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Occupational polycyclic aromatic hydrocarbon exposure and risk of larynx cancer: a systematic
review and meta-analysis.
Exposition professionnelle aux hydrocarbures aromatiques polycycliques et risque de cancer du larynx:
une revue systématique et méta-analyse.
Wagner M et al., Occup Environ Med. 2015 Mar
Polycyclic aromatic hydrocarbons (PAH) are genotoxic substances formed during combustion. Occupational
PAH exposure has been shown to increase the risk of lung cancer and may be associated with other respiratory
cancers. We conducted a systematic review and meta-analysis to clarify the relationship between occupational
PAH exposures and larynx malignancies. We searched EMBASE and MEDLINE (until July 2014) using a series
of search strings developed to seek case-control studies or longitudinal studies of workers (Population) exposed
to PAHs (Exposure) and their risk for larynx cancer incidence and/or mortality (Outcome). Two independent
reviewers screened the titles and abstracts for eligible articles and a third reviewer negotiated consensus. Further
assessments of eligibility and sources of bias were conducted in a similar manner. The study results were pooled
with random effects meta-analysis. The search resulted in 3377 records. The data of 92 full-text articles
representing 63 studies were included and extracted. The majority of studies (n=47) was judged likely to be
biased; only 16 studies were judged as methodologically adequate. The pooled effect size was 1.45 (95% CI 1.30
to 1.62; I(2)=30.7%; [Formula: see text]=0.03) for larynx cancer incidence and 1.34 (95% CI 1.18 to 1.53;
I(2)=23.8%; [Formula: see text]=0.03) for larynx cancer mortality. While few studies allowed an investigation of
dose-response, these indicate a positive dose-response effect. Although most studies may underestimate the true
effect due to inexact approximations of PAH exposure, the meta-analysis suggests a robust positive association
between PAH and larynx cancer.
Dairy consumption and gastric cancer risk: a meta-analysis of epidemiological studies.
Consommation de produits laitiers et risque de cancer gastrique: une méta-analyse d'études
épidémiologiques
Guo Y et al., Nutr Cancer. 2015 May-Jun
Studies investigating the association of dairy consumption with gastric cancer risk have reported inconsistent
findings. We conducted this systematic review and meta-analysis to review and summarize the epidemiologic
evidence on the relation of total dairy and milk consumption with risk of gastric cancer. We summarized the
available literature on this topic using meta-analysis of relative risks (RR) associated with total dairy and milk
intake. The total of 17 case-control and 6 cohort studies (3256 cases) were eligible for inclusion. When
comparing the highest with the lowest category of total dairy intake, the results of cohort studies indicated that
increased consumption of total dairy food was associated with a reduced risk of gastric cancer (RR = 0.76; 95%
CI: 0.64-0.91), whereas case-control studies provided no association. In subgroup analysis, significantly inverse
associations between total diary food consumption and gastric cancer risk were observed in Europe subgroup
(RR = 0.73; 95% CI: 0.54-0.99), U.S. subgroup (RR = 0.78; 95% CI: 0.63-0.98) but not in Asia subgroup.
However, milk consumption was not associated with gastric cancer risk no matter in main or subgroup analysis.
The results of cohort studies, but not case-control studies, suggested that total dairy might be related to the
reduction of gastric cancer risk. Milk consumption was not associated with gastric cancer risk.