The Global and Regional Survival Rate of Women With Breast Cancer: A Systematic Review and Meta-analysis

Breast cancer is the most common cancer among women in the world. The aim of this study was to measure the global and regional survival rates of women with breast cancer. We searched Medline/PubMed, Web of Science, Scopus, and Google Scholar to identify cohort studies on the survival rate of women with primary invasive breast cancer until the end of June 2017. We used random effect models to estimate the pooled 1-, 3-, 5-, and 10-year survival rates. Subgroup analysis and meta-regression models were used to investigate the potential sources of heterogeneity. One hundred twenty-six studies were included in the meta-analysis. Between-study heterogeneities in the 1-, 3-, 5-, and 10-year survival rates were significantly high (all ${\text{I}}^2$s > 50%; P = .001). The global 1-, 3-, 5-, and 10-year pooled survival rates in women with breast cancer were 0.92 (95% confidence interval [CI], 0.90-0.94), 0.75 (95% CI, 0.71-0.79), 0.73 (95% CI, 0.71-0.75), and 0.61% (95% CI, 0.54-0.67), respectively. Subgroup analysis revealed that survival rates varied in different World Health Organization regions, age and stage at diagnosis, year of the studies, and degree of development of countries. Meta-regression indicated that year of the study (β = 0.07; P = .002) and development of country (β = −0.1; P = .0001) were potential sources of heterogeneity. The survival rate was improved in recent decades; however, it is lower in developing regions than developed ones.     

Metformin Is Associated With Survival Benefit in Cancer Patients With Concurrent Type 2 Diabetes: A Systematic Review and Meta‐Analysis

Purpose.

Patients with type 2 diabetes have increased cancer risk and cancer-related mortality, which can be reduced by metformin treatment. However, it is unclear whether metformin can also modulate clinical outcomes in patients with cancer and concurrent type 2 diabetes.

Patients and Methods.

A meta-analysis of 20 publications that included 13,008 subjects was performed to investigate the association between metformin and overall survival (OS) as well as cancer-specific survival (CSS) in patients with cancer and concurrent type 2 diabetes.

Results.

We found that there was a relative survival benefit associated with metformin treatment compared with treatment with other glucose-lowering medications in both OS and CSS (hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.55–0.79 and HR = 0.62; 95% CI: 0.46–0.84, respectively). These associations were also observed in subgroups by cancer type and country.

Conclusion.

These results suggest that metformin is the drug of choice in the treatment of patients with cancer and concurrent type 2 diabetes.     

Quantitative Analysis of Circulating Cell-Free DNA for Correlation with Lung Cancer Survival: A Systematic Review and Meta-Analysis

IntroductionDespite the growing interest in circulating cell-free DNA (cfDNA), no conclusive evidence exists on the value of quantitative analysis of cfDNA for the prediction of lung cancer survival. We performed a systematic review and meta-analysis of primary studies to estimate the impact of higher baseline cfDNA levels on survival outcomes of patients with lung cancer.MethodsA comprehensive search was performed using the PubMed, Web of Knowledge, and Cochrane databases up to March 2016. The methodologic quality of identified studies was assessed by the Newcastle-Ottawa scale. Potential sources of heterogeneity were investigated via subgroup and sensitivity analyses, while publication bias was evaluated by funnel plot and Egger’s test.ResultsAmong the 17 studies identified, 16 studies (n = 1723 patients) and 5 studies (n = 640) were included in the meta-analysis of overall survival (OS) and progression-free survival (PFS), respectively. Despite the fact that the association with PFS did not reach statistical significance (hazard ratio 1.12% [95% confidence interval 0.91–1.37), the pooled analysis for OS showed evidence of an increased risk of death in patients with higher baseline cfDNA levels (hazard ratio 1.76 [95% confidence interval 1.38–2.25]; p < 0.001). Further subgroup and sensitivity analyses confirmed this relationship, although significant between-study heterogeneity was still detected in most comparisons. The Egger’s test revealed no statistical evidence of publication bias in the results.ConclusionOur findings support the clinical validity of quantitative analysis of cfDNA for the prediction of lung cancer survival. Nevertheless, the establishment of a robust standardized method for determination of optimal cutoff thresholds is required to define the clinical relevance of cfDNA quantification for lung cancer management.     

Bisphosphonates for Osteoporosis in Nonmetastatic Prostate Cancer Patients Receiving Androgen-deprivation Therapy: A Systematic Review and Meta-analysis

This systematic review was conducted to assess the efficacy and safety of bisphosphonates for preventionand treatment of osteopenia or osteoporosis in men with non-metastatic prostate cancer receiving androgendeprivationtherapy. We searched for randomised controlled trials (RCTs) of bisphosphonates compared withplacebo from Pubmed, Embase, the Cochrane Library, and ISI - Science Citation Index. Meta-analyses of prespecifiedoutcomes (bone mineral density, fractures, and adverse events) were performed using Review Manager.Ten RCTs with a total patient population of 1,017 were identified. There was generally more improvement in bonemineral density of the lumbar spine for patients who received bisphosphonate treatment than placebo or othermedical treatment at 12 months (WMD 6.02,95%CI 5.39 to 6.65). Similar effects were also observed for totalhip, trochanter or femoral neck bone mineral density. However, there was no significant reduction in fractures.Fever and gastrointestinal symptoms were the most common adverse events (10.4% vs. 1.2%; 0.10% vs. 0.03%).Currently, our meta-analysis suggested that oral and intravenous bisphosphonates caused a rapid increasein spine and hip or femoral BMD in non-metastatic prostate cancer patients receiving androgen-deprivationtherapy. Fever and gastrointestinal symptoms were common with the use of bisphosphonates. These short-termtrials (maximum of 12 months) did not show fracture reduction. In future, more efficient performance of higherquality, more rigorous, large sample, long-term randomised controlled trials (>12 months) are needed whereoutcomes are detailed.     

Sleep Duration and Cancer Risk: a Systematic Review and Meta-analysis of Prospective Studies

To assess the risk of cancers associated with sleep duration using meta-analysis of published cohort studies,we performed a comprehensive search using PubMed, Embase and Web of Science through October 2013.We combined hazard ratios (HRs) from individual studies using meta-analysis approaches. A random effectdose-response analysis was used to evaluate the relationship between sleep duration and cancer risk. Subgroupanalyses and sensitivity analyses were also performed. Publication bias was evaluated using Funnel plots andBegg’s test. A total of 13 cohorts from 12 studies were included in this meta-analysis, which included 723, 337participants with 15, 156 reported cancer outcomes during a follow-up period ranging from 7.5 to 22 years.The pooled adjusted HRs were 1.06 (95% CI: 0.92, 1.23; P for heterogeneity =0.003) for short sleep duration,0.91 (95% CI: 0.78, 1.07; P for heterogeneity <0.0001) for long sleep duration. In subgroup analyses stratifiedby cancer type, long duration of sleep showed an inverse relation with hormone-related cancer (HR=0.79; 95%CI: 0.65, 0.97; P for heterogeneity =0.009) and a greater risk of colorectal cancer (HR=1.29; 95% CI: 1.09, 1.52;P for heterogeneity =0.346). Further meta-analysis on dose-response relationships showed that the relative risksof cancer were 1.00 (95% CI: 0.99, 1.01; P for linear trend=0.9151) for one hour of sleep increment per day, and1.00 (95% CI: 0.98, 1.01; P for linear trend=0.7749) for one hour of sleep increment per night. No significantdose-response relationship between sleep duration and cancer was found on non-linearity testing (P=0.5053). Ourmeta-analysis suggests a positive association between long sleep duration and colorectal cancer, and an inverseassociation with incidence of hormone related cancers like those in the breast. Studies with larger sample size,longer follow-up times, more cancer types and detailed measure of sleep duration are warranted to confirmthese results.     

Breastfeeding and Ovarian Cancer Risk: a Systematic Review and Meta-analysis of 40 Epidemiological Studies

The present systematic review and meta-analysis was conducted to assess any association between breastfeeding and the risk of ovarian cancer. A systematic search of published studies was performed in PUBMED and EMBASE and by reviewing reference lists from retrieved articles through March 2013. Data extraction was conducted independently by two authors. Pooled relative risk ratios were calculated using random-effect models. Totals of 5 cohort studies and 35 case-control studies including 17,139 women with ovarian cancer showed a30% reduced risk of ovarian cancer when comparing the women who had breastfed with those who had never breastfed (pooled RR = 0.70, 95% CI: 0.64-0.76; p = 0.00), with significant heterogeneity in the studies (p = 0.00;I2 = 76.29%). A significant decreasd in risk of epithelial ovarian cancer was also observed (pooled RR = 0.68, 95% CI: 0.61-0.76). When the participants were restricted to only parous women, there was a slightly attenuated but still significant risk reduction of ovarian cancer (pooled RR = 0.76, 95% CI: 0.69-0.83). For total breastfeeding duration, the pooled RRs in the < 6 months, 6-12 months and > 12 months of breastfeeding subgroups were 0.85 (95% CI: 0.77-0.93), 0.73 (95% CI: 0.65-0.82) and 0.64 (95%CI: 0.56-0.73), respectively. Meta-regressionof total breastfeeding duration indicated an increasing linear trend of risk reduction of ovarian cancer with the increasing total breastfeeding duration (p = 0.00). Breastfeeding was inversely associated with the risk of ovarian cancer, especially long-term breastfeeding duration that demonstrated a stronger protective effect.     

Minimal Residual Disease and Survival Outcomes in Patients With Chronic Lymphocytic Leukemia: A Systematic Review and Meta-analysis

BackgroundPatients with chronic lymphocytic leukemia (CLL) who achieve undetectable minimal residual disease (U-MRD) (ie, < 10^-4 detectable leukemic cells in peripheral blood or bone marrow) have better outcomes than those with detectable MRD. To assess the magnitude of improvement of progression-free survival (PFS) or overall survival (OS) in patients who achieved U-MRD after upfront chemotherapy (CT) or chemo-immunotherapy (CIT), we conducted a systematic review and meta-analysis.Materials and MethodsThe screening process adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines. The search strategy yielded 365 records, including 22 articles assessed for eligibility.ResultsEleven studies comprising 2457 patients with CLL treated in upfront with CT or CIT were considered suitable for inclusion in the quantitative meta-analysis. Nine studies (n = 2088) provided data on the impact of MRD on PFS and 6 (n = 1234) on OS. MRD was the main endpoint in only 2 of these studies (n = 213). Tests of heterogeneity revealed significant differences among studies for PFS and OS, which highlights differences across studies. U-MRD status was associated with significantly better PFS overall (P < .001) and in patients who achieved conventional complete remission (P = .01). Regarding OS, U-MRD predicted longer OS globally (P < .001) but not in patients having achieved complete remission (P = .82).ConclusionsU-MRD status after treatment with CT or CIT in newly diagnosed CLL is associated with long-term survival. These findings provide quantitative evidence to support the integration of MRD assessment as an end point in clinical trials of CLL.     

Abiraterone for Treatment of Metastatic Castration-resistant Prostate Cancer: a Systematic Review and Meta-analysis

Introduction: Although most prostate cancers initially respond to castration with luteinizing hormonereleasinganalogues or bilateral orchiectomy, progression eventually occurs. Based on the exciting results ofseveral randomized controlled trials (RCTs), it seems that patients with metastatic castration-resistant prostatecancer (mCRPC) might benefit more from treatment withabiraterone. Therefore we conducted a systematicreview to evaluate the efficacy and toxicity of abiraterone in the treatment of mCRPC. Methods: Literaturewas searched from Embase, PubMed, Web of Science, and Cochrane Library up to July, 2013. Quality of thestudy was evaluated according to the Cochrane’s risk of bias of randomized controlled trial (RCT) tool, then theGrading of Recommendations Assessment, Development and Evaluation (GRADE) System was used to rate thelevel of evidence. Stata 12.0 was used for statistical analysis. Summary data from RCTs comparing abirateroneplus prednisone versus placebo plus prednisone for mCRPC were meta-analyzed. Pooled hazard ratios (HRs)for overall survival (OS), radiographic progression-free survival (RPFS) and time to PSA progression (TTPP);Pooled risk ratios (RR) for PSA response rate, objective response rate and adverse event were calculated. Results:Ten trials were included in the systematic review; Data of 2,283 patients (1,343 abiraterone; 940 placebo) fromtwo phase 3 trials: COU-AA-301 and COU-AA-302 were meta-analyzed. Compared with placebo, abirateronesignificantly prolonged OS (HR, 0.74; 95% confidence interval [CI], 0.66 to 0.84), RPFS (HR, 0.59; 95% CI,0.48 to 0.74) and time to PSA progression (HR, 0.55; 95% CI, 0.43 to 0.70); it also significantly increased PSAresponse rate (RR, 3.63; 95% CI, 1.72 to 7.65) and objective response rate (RR, 3.05; 95% CI, 1.51 to 6.15). Thismeta-analysis suggested that the adverse events caused by abiraterone are acceptable and can be controlled.Conclutios: Abiraterone significantly prolonged OS, RPFS and time to progression patients with mCRPC,regardless of prior chemotherapy or whether chemotherapy-naïve, and no unexpected toxicity was evident.Abiraterone can serve as a new standard therapy for mCRPC.     

Metformin Association with Lower Prostate Cancer Recurrence in Type 2 Diabetes: a Systematic Review and Meta-analysis

Background: Accumulating evidence suggests that metformin possesses anticarcinogenic properties, and itsuse is associated with favorable outcomes in several cancers. However, it remains unclear whether metformininfluences prognosis in prostate cancer (PCa) with concurrent type 2 diabetes (T2D). Materials and Methods:We searched PubMed, EMBASE, and the Cochrane Library from database inception to April 16, 2014 withoutlanguage restrictions to identify studies investigating the effect of metformin treatment on outcomes of PCa withconcurrent T2D. We conducted a meta-analysis to quantify the risk of recurrence, progression, cancer-specificmortality, and all-cause mortality. Summary relative risks (RRs) with corresponding 95% confidence intervals(CIs) were calculated. Publication bias was assessed by Begg’s rank correlation test. Results: A total of eightstudies fulfilled the eligibility criteria. We found that diabetic PCa patients who did not use metformin were atincreased risk of cancer recurrence (RR, 1.20; 95%CI, 1.00-1.44), compared with those who used metformin.A similar trend was observed for other outcomes, but their relationships did not reach statistical significance.Funnel plot asymmetry was not observed among studies reporting recurrence (p=0.086). Conclusions: Ourresults suggest that metformin may improve outcomes in PCa patients with concurrent T2D. Well-designedlarge studies and collaborative basic research are warranted.     

Microvessel Density as a Prognostic Factor in Ovarian Cancer: a Systematic Review and Meta-analysis

Background: The prognostic value of microvessel density (MVD), reflecting angiogenesis, detected in ovariancancer is currently controversial. Here we performed a meta-analysis of all relevant eligible studies. Materials andMethods: A comprehensive search of online PubMed, Medline, EMBASE and Sciencedirect was performed toidentify all related articles. The search strategy was designed as ‘microvessel density’, ‘ovarian cancer’, ‘ovarianneoplasm’, ‘CD34’ and ‘angiogenesis’. Results: The studies were categorized by author/year, number of patients,FIGO stage, histology, cutoff value for microvessel density, types of survival analysis, methods of hazard rations(HR) estimation, HR and its 95% confidence interval (CI). Combined hazard ratios suggested that high MVDwas associated with poor overall survival (OS) and progression-free survival (PFS), with HR and 95% CIs of1.84 (1.33-2.35) and 1.36 (1.06-1.66), respectively. Subgroup analysis showed that high MVD detected by CD34was relevant for OS [HR=1.67 (1.36-2.35)], but not MVD detected with other antibodies [HR=2.11 (0.90-3.31)].Another subgroup analysis indicated that high MVD in patients without pre-chemotherapy, but not with prechemotherapy,was associated with OS [HR=1.88(1.59-2.18 and HR=1.70 (-0.18-3.59)]. Conclusions: The OSand PFS with high MVD were significant poorer than with low MVD in ovarian cancer patients. However, highMVD detected by CD34 seems to be more associated with survival for patients without pre-chemotherapy.     

Quitting Smoking At or Around Diagnosis Improves the Overall Survival of Lung Cancer Patients: A Systematic Review and Meta-Analysis

IntroductionLung cancer (LC) remains a disease with poor prognosis despite recent advances in treatments. Here, we aimed at summarizing the current scientific evidence on whether quitting smoking at or around diagnosis has a beneficial effect on the survival of LC patients.MethodsWe searched MEDLINE and EMBASE for articles published until 31^st October, 2021, that quantified the impact on LC patients’ survival of quitting smoking at or around diagnosis or during treatment. Study-specific data were pooled into summary relative risk (SRR) and corresponding 95% confidence intervals (CI) using random effect meta-analysis models.ResultsTwenty-one articles published between 1980 and 2021 were included, which encompassed a total of over 10,000 LC patients. There was substantial variability across studies in terms of design, patients’ characteristics, treatments received, criteria used to define smoking status (quitters or continued), and duration of follow-up. Quitting smoking at or around diagnosis was significantly associated with improved overall survival (SRR 0.71, 95% CI 0.64–0.80), consistently among patients with non-small cell LC (SRR 0.77, 95% CI 0.66–0.90, n studies = 8), small cell LC (SRR 0.75, 95% CI 0.57–0.99, n studies = 4), or LC of both or unspecified histological type (SRR 0.81, 95% CI 0.68–0.96, n studies = 6).ConclusionsQuitting smoking at or around diagnosis is associated with a beneficial effect on the survival of LC patients. Treating physicians should educate LC patients about the benefits of quitting smoking even after diagnosis and provide them with the necessary smoking cessation support.     

Prevalence of Human Papillomavirus 16 in Esophageal Cancer Among the Chinese Population: a Systematic Review and Meta-analysis

Background and Aim: No firm evidence of HPV infection in esophageal cancer has been established to date.The aim of this meta-analysis was to investigate the prevalence of HPV 16 in esophageal cancer in China, whichhad a high burden of the disease. Materials and Methods: Studies on HPV infection and esophageal cancerwere identified and a random-effects model was used to pool the summary prevalence and corresponding 95%confidence intervals (CIs). Results: A total of 3,429 esophageal cancer cases were evaluated from 26 eligiblestudies in this meta-analysis. The summary estimate for HPV16 prevalence was 0.381 (95% CI: 0.283, 0.479).The prevalence varied by geographical areas of the study, publication year, HPV detection method and types ofspecimen. In sensitivity analysis, HPV 16 prevalence ranged from 0.368 (95% CI: 0.276, 0.460) to 0.397 (95%CI: 0.286, 0.508). Conclusions: The results indicate a relatively high level of HPV 16 prevalence in esophagealcancer among Chinese population, although there was variation between different variables. Further studiesare needed to elucidate the role of HPV in esophageal carcinogenesis with careful consideration of study designand laboratory detection method, providing more accurate assessment of the HPV status in esophageal cancer.     

Interferon Therapy in Myelofibrosis: Systematic Review and Meta-analysis

BackgroundMyelofibrosis (MF) is a Philadelphia chromosome–negative myeloproliferative neoplasm characterized by progressive bone marrow failure, increased risk of progression to acute myeloid leukemia, and constitutional symptoms. For over 3 decades, various formulations of interferon (IFN) have been used for the treatment of MF, with variable results, and the role of IFN in the treatment of MF is evolving.Patients and MethodsFor this systematic review and meta-analysis, Medline and Embase via Ovid, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science were searched from inception through March 2019 for studies of pegylated IFN (peg-IFN) and non–peg-IFN in MF patients. The primary outcome of overall response rate was defined as a composite of complete response, partial response, complete hematologic response, and partial hematologic response. Random-effects models were used to pool overall response rate, and metaregression analyses were performed to compare peg-IFN and non-–peg-IFN formulations.ResultsAmong the 10 studies with 141 MF patients included, the overall response rate was 49.9% (95% confidence interval [CI], 30.4-69.3), and there was no statistically significant difference (P = .99) between peg-IFN (50.0%; 95% CI, 26.2-73.9; I² = 76.9%) and non–peg-IFN (49.6%; 95% CI, 20.5-79.0; I² = 56.7%). Treatment discontinuation resulting from adverse events was common with non–peg-IFN at 35.8% (95% CI, 3.5-68.1) per year, and less in the one study on peg-IFN (0.5% per year).ConclusionIFN can lead to hematologic improvements in a subset of MF patients, but study quality is limited and heterogenous. Biomarkers predicting response to IFN and formulations with improved tolerability are needed.     

Vitamin A and Breast Cancer Survival: A Systematic Review and Meta-analysis

Background

The association between vitamin A intake and breast cancer survival has been inconsistent. We conducted a systemic review and meta-analysis to summarize the results on the association between dietary or supplement vitamin A and its derivatives and breast cancer-specific survival and overall survival (OS).

Diabetes Mellitus and Prostate Cancer Risk in Asian Countries: a Meta-analysis

Background/Aims: Diabetes mellitus (DM) is widely considered to be associated with risk of cancer, but studiesinvestigating the association between DM and prostate cancer in Asian countries have reported inconsistentfindings. We examined this association by conducting a detailed meta-analysis of studies published on the subject.Methods: Cohort or case-control studies were identified by searching Pubmed, Embase and Wanfang databasesthrough May 30, 2012. Pooled relative risk (RR) with its corresponding 95% confidence interval (95% CI) werecalculated using the random-effects model. Subgroup analyses were performed by the study type. Results: Finally,we identified 7 studies (four cohort studies and three case-control studies) with a total of 1,751,274 subjectsfrom Asians. DM was associated with an increased risk of prostate cancer in Asians (unadjusted RR= 2.82, 95%CI 1.73–4.58, P < 0.001; adjusted RR= 1.31, 95% CI 1.12–1.54, P = 0.001). Subgroup analyses by study designfurther confirmed an obvious association. Conclusion: Findings from this meta-analysis strongly support thatdiabetes is associated with an increased risk of prostate cancer in Asians.     

Survival Rate of Colorectal Cancer in Iran: A Systematic Review and Meta-Analysis

Background: Different studies have been conducted to estimate the survival rate of colorectal cancer in Iran butthere is no overall estimate of the survival rate. The aim of this study was to calculate the pooled 1, 3, and 5-year survivalrate of the patients with colorectal cancer in Iran. Methods: To retrieve relevant studies, we conducted a systematicsearch in Iranian databases, including Iran Medex, Magiran, SID, and international databases such as Medlin/PubMed,Scopus, and Google scholar using “Colorectal Neoplasms” and “Survival Rate” as keywords up to December 1st, 2017.We used random effect model to estimate pooled 1, 3, and 5-year survival rates of the patients with colorectal cancerin Iran. To assess the heterogeneity, we used Chi-squared test at the 5 % significance level (p <0.05) and I2 Index. Weused meta-regression and subgroup analysis to find a potential source of heterogeneity. Results: After a systematicsearch, 196 articles were found, of the 38 studies met the eligibility criteria and are included in our meta-analysis. Thepooled 1, 3, and 5-year survival rates in patient with colorectal cancer were 0.84 (95% CI: 0.81-0.87), 0.64 (95%CI:0.59-0.70), and 0.54 (95%CI: 0.49-0.58) respectively. The 5-year survival rate in the subgroup of women was 0.5(0.44-0.56) and in male subgroup was 0.44 (0.40-0.48). In a subgroup of the tumor site, the 5-year survival rate in coloncancer was 0.6 (0.49-0.75) and rectum cancer was 0.54 (0.36-0.69). In multivariable models, there was a significantassociation between years of study and 5-year survival rate as a source of heterogeneity (β = 18.9, P=0.01). Conclusion:According to the results of this study, women had a better survival rate than men, and according to the tumor site, the5-year survival rate in colon cancer was better than the rectum cancer.     

Prognostic Value of Vascular Endothelial Growth Factor Expression in Patients with Prostate Cancer: a Systematic Review with Meta-analysis

Background: The vascular endothelial growth factor (VEGF) mediates vasculogenesis and angiogenesisthrough promoting endothelial cell growth, migration and mitosis, and has involvement in cancer pathogenesis,progression and metastasis. However, the prognostic value of VEGF in patients with prostate cancer remainscontroversial. Objectives: The aim of our study was to evaluate the prognostic value of VEGF in prostate cancer,and summarise the results of related research on VEGF. Methods: In accordance with an established searchstrategy, 11 studies with 1,529 patients were included in our meta-analysis. The correlation of VEGF-expressionwith overall survival and progression-free survival was evaluated by hazard ratio, either given or calculated.Results: The studies were categorized by introduction of the author, demographic data in each study, prostatecancer-relatived information, VEGF cut-off value, VEGF subtype, methods of hazard ratio (HR) estimationand its 95% confidence interval (CI). High VEGF-expression in prostate cancer is a poor prognostic factor withstatistical significance for OS (HR=2.32, 95%CI: 1.40–3.24). However, high VEGF-expression showed no effecton poor PFS (HR=1.30, 95%CI: 0.88–1.72). Using Begg’s, Egger’s test and funnel plots, we confirmed lack ofpublication bias in our analysis. Conclusion: VEGF might be regarded as a prognostic maker for prostate cancer,as supported by our meta-analysis. To achieve a more definitive conclusion enabling the clinical use of VEGF inprostate cancer, we need more high-quality interventional original studies following agreed research approachesor standards.     

Breastfeeding and the Risk of Childhood Hodgkin Lymphoma: A Systematic Review and Meta-analysis

Purpose: Numerous observational epidemiological studies have evaluated associations between breastfeedingand the risk of childhood Hodgkin lymphoma; however, the existing results are inconsistent. We thereforeconducted a systematic review and meta-analysis. Methods: Medical literature was searched in the Pubmed andEmbase databases to identify all English-language relevant studies up to April 10, 2013. Reference lists werethereafter hand-searched for additional articles. Studies that reported relative risk ratios (RRs) or odds ratios(ORs) with 95% confidence intervals (CIs) were included. This meta-analysis was conducted in accordancewith the guidelines for the meta-analysis of observational studies in epidemiology. Results: We finally included10 case-control studies in our meta-analysis, involving 1,618 childhood Hodgkin lymphoma cases and 8,181controls. Overall, we did found a borderline significant association between breastfeeding and reduced riskof childhood Hodgkin lymphoma comparing ever breastfed children to never breastfed children (pooled OR=0.79; 95%CI, 0.58-1.08; P=0.13), with limited evidence for between-study heterogeneity (P =0.12, I2 = 35.70%).Conclusion: There is limited evidence for an inverse association between breastfeeding and risk of childhoodHodgkin lymphoma.     

The Association between Selenium and Prostate Cancer: a Systematic Review and Meta-Analysis

Background: Evidence of relationship between selenium and prostate cancer has been inconsistent. The present metaanalysis was conducted to determine relationship between selenium and prostate cancer. Methods: A systematic review and meta-analysis was carried out using preferred reporting items for systematic reviews and meta-analysis (PRISMA). We searched PubMed, Scopus, Web of Science, ScienceDirect, Embase, CINAHL, Cochrane Library, EBSCO andGoogle scholar search engines and the reference lists of the retrieved papers for relevant data, without any limitationregarding language or time until 2016. Heterogeneity among studies was evaluated using Q test and I2 Index. Finally,a random effects model was used for combining results using STATA software version 11.1. Psignificant. Results: Thirty-eight studies including 36,419 cases and 105,293 controls were included in the final analysis. The pooled relative risk (RR) of relation between selenium and prostate cancer was 0.86 (95% Confidence Interval [CI]:0.78-0.94). Sub-group analyses based on case-control, cohort, and RCT studies gave values of 0.89 (95% CI:0.80-1.00), 0.77 (95% CI: 0.52-1.14) and 0.90 (95% CI: 0.74-1.09), respectively. RRs based on serum, plasma and nail samples were 0.69 (95% CI: 0.51-0.95), 0.85 (95% CI: 0.61-1.17), 0.66 (95% CI: 0.41-1.05), respectively. According to 10 studies, investigated the relation between advanced prostate cancer and selenium in which the RR was 0.67 (95% CI: 0.52-0.87). Conclusions: This meta-analysis indicated that selenium most probably has a protective role against development of prostate cancer and its progression to advanced stages. Therefore, selenium supplementation can be proposed for prevention of prostate cancer.