Does Smoking Weaken the Immune System: A Narrative Review

Smoking has a complex impact on the immune system, affecting both innate and adaptive immunity. It can exacerbate pathogenic immune responses and attenuate defensive immunity, leading to a higher susceptibility to infections and certain diseases. The chemicals in cigarette smoke, such as nicotine and carbon monoxide, can alter immune cell functions and inflammatory responses. Smoking can also have long-term effects on the immune system, with some changes persisting even after quitting [1]. According to a Penn Medicine Physician, the Medical Oncologist Dr. David Porter, “People who are smokers tend to get sicker from infections”, “It may be that smoking impacts the immune system’s ability to respond appropriately”. Thus, such individuals within smoking exposure history might be considered as immunocompromised due to the altered and weakened immune system. Cigarette smoking is a prevalent habit with far-reaching health implications. Among its many adverse effects, smoking significantly alters the immune system’s functionality [1].

Exploring the Impact of Alcohol Consumption and Smoking on Primary Open Angle Glaucoma: A Mendelian Randomization Study

Objective: Utilizing Mendelian Randomization, this study employs Single Nucleotide Polymorphisms (SNPs) as instrumental variables to explore the causal relationships between bibulosity, smoking, and Primary Open Angle Glaucoma (POAG). Methods: GWAS data for bibulosity, smoking, and POAG were obtained from the Social Science Genetic Association Consortium website and the IEU OpenGWAS Project website, respectively. Using a P-value threshold of −8, a linkage disequilibrium coefficient (r2) of 0.001, and a linkage disequilibrium region width of 10,000 kb, the data were aggregated, resulting in 6 SNPs for bibulosity and 253 SNPs for smoking. Three regression models, MR-Egger, Weighted Median Estimator (WME), and Random-Effects Inverse-Variance Weighted (IVW) were applied to analyze the causal impact of bibulosity and smoking on POAG. Results: The GWAS data for alcohol consumption and smoking were derived from European populations, while the GWAS data for Primary Open-Angle Glaucoma (POAG) were sourced from East Asian populations, with no gender restrictions. Analysis using three different regression models revealed that neither excessive alcohol consumption nor smoking significantly increased the risk of developing POAG. Specifically, the odds ratios with 95% confidence intervals for the alcohol consumption group were 0.854 (0.597 - 1.221) in MR-Egger regression, 0.922 (0.691 - 1.231) in WME regression, and 0.944 (0.711 - 1.252) in IVW regression. For the smoking group, the odds ratios were 1.146 (0.546 - 2.406) in MR-Egger regression, 0.850 (0.653 - 1.111) in WME regression, and 0.939 (0.780 - 1.131) in IVW regression. Given the significant heterogeneity in the SNPs associated with smoking, the focus was primarily on the results from the IVW regression model. Conclusion: Alcohol consumption and smoking are not significant risk factors for the development of POAG.

Persuasive Technology for the Future of Smoking Cessation*

This paper explores the integration of persuasive technology into smoking cessation efforts through the development and evaluation of a mobile app, “No-Smoke.” Leveraging compelling features like social support, tracking, planning, and motivation, the app aims to augment user engagement and support the process of quitting smoking. The efficacy of these features has been substantiated through both automated testing and user feedback, highlighting their potential to enhance awareness, motivation, and behavior modification. Despite notable successes, limitations, including a limited user base and uncertainties regarding long-term efficacy, have been acknowledged, stemming from the inherent complexities of smoking cessation. Nevertheless, based on user experiences and feedback, “No-Smoke” represents a promising advancement in the use of technology for public health interventions, particularly in the realm of smoking cessation. To address existing challenges, future research is recommended to encompass a comprehensive, long-term study involving a larger and more diverse user base. Additionally, further investigation should focus on personalization enhancements and the integration of machine learning algorithms to better understand and respond to user behavior.

An Efficient ResNetSE Architecture for Smoking Activity Recognition from Smartwatch

Smoking is a major cause of cancer,heart disease and other afflictions that lead to early mortality.An effective smoking classification mechanism that provides insights into individual smoking habits would assist in implementing addiction treatment initiatives.Smoking activities often accompany other activities such as drinking or eating.Consequently,smoking activity recognition can be a challenging topic in human activity recognition(HAR).A deep learning framework for smoking activity recognition(SAR)employing smartwatch sensors was proposed together with a deep residual network combined with squeeze-and-excitation modules(ResNetSE)to increase the effectiveness of the SAR framework.The proposed model was tested against basic convolutional neural networks(CNNs)and recurrent neural networks(LSTM,BiLSTM,GRU and BiGRU)to recognize smoking and other similar activities such as drinking,eating and walking using the UT-Smoke dataset.Three different scenarios were investigated for their recognition performances using standard HAR metrics(accuracy,F1-score and the area under the ROC curve).Our proposed ResNetSE outperformed the other basic deep learning networks,with maximum accuracy of 98.63%.

Lung Cancer Risk Attributable to Active Smoking in China:A Systematic Review and Meta-Analysis

Objective No consensus exists on the relative risk(RR)of lung cancer(LC)attributable to active smoking in China.This study aimed to evaluate the unified RR of LC attributable to active smoking among the Chinese population.Methods A systematic literature search of seven databases was conducted to identify studies reporting active smoking among smokers versus nonsmokers in China.Primary articles on LC providing risk estimates with their 95%confidence intervals(CIs)for“ever”“former”or“current”smokers from China were selected.Meta-analysis was used to estimate the pooled RR of active smoking.Results Forty-four unique studies were included.Compared with that of nonsmokers,the pooled RR(95%CI)for“ever”“former”and“current”smokers were 3.26(2.79–3.82),2.95(1.71–5.08),and 5.16(2.58–10.34)among men,3.18(2.78–3.63),2.70(2.08–3.51),and 4.27(3.61–5.06)among women,and2.71(2.12–3.46),2.66(2.45–2.88),and 4.21(3.25–5.45)in both sexes combined,respectively.Conclusion The RR of LC has remained relatively stable(range,2–6)over the past four decades in China.Early quitting of smoking could reduce the RR to some extent;however,completely refraining from smoking is the best way to avoid its adverse effects.

Reproductive outcomes of water pipe smoking:A scoping review

Objective:To present an overview of the adverse effects of water pipe smoking on various aspects of reproduction and perinatal complications,covering all the most relevant studies,from descriptive findings to clinical trials.Methods:We reviewed the literature and included full publications in English provided by international biomedical databases,including PubMed,Science Direct,EBSCO,Scopus,and Google Scholar,and Cochrane Library over the last 38 years(May 1985 to June 2023).Search terms(Water pipe,Narghile,Shisha,Dokha,etc.,and Reproduction,Fertility,etc.)were adopted from Medical Subheading(MeSH)and Boolean operators were utilized to improve sensitivity.Results:133 Papers were identified in the initial search,of which 29 were excluded due to duplication.Eliminating search overlap and irrelevant records by reviewing titles and abstracts reduced 42 papers.62 Full-publication articles met the inclusion criteria.We summarized the effects of waterpipe smoke exposure on reproductive health based on three main categories:male and female fertility,fetal and neonatal outcomes,and pregnancy complications.Conclusions:Water pipe smoking has potential adverse effects on different aspects of human reproductive health,including semen parameters,male and female fertility,and fetal and neonatal health,and contributes to many maternal complications and morbidities.

The Prevalence, Pattern, and Factors Affecting Cigarette Smoking among Undergraduate Students in a Tertiary Institution in Plateau State, Nigeria

Background: Cigarette smoking is a modern health hazard, and it is preventable. It starts in adolescence for 90% of adults with an average age of onset ranging between 13 - 15 years and is commoner among males. This study is aimed at the prevalence, pattern, and factors affecting Cigarette smoking among undergraduate students in a tertiary institution in Plateau State. Method: A cross-sectional descriptive study involving 290 undergraduate students of the University of Jos was selected using the multistage sampling method. Results: The prevalence of cigarette use was 5.3%. Seven (70.0%) of students smoke daily, 6 (60.0%), smoke cigarettes before Lecture Hours, and 90.0% are unwilling to stop smoking. Smoking was done to experience the highness feeling, 8 (80.0%), peer smoking 8 (80.0%), to reduce stress and tension 5 (50.0%), and Smoking for Fun 7 (70.0%). Most students first smoked a cigarette when with friends 6 (60.0%). Factors significantly associated with the current use of cigarettes among the respondents were religion (χ2 = 4.167, p = 0.041) Level/year of study (χ2 = 32.266, p ≤ 0.001), and type of family (χ2 = 6.271, p = 0.043). Conclusion: Most students smoke daily, smoke before lectures start, and are unwilling to stop smoking. Health-promotion program to help smoking cessation and prevent initiation of smoking is recommended.

Relationship between anal cancer recurrence and cigarette smoking

BACKGROUND The incidence of anal cancer has been increasing in the United States.Smoking is a well-established risk factor;however,the impact of smoking on disease recurrence and outcome has not been well studied.The aim of this study was to assess the association between anal cancer recurrence and cigarette smoking.AIM To investigate the relationship between cigarette smoking status and anal cancer treatment outcome.METHODS The cancer registry from a single,community hospital was screened for patients with anal cancer between 2010 and 2021.The following characteristics were gathered from the database:Age;sex;cigarette smoking history;American Joint Committee on Cancer Clinical Stage Group;response to therapy;recurrence;time to recurrence;mortality;time to death;and length of follow-up.Patients were divided into the following groups:Current smokers;former smokers;and never smokers.SPSSv25.0 software(IBM Corp.,Armonk,NY,United States)was used for statistical analysis.RESULTS A total of 95 patients from the database met the screening criteria.There were 37 never smokers,22 former smokers,and 36 current smokers.There was no difference between groups in regards to race or sex.There was no difference in the American Joint Committee on Cancer Clinical Stage Group between groups.The former smokers were significantly older when compared to never smokers and current smokers(66.5±13.17 vs 57.4±7.82 vs 63.7±13.80,P=0.011).Former smokers and current smokers had a higher recurrence rate compared to never smokers(30.8%and 20.8%compared to zero,P=0.009).There was not a significant difference in recurrence between former smokers and current smokers.There was no difference in the mortality,non-response rate,or time to death between the groups.CONCLUSION Our data contributes evidence that cigarette smoking status is associated with increased recurrence for patients with anal cancer.

The effects of smoking on blood lipids, C-reactive protein, and homocysteine in young patients with ischemic stroke

Objective:To investigate clinical signif-icance of the effects of smoking on blood lipids, C-reac-tive protein,and homocysteine in young ischemic stroke patients.Methods:The clinical data of 423 young stroke patients in the department of neurology at Taihe Hospi-tal in Shiyan City, China were retrospectively analyzed, including age,gender,drinking history,family history,and atrial fibrillation history. Patients were divided into two groups according to whether they smoked,and the blood lipids, C-reactive protein, and homocysteine were compared between groups.Results:The proportion of smokers was 41.83%.The levels of total cholesterol,tri-glycerides (TG), low density lipoprotein (LDL), and ho-mocysteine were higher in patients who smoked than in those who did not(P < 0.05). High density lipoprotein (HDL) was lower in the smoking group (P < 0.05). C-re-active protein test results were divided into groups ac-cording to whether the levels exceeded the normal range or not, and no correlation was found between C-reactive protein levels and smoking(P>0.05). Conclusion:Total cholesterol, TG, LDL, HDL, and homocysteine were sig-nificantly different between stroke patients who smoked and those who did not. We therefore suggest that smok-ing cessation take place as soon as possible and that it be avoided entirely in order to reduce the incidence of atherosclerosis and stroke.

Incidence of Haematoma Formation in Relation to Smoking in Abdominoplasty Cases

Objective: This study aims at assessing the relation between smoking and the incidence of haematoma formation in abdominoplasty surgery cases. Patients and Methods: This is a 4 years retrospective study involving the patients who underwent abdominoplasty surgery between the period of May 2015 and April 2019 in Zayed Military Hospital, Abu Dhabi, United Arab of Emirates. The incidence of haematoma formation was assessed in relation to tobacco use in these patients. Results: 164 patients met the inclusion criteria of the study. 35 patients were smokers (21.3%) and 129 patients were non-smokers (78.7%). The mean age was 38.4 (21 - 59 years). The mean BMI was 27 kg/m2 (21.4 - 34.7 kg/m2) and the mean hospital stay was 6.5 days (4 - 19). 23 patients in the study developed haematoma (14%). 11 of them had surgical evacuation of the haematoma (6.7%) while the rest were aspirated in the out-patient clinic. Out of the 23 patients who developed haematoma, 17 patients were smokers and 6 were non-smokers. The incidence of haematoma among smokers was 48.6% (17 out of 35 cases) while its incidence among nonsmokers was 4.7% (6 out of 129 cases) showing a clear relationship between smoking and hematoma formation (p Conclusion: Our study shows a direct relationship between smoking and haematoma formation in abdominoplasty cases. Cessation of smoking during the perioperative period is required before embarking on such a procedure.

Difference analysis of the influence of smoking on LDL,Cys-C,and hs-CRP in patients with cerebral infarction

Objective:To compare the effects of smoking on low-density lipoprotein(LDL),cystatin C(Cys-C)and C-reactive protein(hs-CRP)in patients with cerebral infarction.Methods:The clinical data of acute stroke patients classified as large atherosclerosis by the trial of Org 10172 in acute stroke treatment(TOAST)classification were collected,and the differences of gener-al data and results of LDL,Cys-C and hs-CRP in smoking and nonsmoking patients were compared to search for rel-evant clinical data with statistical significance.Results:A total of 116 patients with acute stroke classified as large atherosclerotic by TOAST were collected and divid-ed into groups according to smoking status.Among the smoking patients,gender,age,occupation,drinking,hy-pertension,and diabetes were used as influencing factors to compare whether LDL was greater than or equal to 1.3 mmol/L,Cys-C≥0.8 mg/L and hs-CRP≥4 mg/L,with P values greater than 0.05.There was no statistical differ-ence.Among non-smoking patients,occupation,alcohol consumption,and high blood pressure had statistical sig-nificance for whether LDL was greater than 1.3 mmol/L.Age,occupation,and diabetes had statistical significance for whether Cys-C was greater than 0.8 mg/L.Conclu-sion:In this study,there was no statistically significant impact on the test results of LDL,Cys-C,and CRP whether the patients with ischemic stroke were smokers or nonsmokers.

Impacts of Preoperative Smoking and Smoking Cessation Time on Preoperative Peripheral Blood Inflammatory Indexes and Postoperative Hospitalization Outcome in Male Patients with Lung Cancer and Surgery Treatment

Objectives To investigate the effects of preoperative smoking and smoking cessation time on preoperative peripheral blood inflammatory indexes and postoperative hospitalization outcomes in male patients with lung cancer and surgery therapy.Methods We retrospectively enrolled 637 male patients who underwent curative-intent lung cancer resection between January 2014 and December 2016.Patients were classified as the current smokers,the never smokers,and the ex-smokers based on their smoking history,and the ex-smokers were allocated into five subgroups according to their smoking cessation times(CeT):CeT W6 weeks,6weeks<CeT W lyear,lyear<CeT<5years,5years<CeT<lOyears,CeT>10years.The preoperative peripheral blood white blood cells(WBCs),albumin,neutrophil to lymphocyte ratio(NLR),platelet to lymphocyte ratio(PLR),intraoperative blood loss,30-day mortality,in-hospital days,hospitalization costs,intensive care un辻(ICU),admission days and placement time of closed thoracic drainage tube were compared among difTerent groups.Results There were significant differences in WBC(F=S.275,P<0.001)and albumin(F=2,470,P<0.05)among patients of current smokers,ex-smokers with different smoking cessation time,and never-smokers.The blood WBC count in current smokers(7.7 X 109/L)was significantly higher than that in ex・smokers(7.0 X 109/L)and never-smokers(5.9 X 109/L)(t=-2.145,P<0.05;t=-6.073,P<0.01,respectively).The level of peripheral blood albumin in current smokers(41.1 g/L)was lower than that in ex・smokers(42.1 g/L)and neve—smokers(43.2 g/L)(t=2.323,P<0.05;t=3.995,P<0.01,respectively).The level of peripheral blood NLR in current smokers(3.7)was higher than that in ex-smokers(3.1)and never smokers(2.8)(t—-1.836,P<0.05;t=-2.889,P<0.01,respectively).There was no significant difference in WBC,albumin and NLR among five subgroups of different smoking cessation time.No significant difference was observed in intraoperative blood loss,30-day mortality,hospitalization costs,hospital stay,ICU stay and placement time of closed thoracic drainage tube among groups either.Conclusion Smoking increases the preoperative inflammatory indexes in peripheral blood of lung cancer patients.Smoking cessation has beneficial effect on reducing levels of these inflammatory indexes,which may be not impacted by the time length of smoking cessation.Therefore,lung cancer patients should be encouraged to quit smoking at any time.

Impact of Smoking Status on Lipoprotein Subfractions： Data from an Untreated Chinese Cohort

Objective Cigarette smoking is one of the established risk factors of atherosclerotic cardiovascular disease, however, its impact on lipids is not completely understood, especially in the Chinese population. Therefore, this study evaluated the impact of smoking status （non, former, and current smoking） on the distribution of lipoprotein subfractions in untreated patients with angina-like chest pain. Methods A total of 877 patients were consecutively enrolled and divided into nonsmoking （n = 528）, former smoking （n = 103）, and current smoking （n = 256） groups. Both low- and high-density lipoprotein cholesterol （LDL-C and HDL-C） subfractions were measured using the Quantimetrix Lipoprint System. The distributions of lipoprotein subfractions were evaluated among the groups. Results Compared with nonsmoking subjects, the current smoking group had significantly lower large/medium HDL-C （both P 〈 0.001） concentration and large HDL subfraction percentage but higher small HDL-C and medium LDL-C concentrations as well as medium LDL subfraction percentage. Importantly, former smoking subjects showed elevated levels of large HDL-C concentration, large HDL particle percentage, and mean LDL particle size and attenuation in small HDL/LDL percentages and small LDL-C concentration, but these levels did not reach the optimal status compared with those of the non-smoking group （data not shown）. Conclusion Smoking has an adverse impact on the lipoprotein subfractions, presented as lower large HDL particles besides higher small HDL and medium LDL particles, whereas smoking cessation could reverse these change to a certain degree.

Supporting smoking cessation in healthcare: obstacles in scientific understanding and tobacco addiction management

Despite ongoing efforts to reduce tobacco smoking, the smoking prevalence in many countries has remained stable for years. This may be a consequence of either lack of knowledge about effective ways to reduce smoking, or failing treatment of tobacco addiction in healthcare. This study explored gaps in the current understanding of smoking cessation and the challenges facing tobacco addiction management in order to formulate recommendations for future research and healthcare practice. A narrative review was written to determine areas in which more research is needed as well as areas in which sufficient knowledge is already available. Recommendations for future research were prioritised using a Delphi-procedure. Recommendations for healthcare practice were confirmed by expert’s assessment. Smoking is not widely acknowledged as an addiction and a relatively small number of smokers ask help from a healthcare professional when trying to stop smoking. Most healthcare professionals recognise the importance of advising patients to stop smoking, but experience certain barriers to actually do this. Overall, healthcare professionals need to be convinced that tobacco smoking is an addiction and should be treated likewise. If all healthcare professionals systematically advise their patients to give up smoking, eventually more smokers will successfully stop smoking.

Impact of stopping smoking on metabolic parameters in diabetes mellitus:A scoping review

The purpose of this scoping review is to create a single narrative that describes the impact of smoking cessation on metabolic parameters in people with diabetes.It is generally well accepted that smoking enhances the harmful effects of elevated blood glucose levels,accelerating the vascular damage seen in patients with diabetes.Smoking cessation has clear benefits in terms of reducing cardiovascular morbidity and mortality.However,there is less evidence for the impact of smoking cessation on other diabetes-related complications.Studies in people with diabetes have shown improvement as well as temporary deterioration in glycemic control after ceasing smoking.Only a few studies have described the effect of quitting smoking on insulin resistance and lipid parameters,however,their results have been inconclusive.In this situation,healthcare professionals should not assume that cessation of smoking will improve metabolic parameters in patients with diabetes.It seems they should, first of all, emphasize the prevention of weight gain that may be associatedwith quitting smoking. The lack of data regarding the metabolic effects of smoking and smokingcessation in diabetes is very disappointing and this area needs to be addressed.

Resumption of Smoking by Women after Childbirth: Influence of Spousal Smoking

To investigate factors related to resumption of smoking by women after childbirth, the smoking habits of 241 postnatal women, who initially had stopped smoking after pregnancy, in a rural city in Aomori Prefecture, Japan, were studied at 5 - 6 days, 1 month, and 12 months after childbirth. At 1 month after childbirth, only nine women had resumed smoking, but a total of 40 women had resumed smoking after 12 months. Factors related to smoking resumption after childbirth included the switching from breast feeding to bottle feeding and the influence of smoking by their spouses. Spousal smoking is an important factor in the resumption of smoking by women after childbirth.

Miss Chimp Says No to Smoking

A chimpanzee(大猩猩)in the zoo in Xi'an,Shaanxi Province has given up smoking after 16 years with the help of her keepers(饲养员).The zookeepers,wor- ried about her health,helped 27-year-old“Ai Ai”off tobacco(烟草)by treating her with entertainment(娱乐)and tasty diets.

Dental Implant Patients Grouped by the Brinkman Index: Their Attitude toward Smoking, Nicotine Dependence, and Knowledge of Peri-Implantitis

Purpose: This study investigated the attitude of patients, grouped by the Brinkman index, towards smoking by using the Kano Test for Social Nicotine Dependence (KTSND) and their knowledge of peri-implantitis. Methods: The participants were 3093 new patients who visited the Tokyo Medical and Dental University Hospital from January 2012 to December 2013 for an oral implant. The methodology included a questionnaire about sex, age, smoking status, daily average number of cigarettes, years of smoking, knowledge of peri-implantitis, and the KTSND. The patients were grouped according to their smoking status by calculating their Brinkman index (over 200 or not): current smokers with the possibility of nicotine dependence (BI(+)CS), current smokers with no possibility of nicotine dependence (BI(-)CS), ex-smokers (ES), and non-smokers (NS). The Brinkman index is obtained by multiplying one’s daily average number of cigarettes by the number of years they have been smoking. Results: Data were collected from 2182 respondents (response rate = 71%). The KTSND scores of BI(+)CS (16.89 ± 4.26) were significantly higher than the scores of ES (11.99 ± 4.52) and NS (11.53 ± 5.01). In current smokers, there were no significant differences between BI(+)CS and BI(-)CS. The patients replied “I don’t know” about peri-implantitis most often in all groups;however, there were no significant differences between the groups. Discussion: BI(+)CS were more dependent on nicotine in social situations than the other groups were. In Japan, a Brinkman index over 200 is required for a nicotine-dependence management fee to be instituted for health insurance treatment. This is a major concern for young smokers, who may be excluded from treatment because their years of smoking are substantially less. Results revealed that there were no significant differences between BI(+)CS and BI(-)CS. Therefore, it was suggested that the Brinkman index did not sufficiently group the participants.

Smoking reduction did not promote future smoking cessation in a general population

Introduction: Smoking reduction (SR) has been introduced as a strategy for smokers who are unwilling or unable to quit. We wanted to investi tigate whether SR at one-year follow-up increased the probability of abstinence from smoking at three and five-year follow-up. Methods: we included a random sample from a general population, the Inter99 study, Copenhagen, Denmark. A total of 1975 participants were daily smokers (from both the intervention and the control group) with information on tobacco consumption at both baseline and one-year follow-up (year 1999 to 2001). Of these, 112 had reduced their tobacco consumption substantially, by minimum 50%, at one-year follow-up. Information on tobacco consumption and smoking status was available on 1441 and 1308 participants at three-year and five-year follow-up, respectively. Outcome was self-reported point abstinence at three and five-year follow-up. Logistic regression analyses were adjusted for confounders. Results: One out of five smokers (20.5%) had maintained their reduced tobacco consumption at five-year follow-up. About twice as many reducers as non-reducers reported that they had tried to quit since baseline (p < 0.05). In adjusted logistic regression analyses we found no association between SR at one-year follow- up and being point abstinent at three-year (OR: 0.57;CI: 0.28 - 1.15) or five-year follow-up (OR: 1.08;CI: 0.56 - 2.09). Conclusions: Our study, including smokers from a general population found no association between substantial SR and future smoking cessation at three- and five-year follow-up. No studies so far have reported that SR undermines smoking cessation, but it is still controversial whether SR significantly increases future smoking cessation.

Association of p53/p21 expression with cigarette smoking and prognosis in esophageal squamous cell carcinoma patients

<Abstract>factors,such as cigarette smoking,in esophageal squamous cell carcinoma(ESCC)in northeastern Iran,a region with a high incidence of ESCC.METHODS:The expression of p53 and p21 proteins was investigated immunohistochemically in tumor tissue from 80 ESCC patients and in 60 available paraffinembedded blocks of adjacent normal specimens from the cases,along with normal esophageal tissue from 80 healthy subjects.RESULTS:Positive expression of p53 protein was detected in 56.2%(45/80)of ESCC cases,and in none of the normal esophageal tissue of the control group(P<0.001).Furthermore,73.8%(59/80)of ESCC cases and 43.8%(35/80)of controls had positive expression of p21 protein(P<0.001).Cigarette smoking was significantly associated with p53 over-expression in ESCC cases(P=0.010,OR=3.64;95%CI:1.32-10.02).p21 over-expression was associated with poorer clinical outcome among the ESCC patients(P=0.009).CONCLUSION:Over-expression of p53 in association with cigarette smoking may play a critical role in ESCC carcinogenesis among this high-risk population of northeastern Iran.Furthermore,p21 over-expression was found to be associated with poor prognosis,specifically in the operable ESCC patients.