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Experimental Biology and Medicine... Apr 2017A role for red and processed meat in the development of colorectal cancer has been proposed based largely on evidence from observational studies in humans, especially in... (Review)
Review
A role for red and processed meat in the development of colorectal cancer has been proposed based largely on evidence from observational studies in humans, especially in those populations consuming a westernized diet. Determination of causation specifically by red or processed meat is contingent upon identification of plausible mechanisms that lead to colorectal cancer. We conducted a systematic review of the available evidence to determine the availability of plausible mechanistic data linking red and processed meat consumption to colorectal cancer risk. Forty studies using animal models or cell cultures met specified inclusion criteria, most of which were designed to examine the role of heme iron or heterocyclic amines in relation to colon carcinogenesis. Most studies used levels of meat or meat components well in excess of those found in human diets. Although many of the experiments used semi-purified diets designed to mimic the nutrient loads in current westernized diets, most did not include potential biologically active protective compounds present in whole foods. Because of these limitations in the existing literature, there is currently insufficient evidence to confirm a mechanistic link between the intake of red meat as part of a healthy dietary pattern and colorectal cancer risk. Impact statement Current recommendations to reduce colon cancer include the reduction or elimination of red or processed meats. These recommendations are based on data from epidemiological studies conducted among cultures where meat consumption is elevated and consumption of fruits, vegetables, and whole grains are reduced. This review evaluated experimental data exploring the putative mechanisms whereby red or processed meats may contribute to colon cancer. Most studies used levels of meat or meat-derived compounds that were in excess of those in human diets, even in cultures where meat intake is elevated. Experiments where protective dietary compounds were used to mitigate the extreme levels of meat and meat-derived compounds showed protection against colon cancer, with some essentially negating the impact of meat in the diet. It is essential that better-designed studies be conducted that use relevant concentrations of meat or meat-derived compounds in complex diets representative of the foods consumed by humans.
Topics: Animals; Colonic Neoplasms; Cooking; Diet, Western; Heme; Humans; Iron; Meat; Mutagens; Observational Studies as Topic
PubMed: 28205448
DOI: 10.1177/1535370217693117 -
The Cochrane Database of Systematic... Dec 2016Choroidal neovascularisation (CNV) is a common complication of pathological myopia. Once developed, most eyes with myopic CNV (mCNV) experience a progression to macular... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Choroidal neovascularisation (CNV) is a common complication of pathological myopia. Once developed, most eyes with myopic CNV (mCNV) experience a progression to macular atrophy, which leads to irreversible vision loss. Anti-vascular endothelial growth factor (anti-VEGF) therapy is used to treat diseases characterised by neovascularisation and is increasingly used to treat mCNV.
OBJECTIVES
To assess the effects of anti-vascular endothelial growth factor (anti-VEGF) therapy for choroidal neovascularisation (CNV), compared with other treatments, sham treatment or no treatment, in people with pathological myopia.
SEARCH METHODS
We searched a number of electronic databases including CENTRAL and Ovid MEDLINE, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform ICTRP). We did not use any date or language restrictions in the electronic searches for trials. Electronic databases were last searched on 16 June 2016.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) and quasi-RCTs comparing anti-VEGF therapy with another treatment (e.g. photodynamic therapy (PDT) with verteporfin, laser photocoagulation, macular surgery, another anti-VEGF), sham treatment or no treatment in participants with mCNV.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane. Two authors independently screened records, extracted data, and assessed risk of bias. We contacted trial authors for additional data. We analysed outcomes as risk ratios (RRs) or mean differences (MDs). We graded the certainty of the evidence using GRADE.
MAIN RESULTS
The present review included six studies which provided data on the comparison between anti-VEGF with PDT, laser, sham treatment and another anti-VEGF treatment, with 594 participants with mCNV. Three trials compared bevacizumab or ranibizumab with PDT, one trial compared bevacizumab with laser, one trial compared aflibercept with sham treatment, and two trials compared bevacizumab with ranibizumab. Pharmaceutical companies conducted two trials. The trials were conducted at multiple clinical centres across three continents (Europe, Asia and North America). In all these six trials, one eye for each participant was included in the study.When compared with PDT, people treated with anti-VEGF agents (ranibizumab (one RCT), bevacizumab (two RCTs)), were more likely to regain vision. At one year of follow-up, the mean visual acuity (VA) in participants treated with anti-VEGFs was -0.14 logMAR better, equivalent of seven Early Treatment Diabetic Retinopathy Study (ETDRS) letters, compared with people treated with PDT (95% confidence interval (CI) -0.20 to -0.08, 3 RCTs, 263 people, low-certainty evidence). The RR for proportion of participants gaining 3+ lines of VA was 1.86 (95% CI 1.27 to 2.73, 2 RCTs, 226 people, moderate-certainty evidence). At two years, the mean VA in people treated with anti-VEGFs was -0.26 logMAR better, equivalent of 13 ETDRS letters, compared with people treated with PDT (95% CI -0.38 to -0.14, 2 RCTs, 92 people, low-certainty evidence). The RR for proportion of people gaining 3+ lines of VA at two years was 3.43 (95% CI 1.37 to 8.56, 2 RCTs, 92 people, low-certainty evidence). People treated with anti-VEGFs showed no obvious reduction (improvement) in central retinal thickness at one year compared with people treated with PDT (MD -17.84 μm, 95% CI -41.98 to 6.30, 2 RCTs, 226 people, moderate-certainty evidence). There was low-certainty evidence that people treated with anti-VEGF were more likely to have CNV angiographic closure at 1 year (RR 1.24, 95% CI 0.99 to 1.54, 2 RCTs, 208 people). One study allowed ranibizumab treatment as of month 3 in participants randomised to PDT, which may have led to an underestimate of the benefits of anti-VEGF treatment.When compared with laser photocoagulation, there was more improvement in VA among bevacizumab-treated people than among laser-treated people after one year (MD -0.22 logMAR, equivalent of 11 ETDRS letters, 95% CI -0.43 to -0.01, 1 RCT, 36 people, low-certainty evidence) and after two years (MD -0.29 logMAR, equivalent of 14 ETDRS letters, 95% CI -0.50 to -0.08, 1 RCT, 36 people, low-certainty evidence).When compared with sham treatment, people treated with aflibercept had better vision at one year (MD -0.19 logMAR, equivalent of 9 ETDRS letters, 95% CI -0.27 to -0.12, 1 RCT, 121 people, moderate-certainty evidence). The fact that this study allowed for aflibercept treatment at 6 months in the control group might cause an underestimation of the benefit with anti-VEGF.People treated with ranibizumab had similar improvement in VA recovery compared with people treated with bevacizumab after one year (MD -0.02 logMAR, equivalent of 1 ETDRS letter, 95% CI -0.11 to 0.06, 2 RCTs, 80 people, moderate-certainty evidence).Of the included six studies, two studies reported no adverse events in either group and two industry-sponsored studies reported both systemic and ocular adverse events. In the control group, there were no systemic or ocular adverse events reported in 149 participants. Fifteen people reported systemic serious adverse events among 359 people treated with anti-VEGF agents (15/359, 4.2%). Five people reported ocular adverse events among 359 people treated with anti-VEGF agents (5/359, 1.4%). The number of adverse events was low, and the estimate of RR was uncertain regarding systemic serious adverse events (4 RCTs, 15 events in 508 people, RR 4.50, 95% CI 0.60 to 33.99, very low-certainty evidence) and serious ocular adverse events (4 RCTs, 5 events in 508 people, RR 1.82, 95% CI 0.23 to 14.71, very low-certainty evidence). There were no reports of mortality or cases of endophthalmitis or retinal detachment.There was sparse reporting of data for vision-related quality of life (in favour of anti-VEGF) in only one trial at one year of follow-up. The studies did not report data for other outcomes, such as percentage of participants with newly developed chorioretinal atrophy.
AUTHORS' CONCLUSIONS
There is low to moderate-certainty evidence from RCTs for the efficacy of anti-VEGF agents to treat mCNV at one year and two years. Moderate-certainty evidence suggests ranibizumab and bevacizumab are equivalent in terms of efficacy. Adverse effects occurred rarely and the trials included here were underpowered to assess these. Future research should be focused on the efficacy and safety of different drugs and treatment regimens, the efficacy on different location of mCNV, as well as the effects on practice in the real world.
Topics: Angiogenesis Inhibitors; Bevacizumab; Choroidal Neovascularization; Humans; Laser Coagulation; Macula Lutea; Myopia, Degenerative; Photochemotherapy; Photosensitizing Agents; Porphyrins; Randomized Controlled Trials as Topic; Ranibizumab; Receptors, Vascular Endothelial Growth Factor; Recombinant Fusion Proteins; Vascular Endothelial Growth Factor A; Verteporfin
PubMed: 27977064
DOI: 10.1002/14651858.CD011160.pub2 -
Advances and Technical Standards in... 2016The current first-line treatment of malignant gliomas consists in surgical resection (if possible) as large as possible. The existing tools don't permit to identify the... (Review)
Review
The current first-line treatment of malignant gliomas consists in surgical resection (if possible) as large as possible. The existing tools don't permit to identify the limits of tumor infiltration, which goes beyond the zone of contrast enhancement on MRI. The fluorescence-guided malignant gliomas surgery was started 15 years ago and had become a standard of care in many countries. The technique is based on fluorescent molecule revelation using the filters, positioned within the surgical microscope. The fluorophore, protoporphyrin IX (PpIX), is converted in tumoral cells from 5-aminolevulinic acid (5-ALA), given orally before surgery. Many studies have shown that the ratio of gross total resections was higher if the fluorescence technique was used. The fluorescence signal intensity is correlated to the cell density and the PpIX concentration. The current method has a very high specificity but still lower sensibility, particularly regarding the zones with poor tumoral infiltration. This book reviews the principles of the technique and the results (extent of resection and survival).
Topics: Aminolevulinic Acid; Brain; Brain Neoplasms; Fluorescence; Glioblastoma; Humans; Microscopy, Fluorescence; Microsurgery; Neoplasm Grading; Neoplasm, Residual; Neuronavigation; Protoporphyrins; Sensitivity and Specificity; Statistics as Topic; Surgery, Computer-Assisted
PubMed: 26508406
DOI: 10.1007/978-3-319-21359-0_3 -
Retina (Philadelphia, Pa.) Aug 2015To evaluate the 3-year outcome in eyes with polypoidal choroidal vasculopathy (PCV) treated with photodynamic therapy with verteporfin. (Meta-Analysis)
Meta-Analysis Review
PURPOSE
To evaluate the 3-year outcome in eyes with polypoidal choroidal vasculopathy (PCV) treated with photodynamic therapy with verteporfin.
METHODS
Retrospective study and review of the literature. We performed a retrospective study of patients with PCV who were treated with photodynamic therapy between January 2007 and December 2008. Patients were excluded if they had received photodynamic therapy before the study period, but those who received previous treatment with other modalities (thermal laser or intravitreal therapies) were allowed. The main outcome measures were best-corrected visual acuity, repeat photodynamic therapy, and recurrence of PCV at the end of Years 1, 2, and 3. We further conducted a systematic review of the literature using the terms "polypoidal choroidal vasculopathy" and "photodynamic therapy" and compared the visual outcome of studies over 3 years using meta-analytical methods.
RESULTS
The retrospective study included 68 eyes. The mean best-corrected visual acuity was 0.73 ± 0.56 logMAR (20/107, Snellen equivalent) at baseline, 0.73 ± 0.70 logMAR (20/107, Snellen equivalent) at 1 year, 0.96 ± 0.76 logMAR (20/182, Snellen equivalent) at 2 years, and 1.07 ± 0.81 logMAR (20/235, Snellen equivalent) at 3 years. The cumulative recurrence rates of PCV were 16.1% (1 year), 34.9% (2 years), and 52.7% (3 years) and eyes with recurrence were more likely to suffer ≥3 lines loss compared with eyes without recurrence (63.2 vs. 17.6%, P = 0.006). The systematic review summarized results from 48 published studies and our retrospective study. The pooled analysis from 29 studies (316 eyes reporting the 3-year visual outcome) reported mean best-corrected visual acuity improvement of 0.115 logMAR at 1 year (n = 1,669), 0.066 logMAR at 2 years (n = 701), and 0.027 logMAR at 3 years (n = 316). Reported recurrence rates were 5.9% to 50.0% after 1 year, 9.1% to 83.3% after 2 years, and 40.0% to 78.6% after 3 years or longer of follow-up.
CONCLUSION
The visual outcome in eyes with PCV was stable until 2 years, but the outcome at 3 years worsened, particularly in eyes that experienced recurrence.
Topics: Adult; Aged; Aged, 80 and over; Choroidal Neovascularization; Female; Follow-Up Studies; Humans; Male; Middle Aged; Photochemotherapy; Photosensitizing Agents; Polyps; Porphyrins; Prognosis; Retrospective Studies; Risk Factors; Ultraviolet Rays; Verteporfin; Visual Acuity; Wet Macular Degeneration
PubMed: 25719986
DOI: 10.1097/IAE.0000000000000499 -
The Cochrane Database of Systematic... Aug 2014Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Age-related macular degeneration (AMD) is the most common cause of uncorrectable severe vision loss in people aged 55 years and older in the developed world. Choroidal neovascularization (CNV) secondary to neovascular AMD accounts for most AMD-related severe vision loss. Anti-vascular endothelial growth factor (anti-VEGF) agents, injected intravitreally, aim to block the growth of abnormal blood vessels in the eye to prevent vision loss and, in some instances, improve vision.
OBJECTIVES
To investigate: (1) the ocular and systemic effects of, and quality of life associated with, intravitreally injected anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) for the treatment of neovascular AMD compared with no anti-VEGF treatment; and (2) the relative effects of one anti-VEGF agent compared with another when administered in comparable dosages and regimens.
SEARCH METHODS
We searched Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to March 2014), EMBASE (January 1980 to March 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to March 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We used no date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 27 March 2014.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) that evaluated pegaptanib, ranibizumab, or bevacizumab versus each other or a control treatment (e.g., sham treatment or photodynamic therapy). All trials followed participants for at least one year.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened records, extracted data, and assessed risks of bias. We contacted trial authors for additional data. We analyzed outcomes as risk ratios (RRs) or mean differences (MDs). We used the standard methodological procedures expected by The Cochrane Collaboration.
MAIN RESULTS
We included 12 RCTs including a total of 5496 participants with neovascular AMD (the number of participants per trial ranged from 28 to 1208). One trial compared pegaptanib, three trials ranibizumab, and two trials bevacizumab versus controls; six trials compared bevacizumab with ranibizumab. Four trials were conducted by pharmaceutical companies; none of the eight studies which evaluated bevacizumab were funded by pharmaceutical companies. The trials were conducted at various centers across five continents (North and South America, Europe, Asia and Australia). The overall quality of the evidence was very good, with most trials having an overall low risk of bias.When compared with control treatments, participants who received any of the three anti-VEGF agents were more likely to have gained 15 letters or more of visual acuity, lost fewer than 15 letters of visual acuity, and had vision 20/200 or better after one year of follow up. Visual acuity outcomes after bevacizumab and ranibizumab were similar when the same regimens were compared in the same RCTs, despite the substantially lower cost for bevacizumab compared with ranibizumab. No trial directly compared pegaptanib with other anti-VEGF agents; however, when compared with controls, ranibizumab or bevacizumab yielded larger improvements in visual acuity outcomes than pegaptanib.Participants treated with anti-VEGFs showed improvements in morphologic outcomes (e.g., size of CNV or central retinal thickness) compared with participants not treated with anti-VEGF agents. There was less reduction in central retinal thickness among bevacizumab-treated participants than among ranibizumab-treated participants after one year (MD -13.97 μm; 95% confidence interval (CI) -26.52 to -1.41); however, this difference is within the range of measurement error and we did not interpret it as being clinically meaningful.Ocular inflammation and increased intraocular pressure after intravitreal injection were the most frequently reported serious ocular adverse events. Endophthalmitis was reported in fewer than 1% of anti-VEGF treated participants; no cases were reported in control groups. The occurrence of serious systemic adverse events was comparable across anti-VEGF-treated groups and control groups; however, the numbers of events and trial participants may have been insufficient to detect a meaningful difference between groups. Data for visual function, quality of life, and economic outcomes were sparsely measured and reported.
AUTHORS' CONCLUSIONS
The results of this review indicate the effectiveness of anti-VEGF agents (pegaptanib, ranibizumab, and bevacizumab) in terms of maintaining visual acuity; ranibizumab and bevacizumab were also shown to improve visual acuity. The information available on the adverse effects of each medication do not suggest a higher incidence of potentially vision-threatening complications with intravitreal injection compared with control interventions; however, clinical trial sample sizes may not have been sufficient to detect rare safety outcomes. Research evaluating variable dosing regimens with anti-VEGF agents, effects of long-term use, combination therapies (e.g., anti-VEGF treatment plus photodynamic therapy), and other methods of delivering the agents should be incorporated into future Cochrane reviews.
Topics: Aged; Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Aptamers, Nucleotide; Choroidal Neovascularization; Humans; Intravitreal Injections; Macular Degeneration; Middle Aged; Porphyrins; Randomized Controlled Trials as Topic; Ranibizumab; Vascular Endothelial Growth Factor A; Verteporfin; Visual Acuity
PubMed: 25170575
DOI: 10.1002/14651858.CD005139.pub3