found a trend (P=0.01) for a decrease in the brain metastasis risk in favour of earlier administration of cranial irradiation after the initiation of induction treatment.

AUTHORS' CONCLUSIONS

Prophylactic cranial irradiation significantly improves survival and disease-free survival for patients with small cell lung cancer in complete remission. Further clinical trials are needed to confirm the potential greater benefit on brain metastasis rate suggested when cranial irradiation is given earlier or at higher doses.

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

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

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

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

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

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.

Prophylactic Cranial Irradiation for Extensive Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) has a high predilection for metastasizing to the brain after chemotherapy. This has been blamed on the blood-brain barrier, which prevents chemotherapy from penetrating into the brain, thus creating a sanctuary site. It has been estimated that up to three quarters of patients with SCLC will eventually develop brain metastases. This led investigators to administer prophylactic cranial irradiation (PCI) to decrease this risk. Several trials were performed in patients with SCLC after initial therapy (chemotherapy with or without thoracic radiotherapy) that compared the outcomes of PCI versus no PCI. Early trials generally found that PCI significantly decreased the risk of brain metastases but did not significantly improve survival. These trials were re-evaluated in two larger meta-analyses that included patients with either limited-stage SCLC or extensive-stage SCLC (ESCLC). Both meta-analyses reported that PCI significantly decreased brain metastases and improved survival in patients who had a complete response following initial therapy. These studies were performed before the advent of modern imaging with computed tomography or magnetic resonance imaging (MRI). There have been two modern trials of PCI versus no PCI in patients with ESCLC and both found that PCI decreases brain metastases. The first did not include brain MRI before registration and found that PCI improved survival, whereas the second study did include MRI before registration and at frequent intervals thereafter. That trial found that PCI did not confer a survival advantage. This review will examine the evidence and provide recommendations regarding the role of PCI for patients with ESCLC.

The Role of Advanced Imaging in Assessing Response to Definitive Chemoradiation Before Prophylactic Cranial Irradiation in Limited-Stage Small-Cell Lung Cancer

INTRODUCTION

Prophylactic cranial irradiation (PCI) improves survival for small-cell lung cancer (SCLC). Evidence for PCI in limited-stage SCLC largely derives from studies requiring only chest x-ray (CXR) to determine remission status. We analyzed thoracic chemoradiation therapy (TCRT) outcomes according to imaging modality to determine which patients benefitted most from PCI.

PATIENTS AND METHODS

All limited-stage SCLC patients who received TCRT as well as PCI at our institution were reviewed. Imaging between TCRT end and PCI start was characterized as complete (CR), partial (PR), or other response.

RESULTS

Thirty-eight consecutive patients were assessed for TCRT response before PCI with CXR (n = 21), chest computed tomography (CT; n = 27), and/or positron emission tomography (PET)/CT (n = 11). CR was identified on 71% of CXRs, 41% of CT scans, and 18% of PET/CT scans. Median survival was 28.3 months for the entire cohort and did not differ for patients who had CXR alone versus CT and/or PET/CT for restaging (P = .78) or those with PR using any modality versus CR using all modalities (22.6 months vs. 45.5 months; P = .22). CT CR patients had numerical but not statistically significant improved 2-year (P = .18) and 3-year (P = .13) survival compared with CT PR.

CONCLUSION

CXR remains an appropriate modality to assess TCRT response before PCI in limited-stage SCLC. Advanced imaging did not inform the decision to offer PCI in this study. Because of similar excellent survival profiles independent of imaging modality and TCRT response, this analysis suggests limited-stage SCLC patients with PR using any modality should not be denied PCI, akin to standards for extensive-stage SCLC.

Prophylactic Cranial Irradiation (PCI) versus Active MRI Surveillance for Small Cell Lung Cancer: The Case for Equipoise

Prophylactic cranial irradiation (PCI) for SCLC offers a consistent reduction in the incidence of brain metastases at the cost of measurable toxicity to neurocognitive function and quality of life, in the setting of characteristic pathologic changes to the brain. The sequelae of PCI have historically been justified by the perception of an overall survival advantage specific to SCLC. This rationale has now been challenged by a randomized trial in extensive-stage SCLC demonstrating equivalent progression-free survival and a trend toward improved overall survival with PCI omission in the context of modern magnetic resonance imaging (MRI) staging and surveillance. In this article, we critically examine the randomized trials of PCI in extensive-stage SCLC and discuss their implications on the historical data supporting PCI for limited-stage SCLC from the pre-MRI era. Further, we review the toxicity of moderate doses of radiation to the entire brain that underlie the growing interest in active MRI surveillance and PCI omission. Finally, the evidence supporting prospective investigation of radiosurgery for limited brain metastases in SCLC is reviewed. Overall, our aim is to provide an evidence-based assessment of the debate over PCI versus active MRI surveillance and to highlight the need for contemporary trials evaluating optimal central nervous system management in SCLC.

Treatment of limited disease small cell lung cancer: the multidisciplinary team

Small cell lung cancer (SCLC) presents multiple interdisciplinary challenges with several paradigm shifts in its treatment in recent years. SCLC treatment requires multidisciplinary management and timely treatment. The aim of this review is to focus on the team management aspects in the treatment of limited disease SCLC and how this can contribute towards improving outcomes.

Factors influencing the utilization of prophylactic cranial irradiation in patients with limited-stage small cell lung cancer

Purpose

Brain metastases are common in patients with limited-stage small cell lung cancer (LS-SCLC) due to the inability of most chemotherapeutics to penetrate the blood–brain barrier. Prophylactic cranial irradiation (PCI) is therefore recommended for use in patients with a good response to concurrent chemoradiotherapy. However, PCI is not always delivered; therefore, we investigated the reasons for PCI omission in patients who underwent therapy with curative intent.

Methods and materials

We retrospectively reviewed all patients with LS-SCLC who were treated with curative intent at our institution. Overall survival and cumulative incidence of brain metastasis were estimated by the Kaplan-Meier method. The Pearson χ² test and Mann-Whitney U test were used to examine factors associated with PCI use, and prognostic factors were analyzed with Cox proportional hazards modeling.

Results

We examined 208 patients who were treated for LS-SCLC at our institution. A total of 115 patients (55%) received PCI. The most common documented reason for PCI omission was patient refusal due to neurotoxicity concerns (38%). Physician assessment of being medically unfit (33%) and of advanced age (8%) were the second and third most common reasons, respectively. Karnofsky performance status and clinical American Joint Committee on Cancer stage but not PCI were significantly associated with overall survival. Only clinical stage remained an independent factor on multivariate analysis.

Conclusions

Approximately half of patients with LS-SCLC ultimately receive PCI, generally for guideline-recommended reasons. The most common reason for PCI omission was patient concerns regarding neurotoxicity. Efforts to decrease PCI neurotoxicity, including hippocampal-sparing radiation and memantine use, may increase the use of this survival-improving intervention in eligible patients with LS-SCLC.

Optimal dose and volume for postoperative radiotherapy in brain oligometastases from lung cancer: a retrospective study

PURPOSE

To evaluate intracranial control after surgical resection according to the adjuvant treatment received in order to assess the optimal radiotherapy (RT) dose and volume.

MATERIALS AND METHODS

Between 2003 and 2015, a total of 53 patients with brain oligometastases from non-small cell lung cancer (NSCLC) underwent metastasectomy. The patients were divided into three groups according to the adjuvant treatment received: whole brain radiotherapy (WBRT) ± boost (WBRT ± boost group, n = 26), local RT/Gamma Knife surgery (local RT group, n = 14), and the observation group (n = 13). The most commonly used dose schedule was WBRT (25 Gy in 10 fractions, equivalent dose in 2 Gy fractions [EQD2] 26.04 Gy) with tumor bed boost (15 Gy in 5 fractions, EQD2 16.25 Gy).

RESULTS

The WBRT ± boost group showed the lowest 1-year intracranial recurrence rate of 30.4%, followed by the local RT and observation groups, at 66.7%, and 76.9%, respectively (p = 0.006). In the WBRT ± boost group, there was no significant increase in the 1-year new site recurrence rate of patients receiving a lower dose of WBRT (EQD2) <27 Gy compared to that in patients receiving a higher WBRT dose (p = 0.553). The 1-year initial tumor site recurrence rate was lower in patients receiving tumor bed dose (EQD2) of ≥42.3 Gy compared to those receiving <42.3 Gy, although the difference was not significant (p = 0.347).

CONCLUSIONS

Adding WBRT after resection of brain oligometastases from NSCLC seems to enhance intracranial control. Furthermore, combining lower-dose WBRT with a tumor bed boost may be an attractive option.

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.

Paradigm shift of therapeutic management of brain metastases in EGFR-mutant non-small cell lung cancer in the era of targeted therapy

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations commonly present brain metastases (BM) at the time of NSCLC diagnosis or during the clinical course. Conventionally, the prognosis of BM has been extremely poor, but the advent of EGFR-tyrosine kinase inhibitors (TKIs) has drastically improved the prognosis in these patients. Despite the presence of the blood-brain barrier, EGFR-TKIs have dramatic therapeutic effects on both BM and extracranial disease. In addition, recent systemic chemotherapies reportedly play a role in controlling BM. These treatment modalities can potentially replace whole brain radiotherapy (WBRT) to prevent or delay neurocognitive decline. Therefore, how to utilize these treatments is one issue. The other issue is what kind of treatment is best for recurrence after TKI therapy. Recent reports have shown a positive effect of a combination therapy of EGFR-TKI and radiotherapy on BM. Although neurocognitive decline is underscored when WBRT is considered, a survival benefit from WBRT has been proven especially in the potential long survivors with good prognostic index, especially disease-specific graded prognostic index (DS-GPA). In this review, treatment strategy including chemotherapeutic agents and radiotherapy is discussed in terms of risk-benefit balance in conjunction with DS-GPA.

[Phase I Study of Etoposide and Cisplatin Chemotherapy Dose Escalation with Concurrent Twice-daily Radiotherapy for Patients with Limited-stage Small Cell Lung Cancer]

背景与目的

加速超分割放疗（每日两次方案）联合EP方案同步化疗是美国国立综合癌症网络（National Comprehensive Cancer Network, NCCN）指南推荐的局限期小细胞肺癌的标准治疗方式，但国人对EP方案标准化疗剂量耐受性尚不明确。本研究旨在探讨局限期小细胞肺癌同步放化疗EP方案的最大耐受剂量。

方法

研究纳入病理证实的局限期小细胞肺癌患者，进行加速超分割放疗同步EP方案（依托泊苷+顺铂）化疗，放疗处方剂量为45 Gy/30 f，1.5 Gy/f，每日两次，同一日两次放疗间隔时间≥6 h，5天/周，共3周完成。化疗方案采用依托泊苷联合顺铂，每21天为1周期，具体依托泊苷100 mg/m²，d1-d3，顺铂采用剂量递增的方式（第1组为70 mg/m² d1，第2组为75 mg/m² d1）。主要观察指标为治疗期间的血液学毒性。次要观察指标为非血液学毒性和1年总生存期（overall survival, OS）、无进展生存期（progression free survival, PFS）。根据不良事件常用术语评定标准（Common Terminology Criteria for Adverse Events, NCI-CTCAE）4.0，最大耐受剂量设定为6例患者中不超过1例患者出现剂量限制毒性（4级血液学毒性）的剂量，同时下一剂量组6例患者至少2例出现剂量限制性毒性。

结果

研究共纳入20例局限期小细胞肺癌患者，平均年龄49.50（30-68）岁。第1组入组6例患者，1例患者出现4度中性粒细胞减少；后第2组入组14例患者，1例患者出现4度中性粒细胞减少。其中，第1组有4例患者出现≥3度血液学毒性，1例患者出现3度以上放射性食管炎；第2组有10例患者出现≥3度血液学毒性，无患者出现3度以上放射性食管炎。中位随访9.0个月（3.2个月-36.2个月），1年OS、PFS分别为91%、62%。

结论

局限期小细胞肺癌患者采用加速超分割放疗联合EP方案化疗将顺铂剂量递增至75 mg/m²是安全的，其有效性还需要进一步扩大样本量和随访更长的时间来证实。

Prophylactic cranial irradiation versus observation in patients with extensive-disease small-cell lung cancer: a multicentre, randomised, open-label, phase 3 trial

BACKGROUND

Results from a previous phase 3 study suggested that prophylactic cranial irradiation reduces the incidence of symptomatic brain metastases and prolongs overall survival compared with no prophylactic cranial irradiation in patients with extensive-disease small-cell lung cancer. However, because of the absence of brain imaging before enrolment and variations in chemotherapeutic regimens and irradiation doses, concerns have been raised about these findings. We did a phase 3 trial to reassess the efficacy of prophylactic cranial irradiation in the treatment of extensive-disease small-cell lung cancer.

METHODS

We did this randomised, open-label, phase 3 study at 47 institutions in Japan. Patients with extensive-disease small-cell lung cancer who had any response to platinum-based doublet chemotherapy and no brain metastases on MRI were randomly assigned (1:1) to receive prophylactic cranial irradiation (25 Gy in ten daily fractions of 2·5 Gy) or observation. All patients were required to have brain MRI at 3-month intervals up to 12 months and at 18 and 24 months after enrolment. Randomisation was done by computer-generated allocation sequence, with age as a stratification factor and minimisation by institution, Eastern Cooperative Oncology Group performance status, and response to initial chemotherapy. The primary endpoint was overall survival, analysed in the intention-to-treat population. This trial is registered with the UMIN Clinical Trials Registry, number UMIN000001755, and is closed to new participants.

FINDINGS

Between April 3, 2009, and July 17, 2013, 224 patients were enrolled and randomly assigned (113 to prophylactic cranial irradiation and 111 to observation). In the planned interim analysis on June 18, 2013, of the first 163 enrolled patients, Bayesian predictive probability of prophylactic cranial irradiation being superior to observation was 0·011%, resulting in early termination of the study because of futility. In the final analysis, median overall survival was 11·6 months (95% CI 9·5-13·3) in the prophylactic cranial irradiation group and 13·7 months (10·2-16·4) in the observation group (hazard ratio 1·27, 95% CI 0·96-1·68; p=0·094). The most frequent grade 3 or worse adverse events at 3 months were anorexia (six [6%] of 106 in the prophylactic cranial irradiation group vs two [2%] of 111 in the observation group), malaise (three [3%] vs one [<1%]), and muscle weakness in a lower limb (one [<1%] vs six [5%]). No treatment-related deaths occurred in either group.

INTERPRETATION

In this Japanese trial, prophylactic cranial irradiation did not result in longer overall survival compared with observation in patients with extensive-disease small-cell lung cancer. Prophylactic cranial irradiation is therefore not essential for patients with extensive-disease small-cell lung cancer with any response to initial chemotherapy and a confirmed absence of brain metastases when patients receive periodic MRI examination during follow-up.

FUNDING

The Ministry of Health, Labour and Welfare of Japan.

Frequency of Silent Brain Metastasis Before Prophylactic Cranial Irradiation in Small Cell Lung Cancer

OBJECTIVES

Prophylactic cranial irradiation (PCI) decreases incidence of brain metastasis and improves survival in patients with limited disease-small cell lung cancer (LD-SCLC) who achieved complete response (CR) after treatment. There is no satisfactory evidence about the necessity of new brain imaging for asymptomatic metastasis immediately prior to PCI. The present study aimed to evaluate the frequency of brain metastasis in SCLC patients without neurological symptoms who are candidates for PCI.

MATERIAL AND METHODS

The data files of 243 patients with SCLC referred for cranial irradiation were retrospectively reviewed. The patients with following characteristics were enrolled to the study; 1) LD-SCLC patients with CR after chemoradiotherapy who are candidates for PCI. 2) No neurological signs or symptoms of brain metastasis after chemoradiotherapy. 3) Having brain imaging at initial diagnosis and before PCI.

RESULTS

Ninety-nine patients (83 male, 83.3%) were included in this study. Median age was 60 years. Time interval between initial and reevaluation for brain metastasis was median 5.5 months (range; 4.7-7.1). Asymptomatic brain metastasis rate was 20.2% (18/99).

CONCLUSION

Even if local disease is under control, asymptomatic brain metastasis is not rare. Therefore, patients who are candidates for PCI after completion of chemoradiotherapy should be reimaged for brain metastasis before PCI.

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

Radiotherapy has been shown to play a key role in the management of small cell lung cancer. There are well-established data in the literature for the use of concurrent chemoradiotherapy for stage I-III disease, although key questions remain over the timing of radiation, the optimal dose/fractionation and particularly once versus twice daily treatment, the use of elective nodal irradiation and drug combinations. Data for the use of thoracic radiation in stage IV disease, after chemotherapy, have recently become available and are leading to a change in practice. Prophylactic cranial irradiation has been shown to be of use in both stage I-III and stage IV disease, although uncertainties surround its use in the elderly population and the use of brain imaging before treatment. This overview will address the current available evidence and focus on areas for future research.

Resected small cell lung cancer-time for more?

Small cell lung cancer (SCLC) often presents with either regional or systemic metastases, but approximately 4% of patients present with a solitary pulmonary nodule. Surgical resection can be an option for these patients and is endorsed by the National Comprehensive Cancer Network (NCCN) guidelines. There are no prospective randomized clinical trials evaluating the role of adjuvant systemic therapy in these resected SCLC patients. A recent National Cancer Database analysis found that the receipt of adjuvant chemotherapy alone [hazard ratio (HR), 0.78; 95% CI, 0.63-0.95] or with brain radiation (HR, 0.52; 95% CI, 0.36-0.75) was associated with significantly improved survival as compared to surgery alone. As it is unlikely that a randomized prospective clinical trial addressing this question will be completed, these data should assist with decision making in these patients.

[Radiotherapy for small cell lung carcinoma]

Radiotherapy for small cell lung carcinoma has known significant improvements over the past 10 years especially through routine use of PET-CT in the initial work-up and contouring before treatment. Prophylactic cranial irradiation remains a standard of care for locally advanced disease and is a subject of controversy for metastatic disease. A new indication for thoracic radiotherapy may soon arise for metastatic disease, still confirmation studies are ongoing.

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.

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

AIM

To compare patient demographics, prophylactic cranial irradiation (PCI) utilization and overall survival (OS) of patients with small cell lung cancer (SCLC) referred to a large tertiary center with those reported in large clinical trials.

PATIENTS AND METHODS

A retrospective review was conducted of consecutive patients with limited stage (LS) and extensive stage (ES) SCLC diagnosed at the Princess Alexandra Hospital between January 2008 and December 2013.

RESULTS

Two hundred and three patients with a mean age of 65.4 (±10.7) years were followed for a median duration of 7.6 months (range 0.5-76.5). At diagnosis, 129 (64%) patients had ES-SCLC, including 39 (19.2%) with cerebral metastases. Median OS in LS-SCLC patients receiving PCI was 18.8 months (0.9-69.4), compared with 8.2 months (0.1-34.4) in patients who did not receive PCI (P < 0.001). Median OS in the ES-SCLC cohort receiving PCI was 13.6 months (5.2-37.5) compared to 5.6 months (0.1-73.6) in patients who did not receive the therapy (P < 0.001). There was a significant improvement in intracranial disease-free survival of 7.1 months in patients with ES-SCLC who received PCI. Forty-two LS-SCLC patients (57%) did not receive PCI due to patient suitability.

CONCLUSIONS

In our SCLC cohort, median OS following PCI in LS-SCLC and ES-SCLC is comparable to published data. PCI use at our institution was lower than utilization rates in large meta-analyses, predominately due to poor chemotherapy tolerance and patient suitability. This may be more representative of patients treated in clinical practice rather than those recruited into large phase III trials.

SCLC-State of the Art and What Does the Future Have in Store?

Worldwide, the total number of diagnosed lung cancer cases amounts to 1.8 million every year. Small-cell lung cancer (SCLC) accounts for about 15% to 17% of all diagnosed lung cancers. Despite all progress made in the field of non-small-cell lung cancer, the prognosis and therapeutic options in SCLC are still limited. The resistance of SCLC to conventional therapy as well as its high recurrence rate can be attributed to the heterogeneous genetic structure of SCLC; however, a targeted therapy approach to SCLC may build on this very heterogeneous genetic structure. SCLC is by now a well-characterized cancer with various genetic alterations; for example, mutations in tumor suppressor genes TP53 and RB1, alterations in chromosome 3p, JAK2, FGFR1, and MYC genes were discovered. Based on these findings, various treatment options (eg, aurora kinase inhibitors, PARP inhibition, immune checkpoint inhibition and vaccine therapy) are currently evaluated with the goal of determining their clinical effectiveness. In this article, we review the existing knowledge of SCLC genetics and the current treatment standards and highlight new approaches of immunotherapy and other targeted therapies, which may yield new treatment options and improve the outcome of patients with SCLC.

A Population-based Model of Local Control and Survival Benefit of Radiotherapy for Lung Cancer

AIMS

To estimate the population-based locoregional control and overall survival benefits of radiotherapy for lung cancer if the whole population were treated according to evidence-based guidelines. These estimates were based on a published radiotherapy utilisation (RTU) model that has been used to estimate the demand and planning of radiotherapy services nationally and internationally.

MATERIALS AND METHODS

The lung cancer RTU model was extended to incorporate an estimate of benefits of radiotherapy alone, and of radiotherapy in conjunction with concurrent chemotherapy (CRT). Benefits were defined as the proportional gains in locoregional control and overall survival from radiotherapy over no radiotherapy for radical indications, and from postoperative radiotherapy over surgery alone for adjuvant indications. A literature review (1990-2015) was conducted to identify benefit estimates of individual radiotherapy indications and summed to estimate the population-based gains for these outcomes. Model robustness was tested through univariate and multivariate sensitivity analyses.

RESULTS

If evidence-based radiotherapy recommendations are followed for the whole lung cancer population, the model estimated that radiotherapy alone would result in a gain of 8.3% (95% confidence interval 7.4-9.2%) in 5 year locoregional control, 11.4% (10.8-12.0%) in 2 year overall survival and 4.0% (3.6-4.4%) in 5 year overall survival. For the use of CRT over radiotherapy alone, estimated benefits would be: locoregional control 1.7% (0.8-2.4%), 2 year overall survival 1.7% (0.5-2.8%) and 5 year overall survival 1.2% (0.7-1.9%).

CONCLUSIONS

The model provided estimates of radiotherapy benefit that could be achieved if treatment guidelines are followed for all cancer patients. These can be used as a benchmark so that the effects of a shortfall in the utilisation of radiotherapy can be better understood and addressed. The model can be adapted to other populations with known epidemiological parameters to ensure the planning of equitable radiotherapy services.