Importance of anatomical subsite in correlating risk factors in cancer of the oesophagus--report of a case--control study

Health effects associated with chewing tobacco: a Burden of Proof study

Chewing tobacco use poses serious health risks; yet it has not received as much attention as other tobacco-related products. This study synthesizes existing evidence regarding the health impacts of chewing tobacco while accounting for various sources of uncertainty. We conducted a systematic review and meta-analysis of chewing tobacco and seven health outcomes, drawing on 103 studies published from 1970 to 2023. We use a Burden of Proof meta-analysis to generate conservative risk estimates and find weak-to-moderate evidence that tobacco chewers have an increased risk of stroke, lip and oral cavity cancer, esophageal cancer, nasopharynx cancer, other pharynx cancer, and laryngeal cancer. We additionally find insufficient evidence of an association between chewing tobacco and ischemic heart disease. Our findings highlight a need for policy makers, researchers, and communities at risk to devote greater attention to chewing tobacco by both advancing tobacco control efforts and investing in strengthening the existing evidence base.

Esophageal cancer in relation to alcohol drinking and tobacco use among men in Kerala, India - Karunagappally cohort

BACKGROUND

In the Karunagappally cohort, esophageal cancer is the third most common cancer with an age-adjusted incidence rate of 6.2 per 100,000 person-years among men. The present study analyzed the risk of esophageal cancer in relation to alcohol drinking and tobacco use.

METHODS

The study included 65,528 men aged 30-84 years in the Karunagappally cohort, India.

RESULTS

Poisson regression analysis showed that alcohol drinking significantly increased (P = 0.027) the risk of esophageal cancer and the relative risk (RR) for current drinkers was 1.6, (95 % confidence interval (CI) = 1.1-2.3). The risk increased significantly in heavy alcohol drinkers (250 g of ethanol or above per day) (RR = 2.1, 95 % CI = 1.2-3.5) (P for trend = 0.014) and among current arrack consumers (RR = 1.8, 95 % CI = 0.99-3.29) (P for trend = 0.025). Current bidi and cigarette smokers showed an increase in the trend of cancer risk. A significantly higher risk was seen in those who had started smoking bidi before the age of 18 years, RR = 1.9 (95 % CI = 1.1-3.3) (P for trend = 0.044). Furthermore, increased RR for heavy bidi and cigarette smokers were 1.6 (95 % CI = 1.1-2.5) and 2.4 (95 % CI = 1.3-4.5), respectively.

CONCLUSION

To the best of our knowledge, this is the first cohort study in India to report an increased esophageal cancer risk with respect to alcohol drinking.

Demographic Trends in Carcinoma Esophagus from India along with a Brief Comparative Review of the Global Trends

Background Esophageal cancers (ECs) are more prevalent in the East Asian countries of the world, wherein squamous cell carcinomas (SCCs) are the predominant histological subtype. In contrast, the patterns in the West are a bit heterogeneous, with esophageal adenocarcinoma (AC) being the more frequent histological subtype. There is very sparse published Indian data pertaining to the demographic trends of ECs.

Materials and Methods Our study was a retrospective analysis of the demographic trends of 917 patients afflicted with ECs who were managed at our center over a 10-year period.

Results and Discussion EC accounted for nearly 4.1% of the total cancer burden managed at our center from January 2002 to December 2011. The mean age of our patient cohort was 54.2 years. The male:female ratio was nearly 1.7:1. Tobacco chewing was noted in 25.4%, smoking in 37%, while alcohol consumption was noted in approximately 20% of the patients. SCC was the most common histological subtype (78.3%), while ACs constituted only 9.9%. Eighty-nine percent of our patients presented with locally advanced staged tumors. Definitive chemoradiation was the most common modality of definitive management then; however, over the years, our preferred choice of the management of ECs has shifted to neoadjuvant chemoradiation, followed by surgery in the carefully selected patients of locally advanced resectable ECs.

Conclusion Our study clearly shows SCC to be the most common histological subtype among ECs, a trend that has been observed in the vast majority of the East Asian nations. The epidemic rise in the incidence of esophageal ACs as seen in the West is not seen in our study. Periodic monitoring of the demographic trends of ECs is of great importance both for clinicians and policymakers. We hope that our study will enlighten both policy holders and clinicians to better channelize the efforts toward prevention and more effective management of this deadly cancer.

Demographic Trends in Carcinoma Esophagus from India along with a Brief Comparative Review of the Global Trends

Background  Esophageal cancers (ECs) are more prevalent in the East Asian countries of the world, wherein squamous cell carcinomas (SCCs) are the predominant histological subtype. In contrast, the patterns in the West are a bit heterogeneous, with esophageal adenocarcinoma (AC) being the more frequent histological subtype. There is very sparse published Indian data pertaining to the demographic trends of ECs. Materials and Methods  Our study was a retrospective analysis of the demographic trends of 917 patients afflicted with ECs who were managed at our center over a 10-year period. Results and Discussion  EC accounted for nearly 4.1% of the total cancer burden managed at our center from January 2002 to December 2011. The mean age of our patient cohort was 54.2 years. The male:female ratio was nearly 1.7:1. Tobacco chewing was noted in 25.4%, smoking in 37%, while alcohol consumption was noted in approximately 20% of the patients. SCC was the most common histological subtype (78.3%), while ACs constituted only 9.9%. Eighty-nine percent of our patients presented with locally advanced staged tumors. Definitive chemoradiation was the most common modality of definitive management then; however, over the years, our preferred choice of the management of ECs has shifted to neoadjuvant chemoradiation, followed by surgery in the carefully selected patients of locally advanced resectable ECs. Conclusion  Our study clearly shows SCC to be the most common histological subtype among ECs, a trend that has been observed in the vast majority of the East Asian nations. The epidemic rise in the incidence of esophageal ACs as seen in the West is not seen in our study. Periodic monitoring of the demographic trends of ECs is of great importance both for clinicians and policymakers. We hope that our study will enlighten both policy holders and clinicians to better channelize the efforts toward prevention and more effective management of this deadly cancer.

Circumferential distribution and clinical characteristics of esophageal cancer in lower esophagus: differences related to histological subtype

BACKGROUND

Esophageal adenocarcinoma (EAC) is frequently found on the right-anterior wall of the distal esophagus in short-segment Barrett's esophagus (SSBE) patients. However, the endoscopic characteristics of EAC in cases with long-segment BE (LSBE) and squamous cell carcinoma (ESCC) in the lower esophagus remain to be fully evaluated. Here, we determined the circumferential distribution and clinical characteristics of esophageal cancer occurring in the lower esophagus based on histological subtype.

METHODS

We retrospectively reviewed the medical records of 150 patients with esophageal cancer (ESCC, n = 100; EAC, n = 50) diagnosed at our hospital or a related facility between January 2002 and June 2017, including information regarding endoscopic findings, etiology, and clinical parameters.

RESULTS

Of the 100 patients with ESCC, 28 lesions were located in the lower esophagus, though characteristic circumferential distribution was not seen regardless of location. Those showed a greater frequency of smoking and drinking habit and gastric mucosal atrophy as compared to patients with EAC. Consistent with the previous reports, EAC in SSBE (n = 41) was frequently located on the right-anterior wall. Likewise, EAC at the esophagogastric junction (EGJ) in LSBE was frequently located on the right-anterior wall, while EAC distant from the EGJ showed no characteristic circumferential distribution.

CONCLUSION

Our results showed no circumferential predilection for ESCC in the lower esophagus, suggesting that development of this type of lesion may be less affected by gastroesophageal reflux. In addition, EAC at the EGJ was frequently found on the right-anterior wall irrespective of BE length.

Relationship between type of smokeless tobacco & risk of cancer: A systematic review

Background & objectives:

Causative linkages of smokeless tobacco (SLT) use with oral potentially malignant disorders and cancers of oral cavity, oesophagus and pancreas have been reported. Published meta-analyses have provided pooled risk estimates for major cancers caused by SLT, both on global and regional levels. This systematic review was aimed at summarizing the available studies on occurrence and mortality risk of common cancers due to various SLT products.

Methods:

PubMed and Google Scholar databases were systematically searched from 1985 till January 2018 for observational studies on SLT and cancer. The included studies were evaluated and data were extracted and reviewed.

Results:

The review included 80 studies providing 121 risk estimates for various cancers. Majority of the studies from South-East Asian Region (SEAR) and Eastern Mediterranean Region (EMR) showed a significant positive association of SLT use with oral [odds ratio (OR) ranging from 1.48 to 27.4] and oesophageal cancers (OR between 2.06 and 12.8), while studies from European Region (EUR) reported a positive association with pancreatic cancer (OR between 1.6 and 2.1). Cancer-related mortality was evaluated in a few reports with higher risk of mortality for lung (OR between 2.0 and 9.1), cervical (OR 2.0) and prostate (OR 2.1) cancers. A wide variation was noted in the association of various cancers and specific SLT products based on their nature, methods of use and inherent toxicity. The majority of chewing tobacco products displayed higher risk for oral and oesophageal cancers while the same was not observed for snus.

Interpretation & conclusions:

This review emphasizes on the significantly positive association of SLT use with oral and oesophageal cancers in SEAR and EMR and pancreatic cancer in EUR. Mortality estimates for SLT-associated cancers need further analysis. Risk analysis for cancers of other sites in SLT users also requires multicentric well-designed studies.

The Spatial Predilection for Early Esophageal Squamous Cell Neoplasia: A "Hot Zone" for Endoscopic Screening and Surveillance

Early esophageal squamous cell neoplasias (ESCNs) are easily missed with conventional white-light endoscopy. This study aimed to assess whether early ESCNs have a spatial predilection and the patterns of recurrence after endoscopic treatment. We analyzed the circumferential and longitudinal location of early ESCNs, as well as their correlations with exposure to carcinogens in a cohort of 162 subjects with 248 early ESCNs; 219 of which were identified by screening and 29 by surveillance endoscopy. The circumferential location was identified using a clock-face orientation, and the longitudinal location was identified according to the distance from the incisor. The most common circumferential and longitudinal distributions of the early ESCNs were found in the 6 to 9 o'clock quadrant (38.5%) and at 26 to 30 cm from the incisor (41.3%), respectively. A total of 163 lesions (75%) were located in the lower hemisphere arc, and 149 (68.4%) were located at 26 to 35 cm from the incisor. One hundred eleven (51%) early ESCNs were centered within the "hot zone" (i.e., lower hemisphere arc of the esophagus at 26 to 35 cm from the incisor), which comprised 20% of the esophageal area. Exposure to alcohol, betel nut, or cigarette was risk factors for the development of early ESCNs in the lower hemisphere. After complete endoscopic treatment, the mean annual incidence of metachronous tumors was 10%. In addition, 43% of the metachronous recurrent neoplasias developed within the "hot zone." Cox regression analysis revealed that the index tumor within the hot zone (hazard ratio [HR]: 3.19; 95% confidence interval [CI]: 1.17-8.68; P = 0.02) and the presence of numerous Lugol-voiding lesions in the esophageal background mucosa were independent predictors for metachronous recurrence (HR: 4.61; 95% CI: 1.36-15.56; P = 0.01). We identified a hot zone that may be used to enhance the detection of early ESCNs during endoscopic screening and surveillance, especially in areas that lack resources and have a high prevalence of ESCNs.

Chewing areca nut, betel quid, oral snuff, cigarette smoking and the risk of oesophageal squamous-cell carcinoma in South Asians: a multicentre case-control study

Oesophageal cancer remains an important public health problem worldwide. This multicentre matched case-control study examined the chewing areca nut alone, betel quid with tobacco, oral snuff (snuff dipping) and cigarette smoking as the risk factors for oesophageal squamous-cell carcinoma. We enrolled 91 cases of oesophageal squamous-cell carcinoma and 364 matched controls from three tertiary-care hospitals in Karachi, Pakistan. A structured questionnaire was used to collect the data through face-to-face interview of the participants. Multivariable conditional logistic regression model showed that after adjusting for the effect of ethnicity, ever chewed areca nut alone (adjusted matched odds ratio (mOR(adj))=3.7; 95% confidence interval (CI): 1.6-8.5), ever chewed betel quid with tobacco (mOR(adj)=12.8; 95% CI: 6.3-26.2), ever practiced snuff dipping (mOR(adj)=4.3; 95% CI: 1.6-11.7) and ever smoked cigarettes (mOR(adj)=2.9; 95% CI: 1.4-5.9) were significantly and independently associated with oesophageal squamous-cell carcinoma status. The adjusted summary population attributable risk (PAR) percent for all four substances together was 67.0. Furthermore, despite incomplete synergy, there was manifold increase in the risk of oesophageal squamous-cell carcinoma, if the respondents ever smoked cigarettes and ever chewed betel quid with tobacco (mOR(adj)=21.4; 95% CI: 6.3-72.4) or if they ever smoked cigarettes and ever practiced snuff dipping (mOR(adj)=14.4; 95% CI: 2.3-91.1). The adjusted PAR (%) was higher for the dual practice of smoking cigarettes and chewing betel quid with tobacco (64.3) than the dual practice of smoking cigarettes and snuff dipping (32.2). Public awareness to curtail the addiction to these substances may result in a substantial reduction in the incidence of oesophageal squamous-cell carcinoma and related mortality in this and similar settings.

Food intake and the occurrence of squamous cell carcinoma in different sections of the esophagus in Taiwanese men

OBJECTIVE

The main objective of this study was to further elucidate the effect of consuming various foods on the development of squamous cell carcinoma (SCC) in three different sections of the esophagus.

METHODS

A total of 343 patients with SCC of the esophagus and 755 cancer-free control subjects were recruited for this study from 1996 to 2005.

RESULTS

We found that intake of vegetables, raw onions/garlic, and fruits are significantly protective against esophageal SSC risk, whereas intake of hot foods can significantly increase its risk. There was a significant inverse relation between the frequency of tea consumption and esophageal SCC risk (P for trend = 0.005), with a 0.5-fold lower risk associated with the intake of unfermented tea (green tea, oolong tea, or jasmine tea). The effects of dietary factors on esophageal SCC were similar in all subsites, with the exception of consumption of coffee. Coffee consumption was more pronounced in having a protective effect in the middle third section compared with the lower third section of the esophagus (adjusted odds ratio 0.4, 95% confidence interval 0.2-0.9), although this protective effect was marginally significant (adjusted odds ratio 0.6, 95% confidence interval 0.4-1.0) against esophageal SCC in all subsites. Our data also suggest that discomfort when eating hot foods may exert a carcinogenic effect by direct contact with the esophageal mucosa and tend to have more harmful effects in the upper than in the lower esophagus. In contrast, vegetables, fruits, and tea with components that are thought to inhibit carcinogenesis by absorbed components affected all subsites similarly.

CONCLUSION

Our results add additional information that certain dietary components may affect carcinogenesis locally and systemically.

Areca nut and betel quid chewing among South Asian immigrants to Western countries and its implications for oral cancer screening

The South Asian community is the largest and one of the fastest growing minority groups in Canada, according to the 2006 census. These immigrants bring to Canada talents and skills that can promote Canada's economy and cultural diversity, but they also bring lifestyle habits that may lead to serious health issues. Chewing areca nut and betel quid (paan, with and without tobacco) is a known risk factor for oral cancer. This habit is common in the Indo-Canadian population, as evidenced by its sales in local Indian markets and restaurants. In this article, we present an overview of the sociocultural beliefs, knowledge and practices regarding betel quid/areca nut chewing, and discuss its implications for oral cancer screening among this immigrant population.

Role of BCL2 (ala43thr), CCND1 (G870A) and FAS (A-670G) polymorphisms in modulating the risk of developing esophageal cancer

BACKGROUND

Perturbations in the cell cycle and apoptotic genes have been implicated in human malignancies. A study of BCL2 ala43thr, CCND1 G870A and FAS A-670G gene polymorphisms was undertaken to explore their role in influencing the susceptibility for development of esophageal cancer.

METHODS

A total of 151 patients and age and gender matched 201 controls were investigated for BCL2 ala43thr, CCND1 G870A and FAS A-670G polymorphisms by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).

RESULTS

The ala43ala genotype of BCL2 anti-apoptotic gene was significantly associated with risk of developing esophageal cancer (OR 2.1, 95%CI=1.0-4.4, P=0.03), more so in males (OR 2.6, 95%CI=P=0.03). In CCND1 G870A polymorphism, the AA genotype was marginally associated with higher risk of esophageal cancer (OR 1.5, 95%CI=0.98-2.4, P=0.05). No significant differences in genotype frequencies of FAS A-670G polymorphism were seen between esophageal cancer patients and controls (P=0.32). Interaction of BCL2 ala43ala, CCND1 870AA and FAS -670AA genotypes did not increase the risk multiplicatively. Association with clinical characteristics showed BCL2 ala43ala genotype to be at increased risk for developing tumors in the middle third location (OR 2.3, 95%CI=1.0-5.3, P=0.03), while patients with CCND1 870AA genotypes were at higher risk for the development of cancer in the upper third location (OR 3.8, 95%CI=1.6-9, P=0.002). BCL2 ala43ala genotype did not modulate the cancer risk in tobacco users. However, patients with CCND1 870AA and FAS -670AA genotypes were associated with a significantly lower number of smoking and chewing pack-years, suggesting a dose-dependent interaction in the risk for esophageal cancer (P=0.005).

CONCLUSION

There appears to be an influence of BCL2 ala43ala and CCND1 870AA genotypes on esophageal cancer phenotype, particularly with regard to tumor location, which supports the theory of prevalence of site-specific genetic alterations. FAS A-670G was not associated with the risk of developing esophageal cancer. Gene-environment interaction analysis showed cancer susceptibility in CCND1 870AA and FAS -670AA genotype to be influenced by quantity of tobacco.

Anatomical subsite discrepancy in relation to the impact of the consumption of alcohol, tobacco and betel quid on esophageal cancer

The carcinogenetic impact of risk factors on esophageal cancer (EC) may differ according to the portion of the esophagus where the tumor occurs. It is unclear why more esophageal squamous cell carcinomas (SCC) developed in the middle location. We carried out a multicenter case-control study in Taiwan to assess anatomical subsite risk discrepancy for this neoplasm in regard to the consumption of alcohol, tobacco and betel quid. Four hundred forty seven incident patients with pathology-proven SCC of the esophagus (107 were upper-third [U/3-EC], 199 middle-third [M/3-EC] and 141 lower-third [L/3-EC] cases), as well as 1,022 gender, age and study hospital matched controls were analyzed by unordered polytomous logistic regression. All consumption of the three substances was related to the development of each subsite of EC, with a heterogeneously higher risk for current smokers (adjusted odds ratio (AOR) = 6.2) found in M/3-EC and for current chewers, in U/3-EC (AOR = 4.9). The joint risk of contracting lower two-third EC for drinking and smoking appeared to significantly surpass those estimated by a multiplicative interaction model. Concomitant exposure to these two agents brought the risks of EC at all three subsites up to 10- to 23.9-fold and additional tobacco-free betel quid to a 30.3- to 75.0-fold. In conclusion, tumor subsite discrepancy risk is related to prolonged exposure to tobacco and betel quid with inflorescence. Alcohol interacts with tobacco in a stronger supra-multiplicative way in the middle portion of the esophagus, probably explaining why esophageal SCC occurs more commonly at this anatomical location.

Esophageal cancer in Central and Eastern Europe: Tobacco and alcohol

Esophageal cancer mortality rates in Central and Eastern Europe have been increasing steadily and are expected to increase further in the future. To evaluate the role of risk factors for esophageal cancer in this population, a multicenter study was conducted, with investigation of tobacco and alcohol as one of the principal aims. We have included 192 squamous cell carcinoma (SCC) and 35 adenocarcinoma cases of the esophagus diagnosed at designated hospitals in 5 centers from Romania, Russia, the Czech Republic and Poland. Controls were frequency matched from patients in the same hospital as the cases (n=1,114). Our results showed that the risk of esophageal SCC may be increased by approximately 7-fold for current smokers (OR=7.41, 95% CI 3.98-13.79) and by 3-fold for ever alcohol drinkers (OR=2.86, 95% CI 1.06-7.74). Dose-response relations were evident for both the frequency and duration of tobacco and of alcohol on the risk of esophageal SCC. Risk estimates for tobacco smoking were highest for lower esophageal SCCs, while risk estimates for alcohol drinking were highest for upper esophageal SCCs; though differences were not statistically significant. For adenocarcinoma of the esophagus, our results suggested a more modest increase in risk because of tobacco smoking than that for SCC of the esophagus and no association with alcohol consumption, although our sample size was small. A synergistic interaction between tobacco and alcohol was observed for the risk of esophageal SCC, highlighting the importance of both factors for esophageal cancers in Central and Eastern Europe.

Interaction between cigarette, alcohol and betel nut use on esophageal cancer risk in Taiwan

OBJECTIVE

In 2003 esophageal cancer was the sixth leading cause of death among men in Taiwan, but it is the fastest increasing (70%) alimentary tract cancer. The aim of this study was to investigate the impact of different habits of betel nut chewing on esophageal squamous cell carcinoma (SCC) and its interaction with cigarette use and alcohol consumption.

MATERIALS AND METHODS

All 165 cases were pathologically proven esophageal SCC patients (all male, mean age = 56.0, range = 35-92 years) diagnosed by biopsy during gastroendoscopic examinations. The control group comprised 255 subjects (all male, mean age = 54.8, range = 40-92 years) selected from patients who had visited the Otolaryngology Outpatient or Inpatient Department of KMUH owing to a benign lesion over this field. All were interviewed to collect demographic and substance use information by a trained interviewer using a standardized questionnaire.

RESULTS

Smoking (aOR = 5.4, 95% CI = 2.4-12.9, PAR = 72%), alcoholic beverage drinking (aOR = 17.6, 95% CI = 9.3-35.2, PAR = 76%) and low education level are independent risk factors for esophageal cancer. Although betel nut chewers only had a borderline significant higher risk than nonchewers (aOR = 1.7; 95% CI = 0.8-3.1), those who chewed with a piece of betel inflorescence (aOR = 4.2, 95% CI = 1.4-16.0) and swallow betel-quid juice (aOR = 3.3, 95% CI = 1.3-9.3) had a significant higher risk. Significant dose-response effects were found in daily quantity of drinking and smoking. There is a synergistic effect of these three substances on the development of esophageal cancer.

CONCLUSION

Betel nut chewing plays a relevant role in the development of esophageal SCC but adds to the carcinogenetic effect of smoking and alcohol drinking. Direct mucosal contact of betel juice may contribute to its carcinogenesis.

Calculation of population attributable risk for bidi smoking and oral cancer in south Asia

BACKGROUND

Bidi smoking, which is widely prevalent in India and in other south Asian countries, increases the risk of oral cancer as observed in case-control studies and metaanalysis. However, population attributable risk percent (PAR%) has not been determined yet.

MATERIALS AND METHODS

Twelve case-control studies conducted in India, Pakistan, and Sri Lanka, which included information on bidi smoking and oral cancer, were analyzed countrywise to estimate PAR%.

RESULTS

The cumulative cases and controls were 4778 and 6271, respectively, based on 10 case-control studies conducted in India. Among the cases, 49.1% were bidi smokers and 7.7% cigarette smokers, while they were 19.9% and 10.3%, respectively, among controls. Pooled odds ratio (OR) of bidi smoking for oral cancer was 3.3 [95% confidence interval (CI), 3.0-3.6] and 2.6 (95% CI 1.8-3.8), respectively, based on fixed- and random-effects model. Cigarette smoking, on the other hand, did not show any significant association. PAR% of bidi smoking for oral cancer ranged from 4.7% to 51.6% on individual study basis, while they were 31.4% and 24.1%, respectively, based on OR derived from fixed- and random-effects models. PAR% was 5.8% and 8.7% based on single study estimate from Pakistan and Sri Lanka, respectively.

CONCLUSIONS

Bidi smoking is considered to account for a sizeable number of oral cancers in south Asian countries, which implies that cessation programs should be formulated and implemented vigorously.

Independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer in Taiwan

A multicenter case-control study was conducted in northern and southern Taiwan to clarify the independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer. A total of 513 patients with newly diagnosed and histopathologically confirmed squamous cell carcinoma of the esophagus and 818 gender, age and study hospital-matched controls were included. We found a significant dose-response relationship between the duration and intensity of consumption of the 3 substances and the development of this neoplasm in this site. Although the amount of alcohol consumed had a stronger effect on the risk of esophageal cancer than the number of years it was consumed, however, the number of years one smoked had a stronger effect on the risk than the amount of cigarettes consumed. The strongest risk factor of esophageal cancer was alcohol intake, with highest risk (OR = 13.9) being for those who consumed more than 900 g/day-year. Combined exposure to any 2 of 3 substances brought the risks up to 8.8-19.7 fold and, to all 3 substances, to 41.2-fold. A multiplicative interaction effect for alcohol drinkers who smoked on cancer risk was detected, whereas an additive interaction effect was found among drinkers who chewed. The combined effect of all 3 substances accounted for 83.7% of the attributable fraction of contracting esophageal cancer in this population. In conclusion, these results suggest that the intensity and the length of time alcohol and tobacco are used play different roles in the etiology of esophageal cancer. Alcohol separately interacts with tobacco and betel quid in a differently synergistic way in determining the development of this site of cancer.

Influences of lifestyle habits and p53 codon 72 and p21 codon 31 polymorphisms on gastric cancer risk in Taiwan

Influences of lifestyle habits and p53 codon 72 and p21 codon 31 polymorphisms on the risk for developing primary gastric cancer were examined in 89 gastric adenocarcinoma cases (51 males, 38 females) and 192 controls (106 males, 86 females) in a hospital-based, case-control study in Taiwan. In the final regression model, Helicobacter pylori infection and substance use (cigarette smoking, areca chewing) were significant predictors of risk for developing gastric cancer. Compared with subjects negative for H. pylori infection, positive subjects were 3.65-fold (95% CI = 2.07-6.42) more likely to develop gastric cancer. Compared with non-smokers or non-chewers, subjects with more than a 15 pack-year history or more than a 498 betel-year history (about 20 betel quids/day for 25 years) were 2.27- and 4.86-fold more at risk (95% CI = 1.06-4.84 and 1.20-19.74), respectively. Frequencies of arg/arg, arg/pro and pro/pro in p53 were 11 (12.4%), 53 (59.5%) and 25 (28.1%) in carcinoma cases and 40 (20.8%), 95 (49.5%) and 57 (29.7%) in control cases, respectively. Frequencies of arg/arg, ser/arg and ser/ser in p21 were 26 (29.2%), 36 (40.5%) and 27 (30.3%) in carcinoma cases and 49 (25.5%), 94 (49.0%) and 49 (25.5%) in control cases, respectively. Neither p53, nor p21 polymorphisms were significantly different in cases and controls ( P = 0.16 and P = 0.41, respectively). Results remained insignificant after dichotomizing with respect to cigarette smoking, areca chewing and H. pylori infection. In summary, our data indicate that in Taiwan, H. pylori infection, smoking and areca chewing are significant risk predictors for developing gastric cancer. p53 codon 72 and p21 codon 31 genotypes did not modify these risks.

Smokeless tobacco and health in India and South Asia

South Asia is a major producer and net exporter of tobacco. Over one-third of tobacco consumed regionally is smokeless. Traditional forms like betel quid, tobacco with lime and tobacco tooth powder are commonly used and the use of new products is increasing, not only among men but also among children, teenagers, women of reproductive age, medical and dental students and in the South Asian diaspora. Smokeless tobacco users studied prospectively in India had age-adjusted relative risks for premature mortality of 1.2-1.96 (men) and 1.3 (women). Current male chewers of betel quid with tobacco in case-control studies in India had relative risks of oral cancer varying between 1.8-5.8 and relative risks for oesophageal cancer of 2.1-3.2. Oral submucous fibrosis is increasing due to the use of processed areca nut products, many containing tobacco. Pregnant women in India who used smokeless tobacco have a threefold increased risk of stillbirth and a two- to threefold increased risk of having a low birthweight infant. In recent years, several states in India have banned the sale, manufacture and storage of gutka, a smokeless tobacco product containing areca nut. In May 2003 in India, the Tobacco Products Bill 2001 was enacted to regulate the promotion and sale of all tobacco products. In two large-scale educational interventions in India, sizable proportions of tobacco users quit during 5-10 years of follow-up and incidence rates of oral leukoplakia measured in one study fell in the intervention cohort. Tobacco education must be imparted through schools, existing government health programmes and hospital outreach programmes.

Relationship between site of oesophageal cancer and areca chewing and smoking in Taiwan

Among 309 male patients, those who had heavily consumed betel and tobacco were more likely than nonchewers (OR=2.91; 95% CI=1.36-6.25) and nonsmokers (OR=2.49; 95% CI=1.02-6.08) to develop cancer in the upper and middle third of the oesophagus, respectively; the effects of alcohol did not dominate in any third.

Bidi smoking and oral cancer: a meta-analysis

Several epidemiological studies suggest that bidi smoking increases the risk of oral cancer. No systematic review, however, has been reported to examine how consistent the evidence is across the studies. We undertook a meta-analysis of epidemiological studies investigating the relationship between bidi smoking and oral cancer. Primary studies were identified through a computerized literature search of Medline. Articles abstracted were all epidemiological studies published as original articles in English during 1966-2002 that included quantitative information on bidi smoking and oral cancer. Summary odds ratios (OR) were calculated based on random effects model. A total of 12 case-control studies used for this meta-analysis provided the summary estimates of OR of bidi smoking for oral cancer compared to that of non-smokers. An increased risk of oral cancer was found for bidi smokers compared to never smokers (OR = 3.1, 95% confidence interval [CI] 2.0-5.0) whereas no significant pattern of risk was found for cigarette smokers (OR = 1.1, 95% CI = 0.7-1.8). There was substantial heterogeneity in the pooled OR estimate. Our results clearly indicate that bidi smokers are at increased risk of oral cancer. It is important that this information be incorporated into smoking prevention and cessation efforts, particularly among the urban poor and rural mass in South Asian countries where bidi smoking is widely prevalent.

Independent and combined effects of tobacco smoking, chewing and alcohol drinking on the risk of oral, pharyngeal and esophageal cancers in Indian men

Oral, pharyngeal and esophageal cancers are 3 of the 5 most common cancer sites in Indian men. To assess the effect of different patterns of smoking, chewing and alcohol drinking in the development of the above 3 neoplasms and to determine the interaction among these habits, we conducted a case-control study in Chennai and Trivandrum, South India. The cases included 1,563 oral, 636 pharyngeal and 566 esophageal male cancer patients who were compared with 1,711 male disease controls from the 2 centers as well as 1,927 male healthy hospital visitors from Chennai. We observed a significant dose-response relationship for duration and amount of consumption of the 3 habits with the development of the 3 neoplasms. Tobacco chewing emerged as the strongest risk factor for oral cancer, with the highest odds ratio (OR) for chewing products containing tobacco of 5.05 [95% confidence internal (CI) 4.26-5.97]. The strongest risk factor for pharyngeal and esophageal cancers was tobacco smoking, with ORs of 4.00 (95% CI 3.07-5.22) and 2.83 (95% CI 2.18-3.66) in current smokers, respectively. An independent increase in risk was observed for each habit in the absence of the other 2. For example, the OR of oral cancers for alcohol drinking in never smokers and never chewers was 2.56 (95% CI 1.42-4.64) and that of esophageal cancers was 3.41 (95% CI 1.46-7.99). Furthermore, significant decreases in risks for all 3 cancer sites were observed in subjects who quit smoking even among those who had quit smoking 2-4 years before the interview.

Lifestyle habits and genetic susceptibility and the risk of esophageal cancer in the Thai population

The association of lifestyle habits and polymorphism of ADH2 and ALDH2 genes with the risk of esophageal cancer in Thai population was investigated in a hospital-based case-control study: 202 cases and 261 controls. The results of multivariate logistic analysis showed that alcohol consumption >60g/day, smoking >10 cigarettes/day and chewing betel >or=10 quids/day significantly increased risk (odds ratio (OR) 5.84, 95% confidence interval (CI) 3.15-10.83; 4.65, 95% CI 1.99-10.84; and 4.68, 95% CI 2.05-10.72, respectively). ADH2*1/*1 also increased the risk significantly (OR 1.56, 95% CI 1.01-2.39) while ALDH2 did not (OR of ALDH2*1/*2 1.57, 95% CI 0.89-2.76). However, the combined at risk genotypes, ADH2*1/*1 and ALDH2*1/*2 increased risk to four-fold. In addition, significant gene-environment interaction was found. Heavy drinkers >60g/d harboring ADH2*1/*1 or ALDH2*1/*2 had about an 11-fold increased risk.

Tobacco use and cancer causation: association by tumour type

In the second part of our review we describe the association between tobacco use and risk of specific cancer types. There is evidence for an established association of tobacco use with cancer of the lung and larynx, head and neck, bladder, oesophagus, pancreas, stomach and kidney. In contrast, endometrial cancer is less common in women who smoke cigarettes. There are some data suggesting that tobacco use increases the risk for myeloid leukaemia, squamous cell sinonasal cancer, liver cancer, cervical cancer, colorectal cancer after an extended latency, childhood cancers and cancer of the gall bladder, adrenal gland and small intestine. Other forms of cancer, including breast, ovarian and prostate cancer, are unlikely to be linked to tobacco use.

Risk of betel chewing for oesophageal cancer in Taiwan

Among 104 cases of squamous-cell oesophageal carcinoma patients and 277 controls in Taiwan, after adjusting for cigarette smoking, alcohol consumption, and other confounders, we found that subjects who chewed from 1 to 495 betel-year and more than 495 betel-years (about 20 betel quid per day for 20 years) had 3.6-fold (95% Cl = 1.3-10.1) and 9.2-fold risk (95% Cl = 1.8-46.7), respectively, of developing oesophageal cancer, compared to those who did not chew betel.

Betel nut and tobacco chewing; potential risk factors of cancer of oesophagus in Assam, India

Cancer of the oesophagus is the most commonly diagnosed cancer in males in Assam, in north-eastern India, and ranks second for females. The chewing of betel nut, with or without tobacco and prepared in various ways, is a common practice in the region and a case-control study has been designed to study the pattern of risk associated with different ways of preparing and chewing the nuts. 358 newly diagnosed male patients and 144 female have been interviewed together with 2 control subjects for each case chosen at random from among the attendants who accompanied patients to hospital. There were significant trends in risk ratios associated with the frequency of chewing each day, with the duration of chewing in years and with the age at which the habit was started that were apparent for both males and females and which remained significant after allowance was made for other known risk factors, notably tobacco smoking and alcohol consumption. The adjusted ratios, in comparison with non-chewers, were 13.3 M and 5.7 F for chewing more than 20 times a day, 10.6 M and 7.2 F for persons who had chewed for more than 20 years and 10.3 M and 5.3 F for those who had started before the age of 20. Among the different combinations of ingredients that were chewed the adjusted odds ratios were highest for those who had been using fermented betel nut with any form of tobacco (7.1 M and 3.6 F). The risk associated with tobacco smoking and alcohol consumption, which are high in some parts of the world, were less in Assam than those associated with the chewing of betel nut.

Esophageal cancer: a systematic review

Carcinoma of the esophagus has one of the lowest possibilities of cure, with 5-year survival rates estimated to be approximately 10% overall; these rates are second only to hepatobiliary and pancreatic cancers. This fact and the rapid increase in the incidence of adenocarcinomas of the esophagus in recent years challenges us to identify areas of improvement for all aspects of this disease. We discuss potential reasons for the increase in the incidence of adenocarcinomas, evidence that defines the similarity between tumors of the gastroesophageal junction and the tubular esophagus, and other prognostic factors that may influence future modifications of our staging classification of this disease. Surgical advances have translated into improvements in surgical morbidity and mortality rates. Current therapeutic options and the relative merits of the options are discussed. Improvements in patient outcome most likely hinge on earlier diagnosis, more accurate staging, and the optimal use of combined modalities, coupled with technical advances in the modalities. A systematic review approach was undertaken to evaluate the performance characteristics of newer staging tools and the value of different combined modality approaches with particular focus on the use of those approaches for patients with potentially curable disease. A similar methodologic approach was used to address the utility of the many strategies currently used in practice for the palliation of esophageal tumors, with particular focus on the relief of malignant dysphagia. Finally, a summary of published guidelines and population-based patterns of care are presented. This serves as an overview of how all of this evidence actually translates into the care we are providing. A coordinated international effort in population-based research and randomized controlled trials would be the cornerstone to future advances in this relatively uncommon but devastating disease.

Effect of acute and long-term oral tobacco use on oesophageal motility

BACKGROUND AND AIMS

Nicotine administration is known to decrease lower oesophageal sphincter (LOS) pressure. Although a few studies have assessed the effect of tobacco on the LOS, the effect of acute and long-term oral tobacco use on oesophageal motility is not known. The study was designed to investigate the effect of acute and long-term oral tobacco use on LOS and distal oesophageal motility.

METHODS

Thirty-six healthy men (aged 18-65 years, median 34 years; 18 oral tobacco users, 18 non-tobacco users) underwent oesophageal manometry using a water-perfusion system. After baseline manometry, tobacco users were asked to keep 0.5 g tobacco in their mouth for 10 min; non-users of tobacco were kept in quiet surroundings for a similar period. Manometry was then repeated.

RESULTS

The LOS basal pressures were similar in tobacco users and non-tobacco users (mean +/- SD 15.4 +/- 6.3 vs 13.4 +/- 5.3 mmHg). In the distal oesophageal body, the velocity (4.4 +/- 3.1 vs 4.9 +/- 2.6 cm/s), amplitude (92.7 +/- 38.3 vs 84.8 +/- 33.2 mmHg) and duration of contraction (2.1 +/- 0.7 vs 1.7 +/- 0.9 s) were similar in tobacco users and non-users. Acute tobacco use did not affect these parameters. The numbers of abnormal waves (triple peaks and non-transmitted contractions) were also similar in the two groups.

CONCLUSION

Oral tobacco use does not appear to affect LOS pressures and distal oesophageal motility acutely or in the long term.

Alcohol, smoking and papillomavirus infection as risk factors for esophageal squamous-cell papilloma and esophageal squamous-cell carcinoma in Italy

Esophageal papilloma, an infrequent benign tumor, and esophageal squamous-cell carcinoma sometimes appear to be associated with human papillomavirus (HPV) infection, HPV being implicated in anogenital carcinogenesis. Our aim was to assess whether there is any epidemiological difference in terms of risk factors for papilloma and cancer. From 1989 to 1996, a total of 12,011 patients (53% male, median age 52.7 years) were submitted to esophagogastroduodenoscopy by our Digestive Endoscopy Service. The genome of HPV was sought by PCR using 2 different primer sets. Of the total, 42 subjects (0.35%), 50% male with a mean age of 45.1 years, were suffering from esophageal squamous-cell papilloma and 45 (0.37%), 91% male with a mean age of 63.0 years, from esophageal squamous-cell carcinoma. Of these patients, only 2 with papilloma were HPV(+). Compared with the general endoscopic population, patients with papilloma do not present significantly different characteristics (even in terms of frequency of esophagitis and hiatal hernia). Those with carcinoma differ significantly both from the general endoscopic population and from those with papilloma in that they are more often male (p < 0. 0001), older (p < 0.0001) and drinkers (p < 0.0001); they differ significantly only from the general population, but not from the papilloma patients, in smoking habits. Papilloma appears to be neither a lesion involving a risk of development into a malignancy nor a marker for any such risk. Environmental factors, such as alcohol and smoking, appear to play a decisive role in esophageal carcinogenesis in northern Italy.

Association of thromboangiitis obliterans with cigarette and bidi smoking in Bangladesh: a case-control study

BACKGROUND

In addition to cigarettes, bidi, made of unprocessed and low-grade tobacco, is being smoked widely in Bangladesh and in other south Asian countries. The cause-and-effect relationship is established between thromboangiitis obliterans (TAO) and smoking. However, type of smoking material(s) most strongly related to TAO is not yet determined.

METHODS

We conducted a hospital-based case-control study in Rajshahi, Bangladesh, to examine the relationship of type of smoking materials (cigarette versus bidi) with TAO on 103 pairs of cases and controls matched by age and sex during the period 1995 to 1996. The inclusion criteria for cases were newly diagnosed TAO and current smoker, while those for controls were current smokers admitted to the hospital due to non-cardiovascular diseases.

RESULTS

Among the cases 35.0% and 65.0% were cigarette and bidi smokers, while among the controls 69.9% and 30.1%, respectively. Using logistic regression approach, considering cigarette smoking approximately 10 per day as reference, bidi smoking >20 per day (odds ratio [OR] = 34.76, 95% CI: 6.11-197.67) and 11-20 per day (OR = 7.12, 95% CI: 2.35-21.63) had greater risk of TAO after adjusting confounding factors. Respective OR for bidi smoking approximately 10 per day, cigarette smoking 11-20 per day and cigarette smoking >20 per day, were 2.18 (95% CI: 0.64-7.51), 3.81 (95% CI: 1.37-10.57) and 6.88 (95% CI: 1.87-25.30).

CONCLUSION

Within the limits inherent to case-control study, our findings suggest that bidi smoking may well play a more important role in causing TAO than cigarettes. It leads to the speculation that unprocessed and low-grade tobacco used for producing bidi might play a more potent role to initiate TAO than cigarettes.

Tobacco type and risk of squamous cell cancer of the oesophagus in males: a French multicentre case-control study

BACKGROUND

The association between tobacco smoking and oesophageal cancer is well established. However, some major questions remain unanswered such as the importance of kind of tobacco and smoke inhalation. The aim of this study was to investigate the effect of each kind of tobacco on the risk of squamous cell cancer of the oesophagus in men and to test whether the effect of kind of tobacco is similar whatever the sub-site of cancer. Tobacco consumption was assessed by the number of years of consumption and time since quitting.

METHODS

We conducted a multicentre case-control study in three university hospitals in France (Caen, Dijon, and Toulouse). From 1991 to 1994, 208 cases and 399 controls, all male, were selected. During the interview, the subject's entire tobacco history was recalled, noting each type of tobacco consumed throughout life.

RESULTS

Strong tobacco, dark tobacco and non-filter-tipped cigarettes were associated with an increase in risk whatever the adjustments, whilst light, filter-tipped cigarettes and mild tobacco were not. Hand-rolled cigarettes were more strongly associated with risk than manufactured cigarettes. The effect of hand-rolled cigarettes appeared stronger for the lower third whilst those of strong cigarettes and dark tobacco appeared stronger for the upper third of the oesophagus. The effect of inhaling was confined to the upper third.

CONCLUSIONS

Our results, emphasizing the role of dark tobacco, hand-rolled cigarettes, strong cigarettes and non-filter-tipped cigarettes are in line with previous publications. Moreover, they suggest that the mechanism underlying the tobacco effect could be different according to the sub-site of cancer.