Association between waterpipe smoking and lung cancer: a multicentre case-control study in Iran

OBJECTIVES

This study investigated the association between lung cancer and waterpipe smoking, which is an emerging global public health concern.

STUDY DESIGN

Multicentre case-control study.

METHODS

This study included 627 cases and 3477 controls from the Iranian Study of Opium and Cancer (IROPICAN) study, which was conducted between 2017 and 2020. One frequency-matched control for each lung cancer patient was selected by age, gender and residential place; however, this study used controls of four cancer types in the analyses. The multivariable logistic regression model estimated the odds ratio (OR) and 95% confidence intervals (CIs). Additional analyses were performed among 181 lung cancer cases and 2141 controls who were not cigarette smokers or opium or nass/pipe users.

RESULTS

The odds of lung cancer were higher among waterpipe smokers than never-smokers (OR = 1.3, 95% CI: 1.0-1.7). Results showed a higher OR of lung cancer for those who smoked the waterpipe daily (OR = 2.1, 95% CI: 1.4-3.0), smoked more than two heads per day (OR = 2.7, 95% CI: 1.8-4.0), had smoked for >20 years (OR = 1.9, 95% CI: 1.3-2.7), smoked more than 20 head-years (OR = 2.8, 95% CI: 1.9-4.1) and initiated smoking before the age of 30 years (OR = 1.7, 95% CI: 1.1-2.5). The association was only statistically significant for squamous cell carcinomas (OR = 1.8, 95% CI 1.2-2.7). Furthermore, this study observed a higher OR of lung cancer among exclusive waterpipe smokers (OR = 2.3, 95% CI: 1.6, 3.5).

CONCLUSIONS

Waterpipe smoking was associated with an increased risk of lung cancer. The association was stronger with higher frequency, duration and intensity of exposure to waterpipe smoking. The association increases in exclusive waterpipe smokers, which is likely due to controlling for residual confounding by cigarette smoking and opium consumption, and higher exposure levels in this subpopulation.

A prospective study of tea drinking temperature and risk of esophageal squamous cell carcinoma

Previous studies have reported an association between hot tea drinking and risk of esophageal cancer, but no study has examined this association using prospectively and objectively measured tea drinking temperature. We examined the association of tea drinking temperature, measured both objectively and subjectively at study baseline, with future risk of esophageal squamous cell carcinoma (ESCC) in a prospective study. We measured tea drinking temperature using validated methods and collected data on several other tea drinking habits and potential confounders of interest at baseline in the Golestan Cohort Study, a population-based prospective study of 50,045 individuals aged 40-75 years, established in 2004-2008 in northeastern Iran. Study participants were followed-up for a median duration of 10.1 years (505,865 person-years). During 2004-2017, 317 new cases of ESCC were identified. The objectively measured tea temperature (HR 1.41, 95% CI 1.10-1.81; for ≥60°C vs. <60°C), reported preference for very hot tea drinking (HR 2.41, 95% CI 1.27-4.56; for "very hot" vs. "cold/lukewarm"), and reported shorter time from pouring tea to drinking (HR 1.51, 95% CI 1.01-2.26; for <2 vs. ≥6 min) were all associated with ESCC risk. In analysis of the combined effects of measured temperature and amount, compared to those who drank less than 700 ml of tea/day at <60°C, drinking 700 mL/day or more at a higher-temperature (≥60°C) was consistently associated with an about 90% increase in ESCC risk. Our results substantially strengthen the existing evidence supporting an association between hot beverage drinking and ESCC.

Development of New Modified Simple Polymerase Chain Reaction and Real-time Polymerase Chain Reaction for the Identification of Iranian Brucella abortus Strains

Brucellosis is primarily a worldwide zoonotic disease caused by Brucella species. The genus Brucella contains highly infectious species that are classified as biological threat agents. In this regard, the identification of Brucella can be a time-consuming and labor-intensive process posing a real risk of laboratory-acquired infection to the laboratory staff. This study aimed to present a novel conventional and real-time polymerase chain reaction (PCR) assay for the identification of Brucella abortus strains. Regarding this, two primers (bru ab2) were designed based on the unique loci encoding autotransporter-associated beta strand repeat-containing protein (ID:YP00113760). A total of 56 Brucella strains (e.g., reference, vaccinal, and field isolates) and Yersinia enterocolitica, as a non-Brucella isolate, were evaluated in conventional and real-time PCR systems. The results of the study indicated that 0.4 ng and 400 FG of genomic DNA of B. abortus strains can be detected by conventional and real-time PCR, respectively. The primers, bru ab2, were suitable for both PCR methods. Both methods were specific for the detection of all strains of the bacterium; however, real-time PCR assay was 1000-fold more sensitive than the conventional PCR method. Therefore, this new detection system could be a suitable selective modified method for the accurate identification of all B. abortus strains.

A Case of Identity Confirmation of Brucella abortus S99 by Phage Typing and PCR Methods

Brucellosis is a zoonotic infection that is associated with fever in humans and abortion in animals. The agent of this disease is a facultative intracellular gram-negative coccobacillus called Brucella. There are six classic species, including B. abortus, B. melitensis, B. suis, B. canis, B. neotomae, and B. ovis. In recent years, four new species have been reported, including Brucella ceti, B. microti, B. pinnipedialis, and B. inopinata. Human disease causes hygienic and economic losses, including inactivity of workforces in the community and high cost of treatment. The disease also causes catastrophic losses in the livestock industry. There is no effective vaccine against human brucellosis. Hence, attempts to prevent human infection with Brucella are focused on preventative measures, including control of infection in livestock, which lead to a reduction in its incidence in humans. The common methods for diagnosis of this disease are serologic methods including Rose Bengal, Wright -2 ME and the ring test. B. abortus strain S99 is used to produce these diagnostic antigens. The production of these antigens requires the presence of a well-characterized seed with full identity. The aim of this work was confirmation of the identity of B. abortus S99 by phage typing, AMOS and multiplex PCR techniques. Therefore, it is essential to carry out the identification of the strains used as seed for the production of the brucellosis diagnostic antigens. In this project, B. abortus strain 99 was supplied by the bacterial collection of the Brucellosis Department of Razi Vaccine and Serum Research Institute. Then, the main aim of the present study was the confirmation of the seed identity by doing the tests through the standard phage typing method, AMOS PCR and multiplex PCR (Brucladder) methods. Results were in support of the identity of the studied strain, and the molecular methods could also be used as the sensitive approaches for validation of antigenic seed.

International cancer seminars: a focus on esophageal squamous cell carcinoma

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.

Hypertension and mortality in the Golestan Cohort Study: A prospective study of 50 000 adults in Iran

High blood pressure has been the second most important determinant of disease burden in Iran since the 1990s. Despite well-recognized evidence on the association of high blood pressure and mortality in other countries, this relationship has not been fully investigated in the demographic setting of Iran. The current study is the first large-scale longitudinal study of this association in Iran. Briefly, 50 045 subjects between 40 and 75 years of age have been recruited and followed. Blood pressure measurements were carried out at baseline. Causes of death were reported and verified by verbal autopsy throughout the follow-up period. The outcomes of interest were all-cause deaths and deaths due to ischemic heart disease (IHD) or stroke. Cox proportional hazards regression models were used to estimate hazard ratios (HRs). A total of 46 674 subjects free from cardiovascular disease at baseline were analyzed. Absolute mortality rates increased along with increasing systolic or diastolic blood pressure above 120 and 80 mm Hg, respectively. Adjusted HRs (95% confidence intervals) for each 20 mm Hg increase in systolic blood pressure in all age groups were 1.18 (1.13-1.23) for all-cause mortality, 1.21 (1.13-1.31) for deaths due to IHD and 1.50 (1.39-1.63) for deaths due to stroke. Unadjusted and adjusted HRs were higher in younger subjects and decreased with increasing age of the participants. High blood pressure is a serious threat to the health of Iranians. The entire health-care system of Iran should be involved in a comprehensive action plan for controlling blood pressure.

Polymorphisms in EGFR and IL28B are associated with spontaneous clearance in an HCV-infected Iranian population

Although most hepatitis C virus (HCV)-infected individuals develop chronic infection, about 25% of them are able to clear the virus spontaneously without any therapeutic intervention. The aim of the present study was to identify genes associated with spontaneous HCV clearance in a population of Iranian patients. We genotyped 110 single-nucleotide polymorphisms (SNPs) in 59 selected--candidate--genes in a cohort of 107 HCV-infected participants who spontaneously cleared the infection and 176 participants whose infection persisted. Three out of the 110 SNPs were found to be associated with HCV outcome (P-values<0.03). rs11506105 in EGFR (epidermal growth factor receptor gene), and rs11881222 and rs12979860 in IL28B (interferon-λ3 gene). Multivariate logistic regression of the three markers showed that the A/A genotypes in both rs11506105 (EFGR) and rs11881222 (IL28B), and the C/C genotype in rs12979860 (IL28B) are associated with HCV clearance (recessive model: odds ratio (OR)=2.06, 95% confidence interval (95% CI)=1.09-3.88, P=0.025; OR=2.09, 95% CI=1.23-3.60, P=0.007; and OR=1.95, 95% CI=1.15-3.35, P=0.014 for rs11506105, rs12979860 and rs11881222, respectively). In conclusion, EGFR and IL28B SNPs are strong independent predictive markers of spontaneous viral clearance.

Pilot study of cytological testing for oesophageal squamous cell dysplasia in a high-risk area in Northern Iran

Background:

Oesophageal squamous cell carcinoma (ESCC) is a fatal disease with 5-year survival rates of <5% in Northern Iran. Oesophageal squamous dysplasia (ESD) is the precursor histologic lesion of ESCC. This pilot study was conducted to assess the feasibility, safety, and acceptability of non-endoscopic cytological examination of the oesophagus and to provide initial data on the accuracy of cytological atypia for identifying patients with ESD in this very-high-risk area.

Methods:

Randomly selected asymptomatic participants of the Golestan Cohort Study were recruited. A cytological specimen was taken using a capsule sponge device and evaluated for atypical cells. Sections of the cytological specimen were also stained for p53 protein. Patient acceptability was assessed using a visual analogue scale. The cytological diagnosis was compared with a chromoendoscopic examination using Lugol's solution.

Results:

Three hundred and forty-four subjects (43% male, mean (s.d.) age 55.6 (7.9) years) were referred to the study clinic. Three hundred and twelve met eligibility criteria and consented, of which 301 subjects (96.5%) completed both cytological and endoscopic examinations. There were no complications. Most of the participants (279; 92.7%) were satisfied with the examination. The sensitivity and specificity of the cytological examination for identifying subjects with high-grade ESD were 100 and 97%, respectively. We found an accuracy of 100% (95% CI=99–100%) for a combination of cytological examination and p53 staining to detect high-grade ESD.

Conclusions:

The capsule sponge methodology seems to be a feasible, safe, and acceptable method for diagnosing precancerous lesions of the oesophagus in this population, with promising initial accuracy data for the detection of high-grade ESD.

Large body size and sedentary lifestyle during childhood and early adulthood and esophageal squamous cell carcinoma in a high-risk population

BACKGROUND

Little is known about the association of obesity and physical activity at young ages with subsequent risk of esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Between 2003 and 2007, we conducted a case-control study in a high-risk population in northeastern Iran. Three hundred ESCC cases and 571 matched controls were recruited. Each individual was shown a standard pictogram, to report body size at ages 15 and 30. Demographic and health-related information, including physical activity at these ages was also collected.

RESULTS

In the fully adjusted models, very obese body size (last two pictograms) at age 15 [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.3-7.7] and age 30 (OR 3.1; 95% CI 1.1-8.5) were associated with ESCC in women, but not in men. Sedentary work at age 15 (OR 3.3, 95% CI 1.3-8.3) and 30 (OR 18.2, 95% CI 3.9-86.2) were also associated with ESCC risk in women only. The increased risk in women at age 15 remained high after later reduction in body size, while women who became very obese only at age 30 did not show a significantly increased risk.

CONCLUSION

These results highlight the importance of early lifestyle modifications in the context of cancer prevention, particularly in women.

Th-1/Th-2 cytokine pattern in human amoebic colitis

Amoebiasis, caused by Entamoeba histolytica, is still considered a major health problem in developing countries. Since the immune response during human amoebiasis has not been clearly defined, we chose to evaluate cytokine production in patients suffering from amoebic colitis. A case-control association study was carried out on 62 subjects, including 31 patients with amoebic colitis and 31 healthy controls (age, sex and geographic region-matched). Serum levels of IL-12, IFN-gamma, IL-13 and IL-5 were measured by solid-phase sandwich enzyme linked immunosorbant assay. Serum levels of IFN-gamma, IL-12, IL-13 and IL-5 were higher in the patients with amoebic colitis than in healthy controls, but were only statistically increased for IL-5 (p = 0.04) and IL-13 (p = 0.014). Stratification of patients according to gender revealed that IL-13 was significantly elevated in men as compared to levels measured in women (p = 0.04). These findings suggest that E. histolytica induce a mixed Th-1/Th-2 response with a polarization toward Th-2 during the early stage of amoebiasis, which may aide in developing a clinical illness.

Serum paraoxonase 1 activity is decreased in thyroid dysfunction

Changes in serum lipid and lipoprotein concentrations occur frequently in disorders of thyroid function. LDL-cholesterol (LDL-C) oxidation susceptibility is higher in these patients than in normal population. This study aims at assessing lipids, lipoproteins, apolipoproteins and serum paraoxonase 1 (PON1) activity in patients with thyroid dysfunction. Ninety-nine patients with thyroid dysfunction, (49 hypothyroid and 50 hyperthyroid) were compared with 2 separately age- and sex-matched control groups. A fasting blood sample was obtained and serum total cholesterol, triglycerides, apolipoproteins A-I and B, and PON1 activity were measured. In hyperthyroid patients, significantly lower PON1 activity (45 +/- 23 vs 67 +/- 37 IU/ml, p<0.001), triglycerides (112 +/- 53 vs 166 +/- 130 mg/dl, p<0.05), apolipoprotein A-I (137 +/- 26 vs 154 +/- 21 mg/dl, p<0.001) and apolipoprotein B (75 +/- 18 vs 86 +/- 25 mg/dl, p<0.05) were found. Hypothyroid patients had lower PON1 activity (46 +/- 21 vs 64 +/- 32 IU/ml, p<0.005) compared with controls, and higher total cholesterol (224 +/- 69 vs 185 +/- 41 mg/dl, p<0.001), LDL-C (133 +/- 59 vs 93 +/- 36 mg/dl, p<0.001), and apolipoprotein B (107 +/- 37 vs 84 +/- 23 mg/dl, p<0.001). The results show significant changes of lipid levels in thyroid dysfunction. In addition, a significant reduction in PON1 activity was observed in both hyper- and hypothyroid patients. Increased LDL-C oxidation in thyroid dysfunction observed in other studies, at least to some extent, can be attributed to reduced PON1 activity.

Does immunotherapy with heat-killed Mycobacterium vaccae offer hope for the treatment of multi-drug-resistant pulmonary tuberculosis?

The ability of immunotherapy with heat-killed Mycobacterium vaccae (NCTC 11659), as an addition to the available chemotherapy, to improve the outcome in patients with multi-drug-resistant tubercle bacilli (MDRTB) who had not been cured by chemotherapy alone was evaluated in tuberculosis centres in Estonia, Iran, Kuwait, New Zealand, Romania, Vietnam and the U.K. A total of 337 patients in the above countries received intradermal injections of M. vaccae in addition to chemotherapy. Patients were grouped according to the length of their histories of disease: less than or greater than 2 years duration. Initially, single doses of M. vaccae were given but subsequently up to 12 doses at 2-month intervals were given. Chemotherapy varied from isoniazid alone to drugs selected according to susceptibility tests. Most patients had failed to respond to repeated courses of chemotherapy and the majority, were expected to die from their disease. Results were assessed by sputum smear and culture and by clinical observations. Cured patients were followed for 18-24 months to exclude relapse. Eighteen of 22 (82%) patients with disease for less than 2 years were bacteriologically cured by one or two doses of M. vaccae. Among 315 chronic patients, 24 (7.6%) were cured after one dose, 37.9% after seven doses and 41.6% after 12 doses. Sixty-six chronic patients were lost to follow-up, or died, during the multi-dose regimens. Nine of 33 patients (27%) with advanced disease unaffected by several courses of chemotherapy and discharged on isoniazid alone in Vietnam were cured by 3-12 injections of M. vaccae. The data provide preliminary evidence that the addition of immunotherapy with M. vaccae to chemotherapy improves the rate of cure of MDRTB, most effectively in patients with short histories of disease, but multiple dosing can have beneficial effects in chronic patients in whom chemotherapy has failed. A randomized clinical trial of this immunotherapy in MDRTB patients is therefore required.