Abstract:
BACKGROUND:This review is an update of the first Cochrane publication on selenium for preventing cancer (Dennert 2011).Selenium is a metalloid with both nutritional and toxicological properties. Higher selenium exposure and selenium supplements have been suggested to protect against several types of cancers. OBJECTIVES:Two research questions were addressed in this review: What is the evidence for:1. an aetiological relation between selenium exposure and cancer risk in humans? and2. the efficacy of selenium supplementation for cancer prevention in humans? SEARCH METHODS:We conducted electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL, 2013, Issue 1), MEDLINE (Ovid, 1966 to February 2013 week 1), EMBASE (1980 to 2013 week 6), CancerLit (February 2004) and CCMed (February 2011). As MEDLINE now includes the journals indexed in CancerLit, no further searches were conducted in this database after 2004. SELECTION CRITERIA:We included prospective observational studies (cohort studies including sub-cohort controlled studies and nested case-control studies) and randomised controlled trials (RCTs) with healthy adult participants (18 years of age and older). DATA COLLECTION AND ANALYSIS:For observational studies, we conducted random effects meta-analyses when five or more studies were retrieved for a specific outcome. For RCTs, we performed random effects meta-analyses when two or more studies were available. The risk of bias in observational studies was assessed using forms adapted from the Newcastle-Ottawa Quality Assessment Scale for cohort and case-control studies; the criteria specified in the Cochrane Handbook for Systematic Reviews of Interventions were used to evaluate the risk of bias in RCTs. MAIN RESULTS:We included 55 prospective observational studies (including more than 1,100,000 participants) and eight RCTs (with a total of 44,743 participants). For the observational studies, we found lower cancer incidence (summary odds ratio (OR) 0.69, 95% confidence interval (CI) 0.53 to 0.91, N = 8) and cancer mortality (OR 0.60, 95% CI 0.39 to 0.93, N = 6) associated with higher selenium exposure. Gender-specific subgroup analysis provided no clear evidence of different effects in men and women (P value 0.47), although cancer incidence was lower in men (OR 0.66, 95% CI 0.42 to 1.05, N = 6) than in women (OR 0.90, 95% CI 0.45 to 1.77, N = 2). The most pronounced decreases in risk of site-specific cancers were seen for stomach, bladder and prostate cancers. However, these findings have limitations due to study design, quality and heterogeneity that complicate interpretation of the summary statistics. Some studies suggested that genetic factors may modify the relation between selenium and cancer risk-a hypothesis that deserves further investigation.In RCTs, we found no clear evidence that selenium supplementation reduced the risk of any cancer (risk ratio (RR) 0.90, 95% CI 0.70 to 1.17, two studies, N = 4765) or cancer-related mortality (RR 0.81, 95% CI 0.49 to 1.32, two studies, N = 18,698), and this finding was confirmed when the analysis was restricted to studies with low risk of bias. The effect on prostate cancer was imprecise (RR 0.90, 95% CI 0.71 to 1.14, four studies, N = 19,110), and when the analysis was limited to trials with low risk of bias, the interventions showed no effect (RR 1.02, 95% CI 0.90 to 1.14, three studies, N = 18,183). The risk of non-melanoma skin cancer was increased (RR 1.44, 95% CI 0.95 to 1.17, three studies, N = 1900). Results of two trials-the Nutritional Prevention of Cancer Trial (NPCT) and the Selenium and Vitamin E Cancer Trial (SELECT)-also raised concerns about possible increased risk of type 2 diabetes, alopecia and dermatitis due to selenium supplements. An early hypothesis generated by NPCT that individuals with the lowest blood selenium levels at baseline could reduce their risk of cancer, particularly of prostate cancer, by increasing selenium intake has not been confirmed by subsequent trials. As the RCT participants were overwhelmingly male (94%), gender differences could not be systematically assessed. AUTHORS' CONCLUSIONS:Although an inverse association between selenium exposure and the risk of some types of cancer was found in some observational studies, this cannot be taken as evidence of a causal relation, and these results should be interpreted with caution. These studies have many limitations, including issues with assessment of exposure to selenium and to its various chemical forms, heterogeneity, confounding and other biases. Conflicting results including inverse, null and direct associations have been reported for some cancer types.RCTs assessing the effects of selenium supplementation on cancer risk have yielded inconsistent results, although the most recent studies, characterised by a low risk of bias, found no beneficial effect on cancer risk, more specifically on risk of prostate cancer, as well as little evidence of any influence of baseline selenium status. Rather, some trials suggest harmful effects of selenium exposure. To date, no convincing evidence suggests that selenium supplements can prevent cancer in humans.
journal_name
Cochrane Database Syst Revjournal_title
The Cochrane database of systematic reviewsauthors
Vinceti M,Dennert G,Crespi CM,Zwahlen M,Brinkman M,Zeegers MP,Horneber M,D'Amico R,Del Giovane Cdoi
10.1002/14651858.CD005195.pub3subject
Has Abstractpub_date
2014-03-30 00:00:00pages
CD005195issue
3issn
1469-493Xpub_type
杂志文章,meta分析,评审abstract:BACKGROUND:Studies in traumatic encephalopathy first led to the insight that the damage seen was not just due to direct consequences of the primary injury. A significant, and potentially preventable, contribution to the overall morbidity arose from secondary hypoxic-ischaemic damage. Brain swelling accompanied by raise...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002043
更新日期:2001-01-01 00:00:00
abstract:BACKGROUND:This is an updated version of the Cochrane Review previously published in Issue 3, 2015.The incidence of seizures following supratentorial craniotomy for non-traumatic pathology has been estimated to be between 15% to 20%; however, the risk of experiencing a seizure appears to vary from 3% to 92% over a five...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD007286.pub4
更新日期:2018-05-23 00:00:00
abstract:BACKGROUND:Surgical wounds (incisions) heal by primary intention when the wound edges are brought together and secured - often with sutures, staples, clips or glue. Wound dressings, usually applied after wound closure, provide physical support, protection from bacterial contamination and absorb exudate. Surgical site i...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003091.pub2
更新日期:2011-07-06 00:00:00
abstract:BACKGROUND:Intermittent claudication is pain, caused by chronic occlusive arterial disease, that develops in a limb during exercise and is relieved with rest. Buflomedil is a vasoactive agent claimed to have beneficial effects on the microcirculation. It is used chiefly to treat peripheral vascular disease and to a les...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000988
更新日期:2001-01-01 00:00:00
abstract:BACKGROUND:Controlled clinical trials investigating the efficacy of aminosalicylates for the treatment of mildly to moderately active Crohn's disease have yielded conflicting results. A systematic review was conducted to critically examine current available data on the efficacy of sulfasalazine and mesalamine for induc...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD008870
更新日期:2010-12-08 00:00:00
abstract:BACKGROUND:Colorectal cancer (CRC) is a major cause of morbidity and mortality in industrialized countries. Experimental evidence has supported the hypothesis that dietary fibre may be protective for the development of CRC, although epidemiologic data have been inconclusive. OBJECTIVES:We have conducted a systematic r...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003430
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Advances in minimally invasive surgery for live kidney donors have led to the development of laparoendoscopic single site donor nephrectomy (LESS-DN). At present, laparoscopic donor nephrectomy is the technique of choice for donor nephrectomy globally. Compared with open surgical approaches, laparoscopic don...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010850.pub2
更新日期:2016-05-27 00:00:00
abstract:BACKGROUND:Hemorrhoidectomy is a frequently performed surgical procedure and associated with postprocedural pain. The use of the Ligasure could result in a decreased incidence of pain as coagulation with high frequency currency and active feedback control over the power output has minimal thermal spread and limited tis...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006761.pub2
更新日期:2009-01-21 00:00:00
abstract:BACKGROUND:This is an update of a previously published version of the review (Issue 10, 2011).Epithelial ovarian cancer (EOC) is the seventh most common cause of cancer death among women worldwide. Treatment consists of a combination of surgical debulking and platinum-based chemotherapy. Between 55% and 75% of women wh...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析
doi:10.1002/14651858.CD007927.pub4
更新日期:2018-10-16 00:00:00
abstract:BACKGROUND:Preterm infants experience a range of morbidity related to the immaturity of their organ systems and to concurrent disease states. An unfavourable environment in the neonatal intensive care unit (NICU) may compound this morbidity. Modification of the environment could minimize the iatrogenic effects. Develop...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001814
更新日期:2000-01-01 00:00:00
abstract:BACKGROUND:Vasoactive and neuroprotective drugs such as vinpocetine are used to treat stroke in some countries. OBJECTIVES:To assess the effect of vinpocetine in acute ischaemic stroke. SEARCH STRATEGY:We searched the Cochrane Stroke Group Trials Register (last searched February 2007), MEDLINE (1966 to February 2007)...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD000480.pub2
更新日期:2008-01-23 00:00:00
abstract:BACKGROUND:Indwelling urethral catheters are often used for bladder drainage in hospital. Urinary tract infection is the most common hospital-acquired infection, and a common complication of urinary catheterisation. Pain, ease of use and quality of life are important to consider, as well as formal economic analysis. Su...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD004203.pub3
更新日期:2015-12-10 00:00:00
abstract:BACKGROUND:Lung disease in preterm infants is often complicated with lung edema. OBJECTIVES:The aim of this review was to assess the risks and benefits of administration of a diuretic acting on the loop of Henle (loop diuretic) in preterm infants with or developing chronic lung disease (CLD). Primary objectives were t...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001453
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Inhaled fluticasone propionate (FP) is a relatively new inhaled corticosteroid for the treatment of asthma. OBJECTIVES:To assess efficacy and safety outcomes in studies that compared FP to placebo for treatment of chronic asthma. SEARCH STRATEGY:We searched the Cochrane Airways Group Specialised Register (...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD003135.pub4
更新日期:2008-10-08 00:00:00
abstract:BACKGROUND:Postoperative pulmonary complications (PPCs) have an impact on the recovery of adults after surgery. It is therefore important to establish whether preoperative respiratory rehabilitation can decrease the risk of PPCs and to identify adults who might benefit from respiratory rehabilitation. OBJECTIVES:Our p...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD010356.pub2
更新日期:2015-10-05 00:00:00
abstract:BACKGROUND:Animal and physiological research as well as observational studies suggest that antioxidant supplements may improve survival. OBJECTIVES:To assess the effect of antioxidant supplements on mortality in primary or secondary prevention randomised clinical trials. SEARCH STRATEGY:We searched The Cochrane Libra...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007176
更新日期:2008-04-16 00:00:00
abstract:BACKGROUND:Spinal anaesthesia has been in use since the turn of the late 19th century. The most serious complication of this technique is damage to the spinal cord or nerve roots resulting in lasting neurologic sequelae. Such serious adverse effects seldom happen. There has been an increase in the number of reports dur...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003006
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:Incontinence-associated dermatitis (IAD) is one of the most common skin problems in adults who are incontinent for urine, stool, or both. In practice, products and procedures are the same for both prevention and treatment of IAD. OBJECTIVES:The objective of this review was to assess the effectiveness of var...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD011627.pub2
更新日期:2016-11-10 00:00:00
abstract:BACKGROUND:Gliomas are the most common primary brain tumour. They are graded using the WHO classification system, with Grade II-IV astrocytomas, oligodendrogliomas and oligoastrocytomas. Low-grade gliomas (LGGs) are WHO Grade II infiltrative brain tumours that typically appear solid and non-enhancing on magnetic resona...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD011551.pub2
更新日期:2018-01-22 00:00:00
abstract:BACKGROUND:It is standard clinical practice to combine chemotherapy and chest radiotherapy in treating patients with limited-stage small cell lung cancer. However, the best way to integrate both modalities is unclear. OBJECTIVES:To establish the most effective way of combining chest radiotherapy with chemotherapy for ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD004700.pub2
更新日期:2005-01-25 00:00:00
abstract:BACKGROUND:For early squamous cell carcinoma of the uterine cervix, the outcome is similar after either primary surgery or primary radiotherapy. There are reports that this is not the case for early adenocarcinoma (AC) of the uterine cervix: some studies have reported that the outcome is better after primary surgery. T...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD006248.pub2
更新日期:2010-01-20 00:00:00
abstract:BACKGROUND:Threatened miscarriage occurs in 10% to 15% of all pregnancies. Vaginal spotting or bleeding during early gestation is common, with nearly half of those pregnancies resulting in pregnancy loss. To date, there is no effective preventive treatment for threatened miscarriage. Chinese herbal medicines have been ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD008510.pub2
更新日期:2012-05-16 00:00:00
abstract:BACKGROUND:Circuit class therapy (CCT) offers a supervised group forum for people after stroke to practise tasks, enabling increased practise time without increasing staffing. OBJECTIVES:To examine the effectiveness and safety of CCT on mobility in adults with stroke. SEARCH STRATEGY:We searched the Cochrane Stroke G...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD007513.pub2
更新日期:2010-07-07 00:00:00
abstract:BACKGROUND:Deep vein thrombosis (DVT) and resulting pulmonary embolism (PE) are uncommon but important complications of stroke. There is good evidence that anticoagulants can reduce the risk of DVT and PE after stroke, but this benefit is offset by a small but definite risk of serious haemorrhages. Physical methods to ...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD001922.pub2
更新日期:2004-10-18 00:00:00
abstract:BACKGROUND:Serum monoclonal anti-Myelin Associated Glycoprotein antibodies may be pathogenic in some patients with IgM paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be of benefit in the treatment of the neuropathy. Many potential therapies...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD002827
更新日期:2003-01-01 00:00:00
abstract:BACKGROUND:Depressive illness in older people causes significant suffering and health service utilisation. Relapse and recurrence rates are high. OBJECTIVES:To examine the efficacy of antidepressants and psychological therapies in preventing the relapse and recurrence of depression in older people. SEARCH METHODS:Sea...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD006727.pub2
更新日期:2012-11-14 00:00:00
abstract:BACKGROUND:Oral 5-aminosalicylic (5-ASA) preparations were intended to avoid the adverse effects of sulfasalazine (SASP) while maintaining its therapeutic benefits. Previously, it was found that 5-ASA drugs were more effective than placebo but had a statistically significant therapeutic inferiority relative to SASP. Th...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD000544.pub3
更新日期:2012-10-17 00:00:00
abstract:BACKGROUND:There is increasing evidence that high consumption of fruit and vegetables is beneficial for cardiovascular disease (CVD) prevention. OBJECTIVES:The primary objective is to determine the effectiveness of i) advice to increase fruit and vegetable consumption ii) the provision of fruit and vegetables to incre...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD009874.pub2
更新日期:2013-06-04 00:00:00
abstract:BACKGROUND:Haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) are related conditions with similar clinical features of variable severity. Survival of patients with HUS and TTP has improved greatly over the past two decades with improved supportive care for patients with HUS and by the use o...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,评审
doi:10.1002/14651858.CD003595.pub2
更新日期:2009-01-21 00:00:00
abstract:BACKGROUND:The results from controlled clinical trials investigating the efficacy of azathioprine and 6-mercaptopurine for the treatment of active Crohn's disease were conflicting and controversial. A meta-analysis was performed to assess the effectiveness of these drugs for the induction of remission in active Crohn's...
journal_title:The Cochrane database of systematic reviews
pub_type: 杂志文章,meta分析,评审
doi:10.1002/14651858.CD000545.pub2
更新日期:2009-10-07 00:00:00