Tobacco use and cancer causation: association by tumour type

The Correlation Between Bladder Cancer and Obesity, Overweight, Physical Inactivity, and Tobacco Use: An Ecological Study in Asian Countries

BACKGROUND

Bladder cancer is the ninth most common cancer in the world.

OBJECTIVES

This study aimed to determine the correlation between age-standardized incidence rates of bladder cancer and some risk factors in Asian countries through an extensive ecological analysis.

METHODS

This ecological study evaluated the correlation between age-standardized incidence rates of bladder cancer and obesity, overweight, physical inactivity, and tobacco use in 30 Asian countries. To determine the factors that were significantly related to age-standardized incidence rate of bladder cancer, a univariate analysis was performed using simple linear regression. In the next step, variables with p-values less than 0.25 were entered into a multivariate linear regression model.

RESULTS

The incidence of bladder cancer was higher in countries with higher prevalence of overweight (r2 = 0.36, p < 0.001), obesity (r2 = 0.34, p = 0.001), current daily tobacco use (r2 = 0.17, p = 0.03), and physical inactivity (r2 = 0.13, p = 0.04). The results of multiple regression analysis indicated a direct correlation between the incidence of bladder cancer and overweight (β = 0.15, p < 0.001) and current daily tobacco use (β = 0.21, p = 0.001).

CONCLUSIONS

There was a significant relationship between the incidence of bladder cancer and overweight and current daily tobacco use. Further epidemiological studies are needed to confirm this relationship.

Low-Level Exposure to Arsenic in Drinking Water and Risk of Lung and Bladder Cancer: A Systematic Review and Dose-Response Meta-Analysis

BACKGROUND

Exposure to high levels of arsenic in drinking water has been associated with an increased risk of lung and bladder cancer, but the presence of an increased risk at low levels is questionable.

METHODS

A systematic review and a dose-response meta-analysis were conducted on risk estimates of lung and bladder cancer for exposure to arsenic in drinking water up to 150 µg/L, using a 2-stage approach based on a random-effects model.

RESULTS

Five studies of lung cancer were identified; the meta-relative risk (RR) for an increase of 10 µg/L arsenic level was 1.03 (95% confidence interval [CI]: 0.99-1.06; P heterogeneity = .05). The meta-analysis of bladder cancer included 8 studies; the meta-RR for an increase of 10 µg/L arsenic level was 1.02 (95% CI: 0.97-1.07, P heterogeneity = .01). Sensitivity analyses, including a 1-stage meta-regression, confirmed the main findings.

CONCLUSION

This systematic review and meta-analysis provided evidence of a lack of an increased risk of lung and bladder cancer for exposure to arsenic in drinking water up to 150 µg/L, the highest concentration studied.

Laryngeal Cancer Attributable Factors and the Influence on Survival Rates: A Single Brazilian Institution Experience

Introduction  Epidemiological studies focused on prognostic factors associated with laryngeal cancer in the Brazilian population are poorly reported in the literature.

Objective  To evaluate the influence of certain risk factors on the survival rates of patients with squamous cell carcinoma (SCC) of the larynx.

Methods  This retrospective study was conducted on adult patients who were admitted to the outpatient clinic of the head and neck department in a tertiary care hospital. Evaluation of the influence of risk factors on the survival rates of patients registered in the hospital with laryngeal SCC was performed based on age, sex, initial stage, time of evolution, habits, educational levels and relapse and death. Overall survival (OS), disease-free survival (DFS) and clinical-demographic data were analyzed using the Kaplan-Meier method, Log-rank test and Cox regression.

Results  A total of 107 patients with a mean age of 59.8 years (range 19–81) were included in this study. Stages III and IV were associated with decreased DFS ( p  = 0.02) and OS ( p  = 0.02). Smoking patients had a greater period of disease evolution than non-smoking patients ( p  = 0.003). Alcohol consumption in smokers increased the risk of death by 2.8 ( p  = 0.002) compared with non-drinking smokers. Male patients presented lower DFS average when compared with female patients ( p  = 0.04).

Conclusion  Our study confirms that male gender, smoking habit combined with alcohol consumption, and advanced stages were strongly associated with poor prognosis.

In times of tobacco-free nicotine consumption: The influence of nicotine on vascular calcification

BACKGROUND

Smoking remains the most important avoidable cause of global mortality. Even though the number of cigarette smokers declines in first world countries, the uses of alternative nicotine delivery products increase and may even surpass the sells of cigarettes. In this light, the explicit role of nicotine in the development of cardiovascular diseases should be elucidated.

OBJECTIVES

This narrative review attempts to connect current literature about possible effects of nicotine on the environment of the vasculature to the pathogenesis of vascular calcification, focusing on the tunica media of the vessel wall.

METHODS

For this review, papers found on Pubmed and Medline until December 2018 by searching for the keywords nicotine, vascular calcification, oxidative stress, osteoblastic transdifferentiation and matrix degradation were considered.

RESULTS

Nicotine creates an environment that probably facilitates and maybe even induces osteogenic transdifferentiation of VSMC by inflammation, endothelial dysfunction and reactive oxygen species. This process is believed to be a key event in calcification of the tunica media of the vessel wall. Furthermore, nicotine could lead to the formation of nucleation sites for hydroxyapatite by facilitating matrix vesicles and extracellular matrix degradation.

CONCLUSIONS

There is a growing body of evidence implicating that nicotine alone could impair vascular function and lead to vascular calcification. Further research is necessary to elucidate the explicit influence of nicotine on arteriosclerosis.

miR-506 is a YAP1-dependent tumor suppressor in laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) accounts for 95% of laryngeal cancer incidence. Tobacco use has been shown to have a linear association with the development of the disease. While early diagnosis and treatment of LSCC are critical in improving the 5-year survival rate and quality of life, diagnosis of early-stage LSCC remains challenging because of the unapparent symptoms. Here, we report that miR-506, a critical regulator in many types of cancers, is aberrantly suppressed in LSCC patient tissues and cultured cancer cells. This is likely responsible for the enhanced production of YAP1 protein, a transcriptional factor that is well known for its oncogenic roles in LSCC malignancy. Statistical analysis has confirmed that the expression levels of miR-506 and YAP1 are strongly correlated with the malignant statuses of patient tumors. Restoring the expression level of miR-506 in cultured LSCC cells significantly inhibited proliferation, migration and invasion of the cells. The miR-506 and YAP1 regulatory network seems to affect at least pathways involved in apoptosis. Our study, for the first time, has demonstrated a tumor suppressive role of miR-506 in LSCC. This opens new opportunities for further exploring the molecular details of the development of the disease and thus will facilitate the development of novel diagnosis and therapeutic strategies.

Review on gender differences in non-muscle invasive bladder cancer

Differences in the epidemiology, diagnosis and outcomes according to gender in patients diagnosed with non-muscle invasive bladder cancer (NMIBC) has been widely reported. In this article we present gender-specific differences in NMIBC in terms of epidemiology, risk factors, first clinical presentation, management and clinical outcomes based on systematically review evidence of existing literature. A literature search of English-language publications that included an analysis of the association of gender differences in patients with NMIBC was performed using PubMed. Sixty-four studies were selected for analysis with consensus of all authors. The incidence and mortality for urothelial bladder cancer (UBC) are higher in men, whereas cancer specific mortality to incidence ratio is significantly lower for men than for women. This phenomenon could be partially explained by differences in exposure to bladder cancer carcinogens. However female gender is associated with higher stage at presentation. Thirteen studies with a total of 11,069 patients diagnosed with NMIBC were included for analysis according to outcomes. In studies that found statistically significant differences in outcomes between sexes, female gender was reported as risk factor for disease recurrence, progression or cancer specific mortality. None of included studies found worse outcomes in men when compared to women with NMIBC. Results of our review suggest that female gender in patients diagnosed with NMIBC is associated—though inconsistently—with higher stage at presentation and poorer outcomes. Numerous factors may influence gender gap in incidence rate, clinical management and reported outcomes. Consensus on comparable data collection in routine practice and prospective trials including clinical outcomes are required to identify gender-specific differences in patients diagnosed with NMIBC.

Detection of laryngeal carcinoma in the U.S. elderly population with gastroesophageal reflux disease

BACKGROUND

An association is suggested between gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR) and malignancy of the larynx in elderly patients in the United States. Early detection with flexible fiberoptic laryngoscopy (FFL) or CT remains poorly defined.

METHODS

The Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database was queried from 2003 to 2011.A case-cohort design evaluated patients aged 66 and older with a diagnosis of GERD and/or LPR for the occurrence of FFL or CT within 6 months of the exposure diagnosis.

RESULTS

Of a total 156 426 Medicare beneficiaries, the relative risk of early cancer diagnosis with FFL was 14.61(95% confidence interval [CI], 13.59-15.70), corresponding to a number needed to detect (NND) a case of cancer of 13(95% CI, 13-14). The relative risk of an early cancer diagnosis with CT was 31.83 (95% CI, 29.57-34.26), with a NND of 5 (95% CI, 5-5).

CONCLUSIONS

Early FFL and CT are associated with a higher likelihood of laryngeal cancer diagnosis in elderly individuals with a diagnosis of reflux. Screening trials are necessary to establish this relationship.

Economic evaluation of a brief counselling for smoking cessation in dentistry: a case study comparing two health economic models

OBJECTIVES

This study aimed to compare the cost-effectiveness estimates of a brief counselling of smoking cessation in dentistry by using two different health economic models.

DESIGN AND OUTCOME MEASURES

Intervention effectiveness was estimated in a cluster randomised controlled trial. The number of quitters was estimated based on 7-day abstinence and on smoking reduction at follow-up. Health economic evaluation was performed using two models: (1) a population-based model employing potential impact fractions and (2) a Markov model estimating the cost-effectiveness of the intervention for the actual participants. The evaluation was performed from healthcare and societal perspectives, and health gains were expressed in quality-adjusted life-years (QALYs).

SETTING

Dental clinics in Sweden.

PARTICIPANTS

205 Swedish smokers aged 20-75 years.

INTERVENTIONS

A brief, structured behavioural intervention was compared with 'usual care'.

RESULTS

The cost per quitter was US$552 in the intervention and US$522 in the 'usual care' condition. The net saving estimated with the population-based model was US$17.3 million for intervention and US$49.9 million for 'usual care', with health gains of 1428 QALYs and 2369 QALYs, respectively, for the whole Swedish population during 10 years. The intervention was thus dominated by 'usual care'. The reverse was true when using the Markov model, showing net societal savings of US$71 000 for the intervention and US$57000 for 'usual care', with gains of 5.42 QALYs and 4.74 QALYs, respectively, for lifelong quitters.

CONCLUSION

The comparison of intervention and 'usual care' derived from small-scale studies may be highly sensitive to the choice of the model used to calculate cost-effectiveness.

TRIAL REGISTRATION

The cluster randomised trial is registered in the ISRCTN register of controlled trials with identification number ISRCTN50627997.

An update on larynx cancer

Answer questions and earn CME/CNE Laryngeal cancer remains one of the most common tumors of the respiratory tract. Fortunately, significant advancements have been made over the past decade in the treatment of laryngeal cancer. Although surgery has been the historical mainstay for localized disease and still is an integral part of treatment, nonsurgical options like radiation and systemic therapy have emerged as viable options. In addition, in the metastatic setting, novel agents are showing promise for this patient population. The care for patients with laryngeal cancer continues to evolve and truly requires a multidisciplinary team-based approach. Unique morbidities, such as loss of natural voice, respiration, and airway protection during swallowing, are observed with this disease and require special consideration. CA Cancer J Clin 2017;67:31-50. © 2016 American Cancer Society.

A Hybrid Computer-aided-diagnosis System for Prediction of Breast Cancer Recurrence (HPBCR) Using Optimized Ensemble Learning

Cancer is a collection of diseases that involves growing abnormal cells with the potential to invade or spread to the body. Breast cancer is the second leading cause of cancer death among women. A method for 5-year breast cancer recurrence prediction is presented in this manuscript. Clinicopathologic characteristics of 579 breast cancer patients (recurrence prevalence of 19.3%) were analyzed and discriminative features were selected using statistical feature selection methods. They were further refined by Particle Swarm Optimization (PSO) as the inputs of the classification system with ensemble learning (Bagged Decision Tree: BDT). The proper combination of selected categorical features and also the weight (importance) of the selected interval-measurement-scale features were identified by the PSO algorithm. The performance of HPBCR (hybrid predictor of breast cancer recurrence) was assessed using the holdout and 4-fold cross-validation. Three other classifiers namely as supported vector machines, DT, and multilayer perceptron neural network were used for comparison. The selected features were diagnosis age, tumor size, lymph node involvement ratio, number of involved axillary lymph nodes, progesterone receptor expression, having hormone therapy and type of surgery. The minimum sensitivity, specificity, precision and accuracy of HPBCR were 77%, 93%, 95% and 85%, respectively in the entire cross-validation folds and the hold-out test fold. HPBCR outperformed the other tested classifiers. It showed excellent agreement with the gold standard (i.e. the oncologist opinion after blood tumor marker and imaging tests, and tissue biopsy). This algorithm is thus a promising online tool for the prediction of breast cancer recurrence.

IP3 and calcium signaling involved in the reorganization of the actin cytoskeleton and cell rounding induced by cigarette smoke extract in human endothelial cells

Smoking increases the risk of cardiovascular disorders and leads to damage caused by inflammation and oxidative stress. The actin cytoskeleton is a key player in the response to inflammatory stimuli and is an early target of cellular oxidative stress. The purpose of this study was to investigate the changes in actin cytoskeleton dynamics in human endothelial EA.hy926 cells exposed to cigarette smoke extract (CSE). Immunostaining revealed that CSE exposure resulted in modification of the actin cytoskeleton and led to cell rounding in a dose- and time-dependent manner. In addition, the intracellular calcium concentration was increased by treatment with CSE. Pretreatment with antioxidants (lipoic acid, glutathione, N-acetyl cysteine, aminoguanidine, α-tocopherol, and vitamin C) significantly attenuated the CSE-induced actin cytoskeleton reorganization and cell rounding. Calcium ion chelators (EGTA, BAPTA-AM AM) and a potent store-operated calcium channel inhibitor (MRS 1845) also reduced CSE-induced intracellular calcium changes and attenuated actin cytoskeleton reorganization and cell morphology change. Moreover, the CSE-induced intracellular calcium increase was suppressed by pretreatment with the inositol trisphosphate receptor (IP3R) inhibitor xestospongin C, the phospholipase C (PLC) inhibitor U-73122, and the protein kinase C (PKC) inhibitor GF109203X. These results suggest that reactive oxygen species production and intracellular calcium increase play an essential role in CSE-induced actin disorganization and cell rounding through a PLC-IP3-PKC signaling pathway. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1293-1306, 2016.

Early Origins of Adult Cancer Risk Among Men and Women: Influence of Childhood Misfortune?

OBJECTIVE

To examine the effect of five childhood misfortune domains-parental behavior, socioeconomic status, infectious diseases, chronic diseases, and impairments-on all-site and selected site-specific cancer prevalence and all-site cancer incidence.

METHOD

Panel data from the Health and Retirement Study (2004-2012) were used to investigate cancer risk among adults above the age of 50.

RESULTS

Risky parental behavior and impairment in childhood were associated with higher odds of all-site cancer prevalence, and childhood chronic disease was associated with prostate cancer, even after adjusting for adult health and socioeconomic factors. Moreover, having one infectious disease in childhood lowered the odds of colon cancer. Cancer trends varied by race and ethnicity, most notably, higher prostate cancer prevalence among Black men and lower all-site cancer among Hispanic adults.

DISCUSSION

These findings underscore the importance of examining multiple domains of misfortune because the type and amount of misfortune influence cancer risk in different ways.

Constructing personalized longitudinal holo'omes of colon cancer-prone humans and their modeling in flies and mice

Specific host genes and intestinal microbes, dysbiosis, aberrant immune responses and lifestyle may contribute to intestinal inflammation and cancer, but each of these parameters does not suffice to explain why sporadic colon cancer develops at an old age and only in some of the people with the same profile. To improve our understanding, longitudinal multi-omic and personalized studies will help to pinpoint combinations of host genetic, epigenetic, microbiota and lifestyle-shaped factors, such as blood factors and metabolites that change as we age. The intestinal holo’ome – defined as the combination of host and microbiota genomes, transcriptomes, proteomes, and metabolomes – may be imbalanced and shift to disease when the wrong host gene expression profile meets the wrong microbiota composition. These imbalances can be triggered by the dietary- or lifestyle-shaped intestinal environment. Accordingly, personalized human intestinal holo’omes will differ significantly among individuals and between two critical points in time: long before and upon the onset of disease. Detrimental combinations of factors could therefore be pinpointed computationally and validated using animal models, such as mice and flies. Finally, treatment strategies that break these harmful combinations could be tested in clinical trials. Herein we provide an overview of the literature and a roadmap to this end.

Analysis of cigarette smoking mechanism by real time video-endoscopic documentation

OBJECTIVE

To view, document and analyze the smoking mechanism as seen via video-endoscopic examination during the action of cigarette smoking.

STUDY DESIGN

Observational study.

METHODS

Twenty-two healthy smoking volunteers were examined with a trans-nasal video-laryngoscope while breathing, sniffing and cigarette smoking. Smoking a whole cigarette was recorded in each participant. The different stages of smoking were defined and their duration was measured. The glottic opening angle was calculated during breathing, sniffing and smoking.

RESULTS

A smoking cycle with four distinct stages was recognized. The stages included an oral smoke accumulation, pharyngo-laryngeal jet inhalation, infralaryngeal spread, and finally humidified exhalation stage. The stages' mean duration was 1.93(±1.21), 0.39(±0.31), 2.00(±1.12) and 4.5(±2.70) seconds, respectively. The glottic opening angle during smoke inhalation was wider in 16% (p = 0.02) compared to normal inhalation during breathing. The glottic opening during smoke exhalation was comparable to what was observed during normal exhalation. The reduction in the glottic opening was more significant during the action of smoking compared with normal breathing (p = 0.042).

CONCLUSIONS

Smoking follows a consistent sequence of events, defined by specific anatomic configuration and relatively persistent duration. The fast turbulent flow of the smoke over the narrow glottic aperture and at the areas of bifurcation at the trachea and bronchi may have a role in the high relative risk for carcinoma in these areas.

Impact of Smoking and Excess Body Weight on Overall and Site-Specific Cancer Mortality Risk

BACKGROUND

Smoking and excess body weight are major preventable risk factors for premature death. This study aimed at analyzing their single and combined association with site-specific cancer mortality.

METHODS

Our study population comprised 35,784 men and women of ages 14 to 99 years, who participated in population-based health surveys conducted 1977-1993 in Switzerland and were followed up for mortality until 2008. Multivariable Cox proportional hazards models were calculated for different cancer sites, and population attributable fractions were derived.

RESULTS

The hazard ratio of dying from cancer (all sites) was 2.32 (95% confidence interval, 2.04-2.63) for heavy smokers (vs. never smokers) and 1.15 (1.01-1.32) for obese [body mass index (BMI) ≥ 30 kg/m(2)] vs. normal weight individuals. Heavy smoking (≥20 cigarettes/day) was associated with increased mortality due to cancer of the lung, upper aero-digestive tract, pancreas, bladder, liver, and the total of remaining sites. Obesity was associated with higher risk of dying from cancer of the liver and the female genital tract (essentially corpus or cervix uteri and ovary). More than 20% of all cancer deaths in our population were attributable to ever smoking and overweight (BMI ≥ 25 kg/m(2)).

CONCLUSIONS

Smoking was a much stronger risk factor for cancer than excess body weight. For lung, liver, and pancreatic cancer, the combination of excess body weight and smoking lead to cumulated higher risks.

IMPACT

Our findings support recommendations for obese persons to quit smoking despite potential postcessation weight gain.

Smokeless tobacco (shammah) in Saudi Arabia: a review of its pattern of use, prevalence, and potential role in oral cancer

BACKGROUND

Shammah is a traditional form of chewing tobacco [smokeless tobacco, (ST)] that is commonly used in the Middle East especially in Saudi Arabia (KSA), Yemen and Sudan. The Substance Abuse Research Centre (SARC) at Jazan University noted that no adequate research and information on the prevalence of shammah use in the province of Jazan, and KSA as well, has been provided in the scientific literature.

MATERIALS AND METHODS

An intensive systematic review of online databases was performed, including AMED (The Allied and Complementary Medicine Database), Biological Abstracts, Cochrane Collection Plus, Dentistry and Oral Sciences Source, E-Journals Database, EBSCO Discovery Service, MEDLINE, PEMSoft, PEP Archive, PsycARTICLES, scopus, Sciencedirect and Google Scholar.

RESULTS

Shammah is a mixture of powdered tobacco, lime, ash, black pepper, oils and flavorings. ST in KSA is placed in the buccal or lower labial vestibule of the mouth. The user (or dipper) spits out insoluble debris. The importation of ST products is prohibited in KSA. Accessible information on legislative action to control the use of ST in KSA appeared in 1990. The actual percentage use may be higher, than reported since shammah is illegal in KSA and there may be some reluctance to admit to its use.

CONCLUSIONS

This review paper is an initial step in a funded research project by SARC to understand the pattern of use of shammah and provide adequate epidemiological data. One goal of this review is to generate further data for public health education.

Lung cancer in South Africa: a forecast to 2025 based on smoking prevalence data

OBJECTIVE

This study aims to forecast lung cancer mortality with respect to recent changes in smoking prevalence and compares the results to estimates from GLOBOCAN and the Global Burden of Disease study.

SETTING

An established epidemiological model is applied to detailed smoking prevalence data from South Africa to estimate lung cancer mortality from 2010 to 2025.

PARTICIPANTS

Data from the South Africa Demographic and Health Survey conducted in 2003 was analysed by sex and ethnic group, and combined with longitudinal estimates on smoking prevalence from 1980 to 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

Results provide detailed data on tobacco smoking behaviour by age, sex and ethnic group as well as modelled age-adjusted lung cancer mortality and number of yearly lung cancer deaths.

RESULTS

From 2010 to 2025, a decrease in age-adjusted lung cancer mortality is shown from 17.1 to 14.1 among men; whereas rates were stable around 7.2 among women. As a consequence, the estimated number of yearly lung cancer deaths is expected to increase slightly for men and more for women. With respect to ethnic groups, male mortality is expected to be highest for Asians and lowest for blacks. Female rates were lowest for Asians and highest for whites and for coloured.

CONCLUSIONS

Mortality estimates of this study are close to the WHO mortality database and to Global Burden of Disease estimates for 2010, but significantly lower compared with GLOBOCAN estimates. In conclusion, our study demonstrates the impact of demographic changes and the positive effects of antismoking policy on lung cancer mortality in South Africa. Results may help decision makers to further improve smoking control.

CHRNA9 polymorphisms and smoking exposure synergize to increase the risk of breast cancer in Taiwan

Previous studies indicated that smoking exposure is associated with an increased risk of breast cancer, and α9-nicotine acetylcholine receptors (α9-nAChRs) are involved in breast tumorigenesis. However, no studies have explored the joint effect of α9-nAChRs (CHRNA9) genes and cigarette smoking exposure on breast cancer risk. A case-control study was conducted on 737 breast cancer patients and 719 age-matched healthy controls. Three single-nucleotide polymorphisms (SNPs) of CHRNA9 located in the promoter region were genotyped and compared between cases and controls to identify those SNPs associated with breast cancer susceptibility. A dual-luciferase reporter assay was used to analyze the promoter activities of these SNPs of the CHRNA9 gene. After a Bonferroni correction, the G allele of the CHRNA9 rs7329797 SNP was significantly associated with an increased risk of developing breast cancer compared with A/A genotype carriers (odds ratio, 1.8; 95% confidence interval, 1.2-2.6). A multiplicative interaction between passive smoking exposure and the CHRNA9 rs73229797 SNP on the risk of breast malignancy was observed. A functional assay further showed that rs73229797 was associated with increased promoter activity of the CHRNA9 gene. Our findings support a significant interaction effect existing between the CHRNA9 gene and smoking exposure on the risk of breast cancer development.

Primary and secondary prevention of colorectal cancer

INTRODUCTION

Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. Colorectal cancer (CRC) is the third most frequent cancer in men, after lung and prostate cancer, and is the second most frequent cancer in women after breast cancer. It is also the third cause of death in men and women separately, and is the second most frequent cause of death by cancer if both genders are considered together. CRC represents approximately 10% of deaths by cancer. Modifiable risk factors of CRC include smoking, physical inactivity, being overweight and obesity, eating processed meat, and drinking alcohol excessively. CRC screening programs are possible only in economically developed countries. However, attention should be paid in the future to geographical areas with ageing populations and a western lifestyle.19,20 Sigmoidoscopy screening done with people aged 55–64 years has been demonstrated to reduce the incidence of CRC by 33% and mortality by CRC by 43%.

OBJECTIVE

To assess the effect on the incidence and mortality of CRC diet and lifestyle and to determine the effect of secondary prevention through early diagnosis of CRC.

METHODOLOGY: A comprehensive search of Medline and Pubmed articles related to primary and secondary prevention of CRC and subsequently, a meta-analysis of the same blocks are performed.

RESULTS

225 articles related to primary or secondary prevention of CRC were retrieved. Of these 145 were considered valid on meta-analysis: 12 on epidemiology, 56 on diet and lifestyle, and over 77 different screenings for early detection of CRC. Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. There is no doubt whatsoever which environmental factors, probably diet, may account for these cancer rates. Excessive alcohol consumption and cholesterol-rich diet are associated with a high risk of colon cancer. A diet poor in folic acid and vitamin B6 is also associated with a higher risk of developing colon cancer with an overexpression of p53. Eating pulses at least three times a week lowers the risk of developing colon cancer by 33%, after eating less meat, while eating brown rice at least once a week cuts the risk of CRC by 40%. These associations suggest a dose–response effect. Frequently eating cooked green vegetables, nuts, dried fruit, pulses, and brown rice has been associated with a lower risk of colorectal polyps. High calcium intake offers a protector effect against distal colon and rectal tumors as compared with the proximal colon. Higher intake of dairy products and calcium reduces the risk of colon cancer. Taking an aspirin (ASA) regularly after being diagnosed with colon cancer is associated with less risk of dying from this cancer, especially among people who have tumors with COX-2 overexpression.16 Nonetheless, these data do not contradict the data obtained on a possible genetic predisposition, even in sporadic or non-hereditary CRC. CRC is susceptible to screening because it is a serious health problem given its high incidence and its associated high morbidity/mortality.

CONCLUSIONS

(1) Cancer is a worldwide problem. (2) A modification of diet and lifestyle could reduce morbidity and mortality. (3) Early detection through screening improves prognosis and reduces mortality.

High risk of tobacco-related cancers in CDKN2A mutation-positive melanoma families

BACKGROUND

Germline mutations in the tumour suppressor gene CDKN2A occur in 5-20% of familial melanoma cases. A single founder mutation, p.Arg112dup, accounts for the majority of CDKN2A mutations in Swedish carriers. In a national program, carriers of p.Arg112dup mutation have been identified. The aim of this study was to assess cancer risks in p.Arg112dup carriers and their first degree relatives (FDRs) and second degree relatives (SDRs).

METHODS

In this prospective cohort study, cancer diagnoses in carriers (n=120), non-carriers (n=111), carriers' FDRs (n=275) and SDRs (n=321) and controls (n=3976) were obtained from the Swedish Cancer Registry. Relative risks (RRs) for cancers were calculated (number of cancers/person years). Two-sided 95% CIs were calculated for all RRs.

RESULTS

In carriers prospective RR for non-melanoma cancers was 5.0 (95% CI 3.7 to 7.3), for pancreatic cancer 43.8 (95% CI 13.8 to 139.0), for cancers in upper digestive tissues 17.1 (95% CI 6.3 to 46.5), and in respiratory tissues 15.6 (5.4 to 46.0). In FDRs and SDRs RRs were significantly elevated for cancers in pancreas, respiratory and upper digestive tissues. In ever-smoking carriers compared with never-smoking carriers, the odds ratio (OR) of cancers in pancreas, respiratory or upper digestive tissues was 9.3 (95% CI 1.9 to 44.7).

CONCLUSIONS

CDKN2A p.Arg112dup mutation carriers from melanoma-prone families and their FDRs and SDRs have elevated risk for pancreatic, lung, head and neck and gastro-oesophageal carcinomas. These cancers were mainly seen in ever-smoking carriers. Germline CDKN2A mutations may confer an increased sensitivity to carcinogens in tobacco smoke. CDKN2A mutation carriers should be counselled to abstain from smoking.

Tobacco smoking and mental illness: important considerations

Tobacco smoking is a contributory factor in the death of 50% of individuals who are regular or heavy smokers (The Office of Tobacco Control Ireland defines a regular smoker as someone who smokes 11-20 per day and a heavy smoker as someone who smokes 21 or more cigarettes per day). The World Health Organisation (WHO) regards tobacco smoking as the leading preventable cause of death worldwide. In Ireland, approximately 750,000 people smoke tobacco regularly (23.5% of the population) with 7,000 Irish people dying annually from smoking-related causes. Although there are no exact figures for prevalence rates of smoking in individuals with mental illness in Ireland, international studies unequivocally state that the prevalence of smoking is significantly higher in those with mental illness, with greater nicotine intake and increased prevalence of nicotine dependence also reported. Furthermore people with mental illness experience greater withdrawal symptoms and have lower cessation rates when attempting to stop smoking compared to the general population.

Smoking prevalence and its impacts on lung cancer mortality in Sub-Saharan Africa: an epidemiological study

BACKGROUND

Reliable mortality data are sparse for developing countries. Furthermore, risk factor prevalence information is hardly available and thus not taken into consideration when estimating mortality.

METHODS

The authors used a validated, statistical model combined with representative smoking prevalence from WHO STEPS surveys to estimate lung cancer mortality for six Sub-Saharan African countries (Benin, Malawi, Mozambique, Niger, Sierra Leone, Swaziland). Results were compared to a reference database (GLOBOCAN). Using different smoking prevalence scenarios, future lung cancer deaths were estimated.

RESULTS

The prevalence of current moderate smoking among males ranged from 8.7% to 34.6%. Prevalence was much lower among females. For all countries considered, our mortality estimates were higher than GLOBOCAN estimates that do not consider prevalence: Overall, we estimated 2405 lung cancer deaths for 2008 compared to 531 deaths estimated by GLOBOCAN. Up to 2030, lung cancer deaths are expected to increase in general and by over 100% in Benin and Niger. Even under the assumption of decrease in smoking prevalence, lung cancer mortality will rise.

CONCLUSION

On the bases of detailed smoking prevalence information, our findings implicate a higher lung cancer burden in low income countries. The epidemiologic transition in African low-income countries alludes to the need for targeted health prevention efforts.

Sinonasal squamous cell carcinomas: clinical outcomes and predictive factors

This was a retrospective study of 33 patients treated for sinonasal squamous cell carcinoma between 1995 and 2008. Epidemiological, clinical, histological, and therapeutic aspects of this series of patients were analysed, and their impacts on overall survival and disease-free survival established using the Kaplan-Meier method. A search for prognostic factors was made using a log-rank test. There were 27 men. The average age at diagnosis was 64.7 years. Tobacco-smoking was found to be a risk factor in 24 patients (72.7%). The median follow-up was 66 months (range 0-99 months). Tumours were classified as T1 in 18.3%, T2 in 27.3%, T3 in 6%, and T4 in 48.5% of cases. Disease-free survival rates at 1 and 5 years were 58.5% and 46.1%, respectively, and overall survival rates were 70.3% and 40%, respectively. Overall survival was correlated to tumour status (TNM, American Joint Committee on Cancer) (P = 0.010) and involvement of key structures (skull base, dura mater, brain, orbit, cavernous sinus, infratemporal fossa, skin) (P = 0.049). Surgery followed by radiotherapy improved overall survival (P = 0.005) and disease-free survival (P = 0.028) when compared to other treatment modalities. When compared to surgery alone, it improved disease-free survival (P = 0.049) regardless of tumour stage.

All-cause mortality and cancer incidence among adults exposed to blue asbestos during childhood

BACKGROUND

There are few data on the long-term health outcomes of exposure to asbestos in childhood. This study investigated cancer and mortality of adults exposed to blue asbestos as children.

METHODS

Data linkage to relevant health registries was used to identify cancers and mortality in a cohort of adults (n = 2,460) that had lived in an asbestos mining town during their childhood (<15 years).

RESULTS

There were 217 (93 female) incident cancers and 218 (70 female) deaths among the cohort. Compared with the Western Australian population females had elevated mesothelioma, ovarian and brain cancers, and increased "all cause" and "all cancer" mortality. Males had elevated mesothelioma, leukemia, prostate, brain, and colorectal cancers, and excess mortality from "all causes," "all cancers," circulatory disease, diseases of the nervous system, and accidents.

CONCLUSION

Exposure to blue asbestos in childhood is associated with an increased risk of cancer and mortality in adults.

Molecular basis of urinary bladder cancer

Bladder cancer is a relatively common and potentially life-threatening neoplasm. The diagnosis of urothelial carcinoma usually entails a lifelong surveillance to detect recurrent disease. In recent years, significant progress has been made in understanding the molecular mechanisms of carcinogenesis in urinary bladder. An early step in the process of carcinoma development is establishment of a premalignant abnormal urothelial patch that may give rise to various types of urothelial carcinoma and may provide a fertile ground for development of multifocal synchronous and metachronous tumors. Two distinct molecular pathways are involved. Low-grade papillary carcinoma is associated with mutation in the FGFR3 or in some cases mutations in RAS genes. High-grade in situ/muscle-invasive carcinoma on the other hand is characterized by alteration of p53 and pRB. Loss of function of these key genes, which play a crucial role in the control of cell cycle, leads to accumulation of additional mutations and deletions of genes resulting in an aggressive phenotype. It is hoped that a thorough understanding of the molecular basis of urothelial cancer will facilitate early diagnosis and will lead to development of new modalities for the management and treatment of these carcinomas.

In silico identification of oncogenic potential of fyn-related kinase in hepatocellular carcinoma

MOTIVATION

Cancer development is a complex and heterogeneous process. It is estimated that 5-10% of human genes probably contribute to oncogenesis, whereas current experimentally validated cancer genes only cover 1% of the human genome. Thus hundreds of cancer genes may still remain to be identified. To search for new genes that play roles in carcinogenesis and facilitate cancer research, we developed a systematic workflow to use information saved in a previously established tumor-associated gene (TAG) database.

RESULTS

By exploiting the information of conserved protein domains from the TAG, we identified 183 potential new TAGs. As a proof-of-concept, one predicted oncogene, fyn-related kinase (FRK), which shows an aberrant digital expression pattern in liver cancer cells, was selected for further investigation. Using 68 paired hepatocellular carcinoma samples, we found that FRK was up-regulated in 52% of cases (P < 0.001). Tumorigenic assays performed in Hep3B and HepG2 cell lines revealed a significant correlation between the level of FRK expression and invasiveness, suggesting that FRK is a positive regulator of invasiveness in liver cancer cells.

CONCLUSION

These findings implied that FRK is a multitalented signal transduction molecule that produces diverse biological responses in different cell types in various microenvironments. In addition, our data demonstrated the accuracy of computational prediction and suggested that other predicted TAGs can be potential targets for future cancer research.

AVAILABILITY

The TAG database is available online at the Bioinformatics Center website: http://www.binfo.ncku.edu.tw/TAG/.

Smoking affects mRNA expression of bone morphogenetic proteins in human periosteum

Periosteum is important for bone homoeostasis through the release of bone morphogenetic proteins (BMPs) and their effect on osteoprogenitor cells. Smoking has an adverse effect on fracture healing and bone regeneration. The aim of this study was to evaluate the effect of smoking on the expression of the BMPs of human periosteum. Real-time polymerase chain reaction was performed for BMP-2,-4,-6,-7 gene expression in periosteal samples obtained from 45 fractured bones (19 smokers, 26 non-smokers) and 60 non-fractured bones (21 smokers, 39 non-smokers). A hierarchical model of BMP gene expression (BMP-2 > BMP-6 > BMP-4 > BMP-7) was demonstrated in all samples. When smokers and non-smokers were compared, a remarkable reduction in the gene expression of BMP-2, -4 and -6 was noticed in smokers. The comparison of fracture and non-fracture groups demonstrated a higher gene expression of BMP-2, -4 and -7 in the non-fracture samples. Within the subgroups (fracture and non-fracture), BMP gene expression in smokers was either lower but without statistical significance in the majority of BMPs, or similar to that in non-smokers with regard to BMP-4 in fracture and BMP-7 in non-fracture samples. In smokers, BMP gene expression of human periosteum was reduced, demonstrating the effect of smoking at the molecular level by reduction of mRNA transcription of periosteal BMPs. Among the BMPs studied, BMP-2 gene expression was significantly higher, highlighting its role in bone homoeostasis.

Tobacco smoking and risk of multiple myeloma: a meta-analysis of 40 observational studies

This meta-analysis aims to quantitatively synthesize all available data on the association between tobacco smoking and multiple myeloma (MM) risk. Eligible studies were identified and pooled effect estimates (odds ratios and relative risks) were calculated regarding ever, current and former smoking. Separate analyses were performed on case-control and cohort studies, as well as on males and females. Meta-regression analysis with percentage of males, mean age, years of smoking, pack-years, cigarettes per day, years since quit and age at onset was performed. Forty articles were deemed eligible; of them 27 used a case-control design (4,625 cases and 21,591 controls) and 13 used a cohort design (2,228 incident cases among a total cohort size equal to 1,852,763 subjects). Ever smoking was not associated with MM risk (pooled effect estimate = 0.92, 95% confidence interval (CI): 0.85-1.00); similar results were obtained for current (pooled effect estimate = 0.87, 95% CI: 0.74-1.03) and former smoking (pooled effect estimate = 1.04, 95% CI: 0.96-1.13). Regarding ever smoking, the null association was reproducible upon cohort studies (pooled effect estimate = 1.01, 95%CI: 0.89-1.15), whereas the inverse association in case-control studies (pooled effect estimate = 0.87, 95% CI: 0.78-0.96) was particularly due to the bias-prone hospital-based ones. Meta-regression analysis did not yield statistically significant results. In conclusion, MM does not seem to be associated with tobacco smoking. There is a need to further explore how molecular mechanisms are involved in the resistance of MM progenitor cells toward smoking.

Smoking and alcohol consumption in relation to risk of thyroid cancer in postmenopausal women

BACKGROUND

Few cohort studies have examined smoking and alcohol consumption in relation to risk of thyroid cancer, and their findings are conflicting.

METHODS

We therefore assessed the association of smoking and alcohol intake with risk of thyroid cancer in a cohort of 159,340 women enrolled in the Women's Health Initiative. Over 12.7 years of follow-up 331 cases of thyroid cancer, of which 276 were papillary thyroid cancer, were identified. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Compared to never smokers, ever smokers did not have altered risk. Current smokers had reduced risk for all thyroid cancer (HR 0.54, 95% CI 0.29-1.00) and for papillary thyroid cancer (HR 0.34, 95% CI 0.15-0.78); however, the number of current smokers among cases was small. No associations or trends were seen for amount smoked, age of starting smoking, or age at quitting. Smokers of ≥40 pack-years had a significantly reduced risk of papillary thyroid cancer (HR 0.44, 95% CI 0.21-0.89). In contrast, women who had smoked for < 20 years had increased risk of thyroid cancer (HR 1.35, 95% CI 1.05-1.74) and papillary cancer (HR 1.43, 95% CI 1.09-1.89). Alcohol intake was not associated with risk.

CONCLUSION

Our findings suggest that current smoking and having higher pack-years of exposure are associated with a modestly reduced risk of thyroid cancer, whereas alcohol consumption does not appear to affect risk.

Recency of Pap testing and future testing plans among women aged 18-64: analysis of the 2007 Health Information National Trends Survey

BACKGROUND

Cervical cancer incidence has declined as a result of Papanicolaou (Pap) test use. Current guidelines recommend increasing screening intervals for women of average risk. The objective of this study is to examine current screening intervals, factors associated with recency of Pap testing, and future testing plans.

METHODS

We analyzed data from 2915 female respondents, aged 18-64, using the 2007 Health Information National Trends Survey (HINTS), a biennial national survey of access and use of cancer information in the United States. We divided time since last Pap test into ≤1 year (n=1960), >1 to ≤3 years (n=512), >3 years/never had Pap test (n=443). We performed univariate analyses and multivariate logistic regression, using proportional odds model with cumulative logit link.

RESULTS

Sixty-five percent of women had their most recent Pap test within 1 year. Most expected to be screened again within 1 year (81%). This expectation was highest among women who were tested within the previous year (90.9%). Having had a test within 1 year was positively associated with age groups 31-45 vs. 46-64 years; with being non-Hispanic black vs. non-Hispanic white; with being a college graduate vs. having less education; with being married, divorced, or separated vs. widowed; with having at least one visit to a healthcare provider in the past year; and with being aware of the human papillomavirus (HPV).

CONCLUSIONS

Most women currently are tested and anticipate future testing at annual intervals. To implement guidelines, increased communication and systematic or policy changes may be needed to reduce overtesting.

Passive cigarette smoke exposure during various periods of life, genetic variants, and breast cancer risk among never smokers

The association between passive cigarette smoke exposure and breast cancer risk is inconclusive and may be modified by genotype. The authors investigated lifetime passive cigarette smoke exposures, 36 variants in 12 carcinogen-metabolizing genes, and breast cancer risk among Ontario, Canada, women who had never smoked (2003-2004). DNA (saliva) was available for 920 breast cancer cases and 960 controls. Detailed information about passive smoke exposure was collected for multiple age periods (childhood, teenage years, and adulthood) and environments (home, work, and social). Adjusted odds ratios and 95% confidence intervals were estimated by multivariable logistic regression, and statistical interactions were assessed using the likelihood ratio test. Among postmenopausal women, most associations between passive smoke and breast cancer risk were null, whereas among premenopausal women, nonsignificant positive associations were observed. Significant interactions were observed between certain types of passive smoke exposure and genetic variants in CYP2E1, NAT2, and UGT1A7. While these interactions were statistically significant, the magnitudes of the effect estimates were not consistent or easily interpretable, suggesting that they were perhaps due to chance. Although the results of this study were largely null, it is possible that premenopausal women exposed to passive smoke or carrying certain genetic variants may be at higher risk of breast cancer.

Second cancer incidence and cancer mortality among chronic lymphocytic leukaemia patients: a population-based study

Background:

Patients with chronic lymphocytic leukaemia (CLL) are known to have increased risks of second cancer. The incidence of second cancers after CLL has not been reported in detail for Australia, a country with particularly high levels of ultraviolet radiation (UVR).

Methods:

The study cohort comprised of all people diagnosed with a primary CLL between 1983 and 2005 in Australia. Standardised incidence ratios (SIRs) and standardised mortality ratios (SMRs) were calculated using Australian population rates.

Results:

Overall, the risk of any second incident cancer was more than double that of the general population (SIR=2.17, 95% confidence interval (CI)=2.07, 2.27) and remained elevated for at least 9 years after CLL. Risks were increased for many cancers, particularly melanoma (SIR=7.74, 95% CI=6.85, 8.72). The risk of melanoma increased at younger ages, but was constant across >9 years of follow-up. Chronic lymphocytic leukaemia patients also had an increased risk of death because of melanoma (SMR=4.79, 95% CI=3.83, 5.90) and non-melanoma skin cancer (NMSC; SMR=17.0, 95% CI=14.4, 19.8), suggesting that these skin cancers may be more aggressive in CLL patients.

Conclusion:

We speculate that a shared risk factor, such as general immune suppression, modulated by UVR exposure may explain the increased risk of melanoma and NMSC in CLL patients.

Incidence of non-lung solid cancers in Czech uranium miners: a case-cohort study

OBJECTIVES

Uranium miners are chronically exposed to radon and its progeny, which are known to cause lung cancer and may be associated with leukemia. This study was undertaken to evaluate risk of non-lung solid cancers among uranium miners in Příbram region, Czech Republic.

METHODS

A retrospective stratified case-cohort study in a cohort of 22,816 underground miners who were employed between 1949 and 1975. All incident non-lung solid cancers were ascertained among miners who worked underground for at least 12 months (n=1020). A subcohort of 1707 subjects was randomly drawn from the same population by random sampling stratified on age. The follow-up period lasted from 1977 to 1996.

RESULTS

Relative risks comparing 180 WLM (90th percentile) of cumulative lifetime radon exposure to 3 WLM (10th percentile) were 0.88 for all non-lung solid cancers combined (95% CI 0.73-1.04, n=1020), 0.87 for all digestive cancers (95% CI 0.69-1.09, n=561), 2.39 for gallbladder cancer (95% CI 0.52-10.98, n=13), 0.79 for larynx cancer (95% CI 0.38-1.64, n=62), 2.92 for malignant melanoma (95% CI 0.91-9.42, n=23), 0.84 for bladder cancer (95% CI 0.43-1.65, n=73), and 1.13 for kidney cancer (95% CI 0.62-2.04, n=66). No cancer type was significantly associated with radon exposure; only malignant melanoma and gallbladder cancer showed elevated but non-significant association with radon.

CONCLUSIONS

Radon was not significantly associated with incidence of any cancer of interest, although a positive association of radon with malignant melanoma and gallbladder cancer cannot be entirely ruled out.

Intensity and inhalation of smoking in the aetiology of laryngeal cancer

The carcinogenic effect of smoking on laryngeal cancer is well established; however, the risk pattern for detailed smoking characteristics is less clear. Thus, the aim of this analysis was to quantify the impact of different inhalation behaviours on the risk of laryngeal cancer. We conducted a population-based case control study in Germany, frequency-matched for sex and age, using a standardized questionnaire covering lifelong smoking details, including age at start, time since quitting, types of smoking products, duration, intensity and inhalation behaviour. We found higher risks for increasing duration and intensity of smoking. A clear dose-response relationship was found in all inhalation subgroups, i.e., not only for deep inhalers, but also for those puffing on a cigarette. Clearly reduced risks could be observed for quitting smoking. Changing inhalation habits might be considered as a first step to reducing the risk of developing laryngeal cancer. However, the best way to effectively reduce laryngeal cancer risk is to quit smoking.

Epigenetic effects and molecular mechanisms of tumorigenesis induced by cigarette smoke: an overview

Cigarette smoking is one of the major causes of carcinogenesis. Direct genotoxicity induced by cigarette smoke leads to initiation of carcinogenesis. Nongenotoxic (epigenetic) effects of cigarette smoke also act as modulators altering cellular functions. These two effects underlie the mechanisms of tumor promotion and progression. While there is no lack of general reviews on the genotoxic and carcinogenic potentials of cigarette smoke in lung carcinogenesis, updated review on the epigenetic effects and molecular mechanisms of cigarette smoke and carcinogenesis, not limited to lung, is lacking. We are presenting a comprehensive review of recent investigations on cigarette smoke, with special attentions to nicotine, NNK, and PAHs. The current understanding on their molecular mechanisms include (1) receptors, (2) cell cycle regulators, (3) signaling pathways, (4) apoptosis mediators, (5) angiogenic factors, and (6) invasive and metastasis mediators. This review highlighted the complexity biological responses to cigarette smoke components and their involvements in tumorigenesis.

Lysyl oxidase, a critical intra- and extra-cellular target in the lung for cigarette smoke pathogenesis

Cigarette smoke (CS), a complex chemical mixture, contains more than 4,800 different compounds, including oxidants, heavy metals, and carcinogens, that individually or in combination initiate or promote pathogenesis in the lung accounting for 82% of chronic obstructive pulmonary disease (COPD) deaths and 87% of lung cancer deaths. Lysyl oxidase (LO), a Cu-dependent enzyme, oxidizes peptidyl lysine residues in collagen, elastin and histone H1, essential for stabilization of the extracellular matrix and cell nucleus. Considerable evidences have shown that LO is a tumor suppressor as exemplified by inhibiting transforming activity of ras, a proto oncogene. CS condensate (CSC), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and cadmium (Cd), major components of CS, down-regulate LO expression at such multiple levels as mRNA, protein and catalytic activity in lung cells in vitro and in vivo indicating LO as a critical intra- and extracellular target for CS pathogenesis in the lung. In view of multiple biological functions and regulation characteristics of the LO gene, molecular mechanisms for CS damage to lung LO and its role in emphysema and cancer pathogenesis are discussed in this review.

Mutations in TP53 tumor suppressor gene in wood dust-related sinonasal cancer

The causal role of work-related exposure to wood dust in the development of sinonasal cancer has long been established by numerous epidemiologic studies. To study molecular changes in these tumors, we analyzed TP53 gene mutations in 358 sinonasal cancer cases with or without occupational exposure to wood dust, using capillary electrophoresis single-strand conformation polymorphism analysis and direct sequencing. A significant association between wood-dust exposure and adenocarcinoma histology was observed [adjusted odds ratio (OR) 12.6, 95% confidence interval (CI), 5.0-31.6]. TP53 mutations occurred in all histologies, with an overall frequency of 77%. TP53 mutation positive status was most common in adenocarcinoma (OR 2.0, 95% CI, 1.1-3.7; compared with squamous cell carcinoma), and mutation positivity showed an overall, nonsignificant association with wood-dust exposure (OR 1.6, 95% CI, 0.8-3.1). Risk of TP53 mutation was significantly increased in association with duration (> or =24 years, OR 5.1, 95% CI, 1.5-17.1), average level (>2 mg/m(3); OR 3.6, 95% CI, 1.2-10.8) and cumulative level (> or =30 mg/m(3) x years; OR 3.5, 95% CI, 1.2-10.7) of wood-dust exposure; adjustment for formaldehyde affected the ORs only slightly. Smoking did not influence the occurrence of TP53 mutation; however, it was associated with multiple mutations (p = 0.03). As far as we are aware, this is the first study to demonstrate a high prevalence of TP53 mutation-positive cases in a large collection of sinonasal cancers with data on occupational exposure. Our results indicate that mutational mechanisms, in particular TP53 mutations, are associated with work-related exposure to wood dust in sinonasal cancer.

DNA damage response induced by exposure of human lung adenocarcinoma cells to smoke from tobacco- and nicotine-free cigarettes

Cigarette smoke (CS) is the major cause of lung cancer and contributes to the development of other malignancies. Attempts have been made to construct reduced toxicity cigarettes, presumed to have diminished genotoxic potential. One such product on the market is the tobacco and nicotine free (T&N-free) cigarette type made from lettuce and herbal extracts. We have recently developed a sensitive assay of the genotoxicity of CS based on cytometric analysis of induction of the DNA damage response (DDR) in normal human pulmonary endothelial or A549 pulmonary adenocarcinoma cells. In the present study, we observed that exposure of A549 cells to CS from T/N-free cigarettes induced a smoke-dose dependent DDR as evidenced by phosphorylation (activation) of the Ataxia telangiectasia mutated (ATM) protein kinase and of the histone H2AX (γH2AX). The extent of DDR induced by T&N-free smoke was distinctly greater than that induced by comparable doses of CS from reference cigarettes (2R4F) containing tobacco and nicotine. The pattern of DDR induced by T&N-free smoke was similar to that of 2R4F cigarettes in terms of the cell cycle phase specificity and involvement of reactive oxygen species (ROS). The data also imply that similar to 2R4F exposure of cells to T/N-free smoke leads to formation of double-strand DNA breaks (DSBs) resulting from collapse of replication forks upon collision with the primary ssDNA lesions induced by smoke. Since DSBs are potentially carcinogenic our data indicate that smoking tobacco and nicotine-free cigarettes is at least as hazardous as smoking cigarettes containing tobacco and nicotine.

Feline paediatric oncology: retrospective assessment of 233 tumours from cats up to one year (1993 to 2008)

OBJECTIVES

To determine which types of tumour occur in cats up to the age of 12 months based on biopsies submitted to Idexx Laboratories, Wetherby, UK.

METHODS

Retrospective review of histopathological diagnoses of tumours in cats up to the age of 12 months from biopsies received between September 1993 and March 2008.

RESULTS

A total of 4196 submissions from cats 12 months old or younger were identified; 233 biopsies (6%) were neoplastic and fulfilled the search criteria. Tumours were categorised as haematopoietic (n=73, 31%), malignant epithelial (n=44; 19%), malignant mesenchymal (n=38; 16%), benign epithelial (n=37; 16%), benign mesenchymal (n=30, 13%) and miscellaneous (n=11; 5%). The most frequent tumours were lymphoma (n=51; 22%), soft-tissue sarcoma (n=34; 15%), mast cell tumour (n=22; 9%) and squamous cell carcinoma (n=16; 7%). The most common tumour site was the skin and soft tissues (41% of tumours). In all, 164 neoplasms (70%) were malignant or had malignant potential.

CLINICAL SIGNIFICANCE

These data provide unique epidemiological information on a poorly characterised subgroup of feline cancer patients in the UK.