The effects of prophylactic cranial irradiation versus control on survival of patients with extensive-stage small-cell lung cancer: a meta-analysis of 14 trials

Abstract

BackgroundA recent Japanese study suggested prophylactic cranial irradiation (PCI) failed to improve survival of extensive-stage small-cell lung cancer (SCLC). However, previous studies showed that PCI was beneficial in reducing the rate of mortality for extensive-stage SCLC. In this study, we aimed to evaluate the impact of PCI on the survival of patients diagnosed with extensive-stage SCLC by meta-analysis.MethodsPubMed, Embase, the Cochrane library and Chinese Biomedical Literature database (CBM) were systematically searched to identify eligible clinical studies assessing the efficacy of PCI in extensive-stage SCLC patients. After extracting survival data, brain metastasis, and response rates, the pooled estimates were calculated.ResultsA total of 14 clinical studies were included, involving 1221 cases in the PCI group and 5074 in the control group. The results showed that PCI significantly improved overall survival (Hazard ratio (HR) = 0.57; 95% confidence interval (CI): 0.47, 0.69; p < 0.001) and brain metastasis (risk ratio (RR) =0.47, 95%CI: 0.33, 0.69; p < 0.01). Subgroup analysis along with sensitivity analysis suggested that PCI effects on overall survival were independent of region, pre-PCI brain metastasis status and PCI administration timing.ConclusionPCI improves overall survival in extensive-stage SCLC. More randomized controlled trials are needed to verify our findings.Electronic supplementary materialThe online version of this article (10.1186/s13014-018-1101-3) contains supplementary material, which is available to authorized users.

Clinical Outcomes of Extensive Stage Small Cell Lung Cancer Patients Treated With Thoracic Radiotherapy at Different Timing and Fractionation

“…A phase III clinical trial, led by the European Organization Research and Treatment, elucidated a survival bene t and a reduction of symptomatic brain metastasis for ES-SCLC patients which may include asymptomatic brain metastasis patients who received PCI without brain magnetic resonance imaging routinely carried out before treatment [26], whereas, a Japanese study questioned the ndings and con rmed that PCI failed to provide a similar survival advantage in the context of the mandated brain imaging before enrollment [27]. Similarly, several analyses also demonstrated the OS bene t of PCI in ES-SCLC, which were in line with our results [28][29][30]. However, PCI was only administered to 16 patients and no quality of life and limited neurocognition data were available.…”

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

“…As far as we are aware, this is the first systematic review and meta-analysis to identify risk factors for BM in SCLC. Most current meta-analyses focused on one aspect, such as PCI or not in SCLC (101), ED-SCLC (82,90), and resected SCLC (102). Chen et al conducted a meta-analysis to identify risk factors for BM in NSCLC (97).…”

Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer: A Controversial Area

“…Ge et al published a meta-analysis that was criticized because the heterogeneous population of patients was enrolled (38). This study favored PCI for the improvement in OS (HR: 0.57; 95% CI: 0.47-0.69; P < 0.001) and decrease in the incidence of BM (relative risk = 0.47, 95% CI: 0.33-0.69; P < 0.01).…”