Opium use and risk of colorectal cancer: a multi-center case-referent study in Iran.

BACKGROUND: Opium use has been associated with an increased risk of cancers of the lung, oesophagus, and pancreas, and it was recently classified by the International Agency for Cancer Research as carcinogenic to humans. It is not clear whether opium also increases the risk of colorectal cancer (CRC). The aim of our study was to assess the association between various metrics of opium use and the risk of CRC. METHODS: This case-referent study from seven provinces in Iran comprised 848 CRC cases and 3215 referents. Data on opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure odds ratios (OR) adjusted for age, gender, province, marital status, family history of CRC-linked cancers, consumption of red meat, fruits and vegetables, body shape, occupational physical activity, and socioeconomic status. RESULTS: Regular opium consumption was not associated with the risk of CRC (OR 0.9, 95% confidence interval, CI: 0.7, 1.2) compared to subjects who never used opium. However, frequent opium use more than twice a day was associated with an increased risk of CRC compared to non-users of opium (OR: 2.0, 95% CI: 1.1, 3.8; p for quadratic trend 0.008). CONCLUSION: There seems to be no overall association between opium use and CRC, but the risk of CRC might be increased among persons who use opium many times a day.

Population attributable proportion and number of cancer cases attributed to potentially modifiable risk factors in Iran in 2020.

In the current study, we aimed to calculate the fraction of cancer attributable to modifiable risk factors in Iran in 2020. Population attributable fractions (PAFs) were calculated for established cancer risk factors using three data sources: the national cancer incidence reports, relative risks extracted from global and national meta-analyses, and exposure prevalence from national/subnational population-based surveys. In addition to overall cancers, the PAFs were estimated separately for each cancer site among men and women. Overall, 32.6% of cancers in 2020 in Iran were attributable to known risk factors. The PAF in men (40.2%) was twice as high as in women (21.1%). Cigarette smoking (15.4%), being overweight (5.0%), opium use (3.9%) and H. pylori infection (3.8%) were the leading causes of cancers. For men, the highest PAFs belonged to cigarette smoking (26.3%), opium use (6.8%) and being overweight (3.1%), while for women, the highest PAFs belonged to being overweight (7.2%), H. pylori infection (2.7%) and cigarette smoking (2.7%). Among Iranian men and women, the PAFs of waterpipe smoking were 2% and 0.9%, respectively. A third of incident cancers in Iran are due to modifiable exposures, mainly cigarette smoking, being overweight, and H. pylori infection. Opium consumption and waterpipe smoking collectively accounted for 8.8% of cancer occurrence in men and 1.3% in women in Iran. These emerging risk factors should be taken into consideration in future PAF studies.

Bladder cancer risk in relation to occupations held in a nationwide case-control study in Iran.

Globally, bladder cancer has been identified as one of the most frequent occupational cancers, but our understanding of occupational bladder cancer risk in Iran is less advanced. This study aimed to assess the risk of bladder cancer in relation to occupation in Iran. We used the IROPICAN case-control study data including 717 incident cases and 3477 controls. We assessed the risk of bladder cancer in relation to ever working in major groups of the International Standard Classification of Occupations (ISCO-68) while controlling for cigarette smoking, opium consumption. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI). In men, decreased ORs for bladder cancer were observed in administrative and managerial workers (OR 0.4; CI: 0.2, 0.9), and clerks (OR 0.6; CI: 0.4, 0.9). Elevated ORs were observed in metal processors (OR 5.4; CI: 1.3, 23.4), and workers in occupations with likely exposure to aromatic amines (OR 2.2; CI: 1.2, 4.0). There was no evidence of interactions between working in aromatic amines-exposed occupations and tobacco smoking or opium use. Elevated risk of bladder cancer in men in metal processors and workers likely exposed to aromatic amines aligns with associations observed outside Iran. Other previously confirmed associations between high-risk occupations and bladder cancer were not observed, possibly due to small numbers or lack of details on exposure. Future epidemiological studies in Iran would benefit from the development of exposure assessment tools such as job exposure matrices, generally applicable for retrospective exposure assessment in epidemiological studies.

The carcinogenicity of opium consumption: a systematic review and meta-analysis.

The carcinogenicity of opium consumption was recently evaluated by a Working Group convened by the International Agency for Research on Cancer (IARC). We supplement the recent IARC evaluation by conducting an extended systematic review as well as a quantitative meta-analytic assessment of the role of opium consumption and risk for selected cancers, evaluating in detail various aspects of study quality on meta-analytic findings. We searched the published literature to identify all relevant studies on opium consumption and risk of selected cancers in humans through 31 October, 2022. Meta-relative risks (mRRs) and associated 95% confidence intervals (CIs) were estimated using random-effects models for studies of cancer of the urinary bladder, larynx, lung, oesophagus, pancreas, and stomach. Heterogeneity among studies was assessed using the I2 statistic. We assessed study quality and conducted sensitivity analyses to evaluate the impact of potential reverse causation, protopathic bias, selection bias, information bias, and confounding. In total, 2 prospective cohort studies and 33 case-control studies were included. The overall pooled mRR estimated for 'ever or regular' versus 'never' use of opium ranged from 1.50 (95% CI 1.13-1.99, I2 = 0%, 6 studies) for oesophageal cancer to 7.97 (95% CI 4.79-13.3, I2 = 62%, 7 studies) for laryngeal cancer. Analyses of cumulative opium exposure suggested greater risk of cancer associated with higher opium consumption. Findings were robust in sensitivity analyses excluding studies prone to potential methodological sources of biases and confounding. Findings support an adverse association between opium consumption and cancers of the urinary bladder, larynx, lung, oesophagus, pancreas and stomach.

Opium use and risk of lung cancer: A multicenter case-control study in Iran.

Opium use was recently classified as a human carcinogen for lung cancer by the International Agency for Research on Cancer. We conducted a large, multicenter case-control study evaluating the association between opium use and the risk of lung cancer. We recruited 627 cases and 3477 controls from May 2017 to July 2020. We used unconditional logistic regression analyses to estimate the odds ratios (OR) and 95% confidence intervals (CI) and measured the association between opium use and the risk of lung cancer. The ORs were adjusted for the residential place, age, gender, socioeconomic status, cigarettes, and water pipe smoking. We found a 3.6-fold risk of lung cancer for regular opium users compared to never users (95% CI: 2.9, 4.6). There was a strong dose-response association between a cumulative count of opium use and lung cancer risk. The OR for regular opium use was higher for small cell carcinoma than in other histology (8.3, 95% CI: 4.8, 14.4). The OR of developing lung cancer among opium users was higher in females (7.4, 95% CI: 3.8, 14.5) than in males (3.3, 95% CI: 2.6, 4.2). The OR for users of both opium and tobacco was 13.4 (95% CI: 10.2, 17.7) compared to nonusers of anything. The risk of developing lung cancer is higher in regular opium users, and these results strengthen the conclusions on the carcinogenicity of opium. The association is stronger for small cell carcinoma cases than in other histology.

Lung cancer risk in relation to jobs held in a nationwide case-control study in Iran.

BACKGROUND: Globally, lung cancer is the most frequent occupational cancer, but the risk associated with the occupations or occupational environment in Iran is not clear. We aimed to assess occupations with the risk of lung cancer. METHODS: We used the IROPICAN nationwide case-control study data including 658 incident lung cancer cases and 3477 controls. We assessed the risk of lung cancer in relation to ever working in major groups of International Standard Classification of Occupations, high-risk occupations for lung cancer and duration of employment and lung cancer subtype among construction workers and farmers while controlling for cigarette smoking and opium consumption. We used unconditional regression logistic models to estimate ORs for the association between increased lung cancer risk and occupations. RESULTS: We observed elevated ORs for lung cancer in male construction workers (OR=1.4; 95% CI: 1.0 to 1.8), petroleum industry workers (OR=3.2; 95% CI: 1.1 to 9.8), female farmers (OR=2.6; 95% CI: 1.3 to 5.3) and female bakers (OR=5.5; 95% CI: 1.0 to 29.8). A positive trend by the duration of employment was observed for male construction workers (p< 0.001). Increased risk of squamous cell carcinoma was observed in male construction workers (OR=1.9; 95% CI: 1.2 to 3.0) and female farmers (OR=4.3; 95% CI: 1.1 to 17.2), who also experienced an increased risk of adenocarcinoma (OR=3.8; 95% CI: 1.4 to 9.9). DISCUSSION: Although we observed associations between some occupations and lung cancer consistent with the literature, further studies with larger samples focusing on exposures are needed to better understand the occupational lung cancer burden in Iran.

Opium use and risk of bladder cancer: a multi-centre case-referent study in Iran.

BACKGROUND: Bladder cancer (BC) is the 10th most common type of cancer worldwide and the fourth most common type of cancer in Iran. Opium use is considered as one of the risk factors for BC. We aim to assess the association between various parameters of opium use, which in Iran is mainly ingested or smoked in various forms, and the risk of BC. METHOD: In this multi-centre case-referent study in Iran, 717 BC cases and 3477 referents were recruited to the study from May 2017 until July 2020. Detailed histories of opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure adjusted odds ratio (OR) and 95% confidence intervals (CI). The ORs were adjusted for age, gender, place of residence and pack-years of cigarette smoking. RESULTS: Regular opium consumption was associated with an increased risk of BC (OR 3.5, 95% CI: 2.8, 4.3) compared with subjects who never used opium. Compared with continuous users, the risk decreased to one-third for those who stopped opium more than 10 years ago. The adjusted OR for those who used both crude opium (teriak) and opium juice was 7.4 (95% CI: 4.1, 13.3). There was a joint effect of opium and tobacco (OR for users of both opium and tobacco 7.7, 95% CI: 6.0, 9.7). CONCLUSIONS: Regular opium use is associated with an approximately 4-fold risk for BC. The OR decreases along with the increasing time since stopping opium use.

Occupational Exposure to Carcinogens and Occupational Epidemiological Cancer Studies in Iran: A Review.

INTRODUCTION: The extent of exposure to occupational carcinogens is not well characterized in Iran, and little is known about the burden of occupational cancer. OBJECTIVES: This study aimed to describe exposure to occupational carcinogens and occupational epidemiology studies in Iran. METHODS: Relevant studies up to January 2021 in Iran were identified through three databases (PubMed, Web of Science, and Google Scholar). RESULTS: Forty-nine publications from 2009 to 2020 (one cohort, 11 case-control, 34 exposure monitoring studies, and three cancer burden studies) were included. The exposure monitoring studies were conducted mainly in the petroleum industry, metal industry, manufacturing of electronics, manufacturing of plastics, construction industry, and service industry. A few of the case-control studies also reported increased risk of cancers in relation to work in those industries. CONCLUSIONS: Occupational cancer epidemiology in Iran is at an early stage. Both epidemiological and exposure monitoring studies are generally limited in size to provide robust evidence of occupational cancer risks. A coherent strategy to estimate the occupational cancer burden in Iran should start with conducting epidemiological studies along with systematic monitoring of occupational carcinogens for use in hazard control and research.

Cancer Incidence and Mortality among Petroleum Industry Workers and Residents Living in Oil Producing Communities: A Systematic Review and Meta-Analysis.

Petroleum extraction and refining are major sources of various occupational exposures and of air pollution and may therefore contribute to the global cancer burden. This systematic review and meta-analysis is aimed at evaluating the cancer risk in petroleum-exposed workers and in residents living near petroleum facilities. Relevant studies were identified and retrieved through PubMed and Web of Science databases. Summary effect size (ES) and 95% confidence intervals (CI) were analysed using random effect models, and heterogeneity across studies was assessed (I2). Overall, petroleum industry work was associated with an increased risk of mesothelioma (ES = 2.09, CI: 1.58-2.76), skin melanoma (ES = 1.34, CI: 1.06-1.70 multiple myeloma (ES =1.81, CI: 1.28-2.55), and cancers of the prostate (ES = 1.13, Cl: 1.05-1.22) and urinary bladder (ES = 1.25, CI: 1.09-1.43) and a decreased risk of cancers of the esophagus, stomach, colon, rectum, and pancreas. Offshore petroleum work was associated with an increased risk of lung cancer (ES = 1.20; 95% CI: 1.03-1.39) and leukemia (ES = 1.47; 95% CI: 1.12-1.92) in stratified analysis. Residential proximity to petroleum facilities was associated with childhood leukemia (ES = 1.90, CI: 1.34-2.70). Very few studies examined specific exposures among petroleum industry workers or residents living in oil producing communities. The present review warrants further studies on specific exposure levels and pathways among petroleum-exposed workers and residents living near petroleum facilities.

The Iranian Study of Opium and Cancer (IROPICAN): Rationale, Design, and Initial Findings.

BACKGROUND: The International Agency for Research on Cancer (IARC) recently classified opium use as a Group 1 carcinogen. However, much remains to be studied on the relation between opium and cancer. We designed the Iranian Opium and Cancer (IROPICAN) study to further investigate the association of opium use and cancers of the head and neck, bladder, lung, and colon and rectum. In this paper, we describe the rationale, design, and some initial results of the IROPICAN Study. METHODS: The IROPICAN is a multi-center case-control study conducted in 10 provinces of Iran. The cases were all histologically confirmed and the controls were selected from hospital visitors who were free of cancer, were not family members or friends of the cancer patients, and were visiting the hospital for reasons other than their own ailment. The questionnaires included detailed questions on opium use (including age at initiation, duration, frequency, typical amount, and route), and potential confounders, such as tobacco use (e.g., cigarettes, nass and water-pipe), and dietary factors. Biological samples, including blood and saliva, were also collected. RESULTS: The validation and pilot phases showed reasonably good validity, with sensitivities of 70% and 69% for the cases and controls, respectively, in reporting opium use. The results also showed excellent reliability, with intra-class correlation coefficients of 0.96 for ever opium use and 0.88 (95% CI: 0.80, 0.92) for regular opium use. In the main phase, we recruited 3299 cancer cases (99% response rate) and 3477 hospital visitor controls (89% response rate). The proportion of ever-use of opium was 40% among cases and 18% among controls. CONCLUSION: The IROPICAN study will serve as a major resource in studies addressing the effect of opium on risk of cancers of the head and neck, bladder, lung, and colon and rectum.

Opium use and the risk of head and neck squamous cell carcinoma.

Scant evidence exists to support the association of opium use with head and neck cancer, limited to the larynx and oral cavity. In a multicenter case-control study-Iran Opium and Cancer study, we recruited 633 cases of head and neck squamous cell carcinoma (HNSCC) (254 lip and oral cavity, 54 pharynx, 327 larynx and 28 other subsites within the head and neck) and 3065 frequency-matched controls from April 2016 to April 2019. Odds ratios (ORs) for opium use and 95% confidence intervals (95% CIs) were obtained using mixed-effects logistic regression because of heterogeneity among centers. The adjusted OR (95% CI) for regular opium use was 3.76 (2.96-4.79) for all HNSCC combined. Strong dose-response effects were observed by frequency or amount of use, and duration of use. Regular opium uses significantly increased the risk of HNSCC of the pharynx, larynx and other subsites within the head and neck with OR (95% CI) of 2.90 (1.40-6.02), 6.55 (4.69-9.13) and 5.95 (2.41-14.71), respectively. The observed associations were significant even among never tobacco smokers (including cigarette and water-pipe smoking). Moreover, by the multiplicative interaction scale, the effect of opium use could be varied by cigarette smoking on HNSCC, 8.16 (6.20-10.74). For the first time, the current study showed opium users have an increased risk of several anatomic subsites of HNSCC.

Patterns of platinum drug use in an acute care setting: a retrospective study.

PURPOSE: Platinum drugs have been in use in cancer treatment for more than 40 years, but little is known about the pattern of their use. The aim of this study was to examine the patterns of platinum drug use, with a secondary aim to describe the occurrence of dose reductions. METHODS: A retrospective analysis was conducted of oncology pharmacy dispensing records from a single hospital in Australia. Data related to drug choice, regimen and dose reductions were included in this study if the patient had received their last round of chemotherapy between November 2014 and July 2015. RESULTS: Of the 156 patients included in the study, 46% were dispensed a platinum drug during their treatment. The most commonly dispensed drugs were cisplatin (40%), carboplatin (40%) and oxaliplatin (15%), while some patients (5%) received more than one platinum drug. Dose reductions were more common in patients who were treated with a platinum drug (73%) compared with patients treated with non-platinum drugs (55%). The most common reason for a dose reduction was cytopenia. CONCLUSIONS: The findings suggest that platinum drugs remain one of the most commonly dispensed drugs to treat cancer patients and most patients receive a dose reduction during treatment.

Metabolic Syndrome Is Associated with Health-Related Quality of Life in Suspected Patients with Nonalcoholic Steatohepatitis.

OBJECTIVE: This study was designed to examine the effect of metabolic syndrome (MetS) on health-related quality of life (HRQOL) in patients with suspected nonalcoholic steatohepatitis (NASH). SUBJECTS AND METHODS: Three hundred thirty-two patients (236 males and 96 females) with suspected NASH from the Amol cohort study were included in this study. MetS was diagnosed based on Adult Treatment Panel III criteria and HRQOL was measured using the 12-Item Short-Form Health Survey (SF-12) questionnaire (with 8 subscales and 2 summary components). A multivariable linear regression model was used to assess the independent effect of MetS on HRQOL. RESULTS: The mean age of the study population was 42 ± 13 years (range 18-82). The prevalence of MetS was 43.4% (n = 144) and the mean scores on the Physical Component Summary (PCS) and the Mental Component Summary were 72.4 ± 20.86 and 42.7 ± 12.42, respectively. The multivariable linear regression model showed that MetS was negatively associated with 4 subscales of HRQOL that included: role limitations due to physical problems (RP) (B = -14.05, p = 0.004), bodily pain (BP) (B = -7.37, p = 0.02), vitality (VT) (B = -7.72, p = 0.022), and role limitations due to emotional problems (RE) (B = -12.67, p = 0.005) after adjustment for other variables. Also, MetS had a borderline association with the general health and mental health subscales and the PCS (p < 0.1). CONCLUSION: In this study, there was a strong association between MetS and 4 subscales (RP, BP, VT, and RE) of HRQOL in patients with suspected NASH; this could be considered as a part of health policy to improve general health.

Response shift in quality of life assessment among cancer patients: A study from Iran.

Background: During the course of disease, particularly of chronic diseases, changes in internal standards cause certain changes in the estimation of quality of life (QOL). These changes indicate the phenomenon of 'response shift'. The present study aimed at assessing response shift in different scales of QOL in Iranian cancer patients. Methods: To assess response shift through the 'then test' approach, we asked 211 cancer patients to complete the EORTC QLQ-C30 questionnaire at pretest (at the beginning of the study), posttest (3 months later), and then test (administered immediately after the posttest). Paired t test and Cohen's effect size were used for comparison. Results: Response shift was significant in all 4 scales under study, i.e. fatigue, pain, emotional functioning, and general QOL (p<0.001). Fatigue, pain, and global QOL have deteriorated significantly with then test approach and emotional function was significantly improved. Conclusion: We observed a response shift in Iranian cancer patients in our study. Thus, in light of the multifactorial nature of QOL and the effect of the response shift bias on different aspects of QOL changes, it is of utmost importance to keep this bias in mind when interpreting the results and managing cancer patients' treatment regimens.

Emotional Intelligence: A Comparison between Medical and Non-Medical Students.

BACKGROUND: Emotional intelligence (EI) has recently been considered as one of the necessary elements for success and achievement in medical fields. The present study was conducted in Iran to compare the EI in medical and non-medical students adjusted for the other relevant factors. METHODS: This cross-sectional study was conducted from October 2011 to January 2012 on 872 students of medicine, paramedical and non-medical groups in Tehran University and Tehran University of Medical Sciences, Tehran, Iran selected by multi-stage weighted cluster sampling. The Farsi version of revised Schutte Emotional Intelligence (FEIS) was used to estimate emotional intelligence. RESULTS: The mean of total EI was equal to 124.9 (SD=8.4) out of 205 and the means for its dimensions were as follows: regulation of emotions 39.3 (SD=5.1), utilization of emotions 26.7 (SD=3.6) and appraisal of emotions 33.5 (SD=5.3). While the paramedical and non-medical students' total EI score was significantly higher than the medical students', in the utilization of emotions dimension, the medical students scored significantly higher than the other two groups. CONCLUSION: The lower levels of the medical students' total EI score in comparison with paramedical and non-medical students in this study demands the relevant authorities to pay even more attention to the selection and training of medical students.