Peiwei Li

Aspirin use after diagnosis but not prediagnosis improves established colorectal cancer survival: a meta-analysis

Objective The objective of this meta-analysis was to systematically assess the survival benefit of aspirin use before or after diagnosis for patients with colorectal cancer (CRC). Design Relevant studies were identified through searching PubMed, Embase and Cochrane databases before May 2014. Two investigators extracted data independently for baseline characteristics and outcomes from the included studies. Either a fixed-effects or a random-effects model was derived to composite the pooled HR for overall mortality and CRC-specific mortality of CRC. Results Seven studies on postdiagnosis aspirin therapy and seven studies on prediagnosis aspirin use were finally included in this meta-analysis. The overall survival benefit associated with postdiagnosis aspirin use represented an HR of 0.84 (95% CI 0.75 to 0.94). This effect was observed both in colon cancer (HR=0.78, 95% CI 0.64 to 0.96) and in rectal cancer (HR=0.90, 95% CI 0.83 to 0.98). Besides, the survival benefit of postdiagnosis aspirin use appeared to be confined to those patients with positive prostaglandin endoperoxide synthase 2 (PTGS2, also known as cyclooxygenase-2, COX-2) expression (HR=0.65, 95% CI 0.50 to 0.85) and with mutated PIK3CA tumours (HR=0.58, 95% CI 0.37 to 0.90). Aspirin use postdiagnosis was not associated with CRC-specific mortality (HR=0.77, 95% CI 0.52 to 1.14). We observed no evidence of an association between prediagnosis aspirin use and CRC overall mortality (HR=1.01, 95% CI 0.96 to 1.06) or CRC-specific mortality (HR=0.93, 95% CI 0.82 to 1.05). Conclusions These findings provide further indication that postdiagnosis aspirin therapy improved CRC overall survival, especially for patients with positive PTGS2 (COX-2) expression and mutated PIK3CA tumours.

Association between dietary fiber intake and risk of coronary heart disease: A meta-analysis

BACKGROUND & AIMS The association between coronary heart disease (CHD) and dietary fiber intake is not consistent, especially for the subtypes of dietary fiber. The aim of our study was to conduct a meta-analysis of existing cohort published studies assessing the association between dietary fiber intake and risk of CHD, and quantitatively estimating their dose-response relationships. METHODS We searched PubMed and EMBASE before May 2013. Random-effect model was used to calculate the pool relative risk (RRs) for the incidence and mortality of CHD. Dose-response, subgroup analyses based on fiber subtypes, heterogeneity and publication bias were also carried out. RESULTS Eighteen studies involving 672,408 individuals were finally included in the present study. The pooled-adjusted RRs of coronary heart disease for the highest versus lowest category of fiber intake were 0.93 (95% confidence interval (CI), 0.91-0.96, P < 0.001) for incidence of all coronary events and 0.83 (95% CI, 0.76-0.91, P < 0.001) for mortality. Further subgroup analyses based on fiber subtypes (cereal, fruit, and vegetable fiber), indicated that RRs were 0.92 (95% CI, 0.85-0.99, P = 0.032), 0.92 (95% CI, 0.86-0.98, P = 0.01), 0.95 (95% CI, 0.89-1.01, P = 0.098) respectively for all coronary event and 0.81 (95% CI, 0.72-0.92, P = 0.001), 0.68 (95% CI, 0.43-1.07, P = 0.094), 0.91 (95% CI, 0.74-1.12, P = 0.383) for mortality. In addition, a significant dose-response relationship was observed between fiber intake and the incidence and mortality of CHD (P < 0.001). CONCLUSIONS Our results indicate that consumption of dietary fiber is inversely associated with risk of coronary heart disease, especially for fiber from cereals and fruits. Besides, soluble and insoluble fibers have the similar effect. A significant dose-response relationship is also observed between fiber intake and CHD risk.

Diagnostic value of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for the detection of metastases in non-small-cell lung cancer patients

In the recent years, fluorine 18 fluorodeoxyglucose (18F‐FDG) positron emission tomography (PET)/computed tomography (CT) has emerged as a new modality for staging non–small‐cell lung cancer (NSCLC) patients. The aim of this meta‐analysis was to assess the diagnostic value of 18F‐FDG PET/CT in detecting metastatic lesions in NSCLC patients. Meta‐analysis methods were used to pool sensitivity, specificity, positive and negative likehood ratios, diagnostic odd ratios and to construct a summary receiver‐operating characteristic curve. Data from included studies were pooled to compare the diagnostic accuracy between PET/CT and PET or CT alone in nodal staging. Totally, 56 studies involving 8,699 patients met the inclusion criteria. The pooled sensitivities and specificities of 18F‐FDG PET/CT were 0.72 [95% confidence interval (CI): 0.65–0.78] and 0.91 (95% CI: 0.86–0.94) in determining mediastinal nodal staging; 0.71 (95% CI: 0.60–0.80) and 0.83 (95% CI: 0.77–0.88) in intrathoracic staging; 0.78 (95% CI: 0.64–0.87) and 0.90 (95% CI: 0.84–0.94) in intrathoracic staging on a per‐node basis. For detecting extrathoracic metastases, the pooled sensitivities and specificities of 18F‐FDG PET/CT were 0.77 (95% CI: 0.47–0.93) and 0.95 (95% CI: 0.92–0.97) for all extrathoracic metastases; 0.91 (95% CI: 0.80–0.97) and 0.98 (95% CI: 0.94–0.99) for bone metastases. 18F‐FDG PET/CT is beneficial in detecting lymph node metastases and extrathoracic metastases although PET/CT showed low sensitivity in detecting brain metastases. 18F‐FDG PET/CT confers significantly higher sensitivity and specificity than contrast‐enhanced CT (both p < 0.01) and higher sensitivity than 18F‐FDG PET in staging NSCLC (p < 0.05).

Association between dietary antioxidant vitamins intake/blood level and risk of gastric cancer.

We aimed to systematically evaluate the association between dietary intake/blood levels of antioxidant vitamins (vitamin C, vitamin E, β‐carotene, and α‐carotene) and gastric cancer risk. Systematic literature searches were conducted until April 2013 in Pubmed and Embase to identify relevant studies. Either a fixed‐ or a random‐effects model was adopted to estimate overall odds ratios (ORs). Dose–response, meta‐regression, subgroup, and publication bias analyses were applied. Forty articles were finally included in the present study. Higher dietary intake of vitamin C, vitamin E, β‐carotene, and α‐carotene was inversely associated with gastric cancer risk (for vitamin C, pooled OR = 0.58, 95% CI 0.51–0.65; for vitamin E, pooled OR = 0.65, 95% CI 0.57–0.74; for β‐carotene, pooled OR = 0.59, 95% CI 0.49–0.70; for α‐carotene, pooled OR = 0.69, 95% CI 0.52–0.93). Subgroup analyses suggested the effects of these antioxidant vitamins were different in gastric cancer subtypes. As indicated by dose–response analysis, a 100 mg/day increment of vitamin C intake conferred an OR of 0.78 (95% CI 0.67–0.90); a 15 mg/day increment of vitamin E intake conferred an OR of 0.79 (95% CI 0.66–0.94); and a 5 mg/day increment in β‐carotene intake conferred an OR of 0.80 (95% CI 0.60–1.04). No significant association was observed between blood vitamin C, α‐tocopherol, γ‐ tocopherol, β‐carotene and α‐carotene levels and gastric cancer risk. In conclusion, dietary intake of vitamin C, vitamin E, β‐carotene and α‐carotene was inversely associated with gastric cancer risk while no such association was observed for blood levels of these antioxidant vitamins, thus the results should be interpreted cautiously.

Association between zinc intake and risk of digestive tract cancers: A systematic review and meta-analysis

BACKGROUND & AIMS Association between zinc intake and digestive tract cancers risk has been reported in several epidemiological studies, while the results were controversial. The aim of our study was to get a systemic review of this issue. METHODS PUBMED and EMBASE were searched up to April 2013, supplemented with manual-screening for relevant articles. Two independent reviewers independently extracted data from eligible studies, risk ratio (RR) or odds ratio (OR) with 95% CIs for the highest versus lowest categories of zinc intake was adopted. Either a fixed- or a random-effects model was adopted to estimate overall odds ratios. Besides, dose-response, subgroup, and publication bias analyses were applied. RESULTS Nineteen studies with approximately 400,000 participants were included in this meta-analysis. The pooled relative risk (RR) of overall digestive tract cancers for the highest versus lowest categories of zinc intake was 0.82 (95% CI: 0.70-0.96; p = 0.013). Comparing the highest with lowest categories, higher zinc intake was significantly associated with reduced colorectal cancer risk (pooled RR = 0.80, 95% CI: 0.70-0.92; p = 0.002), while zinc intake was not statistically associated with gastric cancer risk (pooled RR = 0.91, 95% CI: 0.64-1.29; p = 0.581) or esophageal cancer risk (pooled RR = 0.72, 95% CI: 0.44-1.17; p = 0.187). However, subgroup analyses showed that zinc intake was significantly associated with esophageal cancer risk and gastric cancer risk in Asia, but not in America and Europe. CONCLUSIONS Dietary zinc intake was inversely associated with digestive tract cancers, especially colorectal cancer risk in this study.

Association Between Coeliac Disease and Risk of Any Malignancy and Gastrointestinal Malignancy: A Meta-Analysis

AbstractCoeliac disease (CD) is reported to be associated with risk of malignancy; however, this association remains unclear. We aimed to systematically evaluate the association between CD and risk of all malignancies as well as gastrointestinal (GI) malignancy specifically.The PUBMED and EMBASE databases were searched to identify eligible studies from 1960 to March 2015, without restriction. Two reviewers independently performed the study inclusion and data extraction methods. Odds ratios (ORs), risk ratios, or standardized incidence ratios were pooled using either a fixed- or a random-effects model. Sensitivity and subgroup analyses were used to explore sources of heterogeneity.A total of 17 studies were included in this meta-analysis. The pooled OR for risk of all malignancies was 1.25 (95% confidence interval [CI] 1.09–1.44), whereas the pooled OR for risk of GI malignancy was 1.60 (95% CI 1.39–1.84) and suggested an inverse association with CD. Moreover, patients with CD were at a higher risk of esophageal cancer (pooled OR = 3.72, 95% CI 1.90–7.28) and small intestinal carcinoma (pooled OR = 14.41, 95% CI 5.53–37.60), whereas no significant associations were observed for other GI cancers, including gastric, colorectal, liver, and pancreatic cancers. Subgroup analyses also indicated that the results were influenced by the CD diagnostic method, as well as the follow-up time after CD diagnosis.CD was associated with increased risk of all malignancies as well as GI malignancies, including esophageal cancer and small intestinal carcinoma.

Association between vitamin A, retinol intake and blood retinol level and gastric cancer risk: A meta-analysis

BACKGROUND & AIMS The association between dietary vitamin A, retinol intake and blood retinol level and gastric cancer risk has been investigated by many studies. However, the results of these studies were controversial. The aim of our study was to systematically assess this issue. METHODS PUBMED and EMBASE were searched, supplemented with manual-screening for relevant publications. Meta-analyses were performed to evaluate the association between vitamin A, retinol dietary intake or blood retinol level and gastric cancer risk. RESULTS Thirty-one studies were included in this meta-analysis. Comparing the highest with the lowest categories, vitamin A intake significantly reduced gastric cancer risk (pooled RR = 0.66, 95% CI: 0.52-0.84), whereas a marginally inverse association was found between retinol intake (pooled RR = 0.94, 95% CI: 0.87-1.03) or blood retinol level (pooled RR = 0.87, 95% CI: 0.73-1.05) and gastric cancer risk. Interestingly, the results of subgroup analysis indicated that high vitamin A intake and blood retinol level were associated with reduced gastric cancer risk in Western countries, while a marginally inverse association was found between retinol and gastric cancer risk in Western countries. CONCLUSIONS Vitamin A intake was inversely associated with gastric cancer risk, while no significant association was found with retinol intake or blood retinol level.

Diagnostic value of interleukin-8 in colorectal cancer: A case-control study and meta-analysis

AIM To assess the diagnostic value of serum interleukin-8 (IL-8) in the detection of colorectal cancer (CRC). METHODS An original study was conducted to explore the potential value of IL-8 in CRC diagnosis. Receiver operating characteristic (ROC) analysis was performed and the area under the curve (AUC) value was calculated. PUBMED and EMBASE were searched (to October, 2013), supplemented with manual screening for relevant publications. Meta-analysis methods were applied to pool sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratios and to construct a summary receiver-operating characteristic (sROC) curve. Heterogeneity across studies was checked by the I(2) test and Deeks funnel plot method was applied to test publication bias. RESULTS In our original study, serum IL-8 yielded an AUC of 0.742 [95%CI: 0.635-0.849]. The sensitivity and specificity were 85.42% and 54.05%, respectively, at a cut-off value of 5.39. In this meta-analysis, we included five studies with 668 CRC patients and 374 controls and one study in our own center with 48 CRC patients and 37 controls. The pooled sensitivity and specificity of IL-8 were 0.69 (95%CI: 0.42-0.87) and 0.85 (95%CI: 0.68-0.94) for CRC detection. Besides, the area under the sROC curve was 0.86 (95%CI: 0.82-0.88). Subgroup analysis suggested that there was no heterogeneity in the Asian subgroup but some in the European subgroup. In addition, no publication bias was found according to the Deeks funnel plot asymmetry test. CONCLUSION Serum IL-8 is a promising biomarker for CRC detection and may become a clinically useful tool to identify high-risk patients.

Diagnostic and Prognostic Value of Serum Interleukin-6 in Colorectal Cancer.

AbstractThe application of serum interleukin-6 (IL-6) in the diagnosis and prognosis of colorectal cancer (CRC) has been evaluated in many studies, whereas the results were contradictive.The aim of this study was to systematically evaluate this issue.An original study was conducted to explore the diagnostic value of serum IL-6 in CRC. Pubmed, Embase, and Cochrane library databases were searched for eligible studies.For diagnostic meta-analysis, aggregate data (AD) and individual participant data (IPD) meta-analyses were both adopted. The sensitivity and specificity were pooled and a summary receiver-operating characteristic (ROC) curve was constructed. For prognostic meta-analysis, study-specific hazard ratios (HRs) of IL-6 for survival were summarized. Secondary analysis of survival data was performed to synthesize the Kaplan–Meier curves.Total 17 studies (including our study) were included in this meta-analysis. The pooled sensitivity, specificity, and area under curve (AUC) of serum IL-6 were 0.72 (95% CI: 0.46–0.88), 0.74 (95% CI: 0.56–0.86), and 0.79 (95% CI: 0.75–0.82) in CRC diagnosis, respectively. Further, IPD meta-analysis strengthened the diagnostic value of serum IL-6 (the AUC, sensitivity, and specificity were 0.794, 0.606, and 0.839, respectively). For prognostic analysis, the high serum level of IL-6 was inversely associated with overall survival (OS) (pooled HR = 1.76, 95% CI: 1.42–2.19, P < 0.001) and disease-free survival (DFS) (pooled HR = 2.97, 95% CI: 1.76–5.01, P < 0.001). The synthesized Kaplan–Meier curves indicated that CRC patients with higher serum IL-6 level had a worse OS (P = 0.0027) and DFS (P < 0.001), which further support the prognostic value of serum IL-6 in CRC patients.The present study confirmed that serum IL-6 may be a potential biomarker for CRC diagnosis, and the high serum IL-6 level was associated with poor prognosis for both CRC overall survival and disease-free survival.The study has been registered in an international registry of systematic reviews PROSPERO (CRD42013006485).

Growth differentiation factor 15 is a promising diagnostic and prognostic biomarker in colorectal cancer

Although various studies have demonstrated that growth differentiation factor 15 (GDF15) might be a potential diagnostic and prognostic marker in colorectal cancer (CRC) patients, the results are inconsistent and the statistical power of individual studies is also insufficient. An original study was conducted to explore the diagnostic and prognostic value of serum GDF15 in CRC patients. We also conducted a meta‐analysis study which aimed to summarize the diagnostic and prognostic performance of serum GDF15 in CRC. We searched PubMed and ISI Web of Knowledge up to 1 November 2014 for eligible studies. In order to explore the diagnostic performance of GDF15, standardized mean difference (SMD) and their 95% confidence intervals (CI) were estimated and receiver‐operating characteristic (ROC) curves were constructed. For prognostic meta‐analysis, study‐specific hazard ratios (HRs) of serum GDF15 for survival were summarized. A total of eight studies were included in the meta‐analyses. Our results revealed that serum GDF15 levels in CRC patients were higher than those in healthy controls (SMD = 1.08, 95% CI: 0.56–1.59, P < 0.001). For discriminating CRC from healthy controls, the AUC of GDF15 was 0.816 (95% CI: 0.792–0.838). The sensitivity and specificity were 58.9% (95% CI: 55.0–62.8) and 92.08% (95% CI: 89.2–94.4), respectively, when a cut‐off value of 1099 pg/ml was established. Besides, higher GDF15 expression level was associated with worse overall survival for CRC patients (pooled HR = 2.09, 95% CI: 1.47–2.96). In conclusion, the present meta‐analysis suggests that serum GDF15 may be a useful diagnostic and prognostic biomarker for CRC.