Smoking and lung cancer
Department of Chest Diseases, Faculty of Medicine, Karadeniz Technical University, Trabzon, Turkey. Tuberkuloz ve toraks
Nowadays, around one-third of adults are known to be smokers, and smoking rates are increasing among the female population. It is estimated that deaths attributable to tobacco use will rise to 10 million by 2025, and one-third of all adult deaths are expected to be related to cigarette smoking. The association between cigarettes and lung cancer has been proven by large cohort studies. Tobacco use has been reported to be the main cause of 90% of male and 79% of female lung cancers. 90% of deaths from lung cancer are estimated to be due to smoking. The risk of lung cancer development is 20-40 times higher in lifelong smokers compared to non-smokers. Environmental cigarette smoke exposure and different types of smoking have been shown to cause pulmonary carcinoma. DNA adducts, the metabolites of smoke carcinogens bound covalently with DNA, are regarded as an indicator of cancer risk in smokers. In recent decades, there has been a shift from squamous and small cell lung cancer types to adenocarcinoma, due to increasing rates of smoking among female population and rising light cigarette usage. After smoking cessation, the cumulative death risk from lung cancer decreases. Patients who continue smoking experience greater difficulties during cancer treatment. Stopping smoking may prolong survival in cancer patients, and also decreases the risk of recurrent pulmonary carcinoma. In order to save lives and prevent smoking related hazards, physicians should advise both healthy individuals and those with cancer of the benefits of stopping smoking.
- "Cigarette smoke is the leading cause of preventable diseases worldwide and, in the USA alone, smoking causes approximately 400 000 deaths annually1, 2. Smoking is associated with an increased incidence of acute respiratory infections3, periodontitis4, bacterial meningitis5, rheumatoid arthritis6, Crohn's disease7, systemic lupus erythematosus8, atherosclerosis9, chronic obstructive pulmonary diseases10, lung cancer11 and coronary heart disease12. While increasing data indicate that smoking might decrease the incidence and/or severity of several diseases, including ulcerative colitis13, 14, Parkinson's disease (PD)15, 16, 17, 18, some forms of Alzheimer's disease (AD)19, 20, 21, hypersensitivity pneumonitis (HP)22 and type I diabetes23; nicotine also protects the kidneys from renal ischemia/reperfusion injury24. "
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ABSTRACT: Cigarette smoke is a major health risk factor which significantly increases the incidence of diseases including lung cancer and respiratory infections. However, there is increasing evidence that smokers have a lower incidence of some inflammatory and neurodegenerative diseases. Nicotine is the main immunosuppressive constituent of cigarette smoke, which inhibits both the innate and adaptive immune responses. Unlike cigarette smoke, nicotine is not yet considered to be a carcinogen and may, in fact, have therapeutic potential as a neuroprotective and anti-inflammatory agent. This review provides a synopsis summarizing the effects of nicotine on the immune system and its (nicotine) influences on various neurological diseases.Keywords: nicotine, cigarette smoke, immune system
Acta Pharmacologica Sinica 05/2009; 30(6):715-722. DOI:10.1038/aps.2009.67 · 2.91 Impact Factor
Available from: Deeba Syed
- "Epidemiological evidence confirms that exposure to cigarette smoke, a complex mixture of more than 4000 particulate and volatile components, increases the incidence of lung carcinogenesis, a leading cause of cancer deaths in the US and other developed countries (Sasco et al., 2004). The risk of lung cancer development is 20–40 times higher in lifelong smokers compared to non-smokers accounting for 90% of male and 79% of female lung cancers (Ozlu and Bulbul, 2005). Airway inflammation is ubiquitous in the lungs of smokers, regardless of the presence or absence of lung disease. "
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ABSTRACT: Cigarette smoke is a powerful inducer of inflammatory responses resulting in disruption of major cellular pathways with transcriptional and genomic alterations driving the cells towards carcinogenesis. Cell culture and animal model studies indicate that (-)-epigallocatechin-3-gallate (EGCG), the major polyphenol present in green tea, possesses potent anti-inflammatory and antiproliferative activity capable of selectively inhibiting cell growth and inducing apoptosis in cancer cells without adversely affecting normal cells. Here, we demonstrate that EGCG pretreatment (20-80 microM) of normal human bronchial epithelial cells (NHBE) resulted in significant inhibition of cigarette smoke condensate (CSC)-induced cell proliferation. Nuclear factor-kappaB (NF-kappaB) controls the transcription of genes involved in immune and inflammatory responses. In most cells, NF-kappaB prevents apoptosis by mediating cell survival signals. Pretreatment of NHBE cells with EGCG suppressed CSC-induced phosphorylation of IkappaBalpha, and activation and nuclear translocation of NF-kappaB/p65. NHBE cells transfected with a luciferase reporter plasmid containing an NF-kappaB-inducible promoter sequence showed an increased reporter activity after CSC exposure that was specifically inhibited by EGCG pretreatment. Immunoblot analysis showed that pretreatment of NHBE cells with EGCG resulted in a significant downregulation of NF-kappaB-regulated proteins cyclin D1, MMP-9, IL-8 and iNOS. EGCG pretreatment further inhibited CSC-induced phosphorylation of ERK1/2, JNK and p38 MAPKs and resulted in a decreased expression of PI3K, AKT and mTOR signaling molecules. Taken together, our data indicate that EGCG can suppress NF-kappaB activation as well as other pro-survival pathways such as PI3K/AKT/mTOR and MAPKs in NHBE cells, which may contribute to its ability to suppress inflammation, proliferation and angiogenesis induced by cigarette smoke.
Oncogene 03/2007; 26(5):673-82. DOI:10.1038/sj.onc.1209829 · 8.46 Impact Factor
Available from: Benjamin Littenberg
- "Cigarette smoking is somewhat less prevalent in the cancer patients than the non-cancer patients, in spite of the well-known association of tobacco use and cancer incidence. This could be because cancer survivors are highly motivated to quit smoking , or that smokers with cancer die at a higher rate than non-smokers with cancer . "
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ABSTRACT: Peroxisome proliferator-activated receptors (PPARs) have emerged as important drug targets for diabetes. Drugs that activate PPARgamma, such as the thiazolidinediones (TZDs), are widely used for treatment of Type 2 diabetes mellitus. PPARgamma signaling could also play an anti-neoplastic role in several in vitro models, although conflicting results are reported from in vivo models. The effects of TZDs on cancer risk in humans needs to be resolved as these drugs are prescribed for long periods of time in patients with diabetes.
A total of 1003 subjects in community practice settings were interviewed at home at the time of enrolment into the Vermont Diabetes Information System, a clinical decision support program. Patients self-reported their personal and clinical characteristics, including any history of malignancy. Laboratory data were obtained directly from the clinical laboratory and current medications were obtained by direct observation of medication containers. We performed a cross-sectional analysis of the interviewed subjects to assess a possible association between cancer diagnosis and the use of TZDs.
In a multivariate logistic regression model, a diagnosis of cancer was significantly associated with TZD use, even after correcting for potential confounders including other oral anti-diabetic agents (sulfonylureas and biguanides), age, glycosylated hemoglobin A1C, body mass index, cigarette smoking, high comorbidity, and number of prescription medications (odds ratio = 1.59, P = 0.04). This association was particularly strong among patients using rosiglitazone (OR = 1.89, P = 0.02), and among women (OR = 2.07, P = 0.01).
These data suggest an association between TZD use and cancer in patients with diabetes. Further studies are required to determine if this association is causal.
BMC Medicine 02/2007; 5(1):17. DOI:10.1186/1741-7015-5-17 · 7.25 Impact Factor
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