Background. Epidemiological studies have reported inconsistent associations between opium use and cancer risk. We therefore conducted a systematic review and meta-analysis to investigate the relationship between opium use and cancer risk. Methods. We searched PubMed, Scopus, ISI Web of Knowledge, and Google Scholar until February 2021 and references of retrieved relevant articles for observational studies that reported the risk of cancer in relation to opium use. Random-effects models were used to calculate pooled effect sizes (ESs) as well as 95% confidence intervals (CIs) for the association between opium use and cancer risk by considering opium doses and types, duration of consumption, and routes of opium use. Results. In total, 21 observational articles, with a total sample size of 64,412 individuals and 6,658 cases of cancer, were included in this systematic review and meta-analysis. Ever opium users, compared with never opium users, had 3.53 times greater risk of overall cancer (pooled ES: 3.53, 95% CI: 2.60–4.79, P  ≤ 0.01). This positive association was also seen for some individual types of cancers except for esophageal and colon cancers. Also, we found that higher opium doses and higher duration of consumption were associated with an increased risk of overall and individual types of cancer. However, the associations between opium doses and the risk of head and neck and larynx cancers were not significant. In terms of the routes of opium use, both opium ingestion and smoking were positively associated with the risk of cancer. Regarding opium types, we found that using teriak, but not shireh, could increase the risk of cancer. Conclusions. Our findings showed that opium use, particularly in the form of teriak, is a risk factor for cancer.

Background Proteins are essential for the development and progression of cancer and for the human body's defense against tumor onset. The availability of a large panel of protein measurements and whole exome sequence data in the UK Biobank has enabled the simultaneous examination of plasma protein associations with risk across multiple cancer sites and their potential role in cancer etiology. Methods We investigated the associations of plasma proteins with incidence of 19 cancers and 9 cancer subsites in up to 44,645 middle-aged adults in the UK Biobank, who had measurements of 1,463 plasma proteins generated using Olink Explore Proximity Extension Assay in baseline blood samples (2006-2010). Using multivariable-adjusted Cox regression, we estimated the risk of each protein with each cancer overall and by time-to-diagnosis after correction for multiple-testing. Identified protein-cancer associations were further assessed in an analysis of cancer risk using cis-pQTL and exome-wide protein genetic scores (exGS) in all UK Biobank participants (n=337,543). Results We identified 371 proteins associated with the risk of at least one incident cancer, represented by a total of 621 protein-cancer associations. These proteins were associated with cancers of the blood (201 proteins), liver (131), kidney (51), lung (28), esophagus (22), colorectum (15), stomach (8), breast (5), prostate (3), endometrium (3), ovary (2), bladder (1), head and neck (1), and brain (1). 100 of these 621 protein-cancer associations persisted for cases diagnosed more than seven years after blood draw. Of these 621 associations, there was further support from cis-pQTL analyses for the etiological role of TNFRSF14 in risk of non-Hodgkin lymphoma (NHL), and from whole exome protein score (exGS) analyses for 28 other protein-cancer associations, including SRP14 and risk of leukemia. Proteins with directionally concordant evidence from long time-to-diagnosis analyses and from both cis-pQTL and exGS analyses were SFTPA2 for lung cancer, TNFRSF1B and CD74 for NHL, and ADAM8 for leukemia. Conclusions For the first time using an integrated multi-omics and cross-cancer approach, we have comprehensively assessed the plasma proteome in relation to cancer risk and identified multiple novel aetiological candidates. Differences in the levels of many circulating proteins were detectable more than seven years before cancer diagnosis; while some of these are likely to be markers of early cancer processes, that may inform risk stratification, and/or risk factors, concordant evidence from genetic analyses suggests that some may have a role in cancer development.

Background: Due to budget constraints, many national studies are only affordable with small sample sizes. Facing a similar constraint, the national study of “Iran Quality of Care in Medicine Program” (IQCAMP), aims to evaluate the quality and costs of medical care in the country for 8 selected high-cost high-volume diseases by only recruiting 300 participants per disease under study. We proposed and tested a data mining method to efficiently design such national studies with small sample sizes.Methods: We developed a sampling design based on hierarchical clustering method (HCM) and model-based clustering method (MCM). Based on these methods, we used healthcare structure and outcome data to define the optimum clusters of districts and provinces of Iran. An expert group checked the face validity of the defined clusters. We subsequently compared the internal validity of HCM with MCM by within clusters sum of square, average silhouette width, and Dunn index. The stability validity was also examined by statistical indices. We selected the optimum clusters based on the results of these measures. Per cluster, one province was systematically selected for data collection. The features of selected clusters were delineated by the Decision Tree Learning and the most important distinguishing indicators were identified. The efficiency of the selected sampling method was compared with a simple random sampling through simulation.Results: MCM and HCM divided the districts into eight and two clusters, respectively. The measures of internal and stability validity showed that clusters created by MCM were more separated, compact, and stable, thus forming our optimum clusters. The probability of death from stroke, chronic obstructive pulmonary disease, and in-hospital mortality rate were the most important indicators that distinguished the eight clusters. Based on the simulation results, MCM increased the efficiency of the sampling design up to 70% compared to simple random sampling.Conclusions: By using this sampling method we selected 300 participants per health condition across the country only from eight provinces rather than all 31 provinces. Our sampling method benefits studies with small sample sizes by decreasing the level of sampling variability and the overall cost of studies.

Background: The impact of socioeconomic status on cancer survival has already been proven. Early diagnosis of cancer is one of the main reason of this improved survival among High socioeconomic status (SES) people. High SES people are more likely to take part in cancer screening programs for several reason such as better access to, better cancer awareness, and the like, and it seems that diagnosis of cancer is earlier among these people. Despite growing evidence on inequality in cancer survival, diagnosis, and treatment over the past decades there is a lack of evidence on volume and direction of socioeconomic inequality regarding early diagnosis of cancer in Iran. Objectives: To assess socioeconomic inequality in colorectal cancer stage at diagnosis time in Qazvin city, Iran during 2014 - 2016. Methods: A cross-sectional study was conducted on 200 patients who were diagnosed with colorectal cancer (CRC) at the Vellayat hospital of the Qazvin city. The Principal Component Analysis (PCA) approach was used to combine household assets as a proxy of SES. Cancer staging information was extracted from the patient's medical recordsthen a pathology specialist performed cancer staging. Descriptive statistics and a multiple logistic regression model were used to illustrate an association between CRC late diagnosis and socioeconomic status adjusted for age, sex, and residence of the area. We applied the standardized Concentration Index as a measure of socioeconomic inequality in CRC late diagnosis. Results: The overall percentage of late CRC diagnosis was 40.5% (95% confidence interval (CI) 33.8, 47.5), which was slightly higher among women (47.1%, 95% CI 36.8, 57.6) than men (35.4%, 95% CI, 27.0, 44.7). Logistic regression results spotted an association between SES and the late diagnosis of CRC. In Iranian women, CRC tended to be diagnosed at more advanced stages among the third (Odds Ratio (OR) = 7.68), forth (Low) (OR = 17.86) and fifth (Lowest) (OR = 25.60) SES quintiles, while in men it was only significant for the fifth quintiles (OR = 4.17). Furthermore, the concentration index implied that late CRC diagnosis is concentrated among deprived subgroups in Qazvin city, and it was statistically significant (Overall concentration index = -0.33, 95% CI -0.38, -0.28). It was estimated at -0.35 and -0.29 in Iranian men and women, respectively. Conclusions: According to this survey, CRC tends to be diagnosed at more advanced stages among low socioeconomic status groups, and the observed discrimination is more severe in Iranian women.

Using a demolition hammer among the power tools is one of the most challenging job tasks for the operators of these tools, which exposes users to high levels of hand-transmitted vibrations. The focus of this study was for finding the vibration levels transmitted to the handles, the frequency content transmitted by the tool, and the effect of using insert bits with different tip shapes and lengths using conventional demolition hammers under controlled operating conditions on typical concrete slabs in the field. Three demolition hammers (weighing between 14 and 27 kg) with two handles installed were subjected to simultaneous measurements based on ISO 5349 as the field measurement technique. The findings demonstrated that even while the vertical axis dominated, several samples also produced equivalent x-axis results. The impact energy of the tools employed and the transmitted vibration to the tool handles are not significantly correlated with each other. All mean values were higher in the slabs with a thickness of 15 than those with 10 cm. The mean values of the total results for the two forms of flat and point tip inserted bits were 16.85 and 15.86 m/s2, respectively, and in the samples with the same operating factors, this difference was more than 3 m/s2 ( p < .03). The a wrms ( frequency-weighted root mean square acceleration) produced at tools using 60 cm bits were more than those with a length of 40 cm, both for the average of the total results and the average of the results of each hammer. The difference between the average bit length groups over samples with the same factors reached 4.65 m/s2 ( p = .02). Frequency analysis for the flat and point insert bits with 60 cm length in the concrete slabs with a thickness of 15 cm showed that the dominant frequencies detected at lower frequencies for point bits. This difference is almost two frequency parts of 1/3 octave band.