BackgroundThe efficacy of prophylactic cranial irradiation (PCI) in treating patients with small cell lung cancer (SCLC) has not been clear, and recent randomized studies have demonstrated conflicting results from previously published findings. The purpose of this study was to reevaluate the efficacy of PCI in patients with SCLC and to assess factors associated with its efficacy.MethodsWe conducted a quantitative meta-analysis to explore the efficacy of PCI in patients with SCLC. A literature search was performed using EMBASE, MEDLINE, Cochrane and ClinicalTrials.gov databases. We pooled the data and compared overall survival (OS) and brain metastasis (BM) between patients treated with PCI (PCI group) and patients without PCI treatment (observation group).ResultsOf the 1074 studies identified in our analysis, we selected seven studies including 2114 patients for the current meta-analysis. Our results showed that the PCI group showed decreased BM (HR = 0.45, 95% CI: 0.38–0.55, P < 0.001) and prolonged OS (HR = 0.81, 95% CI: 0.67–0.99, P < 0.001). However, in terms of OS, the pooled analysis showed a high heterogeneity (I2 = 74.1%, P = 0.001). In subgroup analyses of OS, we found that the heterogeneity mainly came from patients with brain imaging after initial chemoradiotherapy (HR = 0.94, 95% CI: 0.74–1.18, P = 0.59).ConclusionsThe results of this study showed that PCI has a significant effect on decreasing BM but little benefit in prolonging OS when brain imaging was introduced to confirm lack of BM after initial chemoradiotherapy and before irradiation.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-5251-3) contains supplementary material, which is available to authorized users.

Radiotherapy produces excessive reactive oxygen species (ROS), which can lead to DNA damage and apoptosis in tumor cells, thereby killing malignant cells. Chlorogenic acid (CGA) is a well-known antioxidant in coffee due to its strong ability to remove ROS. However, the effect of CGA on radiotherapeutic efficacy remains unclear. In this study, we showed that CGA could hinder the therapeutic effect of radiotherapy by inhibiting radiation-induced apoptosis and DNA damage via scavenging excessive ROS and activating the NF-E2-related factor 2 (Nrf2) antioxidant system in hepatocellular carcinoma (HCC) cells and a murine model. The knockdown of Nrf2 reversed CGA-mediated radiation resistance in HCC cells. In conclusion, CGA might be a potential tumor-protective compound upon irradiation and reduce the efficacy of radiotherapy via ROS scavenging and Nrf2 activation.

Background. Ribonucleotide reductase (RR) consists of two subunits, the large subunit RRM1 and the small subunit (RRM2 or RRM2B), which is essential for DNA replication. Dysregulations of RR were implicated in multiple types of cancer. However, the abnormal expressions and biologic functions of RR subunits in liver cancer remain to be elucidated. Methods. TCGA, HCCDB, CCLE, HPA, cBioPortal, and GeneMANIA were utilized to perform bioinformatics analysis of RR subunits in the liver cancer. GO, KEGG, and GSEA were used for enrichment analysis. Results. The expressions of RRM1, RRM2, and RRM2B were remarkably upregulated among liver cancer tissue both in mRNA and protein levels. High expression of RRM1 and RRM2 was notably associated with high tumor grade, high stage, short overall survival, and disease-specific survival. Enrichment analyses indicated that RRM1 and RRM2 were related to DNA replication, cell cycle, regulation of nuclear division, DNA repair, and DNA recombination. Correlation analysis indicated that RRM1 and RRM2 were significantly associated with several subsets of immune cell, including Th2 cells, cytotoxic cells, and neutrophils. RRM2B expression was positively associated with immune score and stromal score. Chemosensitivity analysis revealed that sensitivity of nelarabine was positively associated with high expressions of RRM1 and RRM2. The sensitivity of rapamycin was positively associated with high expressions of RRM2B. Conclusion. Our findings demonstrated high expression profiles of RR subunits in liver cancer, which may provide novel insights for predicting the poor prognosis and increased chemosensitivity of liver cancer in clinic.

Background Salivary gland cancer (SGC) is comparatively rare and constitutes a variety of histological subtypes. Previously published studies included SGC patients who were irradiated using conventional radiotherapy or 3-dimensional conformal radiotherapy (3-DCRT) may have led to suboptimal oncological outcomes. Methods We identified 60 patients with major SGC treated with surgery followed by postoperative intensity-modulated radiotherapy (IMRT). Data for overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRRFS), distant metastasis-free survival (DMFS), prognostic factors, and treatment-related toxicities were analyzed. Survival was analyzed using the Kaplan–Meier method and compared using the log-rank test. Results Adenoid cystic carcinoma (ACC) was the most common histology (n = 21; 35%). With a median follow-up of 55.5 months, OS and PFS were 90.7%, 85.1%, and 85.1%; and 80.1%, 72.7%, and 63.1%, at 3, 5, and 10 years, respectively. LRRFS and DMFS at 3, 5, and 10 years were 87.4%, 82.1%, and 82.1%; and 85.3%, 78.4%, and 66.1%, respectively. Five-year OS, PFS, LRRFS, and DMFS for ACC was 100%, 67.7%, 76.2%, and 90.2%, respectively. In multivariable analysis (MVA), N stage was an independent predictor of PFS (p = 0.047). Positive margin was a significant prognostic factor for PFS, LRRFS, and DMFS (p = 0.036, 0.026, and 0.011, respectively). Major nerve involvement was significantly correlated with PFS and DMFS (p = 0.034 and 0.008, respectively). Interval from surgery to radiotherapy (RT) predicted PFS and DMFS (p = 0.036 and 0.012, respectively). The most common acute toxicities were mucositis and dermatitis, and xerostomia was the most common late adverse event. Lung metastasis was the most common pattern of distant failure. Conclusion Postoperative IMRT leads to improved survival for SGC patients with acceptable toxicities.