Cigarettes, alcohol, coffee, and caffeine as risk factors for colorectal adenomatous polyps

Risk factors including night shift work of colorectal polyp

Background

The destruction of circadian rhythms by night shift work affects major circadian genes, which are known to play a role in advancing or killing the cell cycle through tumor suppressor genes. To find out whether night shift work affects the incidence of colorectal cancer, which was found to be associated with long-term night shift work in previous studies, we surveyed effect of night shift work on colorectal polyps that have a higher incidence than colorectal cancer and can progress to colorectal cancer.

Methods

To examine the correlation between rotating night shifts and colorectal polyps, a survey was conducted with 299 men aged 40–60 years from two university hospitals. We examined lifestyle, work history, work patterns, and colonoscopy results. The differences in prevalence among the groups was compared, and prevalence ratio (PR) was calculated via generalized linear modeling.

Results

The prevalence of colorectal polyps in night shift and non-shift workers were 53.0% and 33.5%, respectively. After adjusting for age, smoking status, dietary habits, family history of colorectal cancer, obesity, job type, night shift work (PR: 1.13, 95% CI: 1.02–1.25) was a risk factor of colorectal polyps.

Conclusions

The risk of colorectal polyps was greater in night shift workers than non-shift workers. Also risk of colorectal polyp was higher in older group. Our study investigated colorectal polyp instead of colorectal cancer and lacks information about types and gene mutations of colorectal polyps. Further study is needed to clarify effect of night shift work on development of colorectal cancer.

Colorectal Polyp Prevalence According to Alcohol Consumption, Smoking and Obesity

This study aimed to analyze colorectal polyp prevalence associated with health behavior. Data from 1180 Korean men (young adult (YA), aged 40-49; middle age (MA) aged 50-59; old aged (OA), aged 60-79 years) were collected. Health behavior included alcohol consumption, smoking status, and obesity. Obesity was determined using body mass index (BMI) and waist circumference (WC). Odds ratio (OR) was calculated by logistic regression. The prevalence of polyps increased for current smokers by 2.642 times in the YA group, 3.468 times in the MA group, and 3.104 times in the OA group compared to the never-smokers. The OR for WC increased in subjects with obesity by 1.514 in the MA and 1.451 in the OA group compared to normal. The prevalence of three or more polyps increased with WC obesity by 2.3 times in YA, 2.2 times in MA, and 1.9 times in OA compared to normal WC. Therefore, smoking cessation and obesity management may reduce the risk of colorectal polyps.

RIESGO DE CÁNCER DE COLON EN DOCENTES UNIVERSITARIOS DE SALUD Y HUMANIDADES, UN ESTUDIO COMPARATIVO

<p><strong>Introducción:</strong> En México, el cáncer de colon ocupa el cuarto lugar de morbi-mortalidad con referencia a otros tipos de cáncer. Los factores de riesgo relacionados a la patología son: dieta hiperlipídica, sedentarismo, estrés, toxicomanías, enfermedades inflamatorias gastrointestinales; entre otros. La identificación de poblaciones expuestas, permite extender los alcances de la prevención primaria contra el cáncer de colon. La presente investigación, tuvo como O<strong>bjetivo:</strong> comparar el nivel de riesgo para desarrollar cáncer de colon en profesores de la Facultad de Estudios Superiores Iztacala (FES-I), con formación en ciencias de la salud y profesores de la Facultad de Estudios Superiores Acatlán (FES-A), dedicados a ciencias sociales y humanidades. <strong>Metodología:</strong> Se realizó un estudio cuantitativo, comparativo transversal, con muestra probabilística de 92 académicos de FES-A y 93 de FES-I. Se aplicó un instrumento de 40 ítems, fundamentado en los principales elementos que propician la aparición de cáncer de colon. <strong>Resultados: </strong>el análisis de datos, revela mayor porcentaje de obesidad, alto consumo de alcohol, tabaco y carnes rojas, así como menor conocimiento sobre factores predisponentes a la enfermedad, en docentes de FES-A. <strong>Conclusiones:</strong> los académicos de FES-A presentan más factores de riesgo que los profesores de FES-I. Es necesario difundir conocimiento de calidad sobre ésta patología para concientizar sobre hábitos inadecuados en la dieta, así como el consumo de alimentos protectores dentro de ella, para la prevención de esta neoplasia.</p>

Dietary natural methylxanthines and colorectal cancer: a systematic review and meta-analysis

Some evidence suggests that caffeine, theophylline, and theobromine, as natural methylxanthines (MTXs), possess anti-cancer effects.

Dose-response meta-analysis of coffee consumption and risk of colorectal adenoma

BACKGROUND

The association between coffee and colorectal adenoma risk remains controversial. We conducted a meta-analysis of cohort and case-control studies to sum up the existing proof about this matter.

METHODS

We searched Pubmed, Medline, and Embase for studies published before 1 September 2018 on coffee consumption and colorectal adenoma in any language. The different ORs were calculated for cohort and case-control studies in this study, and we use a random-effects model to aggregate the relative risks of individual studies and conduct dose response, heterogeneity, and publication bias.

RESULTS

A total of 8 studies (6 case-control studies, 2 cohort studies) were identified, including 7090 subjects. In a summary analysis of all studies, high coffee intake (compared the highest with the lowest categories) was associated with a reduced risk of colorectal adenoma (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.55-0.90). The results of subgroup analysis of adenoma location were similar with the pooled analysis, except for rectal adenoma. In the dose-response meta-analysis study, the estimated total odds ratio for increasing coffee consumption by 150 ml per day (about one cup) was 0.91 (95% CI = 0.87-0.95).

CONCLUSIONS

The meta-analysis demonstrates possible evidence that increased coffee intake is related to a reduced risk of colon adenoma. However, because of latent confusion and different exposure classification, this finding should be carefully considered.

The Safety of Ingested Caffeine: A Comprehensive Review

Caffeine is the most widely consumed psychoactive drug in the world. Natural sources of caffeine include coffee, tea, and chocolate. Synthetic caffeine is also added to products to promote arousal, alertness, energy, and elevated mood. Over the past decade, the introduction of new caffeine-containing food products, as well as changes in consumption patterns of the more traditional sources of caffeine, has increased scrutiny by health authorities and regulatory bodies about the overall consumption of caffeine and its potential cumulative effects on behavior and physiology. Of particular concern is the rate of caffeine intake among populations potentially vulnerable to the negative effects of caffeine consumption: pregnant and lactating women, children and adolescents, young adults, and people with underlying heart or other health conditions, such as mental illness. Here, we review the research into the safety and safe doses of ingested caffeine in healthy and in vulnerable populations. We report that, for healthy adults, caffeine consumption is relatively safe, but that for some vulnerable populations, caffeine consumption could be harmful, including impairments in cardiovascular function, sleep, and substance use. We also identified several gaps in the literature on which we based recommendations for the future of caffeine research.

Associations between amount of smoking and alcohol intake and risk of colorectal neoplasm

BACKGROUND AND AIM

Although smoking and alcohol has been linked to an increased risk of colorectal neoplasm (CRN), large-scale studies to identify dose-dependent relationship between amount of smoking and alcohol consumption and risk of CRN are rare. We aimed to investigate the risk for CRN according to the amount of smoking and alcohol intake in a large sample of Korean adults.

METHODS

A cross-sectional study was performed on 31,714 examinees aged ≥30 years undergoing their first colonoscopy as part of routine preventive health care between 2010 and 2011. Never smokers were compared with six groups of smokers according to smoking amount, and individuals with alcohol intake of ≤ 6.25 g ethanol per day were compared with three groups according to alcohol amount.

RESULTS

In adjusted models, the risk of overall CRN increased with increasing amount of smoking (P for trend < 0.001). The adjusted odds ratios for overall CRN comparing never smokers with six smoker groups according to smoking amount (≤2.50, 2.51-5.60, 5.61-9.00, 9.01-13.00, 13.01-19.50, and ≥19.51 pack-years) were 1.02, 1.19, 1.35, 1.53, 1.63, and 2.03, respectively. In addition, the risk of both non-advanced and advanced CRN increased with increasing amount of smoking (both P for trend < 0.001). However, the amount of alcohol consumption was not correlated with the risk of CRN.

CONCLUSIONS

The prevalence of CRN was associated with increasing amount of smoking in a dose-response manner, whereas it was not associated with the amount of alcohol consumption. Our study suggests that smoking amount as well as smoking status should be considered for CRN risk stratification.

Alcohol Consumption-Related Metabolites in Relation to Colorectal Cancer and Adenoma: Two Case-Control Studies Using Serum Biomarkers

Alcohol is a known carcinogen that may be associated with colorectal cancer. However, most epidemiologic studies assess alcoholic beverage consumption using self-reported data, leading to potential exposure misclassification. Biomarkers of alcohol consumption may provide an alternative, complementary approach that reduces misclassification and incorporates individual differences in alcohol metabolism. Therefore, we evaluated the relationship between previously identified alcohol consumption-related metabolites and colorectal cancer and adenoma using serum metabolomics data from two studies. Data on colorectal cancer were obtained from a nested case-control study of 502 US adults (252 cases, 250 controls) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Data on colorectal adenoma were obtained from a case-control study of 197 US adults (120 cases, 77 controls) from the Navy Colon Adenoma Study. Unconditional multivariable logistic regression models were fit to calculate odds ratios (OR) and 95% confidence intervals (CI) for eight alcohol consumption-related metabolites identified in a previous analysis: ethyl glucuronide; 4-androstene-3beta,17beta-diol disulfate 1; 5-alpha-androstan-3beta,17beta-diol disulfate; 16-hydroxypalmitate; bilirubin (E,Z or Z,E); cyclo (-leu-pro); dihomo-linoleate (20:2n6); and palmitoleate (16:1n7). We found no clear association between these alcohol consumption-related metabolites and either endpoint. However, we did observe an inverse association between cyclo (-leu-pro) and colorectal adenoma that was only observed in the highest metabolite quantile (OR _{4th vs. 1st Quantile} = 0.30, 95% CI: 0.12–0.78; P-trend = 0.047), but no association for colorectal cancer. In conclusion, there were no adverse associations between alcohol consumption-related metabolites and colorectal cancer or adenoma.

Coffee intake and the risk of colorectal adenoma: The colorectal adenoma study in Tokyo

Coffee is a commonly consumed beverage which contains several potential anticarcinogenic and chemopreventive compounds, and has been hypothesized to have protective effects in colorectal neoplasia. However, the limited available data on coffee consumption in relation to colorectal adenoma (CRA), a precursor lesion to most colorectal cancers, remain largely inconsistent. In this study, we evaluated the association of coffee intake with the risk of CRA in a middle-aged Japanese population. Study subjects were selected from examinees who underwent total colonoscopy as part of a cancer screening program and responded to self-administered dietary and lifestyle questionnaires. A total of 738 patients with adenoma and 697 controls were included in the study. Coffee intake was assessed with a food frequency questionnaire, and divided into quartiles based on the distribution among controls. Unconditional logistic regression models were used to estimate odds ratio (OR) and 95% confidence interval (CI) of CRA, with adjustment for potential confounding factors. High coffee consumption was associated with a reduced risk of CRA, with a multivariate-adjusted OR for the highest versus lowest quartile of coffee intake of 0.67 (95% CI = 0.48-0.93; ptrend  = 0.02). The inverse association of coffee intake was limited to proximal (OR = 0.64; 95%CI = 0.44-0.95; ptrend  = 0.04) and distal colon adenoma (OR = 0.62; 95%CI = 0.39-0.99; ptrend  = 0.06), and appeared to be more evident with small (OR = 0.68; 95%CI = 0.49-0.96; ptrend  = 0.04) and single adenomas (OR = 0.65; 95%CI = 0.44-0.95; ptrend  = 0.02). Green tea intake was not found to be associated with CRA risk. This study provides support for the protective effect of coffee drinking on colon adenomas, a precursor of colon cancer.

Patient age and duration of colonoscopy are predictors for adenoma detection in both proximal and distal colon

AIM: To investigate the relation of patient characteristics and procedural parameters to the endoscopic detection rate of colonic adenomas. Further to study, which factors may be capable to predict the localization of adenomatous lesions.

METHODS: We used the data base of a prospective randomized colonoscopy study (The ColoCap trial) to identify patients being diagnosed with colon adenoma. Logistic regression analysis was conducted to reveal predictors for adenoma detection in the entire colon and also with respect to the proximal and distal part. Covariates including age, gender, duration of colonoscopy and comorbidities were defined to determine association between predictors and adenoma detection.

RESULTS: Equal numbers of adenomas were detected in the proximal and distal side of the splenic flexure [126 (57%) vs 94 (43%), P = 0.104]. Simultaneous occurrence of adenomas in both sides of the colon was rare. The appearance of both proximal and distal adenoma was associated with increasing age (P = 0.008 and P = 0.024) and increasing duration of colonoscopy (P < 0.001 and P = 0.001). Male gender was a predictor for adenoma detection in the proximal colon (P = 0.008) but statistical significance was slightly missed with respect to the distal colon (P = 0.089). Alcohol abuse was found to be a predictor for the detection of distal adenoma (P = 0.041).

CONCLUSION: Increasing age and longer duration of colonoscopy are factors with a strong impact on adenoma detection both in the proximal and distal colon. Since proximal adenomas occurred in absence of distal adenomas, complete colonoscopy should be performed for screening.

Alcohol intake, smoking, and colorectal adenoma

Background:

Colorectal cancer is the third most common cancer in Korea. Because colorectal adenoma is a precursor lesion of colorectal cancer, primary prevention of colorectal adenomas may be important for reducing morbidity and mortality from the disease. The aim of this study is to examine the association of alcohol consumption and cigarette smoking in relation with colorectal adenoma in a cross-sectional study of Korean adults.

Methods:

A total of 366 participants who underwent colonoscopy were included (113 cases and 255 controls) in this study. Information on alcohol intake and cigarette smoking was collected from structured questionnaires. The odds ratio (ORs) and 95% confidence intervals (CIs) were calculated using the multivariate logistic regression models.

Results:

Alcohol intake was associated with a higher prevalence of colorectal adenoma in men; compared to non-drinkers, ORs (95% CIs) were 11.49 (2.55–51.89) for 10–20 g/day of alcohol intake and 14.15 (3.31–60.59) for â 20 g/day of alcohol intake (P for trend = 0.003). There was a weaker association of alcohol intake for women than men; however, there was a suggestive increase in the prevalence of colorectal cancer in women. Cigarette smoking was not associated with colorectal adenoma, but we cannot rule out the possibility that this was due to low statistical power.

Conclusion:

Our study provides evidence to suggest that alcohol intake may contribute to colorectal adenoma in the Korean population. Our study results demonstrate that a larger epidemiologic study is needed.

Metabolic syndrome, lifestyle risk factors, and distal colon adenoma: A retrospective cohort study

AIM: To investigate relationships between colorectal adenoma incidence, metabolic syndrome (MS) components and lifestyle factors.

METHODS: We conducted a retrospective cohort study using data from individuals who had multiple sigmoidoscopies for colon cancer at the Health Promotion Center of Ulsan University Hospital in Korea from 1998 to 2007.

RESULTS: By multivariate analysis, the incidence of distal colon adenoma was increased by more than 1.76 times in individuals with at least one component of MS compared to those without a component of MS. After adjustment for age, gender, smoking, drinking, and physical exercise, only high body mass index (BMI) was significantly associated with the incidence of distal colon adenoma (Hazard ratio 1.66, 95% confidence interval 1.05-2.62).

CONCLUSION: Our results suggest that high BMI may increase the risk of colorectal adenoma in Korean adults.

Associations of cigarette smoking and alcohol consumption with advanced or multiple colorectal adenoma risks: a colonoscopy-based case-control study in Korea

The associations between alcohol consumption and cigarette smoking habits and the risk for colorectal adenomatous polyps according to the detailed clinical information about polyps were assessed in a large colonoscopy-based study. The study enrolled participants who visited the National Cancer Center of the Republic of Korea for cancer screening between April 2007 and April 2009. In 1,242 newly diagnosed colorectal adenoma patients and 3,019 polyp-free controls, past smokers (odds ratio (OR) = 1.31, 95% confidence interval (CI): 1.04, 1.65) and current smokers (OR = 1.70, 95% CI: 1.37, 2.11) had increased risks for adenomas compared with nonsmokers. Cigarette smoking conferred an even higher risk for advanced adenomas and 3 or more adenomas than for low-risk adenomas or a single adenoma. Dose-response relations were observed among the daily number of cigarettes smoked, the duration of smoking, the pack-years of smoking, and the risk for adenomas. A longer duration of alcohol consumption was associated with a higher risk for advanced adenomas (for >28 years of consumption: OR = 2.0, 95% CI: 1.10, 3.64) and 3 or more adenomas (OR = 2.19, 95% CI: 1.27, 3.76). In conclusion, cigarette smoking and alcohol consumption play roles in colorectal carcinogenesis, and the association differs by the clinical features of the adenomas.

Cigarette smoking, genetic variants in carcinogen-metabolizing enzymes, and colorectal cancer risk

The risk of colorectal cancer associated with smoking is unclear and may be influenced by genetic variation in enzymes that metabolize cigarette carcinogens. The authors examined the colorectal cancer risk associated with smoking and 26 variants in carcinogen metabolism genes in 1,174 colorectal cancer cases and 1,293 population-based controls recruited in Canada by the Ontario Familial Colorectal Cancer Registry from 1997 to 2001. Adjusted odds ratios were calculated by multivariable logistic regression. Smoking for >27 years was associated with a statistically significant increased colorectal cancer risk (adjusted odds ratio (AOR) = 1.25, 95% confidence interval (CI): 1.02, 1.53) in all subjects. Colorectal cancer risk associated with smoking was higher in males for smoking status, duration, and intensity. The CYP1A1-3801-CC (AOR = 0.47, 95% CI: 0.23, 0.94) and CYP2C9-430-CT (AOR = 0.82, 95% CI: 0.68, 0.99) genotypes were associated with decreased risk, and the GSTM1-K173N-CG (AOR = 1.99, 95% CI: 1.21, 3.25) genotype was associated with an increased risk of colorectal cancer. Statistical interactions between smoking and genetic variants were assessed by comparing logistic regression models with and without a multiplicative interaction term. Significant interactions were observed between smoking status and SULT1A1-638 (P = 0.02), NAT2-857 (P = 0.01), and CYP1B1-4390 (P = 0.04) variants and between smoking duration and NAT1-1088 (P = 0.02), SULT1A1-638 (P = 0.04), and NAT1-acetylator (P = 0.03) status. These findings support the hypothesis that prolonged cigarette smoking is associated with increased risk of colorectal cancer and that this risk may be modified by variation in carcinogen metabolism genes.

The comparison of the clinical manifestations and risk factors of colorectal cancer and adenomas: results from a colonoscopy-based study in southern Chinese

BACKGROUND AND AIMS

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors in the world. This study aimed to compare the clinical manifestations and risk factors of CRC and adenomas in native patients of Guangzhou.

METHODS

Patients who underwent colonoscopy for the first time at Nanfang Hospital between July 2008 and July 2009 were recruited. Data on demographic information, main clinical manifestations, results of endoscopies and pathology, and possible risk factors of colorectal tumor were collected. Chi-square test and logistic regression were used to compare the clinical characteristics and risk factors for CRC and adenomas.

RESULTS

Hematochezia and body weight loss were more frequent in proximal and distal CRC groups, respectively (P ≤  0.05). Older age [odds ratio (OR), 1.079; 95% confidence interval (CI), 1.065-1.093], smoking status (OR, 1.712; 95% CI, 1.158-2.531), BMI =18.5-24.9 and  ≥ 25.0 (OR, 2.384; 95% CI, 1.250-4.549; OR, 2.162; 95% CI, 1.044-4.478, respectively) were significant risk factors for advanced adenoma, while female (OR, 0.638; 95% CI, 0.429-0.949) and using aspirin (OR, 0.188; 95% CI, 0.042-0.845) were significant protective factors. Hyperlipemia (OR, 0.109; 95% CI, 0.013-0.886) was identified as a protective factor for proximal CRC. Smoking (OR, 1.717; 95% CI, 1.093-2.696), drinking (OR, 1.817; 95% CI, 1.145-2.883), DM history (OR, 2.204; 95% CI, 1.044-4.652) were identified as independent risk factors for distal CRC, and using aspirin (OR, 0.190; 95% CI, 0.043-0.840) was a protective factor. Drinking (OR, 3.288; 95% CI, 1.546-6.994; OR, 1.862; 95% CI, 1.037-3.343, respectively) was an independent risk factor for both poorly to moderately differentiated CRC and well-differentiated CRC. Besides, DM (OR, 3.761; 95% CI, 1.615-8.762) and hypertension (OR, 0.384; 95% CI, 0.178-0.828) were identified as independent risk factor and protective factor for well-differentiated CRC, respectively.

CONCLUSIONS

Hematochezia and body weight loss were representative manifestations for distal and proximal CRC, respectively. For southern Chinese the most important influential factors for colorectal tumor are age, smoking, drinking, nutritional state, DM, hypertension, and the use of aspirin.

Colorectal cancer occurs earlier in those exposed to tobacco smoke: implications for screening

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in the USA. While various lifestyle factors have been shown to alter the risk for colorectal cancer, recommendations for the early detection of CRC are based only on age and family history.

METHODS

This case-only study examined the age at diagnosis of colorectal cancer in subjects exposed to tobacco smoke. Subjects included all patients who attended RPCI between 1957 and 1997, diagnosed with colorectal cancer, and completed an epidemiologic questionnaire. Adjusted linear regression models were calculated for the various smoking exposures.

RESULTS

Of the 3,540 cases of colorectal cancer, current smokers demonstrated the youngest age of CRC onset (never: 64.2 vs. current: 57.4, P < 0.001) compared to never smokers, followed by recent former smokers. Among never smokers, individuals with past second-hand smoke exposure were diagnosed at a significantly younger age compared to the unexposed.

CONCLUSION

This study found that individuals with heavy, long-term tobacco smoke exposure were significantly younger at the time of CRC diagnosis compared to lifelong never smokers. The implication of this finding is that screening for colorectal cancer, which is recommended to begin at age 50 years for persons at average risk should be initiated 5-10 years earlier for persons with a significant lifetime history of exposure to tobacco smoke.

Cigarette smoking and adenomatous polyps: a meta-analysis

BACKGROUND & AIMS

Through the past 2 decades, a consistent association between cigarette smoking and colorectal adenomatous polyps, recognized precursor lesions of colorectal cancer, has been shown. We performed a meta-analysis to provide a quantitative pooled risk estimate of the association, focusing on the different characteristics of the study populations, study designs, and clinical feature of the polyps.

METHODS

We performed a comprehensive literature search of studies linking cigarette smoking and adenomas. We used random effects models to evaluate pooled relative risks and performed dose-response, heterogeneity, publication bias, and sensitivity analyses.

RESULTS

Forty-two independent observational studies were included in the analysis. The pooled risk estimates for current, former, and ever smokers in comparison with never smokers were 2.14 (95% confidence interval [CI], 1.86-2.46), 1.47 (95% CI, 1.29-1.67), and 1.82 (95% CI, 1.65-2.00), respectively. The association was stronger for high-risk adenomas than for low-risk adenomas. Studies in which all controls underwent full colonoscopy showed a higher risk compared with studies in which some or all controls underwent partial colon examination.

CONCLUSIONS

This meta-analysis provides strong evidence of the detrimental effect of cigarette smoking on the development of adenomatous polyps. Smoking is important for both formation and aggressiveness of adenomas.

XRCC1, XRCC3, and XPD polymorphisms as modifiers of the effect of smoking and alcohol on colorectal adenoma risk

Using a sigmoidoscopy-based case-control study (753 cases, 799 controls) in Los Angeles County, we investigated the potential modifier role in the effect of alcohol and smoking of single-nucleotide polymorphisms (SNP) in three DNA repair genes, XRCC1 (Arg194Trp and Arg399Gln), XRCC3 (Thr241Met), and XPD (Lys751Gln). We have previously reported an inverse association between the XRCC1 codon 399 SNP and adenoma risk among these subjects. We now report that subjects with the XPD Gln/Gln genotype were inversely associated with adenoma risk [odds ratio (OR), 0.7; 95% confidence interval (95% CI), 0.5-1.0] when compared with subjects with the Lys/Lys and Lys/Gln genotypes combined. This association differed between different ethnic groups (gene x race heterogeneity likelihood ratio test, P = 0.009), with a stronger inverse association among Latinos (OR, 0.1; 95% CI, 0.01-0.5) than among non-Latinos (OR, 0.9; 95% CI, 0.-1.3). We found no evidence of an XRCC3 x smoking or alcohol interaction or an XRCC1 x alcohol interaction. Instead, our data supported an XRCC1 x smoking interaction (P = 0.048). Whereas XPD did not modify the effect of smoking, our data suggested an XPD x alcohol interaction. Analyses ignoring XPD showed no association between alcohol intake and adenoma prevalence; however, among carriers of the codon 751 Gln/Gln genotype, we found a significant positive association (OR, 2.5; 95% CI, 1.2-5.2 for ever drinkers; test of interaction P = 0.04). Our data suggest that the effects of smoking and alcohol may vary depending on the genetic background of proteins that participate in the base excision repair and nucleotide excision repair pathways.

Coffee and health: a review of recent human research

Coffee is a complex mixture of chemicals that provides significant amounts of chlorogenic acid and caffeine. Unfiltered coffee is a significant source of cafestol and kahweol, which are diterpenes that have been implicated in the cholesterol-raising effects of coffee. The results of epidemiological research suggest that coffee consumption may help prevent several chronic diseases, including type 2 diabetes mellitus, Parkinson's disease and liver disease (cirrhosis and hepatocellular carcinoma). Most prospective cohort studies have not found coffee consumption to be associated with significantly increased cardiovascular disease risk. However, coffee consumption is associated with increases in several cardiovascular disease risk factors, including blood pressure and plasma homocysteine. At present, there is little evidence that coffee consumption increases the risk of cancer. For adults consuming moderate amounts of coffee (3-4 cups/d providing 300-400 mg/d of caffeine), there is little evidence of health risks and some evidence of health benefits. However, some groups, including people with hypertension, children, adolescents, and the elderly, may be more vulnerable to the adverse effects of caffeine. In addition, currently available evidence suggests that it may be prudent for pregnant women to limit coffee consumption to 3 cups/d providing no more than 300 mg/d of caffeine to exclude any increased probability of spontaneous abortion or impaired fetal growth.

The Association Between Cigarette Smoking and Colorectal Polyp Recurrence (United States)

OBJECTIVE

Although evidence exists linking smoking to precancerous colorectal adenomatous polyps, few studies have examined the association between cigarette smoking and recurrence of colorectal polyps. This association was investigated prospectively with data from the Polyp Prevention Trial.

METHODS

Cigarette smoking data were collected through baseline interviews. The study was completed by 1872 men and women with presence of adenomas at baseline colonoscopy. Multiple logistic regression analysis was used to examine the association between cigarette smoking and polyp recurrence (adenomatous and hyperplastic) up to four years from baseline.

RESULTS

Adenoma recurrence was not related to cigarette smoking. Current smokers had increased odds of hyperplastic polyps at follow-up compared to never smokers (OR 2.88, 95% CI 2.06-4.01). Current smoking was associated with subsequent distal (OR 3.44, 95% CI 2.38-4.95) and rectal (OR 3.53, 95% CI 2.15-5.78) hyperplastic polyps, but not subsequent proximal hyperplastic polyps. Cigarette smoking was associated with subsequent multiple and small size (4 mm) hyperplastic polyps. Significant linear trends were observed between development of subsequent hyperplastic polyps and all smoking variables.

CONCLUSIONS

Although no association with recurrent adenomas was observed, cigarette smoking was significantly associated with hyperplastic polyp development, except for those in the proximal colon. This prospective study confirms that cigarette smoking has a significant effect on the development of hyperplastic colorectal polyps.

CYP1A1 Val462 and NQO1 Ser187 polymorphisms, cigarette use, and risk for colorectal adenoma

Cigarette use is a risk factor for colorectal adenoma, a known precursor of colorectal cancer. Polymorphic variants in NQO1 and CYP1A1 influence the activation of carcinogenic substances in tobacco smoke, possibly impacting on tobacco-associated risks for colorectal tumors. We investigated the association of cigarette smoking with risk for advanced colorectal adenoma in relation to the CYP1A1 Val(462) and NQO1 Ser(187) polymorphic variants. Subjects were 725 non-Hispanic Caucasian cases with advanced colorectal adenoma of the distal colon (descending colon, sigmoid and rectum) and 729 gender- and ethnicity-matched controls, randomly selected from participants in the prostate, lung, colorectal and ovarian cancer screening trial. Subjects carrying either CYP1A1 Val(462) or NQO1 Ser(187) alleles were weakly associated with risk of colorectal adenoma; however, subjects carrying both CYP1A1 Val(462) and NQO1 Ser(187) alleles showed increased risks (OR = 2.2, 95% CI = 1.1-4.5), particularly among recent (including current) (OR = 17.4, 95% CI = 3.8-79.8, P for interaction = 0.02) and heavy cigarette smokers (>20 cigarettes/day) (OR = 21.1, 95% CI = 3.9-114.4, P for interaction = 0.03) compared with non-smokers who did not carry either of these variants. These genotypes were unassociated with risk in non-smokers. In analysis of adenoma subtypes, the combined gene variants were most strongly associated with the presence of multiple adenoma (P = 0.002). In summary, joint carriage of CYP1A1 Val(462) and NQO1 Ser(187) alleles, particularly in smokers, was related to colorectal adenoma risk, with a propensity for formation of multiple lesions.

Relation of cigarette smoking and alcohol use to colorectal adenomas by subsite: the self-defense forces health study

While smoking has consistently been shown to be related to increased risk of colorectal adenomas, few studies have addressed the association between smoking and site-specific colorectal adenomas. The reported association between alcohol use and colorectal adenomas has been inconsistent. We evaluated risks of adenomas at the proximal colon, distal colon, and rectum in relation to cigarette smoking and alcohol use, and their interaction. Subjects were 754 cases with histologically proven colorectal adenomas and 1547 controls with normal colonoscopy among male officials of the Self-Defense Forces (SDF) undergoing total colonoscopy at two SDF hospitals. Statistical adjustment was made for hospital, rank, body mass index, physical activity, and either smoking or alcohol drinking. Cigarette smoking was significantly associated with an increased risk of adenomas, regardless of the location of the adenomas, but the increased risk associated with smoking was more pronounced for rectal adenomas. Alcohol use was associated with moderately increased risks of distal colon and rectal adenomas, but not of proximal colon adenomas. Cigarette smoking, but not alcohol drinking, was associated with greater increases in the risk of large adenomas and of multiple adenomas across the colorectum. There was no measurable interaction of cigarette smoking and alcohol drinking on colorectal adenomas. The findings corroborate an increased risk of colorectal adenomas associated with smoking and a weak association between alcohol use and colorectal adenomas. Further studies are needed to confirm whether smoking is more strongly related to rectal adenomas, large adenomas, or multiple adenomas.

Effects of caffeine on human health

Caffeine is probably the most frequently ingested pharmacologically active substance in the world. It is found in common beverages (coffee, tea, soft drinks), in products containing cocoa or chocolate, and in medications. Because of its wide consumption at different levels by most segments of the population, the public and the scientific community have expressed interest in the potential for caffeine to produce adverse effects on human health. The possibility that caffeine ingestion adversely affects human health was investigated based on reviews of (primarily) published human studies obtained through a comprehensive literature search. Based on the data reviewed, it is concluded that for the healthy adult population, moderate daily caffeine intake at a dose level up to 400 mg day(-1) (equivalent to 6 mg kg(-1) body weight day(-1) in a 65-kg person) is not associated with adverse effects such as general toxicity, cardiovascular effects, effects on bone status and calcium balance (with consumption of adequate calcium), changes in adult behaviour, increased incidence of cancer and effects on male fertility. The data also show that reproductive-aged women and children are 'at risk' subgroups who may require specific advice on moderating their caffeine intake. Based on available evidence, it is suggested that reproductive-aged women should consume </=300 mg caffeine per day (equivalent to 4.6 mg kg(-1) bw day(-1) for a 65-kg person) while children should consume </=2.5 mg kg(-1) bw day(-1).

Effect ofSULT1A1 andNAT2 genetic polymorphism on the association between cigarette smoking and colorectal adenomas

Cigarette smoke contains polycyclic hydrocarbons and arylamines that may both be activated by sulfotransferase, encoded by SULT1A1. A genetic polymorphism leads to an Arg213His substitution, thereby decreasing enzyme activity and stability and might thus modify the association between smoking and colorectal adenomas. We investigated this in a Dutch case-control study. Additionally, we evaluated potential roles of epoxide hydrolase (EPHX), N-acetyltransferases (NAT1 and NAT2) and glutathione S-transferases (GSTM1 and GSTT1). The data analysis included 431 adenoma cases and 432 polyp-free controls (54% women; mean age, 54.6 years) enrolled at endoscopy in 8 Dutch hospitals between 1997 and 2000. All participants provided data on smoking habits and blood for DNA isolation. Genotyping was performed using appropriate polymerase chain reaction-restriction fragment length polymorphism procedures. Multivariate models included age, sex, endoscopy indication, consumption of snacks and alcohol and, if appropriate, daily smoking dose or smoking duration. Smoking increased colorectal adenoma risk, most importantly by duration. Smoking for more than 25 years more than doubled adenoma risk (OR = 2.4, 95% CI = 1.4-4.1) compared to never smoking. Combinations of SULT1A1 fast sulfation (*1/*1) and of NAT2 slow acetylation with smoking resulted in a 4 times higher risk of adenomas compared to never smokers with other inherited gene variants, although there was no statistically significant effect modification. We found no clear effects of the other genetic polymorphisms on the association between smoking and adenomas. We conclude that smoking increases risk of colorectal adenomas and that SULT1A1 and NAT2 only modestly modify this association.

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.

The adverse health effects of tobacco and tobacco-related products

Tobacco use continues to occur in epidemic proportions and with it, significant morbidity and mortality. One third of smokers will die prematurely of a smoking-related disease. This article reviews the adverse health effects of tobacco use so that clinicians can be aware of the benefits patients will reap when they stop using this lethal substance.

Colorectal cancer: molecules and populations

The epidemiology and molecular biology of colorectal cancer are reviewed with a view to understanding their interrelationship. Risk factors for colorectal neoplasia include a positive family history, meat consumption, smoking, and alcohol consumption. Important inverse associations exist with vegetables, nonsteroidal anti-inflammatory drugs (NSAIDs), hormone replacement therapy, and physical activity. There are several molecular pathways to colorectal cancer, especially the APC (adenomatous polyposis coli)-beta-catenin-Tcf (T-cell factor; a transcriptional activator) pathway and the pathway involving abnormalities of DNA mismatch repair. These are important, both in inherited syndromes (familial adenomatous polyposis [FAP] and hereditary nonpolyposis colorectal cancer [HNPCC], respectively) and in sporadic cancers. Other less well defined pathways exist. Expression of key genes in any of these pathways may be lost by inherited or acquired mutation or by hypermethylation. The roles of several of the environmental exposures in the molecular pathways either are established (e.g., inhibition of cyclooxygenase-2 by NSAIDs) or are suggested (e.g., meat and tobacco smoke as sources of specific blood-borne carcinogens; vegetables as a source of folate, antioxidants, and inducers of detoxifying enzymes). The roles of other factors (e.g., physical activity) remain obscure even when the epidemiology is quite consistent. There is also evidence that some metabolic pathways, e.g., those involving folate and heterocyclic amines, may be modified by polymorphisms in relevant genes, e.g., MTHFR (methylenetetrahydrofolate reductase) and NAT1 (N-acetyltransferase 1) and NAT2. There is at least some evidence that the general host metabolic state can provide a milieu that enhances or reduces the likelihood of cancer progression. Understanding the roles of environmental exposures and host susceptibilities in molecular pathways has implications for screening, treatment, surveillance, and prevention.

Cigarette smoking, alcohol use, and colorectal adenoma in Japanese men and women

PURPOSE

The aim of this study was to examine the relationships between smoking and alcohol use and risk of colorectal adenoma.

METHODS

Information about smoking, alcohol use, and other lifestyle variables were obtained prospectively from 14,427 male and 17,125 female residents in a city of Gifu Prefecture, Japan, by a self-administered questionnaire in September, 1992. Colorectal adenomas were newly diagnosed in 181 men and 78 women in this cohort between January, 1993 and December, 1995 by colonoscopic examination at two major hospitals of the city. Gender-specific and site-specific relative risks and 95 percent confidence intervals adjusted for age and for age plus other potential confounding factors were calculated by using logistic regression models.

RESULTS

Thirty or more years of smoking was significantly associated with risk of adenoma in general compared with never having smoked in both men and women (relative risk, 1.60; 95 percent confidence interval, 1.02-2.62 and relative risk, 4.54; 95 percent confidence interval, 2.04-9.08, respectively). Effect of smoking was stronger in the proximal colon. After adjusting for age and carbohydrate intake, total alcohol intake was not associated with risk of adenoma in any site in the colon in men. Sake drinkers were at significantly increased risk of adenoma in general, but the dose-response relationship was not statistically significant. Risk of adenoma in the rectum was not significantly increased for those who consumed >30.3 g/day of ethanol (relative risk, 5.7).

CONCLUSION

These data suggest that smoking is a risk factor of adenoma in Japanese men and women. The role of alcohol, however, is less clear.

Risk factors for self-reported colon polyps

OBJECTIVE

Investigate risk factors for colon polyp using multivariate analyses.

DESIGN

In a group responding to a 1992 mail survey, we assessed the association between physician-diagnosed colon polyp and possible risk factors reported primarily 10 years earlier.

SETTING

Survey respondents within the Cancer Prevention Study II.

PARTICIPANTS

Respondents, 72,868 men and 81,356 women, who reported no polyp diagnosis when questioned in 1982 at ages 40 to 64 years.

MEASUREMENTS AND MAIN RESULTS

The characteristics of 7,504 men (10.3%) and 5,111 women (6.3%) reporting a first colon polyp were compared with those of participants who did not report a polyp. After adjustments for age, family history of colorectal cancer, and other potential risk factors, polyp occurrence was associated with 1982 histories of smoking, former smoking, alcohol use of at least two drinks per day (odds ratios [ORs] from 1.5 to 1.1; all p < .005), and a body mass index > or = 28 kg/m2 (men's OR 1.06; 95% confidence interval [CI] 1.00, 1.13; women's OR 1.08; 95% CI 0.99, 1.17). Polyps were also associated with a diagnosis of gallbladder disease or gallstone at any time and with gallbladder surgery up to 1982 (OR from 2.7 to 1.3; all p < .001). Polyp occurrence was inversely associated with 1982 histories of high exercise level (men's OR 0.83; 95% CI 0.76, 0.91; women's OR 0.90; 95% CI 0.78, 1.03), frequent aspirin use in women (OR 0.85; 95% CI 0.77, 0.95), and high parity in women (OR 0.84; 95% CI 0.75, 0.94). Among participants lacking a clinically normal gallbladder, the polyp risks associated with smoking and high body mass index were reduced (p < .04 for interactions).

CONCLUSIONS

Despite the limitations and potential biases in these self-reported data, the risk factors described here may be useful for identifying persons at modestly increased risk of having a colon polyp. The effect-modifying role of gallbladder status deserves further investigation.

Folate intake, alcohol consumption, cigarette smoking, and risk of colorectal adenomas

BACKGROUND

Recent evidence suggests that folic acid (and derivatives) could contribute to the protective effect of fruits and vegetables against the risk of large-bowel cancer. Other evidence indicates that alcohol drinking and cigarette smoking may impair the biologic actions of folate. We used data from an adenoma prevention trial to investigate the occurrence of colorectal adenomas (possible precursors of colorectal cancer) in association with folate intake, alcohol consumption, and cigarette smoking.

METHODS

Patients with at least one recent large-bowel adenoma were followed with colonoscopy 1 year and 4 years after their qualifying colon examinations. Adenomas detected after the year 1 examination were used as end points. A food-frequency questionnaire was administered at study entry and at study completion; nutrient intake at study entry was used in this analysis. All statistical tests were two-sided.

RESULTS

After adjustment for caloric intake, dietary folate had a significant protective association with the risk of recurrence of large-bowel adenoma (P for trend = .04). However, this inverse association was attenuated by further adjustment for intake of dietary fiber and fat. Use of folate supplements was not associated with a reduction in risk. Alcohol intake (seven or more drinks/week) was associated with increased risk (odds ratio = 2.04; 95% confidence interval = 1.28-3.26). Cigarette smoking, even smoking for long duration, was not related to adenoma recurrence.

CONCLUSIONS

These data provide only modest support for previous findings suggesting beneficial effects of folate on colorectal adenoma risk. We find no evidence that cigarette smoking increases risk. These findings do suggest a substantial increase in risk with alcohol consumption.

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.

Leisure and occupational physical activity and risk of colorectal adenomatous polyps

Multiple studies have shown a protective effect for physical activity on the incidence of colorectal cancer, but few have addressed its association with incident adenomas and none have investigated its association with metachronous adenomas. We interviewed 2,001 patients undergoing colonoscopy in 3 New York City practices between 1986-1988. Of these, 298 had a first diagnosis of adenomas, 506 had normal colonoscopies, 197 had metachronous adenomas and 345 had normal colonoscopies with a past history of adenomas. Subjects were queried regarding use of moderate amounts of recreational exercise (swimming, jogging, biking, racket sports and other sports) on a regular basis, and were also asked to estimate their level of physical activity. Occupational physical activity was assessed through a blinded coding of occupational titles. After adjusting for age, years of education, body mass index, total caloric intake, dietary fiber intake, dietary fat intake and years of cigarette smoking, protective effects of borderline significance were observed among males for leisure physical activity for metachronous and incident cases. Occupational physical activity was found to be significantly protective in male incident cases. Men with increased levels of either occupational or leisure activity showed a reduction for incident and metachronous cases. No effects were observed for females. Thus, in this study, both leisure and occupational physical activity were associated with a reduced risk of incident and metachronous adenomas among men but not women.

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.

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.

Relationship of cigarette smoking, alcohol use, and dietary habits with sigmoid colon adenomas

The relationship between cigarette smoking, alcohol use, and dietary factors and the risk of adenomas of the sigmoid colon was examined in male self-defense officials who received a preretirement health examination at three Self-Defense Forces hospitals in Japan. In the comparison between 228 patients with sigmoid adenomas and 1484 control subjects with normal colonoscopy findings (> or = 60 cm from the anus), a clear dose-response relationship was observed between cigarette smoking and risk of adenoma. After adjustment for rank, body mass index, alcohol use, and physical activity as well as for hospital and survey season, the odds ratios (and 95% confidence intervals (CIs)) for the categories of 0, 1 to 399, 400 to 799, and 800 or more cigarette-years were 1.0, 2.1 (1.2 to 3.5), 2.8 (1.8 to 4.3), and 3.5 (2.1 to 5.8), respectively. Current alcohol drinkers tended to have an increased risk, but without a dose-response relation. Among four types of alcoholic beverages (shochu, sake, beer, and whiskey), only whiskey showed a weak association with risk of adenoma. None of the 13 dietary items studied (including meat and rice consumption) was measurably associated with adenoma risk. The present findings provide additional evidence that cigarette smoking is a risk factor for colon adenomas. It is inconclusive regarding alcohol intake's association with adenoma risk.

The relation of smoking, alcohol use and obesity to risk of sigmoid colon and rectal adenomas

We conducted a case-control study, using 429 cases with histologically confirmed sigmoid adenoma, 75 cases with rectal adenoma, and 3101 controls showing normal colonoscopy at least up to 60 cm from the anus. The subjects were male Self-Defense Forces personnel aged 48-56 who received a retirement health examination including a routine sigmoid- or colonoscopy. Lifestyle characteristics were ascertained by a self-administered questionnaire. Smoking in the recent past (< or = 10 years preceding the colonoscopy) and smoking in the remote past (> 10 years before the colonoscopy) were both significantly associated with risk of sigmoid adenoma but not with rectal adenoma as a whole. After reciprocal adjustment for smoking in the two periods, only smoking in the recent past was associated with both sigmoid colon and rectal adenomas. Odds ratios (OR) of sigmoid adenoma (and 95% confidence interval) for the categories of 0, 1-150, 151-250 and > or = 251 cigarette-years were 1.0 (reference), 1.9 (1.3-2.8), 2.1 (1.4-3.0) and 3.0 (1.9-4.7), respectively (P for trend < 0.01), and those for rectal adenoma were 1.0 (reference), 1.2 (0.4 3.2), 3.5 (1.4-8.5) and 2.0 (0.6 6.7), respectively (P for trend = 0.03). Alcohol use was significantly positively associated with sigmoid adenoma, and insignificantly associated with rectal adenoma. Body mass index was significantly positively associated with sigmoid adenoma, especially large ones. No such association was found for rectal adenoma. These findings suggest that smoking, especially in the recent past, and alcohol use are common risk factors for sigmoid colon and rectal adenomas while obesity may be exclusively related to the growth of sigmoid adenoma.

Coronary artery disease and colorectal neoplasia

PURPOSE

This study was designed to determine whether patients with coronary artery disease are at elevated risk for colorectal neoplasia.

METHODS

A case-control study was conducted among consecutive patients in three colonoscopy practices in New York City from 1986 to 1988. All study participants completed an interview questionnaire covering demographics, diet, environmental and behavioral exposures, family and personal medical history, and other variables. For the present study, 298 newly diagnosed colorectal adenoma cases and 107 incident cancer cases were compared with 507 colonoscoped controls without colorectal neoplasia or other significant findings on colonoscopy. Data on history of coronary artery disease (angina and/or heart attack) were obtained solely from the study participants' questionnaire responses.

RESULTS

No association was observed between angina, heart attack, or either and colorectal adenomas in males. However, prior coronary artery disease was found to be associated with colorectal cancer in males more than 60 years of age and with colorectal adenomas in females aged 50 years or younger.

CONCLUSION

Men with coronary artery disease may be at elevated risk for subsequent colorectal cancer. Young women with coronary artery disease also may be at elevated risk for colorectal neoplasia.

Incidence and recurrence rates of colorectal adenomas: a prospective study

BACKGROUND/AIMS

The frequency of colorectal adenomas, the precursor lesions for most cases of colorectal carcinoma, has been generally measured as prevalence rates of adenomas at autopsy or colonoscopy. The aim of this study was to estimate the incidence rate of adenomas and compare it with the adenoma recurrence rate.

METHODS

Data on colonoscopies performed in three New York City practices were collected prospectively. The cumulative rate of adenoma diagnosis on repeat colonoscopy was calculated for patients with no abnormalities on index colonoscopy ("incidence" rate) and for patients with adenomas on the index colonoscopy ("recurrence" rate).

RESULTS

The cumulative incidence rate of adenomas at 36 months was 16%, and the cumulative recurrence rate at 36 months was 42% (P < 0.004). The recurrence rate was higher in patients with multiple adenomas than in those with a single adenoma on index colonoscopy, although the increase was not statistically significant.

CONCLUSIONS

Although the recurrence rate has always been assumed to be elevated, this study is the first to compare the recurrence rate of adenomas with the incidence rate directly and to show that the recurrence rate is indeed elevated.

Cigarette smoking and other behavioral risk factors for recurrence of colorectal adenomatous polyps (New York City, NY, USA)

Adenomatous polyps (hereinafter referred to as adenomas) are known precursors of colorectal cancer. Cigarette smoking has been associated with adenomas but not with colorectal cancer, while alcohol and fat intake have been associated with both adenomas and cancer in some studies. Approximately 30 percent of patients with resected adenomas develop another adenoma within three years. This case-control study explores the association of cigarette smoking with adenoma recurrence. Between April 1986 and March 1988, we administered a questionnaire to colonoscoped patients aged 35 to 84 years in three New York City (NY, USA) practices. We compared 186 recurrent polyp cases (130 males, 56 females) and 330 controls (187 males, 143 females) who had a history of polypectomy but normal follow-up colonoscopy, by cigarette-smoking pack-years adjusted for possible confounders. Risk for a metachronous or recurrent adenoma was significantly greater in the highest quartile of smokers than in never-smokers among both men (odds ratio [OR] = 1.8, 95 percent confidence interval [CI] = 1.0-3.4) and women (OR = 3.6, CI = 1.7-7.6). Adjustment for time since smoking cessation reduced risk only slightly, as did adjustment for dietary fat intake, which itself remained significant. No association was found between alcohol intake and risk of recurrence. Cigarette smokers appear to have an elevated risk of adenoma recurrence that is not eliminated entirely by smoking cessation. Intervention trials that use adenoma recurrence as an endpoint should take smoking into account.