Effect of cigarette smoking and alcohol consumption in the etiology of cancers of the digestive tract

Association Between Wine Consumption and Cognitive Decline in Older People: A Systematic Review and Meta-Analysis of Longitudinal Studies

Background

Low-to-moderate alcohol consumption appears to have potential health benefits. Existing evidence concludes that wine may be associated with a lower incidence of certain diseases. This systematic review and meta-analysis aim to examine evidence on the association between wine consumption and cognitive decline and to analyze whether this association varies depending on the wine consumption level or is affected by individual and study characteristics, including mean age, percentage of women participants, and follow-up time.

Methods

In this systematic review and meta-analysis, we undertook a search in MEDLINE (via PubMed), Scopus, Cochrane, and Web of Science databases for longitudinal studies measuring the association between wine consumption and cognitive decline from their inception to May 2021. Effect sizes were calculated using the DerSimonian and Laird and Hartung-Knapp-Sidik-Jonkman methods.

Results

The search retrieved 6,055 articles, 16 of which were included in this systematic review. In total, 12 studies were included in the meta-analysis. The studies were published between 1997 and 2019. They were conducted in nine different countries. The sample size of the included studies ranged from 360 to 10,308 with a mean age of 70 years old. Using the DerSimoniand and Laird method, the pooled RR for the effect of wine consumption on cognitive decline was 0.72 (95% CI 0.63–0.80; I² = 82.4%; τ²: 0.0154). Using the Hartung-Knapp-Sidik-Jonkman method, the RR was 0.65 (95% CI 0.52–0.79; I² = 94,531%; τ²: 0.057).

Conclusions

This study may show a protective effect of wine consumption against cognitive decline. However, it would be important for future research to differentiate the types of wine within consumption.

Alcohol consumption and risk of stomach cancer: A meta-analysis

Stomach cancer is one of the most common cancers in the world. The relationship between alcohol consumption and the risk of stomach cancer remains unclear. Epidemiology studies investigating this relationship have shown inconsistent findings. A meta-analysis was performed to explore the association between alcohol consumption and increased stomach cancer risk. Eighty-one epidemiology studies, including 68 case-control studies and 13 cohort studies, were included in this study. A significant association was found between alcohol consumption and increased risk of stomach cancer (OR = 1.20, 95% CI 1.12-1.27). To explore the source of the significant heterogeneity (p < 0.05, I² = 86%), analysis was stratified by study type (case-control study and cohort study), control type (hospital-based control and population-based control), gender (male, female, and mix), race (White and Asian), region (United States, Sweden, China, Japan), subsite of stomach cancer, and type of alcohol. The stratified analyses found that region and cancer subsite are major sources of the high heterogeneity. The inconsistent results in different regions and different subsites might be related to smoking rates, Helicobacter pylori infection, obesity, and potential genetic susceptibility. The positive association between drinking and increased risk of stomach cancer is consistent in stratified analyses. The dose-response analysis showed a clear trend that a higher daily intake of alcohol is associated with a higher risk of stomach cancer.

Alcohol, Alcoholic Beverages and Risk of Esophageal Cancer by Histological Type: A Dose–Response Meta-Analysis of Observational Studies

Aims

We conducted a dose–response meta-analysis to explore the association between alcohol and particular alcoholic beverages with risk of esophageal cancer (EC) by histological type [esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC)] and whether the association differs according to gender.

Methods

PubMed and Web of Science databases were searched for relevant articles published between January 1960 and December 2019. The pooled relative ratios (RRs) and 95% confidence interval (CI) were calculated with the fixed or random effect model. The dose–response relationship was assessed by restricted cubic spline.

Results

A total of 74 published articles involving 31,105 cases among 3,369,024 participants were included in this meta-analysis. The pooled RRs of the highest versus lowest alcohol intake were 3.67 (95% CI, 2.89,4.67) for EC, 5.11 (95% CI, 3.60,7.25) for ESCC and 0.96 (95% CI, 0.79,1.16) for EAC. The above-mentioned associations were observed in cohort design, for different alcoholic beverages (beer, wine and liquor/spirits) and gender. Evidence of a nonlinear dose–response relationship for EC risk with alcohol intake was found (Pnon-linearity &lt; 0.001), and a linear relationship (Pnon-linearity = 0.216) suggested that the risk of ESCC increased by 33% for every 12.5 g/day increment of alcohol intake.

Conclusions

This meta-analysis suggests that alcohol intake might significantly increase the incidence of EC, especially for ESCC.

Cigarette smoking as a risk factor for the development of and mortality from hepatocellular carcinoma: An updated systematic review of 81 epidemiological studies

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and its incidence has increased during the past decade. While hepatitis B and C virus infections and alcohol were established risk factors, the impact of smoking on the incidence and mortality of HCC was needed to be confirmed.

METHODS

We reviewed cohort and case-control studies evaluating the association between cigarette smoking and incidence and mortality of HCC from MEDLINE and Google Scholar. We also checked reference lists of original studies and review articles manually for cross-references up to February 2016. We extracted the relevant information on participant characteristics and study outcomes, as well as information on the methodology of the studies. We also assessed the quality of the included trials using critical appraisal skills program checklists. Meta-analysis was performed by using RevMan 5.3 software.

RESULTS

A total of 81 studies were included in the systematic review. Pooled OR for HCC development with current smokers was 1.55 (95% CI: 1.46 to 1.65; P < 0.00001). Pooled OR for HCC development with former smokers was 1.39 (95% CI: 1.26 to 1.52; P < 0.00001) and pooled OR for HCC development with heavy smokers was 1.90 (95% CI: 1.68 to 2.14; P < 0.00001). Pooled OR for the mortality of current smokers with HCC was 1.29 (95% CI: 1.23 to 1.34; P < 0.00001); and for former smokers with HCC, it was 1.20 (95% CI: 1.00 to 1.42; P = 0.04).

CONCLUSIONS

Cigarette smoking increases the incidence and mortality of HCC. Further studies are needed to evaluate possible impact of quitting smoking on decreasing this risk.

Are male and female smokers at equal risk of smoking-related cancer: evidence from a Swedish prospective study

This study examines sex differences in the relative risks of lung cancer and other smoking-related cancers (i.e. cancers of the upper respiratory tract, oesophagus, pancreas, bladder, and renal pelvis). Data on smoking habits in 1963 from a random sample of 56,000 men and women were linked with information on new cases of cancer for 1964 - 89. Compared with people who have never smoked, the relative risks of lung cancer at different levels of pack-years completed in 1963 (>5, 6 - 15, 16 - 25 and 25+ pack-years) were 1.6, 4.4, 14.2, and 17.9 for men, and 2.1, 6.3, 10.3, and 16.5 for women. The corresponding relative risks of other smoking-related cancers were 1.8, 3.0 5.4, and 6.4 for men, and 2.0, 3.1, 5.0, and 6.5 for women. These results suggest that men and women have similar relative risks of smoking-related cancers at different levels of smoking.

Alcohol consumption and liver cancer risk: a meta-analysis

PURPOSE

Alcohol is a confirmed risk factor of liver cancer. Yet, its dose-response function and synergistic effects with other risk factors remain unclear.

METHODS

We performed a meta-analysis on publications up to May 2014. A total of 112 publications were identified. The meta-relative risk (mRR) and the dose-response trend were calculated. Tests for heterogeneity, publication bias, and sensitivity analyses were performed. The synergy index (SI) was recorded or calculated, whenever possible.

RESULTS

Compared to individuals who never drank or drank at very low frequencies, the mRR for ever drinkers was 1.29 (95% confidence interval, CI 1.16-1.42) and 1.46 (95% CI 1.27-1.65) for case-control studies, and 1.07 (95% CI 0.87-1.27) for cohort studies. Being a current drinker was associated with an increased liver cancer risk in case-control studies (mRR = 1.55, 95% CI 0.38-2.73), but not in cohort studies (mRR = 0.86, 95% CI 0.74-0.97). The dose-response relation between alcohol and liver cancer was apparent with RR = 1.08 (95% CI 1.04-1.11) for 12 g/day (~1 drink), 1.54 (95% CI 1.36-1.74) for 50 g/day, 2.14 (95% CI 1.74-2.62) for 75 g/day, 3.21 (95% CI 2.34-4.40) for 100 g/day, and 5.20 (95% CI 3.25-8.29) for 125 g/day of alcohol consumption. There were synergistic effects of alcohol consumption with hepatitis (S = 2.14, 95% CI 1.31-2.98) and with diabetes (S = 3.57, 95% CI 2.29-4.84) on the risk of liver cancer, although this may be subject to publication bias.

CONCLUSION

Overall, one alcoholic drink per day (~12 g/day) may be associated with a 1.1 times higher liver cancer risk. Further studies on the synergistic effects of alcohol consumption and other major risk factors are warranted.

Alcohol Drinking, Cigarette Smoking and Risk of Colorectal Cancer in the Korean Multi-center Cancer Cohort

BACKGROUND

The present study aimed to examine the association between cigarette smoking, alcohol consumption and colorectal cancer risk among Korean adults.

METHODS

Data from the Korean Multi-center Cancer Cohort between 1993 and 2005 were analyzed. The study population comprised 18,707 subjects aged older than 20 years old. The subjects were followed until December 31, 2011 (median follow-up of 11.2 years). The Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence intervals of cigarette smoking and alcohol consumption for colorectal cancer risk.

RESULTS

In men, longer duration and higher average amount of alcohol consumption were associated with elevated risk of colorectal cancer (HR 1.93 [1.17-3.18] for ≥ 30 years of consumption compared to non-drinkers; HR 2.24 [1.31-3.84] for ≥ 30 g/d). Former smokers showed a non-significantly elevated risk of colorectal cancer in men. There was no apparent association between alcohol consumption or cigarette smoking and colorectal cancer risk among women.

CONCLUSIONS

Alcohol consumption was associated with increased colorectal cancer risk among Korean men, and both a longer duration and a higher amount of consumption were associated with elevated risk.

Alcohol drinking and esophageal squamous cell carcinoma with focus on light-drinkers and never-smokers: a systematic review and meta-analysis

Quantification of the association between alcohol drinking and risk of esophageal squamous cell carcinoma (ESCC) is an open issue, particularly among light alcohol drinkers, never-smokers, and Asian populations, in which some high-risk polymorphisms in alcohol metabolizing genes are more prevalent. To address these issues, we conducted a systematic review and meta-analysis using 40 case-control and 13 cohort studies that reported on the risk associated with alcohol drinking for at least three levels of consumption. In studies adjusted for age, sex, and tobacco smoking, the relative risk (RR) and 95% confidence interval (CI) for the association between light alcohol drinking (≤ 12.5 g/d) and risk of ESCC was 1.38 (1.14-1.67). The association was slightly stronger in Asian countries than in other populations. The adjusted RRs (95% CIs) were 2.62 (2.07-3.31) for moderate drinking (>12.5-<50 g/d) and 5.54 (3.92-7.28) for high alcohol intake (≥50 g/d); the RRs were slightly higher in non-Asian populations. In prospective studies, the RR (95% CI) was 1.35 (0.92-1.98) for light, 2.15 (1.55-2.98) for moderate, and 3.35 (2.06-5.46) for high alcohol intakes; light drinking showed an association with ESCC in Asia (five studies) but not in other regions (three studies). Among never-smokers (nine studies), the RR (95% CI) was 0.74 (0.47-1.16) for light, 1.54 (1.09-2.17) for moderate, and 3.09 (1.75-5.46) for high intakes. This meta-analysis further corroborates the association of moderate and high alcohol intake with risk of ESCC and provides risk estimates based on multiple prospective studies. Light alcohol intake appears to be associated to ESCC mainly in studies in Asia, which suggests a possible role of genetic susceptibility factors.

Alcohol drinking and colorectal cancer risk: an overall and dose-response meta-analysis of published studies

BACKGROUND

The International Agency for Research on Cancer (IARC) concluded that alcohol consumption is related to colorectal cancer (CRC). However, several issues remain unresolved, including quantification of the association for light (≤1 drink/day) and moderate (2-3 drinks/day) alcohol drinking, investigation of the dose-response relationship, and potential heterogeneity of effects by sex, colorectal site, and geographical region.

METHODS

Twenty-seven cohort and 34 case-control studies presenting results for at least three categories of alcohol intake were identified from a PubMed search of articles published before May 2010. The summary relative risks (RRs) were estimated by the random effects model. Second-order fractional polynomials and random effects meta-regression models were used for modeling the dose-risk relation.

RESULTS

The RRs were 1.21 [95% confidence interval (CI) 1.13-1.28] for moderate and 1.52 (95% CI 1.27-1.81) for heavy (≥4 drinks/day) alcohol drinking. The RR for moderate drinkers, compared with non-/occasional drinkers, was stronger for men (RR = 1.24, 95% CI 1.13-1.37) than for women (RR = 1.08, 95% CI 1.03-1.13; P(heterogeneity) = 0.02). For heavy drinkers, the association was stronger in Asian studies (RR = 1.81, 95% CI 1.33-2.46; P(heterogeneity) = 0.04). The dose-risk analysis estimated RRs of 1.07 (95% CI 1.04-1.10), 1.38 (95% CI 1.28-1.50), and 1.82 (95% CI 1.41-2.35) for 10, 50, and 100 g/day of alcohol, respectively.

CONCLUSIONS

This meta-analysis provides strong evidence for an association between alcohol drinking of >1 drink/day and colorectal cancer risk.

Effect of cigarette taxes on the consumption of cigarettes, alcohol, tea and coffee in Taiwan

OBJECTIVES

To analyse whether a health tax of 10 New Taiwan Dollars (NT$) (US$0.3) imposed on cigarettes in 2009 will help to reduce cigarette consumption, and whether or not the cigarette tax will affect consumption of alcohol, coffee and tea.

STUDY DESIGN

Time series data for consumption and retail prices of tobacco, alcohol, tea and coffee were collected and analysed for the period 1973-2007.

METHODS

To establish the Central Bureau of Statistics demand function to estimate the overall demand price elasticities of cigarettes, alcohol, tea and coffee, a seemingly unrelated regression analysis was used. The independent variables were annual consumption of cigarettes, alcohol, tea and coffee. The dependent variables were prices of and expenditures on cigarettes, alcohol, tea and coffee.

RESULTS

The estimated own-price elasticities for cigarettes and alcohol are close to -0.726. The own-price elasticities for tea and coffee are less than those for cigarettes and alcohol. Hence, it is predicted that the NT$10 health tax on cigarettes will reduce cigarette consumption by a significant 13.19%. Analysis of cross-price elasticity reveals that alcohol is complementary to cigarettes.

CONCLUSIONS

Taxation is an effective smoking control policy tool that not only helps to reduce consumption of cigarettes, but also reduces consumption of alcoholic beverages.

Primary prevention of colorectal cancer

Colorectal cancer has been strongly associated with a Western lifestyle. In the past several decades, much has been learned about the dietary, lifestyle, and medication risk factors for this malignancy. Although there is controversy about the role of specific nutritional factors, consideration of dietary pattern as a whole appears useful for formulating recommendations. For example, several studies have shown that high intake of red and processed meats, highly refined grains and starches, and sugars is related to increased risk of colorectal cancer. Replacing these factors with poultry, fish, and plant sources as the primary source of protein; unsaturated fats as the primary source of fat; and unrefined grains, legumes and fruits as the primary source of carbohydrates is likely to lower risk of colorectal cancer. Although a role for supplements, including vitamin D, folate, and vitamin B6, remains uncertain, calcium supplementation is likely to be at least modestly beneficial. With respect to lifestyle, compelling evidence indicates that avoidance of smoking and heavy alcohol use, prevention of weight gain, and maintenance of a reasonable level of physical activity are associated with markedly lower risks of colorectal cancer. Medications such as aspirin and nonsteroidal anti-inflammatory drugs and postmenopausal hormones for women are associated with substantial reductions in colorectal cancer risk, though their utility is affected by associated risks. Taken together, modifications in diet and lifestyle should substantially reduce the risk of colorectal cancer and could complement screening in reducing colorectal cancer incidence.

The risk of upper aero digestive tract cancer associated with smoking, with and without concurrent alcohol consumption

BACKGROUND

Smoking and alcohol are major causal factors for upper aerodigestive tract cancer, but reliable quantification of the combined impact of smoking and alcohol on this cancer and its major subtypes has not been performed.

METHODS

A meta-analysis of studies that had published quantitative estimates of smoking and upper aerodigestive tract cancer by January 2007 was performed. Pooled estimates of relative risks were obtained. Publication bias was investigated through funnel plots and corrected if found to be present.

RESULTS

Overall, 85 studies with information on 53,940 individuals with upper aerodigestive tract cancer were included. The pooled estimate for the association between smoking and the risk of this cancer was 3.47 (95% confidence interval, 3.06-3.92). The risk remained elevated for a decade after smoking cessation but declined thereafter. Individuals who both smoked and consumed alcohol had double the risk of upper aerodigestive tract cancer in comparison with those who only smoked: the relative risk was 6.93 (95% confidence interval, 4.99-9.62) for the former and 2.56 (95% confidence interval, 2.20-2.97) for the latter (P < 0.001).

CONCLUSIONS

Public health interventions that simultaneously discourage smoking and heavy drinking would have greater benefits than would be expected from those that target only one of these risk factors.

Meta-analysis of epidemiologic studies on cigarette smoking and liver cancer

BACKGROUND

Whereas the International Agency for Research on Cancer (IARC) Monograph concluded that the evidence for the relationship between cigarette smoking and liver cancer is sufficient, the US Surgeon General's report summarized the data as suggestive but not sufficient.

METHODS

A meta-analysis of previous epidemiologic studies may help to clarify the potential association. We identified 38 cohort studies and 58 case-control studies in a systematic literature search for studies on liver cancer and cigarette smoking. The meta-relative risk (mRR) of liver cancer and dose-response trends were calculated. Tests for heterogeneity, publication bias assessment and influence analyses were performed.

RESULTS

Compared with never smokers, the adjusted mRR was 1.51 [95% confidence interval (CI) 1.37-1.67] for current smokers and 1.12 (95% CI 0.78-1.60) for former smokers. The increased liver cancer risk among current smokers appeared to be consistent in strata of different regions, study designs, study sample sizes and publication periods.

CONCLUSION

The results of our meta-analysis show that tobacco smoking is associated with liver cancer development, which supports the conclusion by the IARC Monograph. This conclusion has an important public health message for areas with high smoking prevalence and high liver cancer incidence such as China.

No association of high-risk human papillomavirus with esophageal squamous cell carcinomas among Koreans, as determined by polymerase chain reaction

The incidence of esophageal squamous cell carcinoma varies greatly with race and geographic location. It has been suggested that human papillomavirus (HPV) is involved in the pathogenesis of esophageal cancers, and that the incidence of esophageal cancers associated with HPV depends on the geographic location of the patient population. In studies performed on tumor specimens collected from areas with a low incidence of esophageal squamous cell carcinomas, HPV infection was detected in only a small percentage of tumors, whereas studies performed on specimens obtained from areas with a high incidence of esophageal squamous cell carcinomas provided strong evidence that HPV plays a significant role in esophageal carcinogenesis. To elucidate the putative role of HPV infection in the etiology of esophageal cancer in Korea, a total of 129 formalin-fixed, paraffin-embedded tumor specimens, eight fresh tumor tissues and 40 normal esophageal tissues were screened for HPV infection by polymerase chain reaction using consensus primers for HPV types 16, 18, 31, 33, 35, 52b and 58 and type 16-specific primers. SiHa cell line, formalin-fixed, paraffin-embedded cervical squamous cell carcinoma specimens were used as positive controls for HPV infection. Fragments of human beta-globin gene, which served as the internal controls, were successfully amplified from 102 of the 129 cancer specimens and from all the normal and fresh cancer tissues, while consensus and type 16-specific primers failed to detect HPV DNA sequences in any of the esophageal samples. The DNA extracted from the SiHa cell line and uterine cervical cancers were positive when both the consensus and type-specific primers were used. The results of this study suggest that HPV is not associated with esophageal carcinogenesis in Korea.

The synergistic effect of cigarette taxes on the consumption of cigarettes, alcohol and betel nuts

BACKGROUND

Consumption of cigarettes and alcoholic beverages creates serious health consequences for individuals and overwhelming financial burdens for governments around the world. In Asia, a third stimulant--betel nuts--increases this burden exponentially. For example, individuals who simultaneously smoke, chew betel nuts and drink alcohol are approximately 123 times more likely to develop oral, pharyngeal and laryngeal cancer than are those who do not. To discourage consumption of cigarettes, the government of Taiwan has imposed three taxes over the last two decades. It now wishes to lower consumption of betel nuts. To assist in this effort, our study poses two questions: 1) Will the imposition of an NT$10 Health Tax on cigarettes effectively reduce cigarette consumption? and 2) Will this cigarette tax also reduce consumption of alcoholic beverages and betel nuts? To answer these questions, we analyze the effect of the NT$10 tax on overall cigarette consumption as well as the cross price elasticities of cigarettes, betel nuts, and alcoholic beverages.

METHODS

To establish the Central Bureau of Statistics demand function, we used cigarette, betel nut, and alcoholic beverage price and sales volume data for the years 1972-2002. To estimate the overall demand price elasticity of cigarettes, betel nuts, and alcoholic beverages, we used a seemingly unrelated regression analysis.

RESULTS

We find that the NT$10 health tax on cigarettes will reduce cigarette consumption by a significant 27.22%. We also find that cigarettes, betel nuts, and alcoholic beverages have similar inherent price elasticities of -0.6571, -0.5871, and -0.6261 respectively. Because of this complementary relationship, the NT$10 health tax on cigarettes will reduce betel nut consumption by 20.07% and alcohol consumption by 7.5%.

CONCLUSION

The assessment of a health tax on cigarettes as a smoking control policy tool yields a win-win outcome for both government and consumers because it not only reduces cigarette consumption, but it also reduces betel nut and alcoholic beverage consumption due to a synergistic relationship. Revenues generated by the tax can be used to fund city and county smoking control programs as well as to meet the health insurance system's current financial shortfall.

Socioeconomic position and the risk of gastric and oesophageal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST)

OBJECTIVES

To evaluate the association of socioeconomic position with adenocarcinoma of the oesophagus and stomach.

METHODS

The European Prospective Investigation into Cancer and Nutrition (EPIC) cohort comprises about 520 000 participants mostly aged 35-70 years. Information on diet and lifestyle was collected at recruitment. After an average follow-up of 6.5 years, 268 cases with adenocarcinoma of the stomach and 56 of the oesophagus were confirmed. We examined the effect of socioeconomic position on cancer risk by means of educational data and a computed Relative Index of Inequality (RII). In a nested case-control study, adjustment for Helicobacter pylori (H. pylori) infection was performed.

RESULTS

Higher education was significantly associated with a reduced risk of gastric cancer [vs lowest level of education, hazard ratio (HR): 0.64, 95% Confidence intervals (CI): 0.43-0.98]. This effect was more pronounced for cancer of the cardia (HR: 0.42, 95% CI: 0.20-0.89) as compared to non-cardia gastric cancer (HR: 0.66, 95% CI: 0.36-1.22). Additionally, the inverse association of educational level and gastric cancer was stronger for cases with intestinal (extreme categories, HR: 0.13, 95% CI: 0.04-0.44) rather than diffuse histological subtype (extreme categories, HR: 0.71 95% CI: 0.37-1.40). In the nested case-control study, inverse but statistically non-significant associations were found after additional adjustment for H. pylori infection [highest vs lowest level of education: Odds ratio (OR) 0.53, 95% CI: 0.24-1.18]. Educational level was non-significantly, inversely associated with carcinoma of the oesophagus.

CONCLUSION

A higher socioeconomic position was associated with a reduced risk of gastric adenocarcinoma, which was strongest for cardia cancer or intestinal histological subtype, suggesting different risk profiles according to educational level. These effects appear to be explained only partially by established risk factors.

Cigarette smoking and colorectal cancer risk in Germany: a population-based case-control study

Studies have shown fairly consistent positive relationships between smoking and risk of colorectal adenomas, but have yielded inconsistent results for colorectal cancer. Issues relating to the duration, cumulative dose of smoking and the effect of smoking cessation on colorectal cancer risk still need clarification. In a population-based case-control study in Germany, we recruited 540 incident cases of colorectal cancer and 614 controls matched to cases by sex, 5-year age groups and county of residence from January 2003 to June 2004. Subjects were aged>or=30 years, and provided information on risk factors of colorectal cancer, including lifetime cigarette smoking habits, in personal interviews. Odds ratios (OR) and 95% confidence intervals (CI) were computed using conditional logistic regression models, adjusting for potential confounders. Compared with nonsmokers, there was an increased risk for smoking for >or=30 years (OR: 1.25, 95% CI: 0.90-1.75) and a significant risk increase for >or=40 pack-years of smoking (OR: 1.92, 95% CI: 1.13-3.28). Stratification by sex yielded higher risk estimates among females than that among males, with adjusted ORs of 3.5 (95% CI: 1.29-9.52) and 1.15 (0.69-1.91) for women and men, respectively, following >or=30 pack-years of smoking (pinteraction=0.18). Among smokers, risk reduction was observed after >or=20 years of quitting smoking and was significant for >or=40 years (OR: 0.46; 95% CI: 0.21-0.98), when compared to current smokers (p for linear trend=0.05). This study supports the hypothesis that smoking for a long duration at a high cumulative dose increases the risk for colorectal cancer, particularly among women, and suggests that there is risk reduction after longterm smoking cessation.

Prospective study of educational background and stomach cancer in Japan

BACKGROUND

Different lifestyle choices are commonly regarded as a reflection of socioeconomic status, and the latter is inversely correlated with the risk of developing stomach cancer. However, the details of this association are still unclear in terms of the degree to which lifestyle factors are having impact. To explain the correlation between socioeconomic status and stomach cancer, we therefore examined the roles played by different lifestyle factors.

METHODS

A prospective cohort study of diet and cancer was initiated in Japan during 1988. Data were collected by means of a self-administered questionnaire. A follow-up survey was conducted annually, and the cause of death was recorded from the death certificate. The total of 127,477 study participants resided in 45 areas of Japan, and we retrieved data for 18,746 men and 26,184 women for the present analysis. After 328,030 person-years of follow-up, 379 deaths from stomach cancer were detected: 261 in men and 118 in women.

RESULTS

For men, the age-adjusted relative risk was lowest in the highly educated group (relative risk = 0.72, 95% CI: 0.50-1.04). Relative risk after adjustment for age and dietary choices (including pickles, vegetables, fruit, green tea, and preference for salty foods) was the same as the age-adjusted relative risk (relative risk = 0.72, 95% CI: 0.50-1.04).

CONCLUSION

The expected inverse correlation between education level and death from stomach cancer was observed in men. However, this association could not be explained by differences in dietary habits, smoking, or alcohol consumption associated with socioeconomic status.

Primary prevention of colorectal cancer: diet and drugs

Primary prevention of colonic adenomas and cancer through dietary interventions or chemoprevention has great appeal. This article discusses primary prevention goals and promising nutritional or chemopreventive strategies. There is substantial observational evidence that diets high in total calories and fat and or low in fruits and vegetables or total fiber as well as low levels of physical activity are related to the risk of colonic neoplasia. Similar observational data indicate that diets high in specific nutrients such as antioxidant vitamins or calcium may be protective. The article describes some of the newer chemopreventive agents and reviews the data linking diet and lifestyle to colorectal cancer risk, focusing on interventions that have also been studied in prospective clinical trials. Finally the evidence supporting the role of non-steroidal anti-inflammatory drugs for the chemoprevention of CRC is reviewed and the status of several other promising newer agents that are entering human trials is summarized.

Cigarette smoking and risk of bladder, pancreas, kidney, and colorectal cancers in Iowa

PURPOSE

Although there are numerous reports on the effects of cigarette smoking and cancer, they have infrequently compared risks at more than one cancer site after multivariate adjustment. We analyzed data from a population-based case-control study that included five anatomic sites to evaluate the association between cigarette smoking and each cancer site and to rank the associations by site.

METHODS

Study respondents included 1452 bladder, 406 kidney, 376 pancreatic, 685 colon, and 655 rectal cancer cases, as well as 2434 population controls. A self-administered questionnaire was used to collect information on cigarette smoking and other potential confounders including occupation, drinking water source, and dietary practices. Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), after adjustment for age, total energy intake, and other site- and sex-specific confounders.

RESULTS

In both sexes, cigarette smoking (ever vs. never) was associated with risk of bladder cancer (OR = 2.5; 95% CI, 2.0-3.1 for males; OR = 2.7; 2.0-3.6 for females) and pancreatic cancer (OR = 1.8; 1.2-2.8 for males; OR = 2.1; 1.4-3.1 for females). Cigarette smoking also increased the risk of kidney cancer among males (OR = 1.8; 1.3-2.7), and to a lesser degree, among females (OR = 1.2; 0.8-1.8). No association was found for colon or rectal cancer in either sex.

CONCLUSIONS

Cigarette smoking increased the risk of bladder, kidney, and pancreatic cancer in men and women. The rankings of multivariate-adjusted ORs from highest to lowest were bladder, pancreas, kidney, and colorectum, with little difference between men and women.

Exposure to N-nitroso compounds in a population of high liver cancer regions in Thailand: volatile nitrosamine (VNA) levels in Thai food

The recent case-control studies in Thailand indicate that a high incidence of liver cancer in Thailand has not been associated with common risk factors such as hepatitis B infection, aflatoxin intake and alcohol consumption. While the infestation by the liver fluke Opisthorchis viverrini (OV) accounted for the high risk in north-east Thailand, there was no such exposure in the other regions of the country where the incidence of liver cancer is also high. Case-control studies suggest that exposure to exogenous and possibly endogenous nitrosamines in food or tobacco in betel nut and cigarettes may play a role in the development of hepatocellular carcinoma (HCC), while OV infestation and chemical interaction of nitrosamines may also be aetiological factors in the development of cholangiocarcinoma (CCA). Over 1800 samples of fresh and preserved food were systematically collected and tested between 1988 and 1996. All the food items identified by anthropological studies to be consumed frequently in four major regions of Thailand were analysed for volatile nitrosamines using gas chromatography combined with a thermal energy analyser. Relatively high levels of N-nitrosodimethylamine (NDMA), N-nitrosopiperidine (NPIP) and N-nitrosopyrrolidine (NPYR) were detected in fermented fish ("Plasalid"). NDMA was also detected at levels ranging from trace amounts to 66.5 microg/kg in several salted and dried fish ("Larb-pla" and "Pla-siu"). NDMA and NPYR were frequently detected in several vegetables, particularly fermented beans ("Tau-chiau") at levels ranging between 1 and 95.1 microg/kg and 0-146 microg/kg, respectively. The possible role of nitrosamines in Thai food in the aetiology of liver cancer (HCC, CCA) is discussed.

Esophageal cancer: therapeutic approaches and nursing care

OBJECTIVES

To review the various treatment approaches, complications, and nursing management of patients with esophageal cancer.

DATA SOURCES

Review articles, staging manual, textbook chapters, and research studies.

CONCLUSIONS

The diagnosis and treatment of esophageal cancer is a complicated process. Combined multimodal therapy with chemotherapy, radiotherapy, and surgery is showing promising results. However, each treatment approach has complications and side effects that must be managed.

IMPLICATIONS FOR NURSING PRACTICE

Nursing care is complicated and requires coordinating various support services, patient and family education, clinical assessment, nutritional management, management of side effects, and palliative care.

Socioeconomic status and stomach cancer incidence in men: results from The Netherlands Cohort Study

STUDY OBJECTIVE

To study the association between socioeconomic status (SES) and stomach cancer incidence (cardia and non-cardia) and the role of lifestyle factors in explaining this association.

DESIGN

Prospective cohort study on diet and cancer that started in 1986. Data were collected by means of a self administered questionnaire.

SETTING

Population originating from 204 municipalities in the Netherlands.

PARTICIPANTS

58,279 men aged 55-69 years. After 4.3 years of follow up, 162 incident stomach cancer cases were detected (49 cardia and 113 non-cardia cases).

MAIN RESULTS AND CONCLUSIONS

After adjustment for age, a lower overall stomach cancer risk was found for men with the highest attained level of education (RR highest/lowest level = 0.54, 95% CI 0.33, 0.89, trend, p = 0.02). This association became less strong after additional adjustment for smoking, intake of vitamin C, beta carotene, alcohol and coffee, family history of stomach cancer, and history of stomach disorders (RR = 0.61, 95% CI 0.34, 1.07, trend, p = 0.11). No clear association was found between occupation based SES indicators and stomach cancer risk. Analyses per subsite of stomach cancer revealed that for people with the highest level of education the age adjusted rate ratio for cardia cancer changed from 0.37 (95% CI = 0.13, 1.00) to 0.60 (95% CI = 0.19, 1.87) after additional adjustment for lifestyle variables, whereas the rate ratio for non-cardia cancer (RR = 0.59, 95% CI 0.33, 1.05) did not change after additional adjustment.

Cancer incidence in female smokers: a 26-year follow-up

A random sample of 26,000 Swedish women who were asked about their smoking habits in the early 1960s have now been followed for 26 years with respect to cancer incidence. Most findings regarding tobacco smoking and cancer from studies of men were confirmed also among the women. Elevated relative risk for current smokers compared with women who never smoked regularly were seen for cancers of the lung, upper aerodigestive sites, pancreas, bladder, cervix and all cancers combined, as well as a notably high relative risk for cancers of organs of the urinary tract other than kidney and bladder. Relative risk increased with dose, measured as grams of tobacco smoked per day, for cancers of the upper aerodigestive sites, lung, cervix, bladder, organs of the urinary tract other than kidney and bladder and all cancers combined. For cancers of the lung, bladder and cervix, there was an inverse relationship with age when starting to smoke tobacco. The reported inverse relationship between smoking and endometrial cancer could not be corroborated, nor was there any significant relationship between smoking and colorectal or breast cancer.

Risk factors for the development of colorectal carcinoma and their modification

In this article the authors review factors determining risk for the development of colorectal cancer (CC) and their modification. Emphasis is placed on understanding the difference between average risk and high risk individuals. Risk factors including genetics, diet, environment, and coexistent diseases are discussed. The data regarding modification of risk via dietary, pharmaceutical, and prophylactic endoscopic and surgical interventions are reviewed.

Cancer, cigarette smoking and premature death in Europe: a review including the Recommendations of European Cancer Experts Consensus Meeting, Helsinki, October 1996

Cigarette smoking has been clearly and unambiguously identified as a direct cause of cancers of the oral cavity, oesophagus, stomach, pancreas, larynx, lung, bladder, kidney and leukaemia, especially acute myeloid leukaemia. Additionally, cigarette smoking is a direct cause of ischaemic heart disease (the commonest cause of death in western countries), respiratory heart disease, aortic aneurysm, chronic obstructive lung disease, stroke, pneumonia and cirrhosis and cancer of the liver. Cigarette smoking can kill in 24 different ways and, although smoking protects against several fatal and non-fatal conditions, the adverse effect of smoking on health is largely negative. In developed countries as a whole, tobacco is responsible for 24% of all male deaths and 7% of all female deaths: these figures rise to over 40% in men in some countries of central and eastern Europe and to 17% in women in the United States. The average loss of life of smokers is 8 years. Among United Kingdom doctors followed for 40 years, overall death rates in middle age were about three times higher among doctors who smoked cigarettes as among doctors who had never smoked regularly. About half of all regular cigarette smokers will eventually be killed by their habit. The important information is that it is never too late to stop smoking: among United Kingdom doctors who stopped smoking, even in middle age, there was a substantial improvement in life expectancy. World-wide, smoking is killing three million people each year and this figure is increasing. In most countries the worst is yet to come, since by the time the young smokers of today reach middle or old age there will be about 10 million deaths/year from tobacco. Approximately 500 million individuals alive today can expect to be killed by tobacco, 250 million of these deaths will occur in middle age. Tobacco is already the biggest cause of adult death in developed countries. Over the next few decades tobacco could well become the biggest cause of adult death in the world. For men in developed countries, the full effects of smoking can already be seen. Tobacco now causes one-third of all male deaths in middle age (plus one fifth in old age). Tobacco is a cause of about half of all male cancer deaths in middle age (plus one-third in old age). Of those who start smoking in their teenage years and keep on smoking, about half will be killed by tobacco. Half of these deaths will be in middle age (35-69) and each will lose an average of 20-25 years of non-smoker life expectancy. In non-smokers in many countries, cancer mortality is decreasing slowly and total mortality rapidly. The war against cancer is being won slowly: the effects of cigarette smoking are holding back this victory. Lung cancer now kills more women in the United States each year than breast cancer. For women in developed countries, the peak of the tobacco epidemic has not yet arrived. Tobacco now causes almost one-third of all deaths in women in middle age in the United States. Although it has only 5% of the world's female population, the United States has 50% of the world's deaths from smoking in women. Tobacco smoking is a major cause of premature death. Throughout Europe, in 1990 tobacco smoking caused three quarters of a million deaths in middle age (between 35 and 69). In the Member States of the European Union in 1990 there were over one quarter of a million deaths in middle age directly caused by tobacco smoking: there were 219700 in men and 31900 in women. There were many more deaths caused by tobacco at older ages. In countries of central and eastern Europe, including the former USSR, there were 441200 deaths in middle age in men and 42100 deaths in women. There is a need for urgent action to help contain this important and unnecessary loss of life. In formulating Recommendations, the European Cancer Experts Consensus Committee recognised that Tobacco Control depends on various parts of society and not only on the individual.

The relationship between smoking exposure and p53 overexpression in colorectal cancer

Although epidemiological studies of the relationship between cigarette smoking and colorectal cancer risk have been equivocal, a positive association is consistently found for colorectal adenoma development. We performed an epidemiological study to determine whether p53 protein overexpression, in tumours obtained at the time of resection, is associated with cigarette exposure in colorectal cancer. A total of 163 colorectal cancer cases and 326 healthy controls responded to a standardised questionnaire on colorectal cancer risk factors including detailed information on their history of cigarette smoking. All patients' tumours were analysed immunohistochemically for p53 overexpression using an avidin-biotin immunoperoxidase procedure and polyclonal anti-p53 antibody CM1. Comparison of colorectal cases with controls revealed an elevated risk for ex-smokers (OR = 1.34, 95% CI 0.85-2.12) and current smokers (OR = 1.13, 95% CI 0.63-2.02) when compared with non-smokers. No dose-response relationship was found for total pack-years of smoking (trend test: P = 0.19). However, a trend for total pack-years of smoking was found when p53-positive cases were compared with p53-negative cases suggesting aetiological, heterogeneity (trend test: P = 0.06). Estimating the individual relative risk of developing a p53-positive tumour relative to controls showed no associations for smoking status or total pack-years of smoking. However, when p53-negative cases were compared with controls, an elevated risk was found for ex-smokers (OR = 1.84, 95% CI 1.00-3.37) and current years of smoking (trend test: P = 0.03). Colorectal tumours developing through p53-positive dependent pathways were not associated with smoking exposure. A significant increase in risk was observed for the p53-negative independent pathway with smoking. p53 overexpression appears to be associated with smoking exposure in colorectal cancer.

Epidemiologic data on alcoholic beverage consumption and risk of cancer

Recent epidemiologic data confirm the results of earlier studies in supporting that alcoholic beverage consumption is a cause of cancer of the mouth, pharynx, larynx, esophagus, and liver. The effect of a specified level of alcohol intake on absolute risk of cancers of the head, neck, and esophagus depends on the presence of other risk factors, especially smoking. Whether alcoholic beverage consumption is a cause of cancer of the breast or large bowel is unclear. Alcohol intake appears not to increase risk of cancer of the lung, bladder, prostate, stomach, ovary, endometrium, or of melanoma. Indirect epidemiologic evidence suggests that alcohol may be a weak causal factor for pancreatic cancer. Although heavy alcohol consumption increases risk of cancer of the head, neck, esophagus, and liver, whether moderate alcohol consumption increases risk at these sites is unclear.

Nutrition and colorectal cancer

Epidemiologic evidence on the relation between nutrition and colorectal cancer is reviewed. Colon cancer varies approximately 20-fold internationally. Although there is clear evidence of genetic predisposition to colon cancer, much of this variation appears to be related to differences in dietary habits. At present, the data suggest that vegetables are associated with lower risk, and that fiber alone does not account for this association. Further, meat consumption is associated with increased risk but this, too, is not explained solely by its fat content. Several microconstituents of the diet may be associated with reduced risk--including folate and calcium--but phytochemicals of other sorts may be relevant. Mutagenic compounds, particularly heterocyclic amines, produced when protein is cooked, plausibly explain the meat association. The most consistent inverse association is with physical activity. Alcohol is associated, though inconsistently, with increased risk. Rectal cancer is less well studied but, at present, there are few data to suggest that the dietary risk factors are markedly different. Physical activity does not appear to be associated with a lower risk. Colorectal adenomatous polyps also appear to share the spectrum of risk factors seen with colon cancer, although, for adenomas, tobacco smoking is also a clear and consistent risk factor. There are a variety of links between the dietary epidemiology and physiology of colorectal neoplasia and the relevant pathologic and molecular changes. Other causal connections remain to be explicated.

Risk factors for the development of oesophageal cancer as a second primary tumour

Exposure to irradiation or chemotherapy as well as prolonged exposure to risk factors, such as alcohol and tobacco, may induce a second primary carcinoma of the oesophagus. To estimate the potential risk of previous treatment regimens, we performed a case-control study. In the Tumour Registry of The Netherlands Cancer Institute, from 1955, 27 cases of squamous cell carcinoma of the oesophagus were identified following treatment for malignant lymphoma (n = 11), breast cancer (n = 8) and lung cancer (n = 8). The median interval was 6.6 years (range 1-16). Preferably 3 controls from the same tumour registry were matched to each case on the basis of sex, age, primary tumour, location of primary treatment (academic or general hospital), calendar year at diagnosis of primary tumour and duration of follow-up. Clinical data and details of treatment were obtained from the medical records. In patients who had smoked for more than 5 years, there was a 3.2-fold increased risk of oesophageal carcinoma (P = 0.04); for those with a regular alcohol intake the relative risk was 3.3 (P = 0.01). There was no significant relationship between irradiation of the mediastinum and subsequent risk for oesophageal cancer. The number of chemotherapy-treated patients was too small to calculate the relative risk associated with cytostatic drugs. In conclusion, oesophageal cancer as second primary cancer is extremely rare. Risk factors include the well known abuse of alcohol and tobacco. No significant relationship with previous mediastinal irradiation could be demonstrated.

Mortality among New York State highway maintenance workers: 1958-1980

The mortality profile of 9585 male New York State Department of Transportation (NYSDOT) highway maintenance workers was examined by calculating age-era standard mortality ratios (SMRs), using the general male population of upstate New York as a reference group, for the period 1958-1980. The SMR for all workers was 1.14 (95% CI = 1.09, 1.18), with the greatest all-cause mortality among laborers (SMR = 1.23, 95% CI = 1.16, 1.29). The major contributors to this increase among laborers were circulatory system diseases (SMR = 1.18, 95% CI = 1.10, 1.27), diseases of the respiratory system (SMR = 1.34, 95% CI = 1.09, 1.64), digestive system diseases (SMR = 1.57, 95% CI = 1.26, 1.94), genitourinary system diseases (SMR = 1.61, 95% CI = 1.02, 2.41) and accidents, poison, and violence (SMR = 1.44, 95% CI = 1.19, 1.74). Some of the elevated risks observed may be attributed to cigarette smoking and other life-style factors that could not be assessed with the data available. However, the mortality risks for laborers increased with length of employment and latency, suggesting that occupational exposures may be contributing to the elevated risk in this cohort. Further studies should include information on life-style variables and other confounders as well as more detail on specific occupational exposures.

Differences in cancer incidence and mortality among socio-economic groups

OBJECTIVES

In this article studies on the association between socioeconomic status (SES) and risk for cancer at different sites are reviewed.

METHODS

The review is restricted to studies conducted in affluent societies, after 1970. Only studies using income, education and/or occupation as SES indicators are included.

RESULTS

A more or less consistent positive association between SES and cancer risk was found for colon and breast cancer. More or less consistent inverse associations were found for lung, stomach, oropharyngeal and esophageal cancer. Inconsistent associations were reported for cancer of the rectum and pancreas. Possible explanations for SES differences in cancer risk are discussed with special emphasis on lifestyle variables related to cancer risk.

CONCLUSIONS

It is concluded that it is still unclear whether the reported associations can be (partially) attributed to lifestyle related risk factors for cancer such as smoking, nutritional habits, drinking habits and reproductive factors.

Alcohol consumption and risk of cancer in humans: an overview

Recent epidemiologic data continue to support alcoholic beverage consumption as a cause of cancer of the mouth, pharynx, larynx, esophagus, and liver. The effect of a given alcohol intake on absolute risk of these cancers depends on the prevalence of other risk factors. Whether alcoholic beverage consumption is a cause of cancer of the breast or large bowel is unclear. Alcohol intake appears not to increase risk of cancer of the lung, bladder, prostate, stomach, ovary, endometrium, or of melanoma. Indirect epidemiologic evidence suggests that alcohol may be a weak causal factor for pancreatic cancer. Additional research is needed to determine whether middle-aged women who drink moderately may experience a slight increase in longevity if they decrease alcohol intake. A number of biologically plausible mechanisms exist by which alcohol may cause cancer.

Oesophageal and gastric cancer in Scotland 1960-90

In Scotland over the last 31 years the incidence of gastric cancer has significantly declined by 0.6% per annum in males and 1.1% in females. In contrast, for oesophageal cancer, incidence rates have risen significantly by 3.0% and 2.0% per annum in males and females respectively. Increasing incidence of both adenocarcinomas and squamous carcinomas of the oesophagus in men and squamous and recently adenocarcinomas in women has been observed. This cannot be entirely accounted for by a growth in the proportion of histologically verified (HV) tumours over time. The incidence of adenocarcinoma of the stomach increased over the study period, most likely because of increasing proportions of HV tumours and improved diagnostic precision. Areas with high levels of deprivation in Scotland are strongly associated with high rates of oesophageal cancer in men, and of gastric cancer in both men and women. All these observations are discussed in the context of current knowledge of risk factors for these diseases.

Subsite-specific risk factors for colorectal cancer: a hospital-based case-control study in Japan

To investigate the subsite-specific risk factors for colorectal cancer, we conducted a case-control study, using a common questionnaire which inquired about general lifestyles over the past five years (1988-92), at the Aichi Cancer Center Hospital, Nagoya, Japan. This study compared 432 patients with histopathologically diagnosed colorectal cancer (94 proximal colon [cecum, ascending colon, transverse colon]; 137 distal colon [descending colon, sigmoid colon]; 201 rectum [rectosigmoid, rectum]); and 31,782 first-visit outpatient controls who were free from cancer. In both genders, habitual smoking selectively increased the risk for rectum cancer. Soft or loose feces increased the risk for all subsites of colorectal cancer, particularly in female rectum cancer (odds ratio [OR] = 4.5). Among female dietary habits, Japanese-style foods decreased the risk for distal colon cancer, but increased the risk for proximal colon cancer. These results suggested that the risk factors for colorectal cancer differ by subsite among such a low-risk population as the Japanese. It is suggested also that 'irritable bowel' (soft or loose feces) might be associated with distal subsites of colorectal cancer, independently or combined with habitual smoking.

Increased risk of colorectal cancer among smokers: results of a 26-year follow-up of US veterans and a review

To clarify the relationship between tobacco use and risk of colorectal cancer, we evaluated a cohort of 248,046 American veterans followed prospectively for 26 years. In comparison with veterans who had never used tobacco, the risk of death was significantly increased for colon cancer and rectal cancer among current and former cigarette smokers and among pipe or cigar smokers, controlling for social class and occupational physical activity. Rectal-cancer risk was also significantly elevated among users of chewing tobacco or snuff. For both sites, risk increased significantly with pack-years, earlier age at first use, and number of cigarettes. These results reinforce 2 recent reports of the association of cigarette smoking and colorectal cancer in men and women. Inconsistencies in the findings of earlier epidemiologic studies appear to be due in large part to differences in length of follow-up or in choice of controls. Studies with at least 20 years of follow-up or population-based controls have tended to find elevated risk with tobacco smoking, while those with shorter follow-up or hospital controls have not. This, plus the strength and consistency of the association of smoking and colon polyps, suggest that smoking may primarily affect an early stage in the development of colon cancer. If this association is causal, tobacco use may be responsible for 16% of colon-cancer and 22% of rectal-cancer deaths among these veterans.

Prospective study on alcohol consumption and the risk of cancer of the colon and rectum in the Netherlands

The association between alcohol consumption and cancer of the colon and rectum was investigated in a prospective cohort study, conducted in the Netherlands from 1986 onwards among 120,852 men and women, aged 55 to 69 years. During 3.3 years of follow-up, 312 and 166 cases of colon and rectal cancer had accumulated, respectively. After exclusion of cases diagnosed in the first year of follow-up, the analysis was based on 217 incident cases of colon cancer (107 men and 110 women) and 113 cases of rectal cancer (75 men and 38 women). For colon cancer, no association with total intake of alcohol nor with the consumption of beer and wine, specifically, could be demonstrated; for liquor intake, a significant (P = 0.04) decreasing risk with increasing consumption was observed. For rectal cancer in men, positive trends were observed for total alcohol intake (P = 0.04), beer (P = 0.05), and liquor (P = 0.06). Results for rectal cancer in women were consistent with those in men, but data were too sparse to provide stable estimates. Simultaneous adjustment for beverage type and quantity appeared to strengthen the association of rectal cancer with drinking beer (relative rate (yes/no) = 2.0, 95 percent confidence interval = 1.1-3.9), although a dose-response effect was not observed. When alcohol intake from beer, wine, and liquor were included as continuous variables, the association was somewhat stronger for liquor than for beer, but none of the associations were statistically significant. It is concluded that consumption of alcoholic beverages (beer, in particular) is associated with an increased risk for rectal but not colon cancer.

Gastrointestinal protein turnover and alcohol misuse

Acute and chronic ethanol ingestion causes a variety of pathological changes in the gastrointestinal tract, including gross morphological lesions and functional changes. We review whether these alterations also include changes in protein turnover, to explain the frequently observed villus atrophy and smooth muscle myopathy. The possibility that different regions of the gastrointestinal tract express diverse sensitivities is explored. Acute ethanol dosage profoundly reduced the synthesis of proteins in proximal regions of the rat gastrointestinal tract, but distal regions were less affected. In response to chronic ethanol exposure, similar regional sensitivities of the intestine were observed. In chronic studies the small intestine effects were characterised by selective losses of RNA, principally from the stomach and jejunum. We speculate whether the effects on protein synthesis were primarily due to ethanol or the consequence of acetaldehyde formation. We also determined whether changes in protein synthesis occurred secondary to alterations in nucleotide composition. The possible mediation by free-radical formation or impaired antioxidant status are also discussed. The overall results indicate that both acetaldehyde and ethanol are potent protein synthetic inhibitors and may contribute to the genesis of intestinal myopathy, possibly contributing towards motility disturbances and secondary malnutrition via malabsorption.

Alcohol consumption and the etiology of colorectal cancer: a review of the scientific evidence from 1957 to 1991

The relationship between alcohol consumption and colorectal cancer in humans has been examined in 52 major studies in the past 35 years. An association was found in five of the seven correlational studies. An elevated risk was found in about half of the 31 case-control studies and, of these, in 9 of the 10 studies using community controls but in only 5 of the 17 studies using hospital controls (p = 0.008), suggesting that the absence of association when hospital controls are used is due to a high prevalence of alcohol consumption/alcohol-related illness in the hospital controls. Of the 14 cohort studies, an association with alcohol was found in 10, while in 3 of the 4 cohort studies in which an association was not found the alcohol data obtained were somewhat restricted. A positive dose-response effect was found in two of three cohort studies and in all four case-control studies with community controls in which this effect was examined. In both case-control and cohort studies, the association was found for females and males and for colon and rectal cancer. When the type of alcohol consumed was examined separately, beer was the principal type of at-risk alcoholic beverage, with much less risk for spirits and least risk for wine. Statistically significant elevations of risk were more often found in males than in females and slightly more frequently for rectal than for colon cancer and were related almost entirely to beer, rather than to wine or spirit, consumption. The alcohol risk was independent of the dietary risk in those studies that controlled for this factor. There was some confirmatory evidence for alcohol augmentation in rodent models of chemically induced carcinogenesis in six of nine studies. The hypotheses of alcohol as a direct and specific colorectal carcinogen include increased mucosal cell proliferation, the activation of intestinal procarcinogens, and the role of unabsorbed carcinogens, particularly in beer. Also, five of six other human studies showed an association between alcohol/beer consumption and adenomatous polyps, consistent with the hypothesis that alcohol stimulates the colorectal mucosa. General or indirect carcinogenic effects of alcohol include immunodepression, activation of liver procarcinogens, and changes in bile composition, as well as nitrosamine content of alcoholic beverages and increased tissue nitrosamine levels. With alcohol/beer consumption, the overall conclusion on present evidence is that alcohol, particularly beer consumption, is an etiologic factor for colon and rectal cancer for females and males.(ABSTRACT TRUNCATED AT 400 WORDS)