Alcohol & Colorectal Cancer: Increased Risk or Prevention?

Over the last quarter century there have only been a half dozen studies that examined the potential relationship between alcohol consumption and colorectal cancer.  The early research suggested there was a modest positive relationship.  A recent study (June 2012) suggests that alcohol can indeed pose a risk to increased colorectal cancers but may also prevent them.  The key in part seems to be intake moderation.  Similar to findings in cardiovascular disease research, limited alcohol intake appears to decrease the risk of colorectal cancer.  High quantities increase the risk.  This study notes that the preventive effect was the same for both men and women.  However, because of the Mediterranean diet consumed by the subjects in this study the authors further suggest that the risk may be mitigated by the source of the alcohol, specifically red wine.

Note:  These mini-reviews are designed as updates and direct the reader to the full text of current research.  The abstracts presented here are no substitute for reading and critically reviewing the full text of the original research.  Where permitted we will direct the reader to that full text.

Alcohol consumption and colorectal cancer in a mediterranean population: a case-control study.  [Link]

Dis Colon Rectum. 2012 Jun;55(6):703-10.

Kontou N, Psaltopoulou T, Soupos N, Polychronopoulos E, Xinopoulos D, Linos A, Panagiotakos D.
Department of Nutrition and Dietetics, Harokopio University, Athens, Greece 2School of Medicine, University of Athens, Athens, Greece 3Saint Savvas Cancer Hospital, Athens, Greece.

BACKGROUND: Alcohol is considered to be a cocarcinogen or a tumor promoter, and various studies have shown a linear dose-dependent association between alcohol consumption and colorectal cancer. However, a few studies suggest that moderate alcohol consumption may have a protective effect, similar to that in cardiovascular disease.

OBJECTIVE: The aim of this study was to evaluate the relationship of colorectal cancer to quantity and type of alcohol consumed.

DESIGN: This was case-control study.

SETTINGS: The study was conducted in the area of Attica, Greece.

PARTICIPANTS: A total of 250 consecutive patients with a first diagnosis of colorectal cancer were matched for age group and sex with 250 controls recruited from the community. The mean age was 63 (SD, 12) years for the patient group (147 men, 59%; 103 women, 41%) and 55 (SD, 13) years for the control group (112 men; 44.8%; 138 women, 55.2%).

MAIN OUTCOME MEASURES: Questionnaires were administered by trained interviewers to assess sociodemographic, clinical, and lifestyle characteristics, in addition to dietary habits and quantity and type of alcoholic beverages usually consumed during the preceding year. Adherence to the Mediterranean diet was evaluated with the MedDietScore (theoretical range, 0-55).

RESULTS: With intake of less than 12 g of alcohol per day as the reference, moderate alcohol intake (12-35 g/day) was associated with a significantly decreased likelihood of colorectal cancer in men (OR, 0.35; 95% CI, 0.16-0.74) and in women (OR, 0.40; 95% CI, 0.18-0.91). High alcohol intake (more than 48 g/day) was associated with an increased likelihood, which was significant in men (OR, 3.45; 95% CI, 1.35-8.83) but not in women (OR, 3.40; 95% CI, 0.50-22.92). Drinking red wine was associated with reduced odds of colorectal cancer, significant in men (OR, 0.47; 95% CI, 0.23-0.96) but not in women (OR, 0.54; 95% CI, 0.23-1.30). None of the associations between other beverage types and colorectal cancer were significant. Adherence to the Mediterranean diet was independently associated with lower odds of colorectal cancer overall (p < 0.001), in men (OR, 0.90; 95% CI, 0.83-0.97), and in women (OR, 0.87; 95% CI, 0.80-0.94).

LIMITATIONS: The major limitations of this study included the inability of a case-control design to determine causation and the potential for recall bias.

CONCLUSIONS: The association between quantity of alcohol consumed and the presence of colorectal cancer followed a J-shaped curve. While demonstrating the detrimental effect of consuming large amounts of alcohol, the results of this study suggest that moderate alcohol consumption exerts a protective effect on colorectal cancer in both men and women, possibly related to the effects of red wine.

Alcohol consumption, type of alcoholic beverage and risk of colorectal cancer at specific subsites.  [Link]

Int J Cancer. 2008 Nov 15;123(10):2411-7.

Bongaerts BW, van den Brandt PA, Goldbohm RA, de Goeij AF, Weijenberg MP.
Department of Epidemiology, GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands. [email protected]

Within the Netherlands Cohort Study on diet and cancer, we investigated associations between total alcohol consumption, specific alcoholic beverage consumption and risk of colorectal cancer (CRC) according to anatomical subsite. Hazard Ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. Analyses were performed on 2,323 CRC cases, available after 13.3 years of follow-up. Compared to abstaining, alcohol consumption of >/=30.0 g/day ( approximately 3 alcoholic drinks) was positively associated with the risk of CRC (HR: 1.32, 95% CI: 1.06-1.65). Analyses restricted to subjects who reported to have consumed equal amounts of alcohol 5 years before baseline compared to baseline, showed elevated risk estimates for consumers of >/=30.0 g of total alcohol per day as well (HR: 1.53, 95% CI: 1.16-2.01). Suggestive of a subsite-specific effect, cancer risk seemed to increase from proximal colon through rectum; HR: 1.29, 95% CI: 0.85-1.96 for proximal colon cancer, HR: 1.41, 95% CI: 0.94-2.11 for distal colon cancer, HR: 2.07, 95% CI: 1.03-4.18 for rectosigmoid cancer and HR: 1.69, 95% CI: 1.08-2.64 for rectal cancer. No associations were observed between consumption of alcoholic beverages and CRC risk when compared with the nondrinkers of the specific beverage and after adjustment for total alcohol intake. No evidence was found for sex-specific effects of alcohol and alcoholic beverages. In conclusion, our data showed a positive association between alcohol consumption and risk of CRC, which seemed to be mainly explained by the alcoholic content of alcoholic beverages, rather than other constituents. Also, cancer risk may vary according to anatomical subsite.

Alcohol drinking and colorectal cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population.  [Link]

Jpn J Clin Oncol. 2006 Sep;36(9):582-97. Epub 2006 Jul 26.

Mizoue T, Tanaka K, Tsuji I, Wakai K, Nagata C, Otani T, Inoue M, Tsugane S; Research Group for the Development and Evaluation of Cancer Prevention Strategies in Japan.
Department of Preventive Medicine, Kyushu University, Fukuoka, Japan. [email protected]

BACKGROUND: It remains unclear whether alcohol drinking is causally associated with colorectal cancer. On the basis of a systematic review of epidemiological evidence, we evaluated this association among the Japanese population, who may be more susceptible to alcohol-related diseases than Western populations.

METHODS: Original data were obtained from searches of MEDLINE using PubMed, complemented with manual searches. The evaluation of associations was based on the strength of evidence and the magnitude of association, together with biological plausibility as previously evaluated by the International Agency for Research on Cancer.

RESULTS: We identified 5 cohort studies and 13 case-control studies. A moderate or strong positive association was observed between alcohol drinking and colon cancer risk in all large-scale cohort studies, with some showing a dose-response relation, and among several case-control studies. The risk of colon or colorectal cancer was increased even among moderate drinkers consuming <46 g of alcohol per day, levels at which no material increase in the risk was observed in a pooled analysis of Western studies. A positive association with rectal cancer was also reported, but it was less consistent, and the magnitude of the association was generally weaker compared with colon cancer.

CONCLUSION: We conclude that alcohol drinking probably increases the risk of colorectal cancer among the Japanese population. More specifically, the association for the colon is probable, whereas that for the rectum is possible.

Alcohol intake and colorectal cancer: a pooled analysis of 8 cohort studies.  [Link]

Ann Intern Med. 2004 Apr 20;140(8):603-13.

Cho E, Smith-Warner SA, Ritz J, van den Brandt PA, Colditz GA, Folsom AR, Freudenheim JL, Giovannucci E, Goldbohm RA, Graham S, Holmberg L, Kim DH, Malila N, Miller AB, Pietinen P, Rohan TE, Sellers TA, Speizer FE, Willett WC, Wolk A, Hunter DJ.
Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Harvard School of Public Health, and Harvard Center for Cancer Prevention, Boston, Massachusetts 02115, USA. [email protected]

BACKGROUND: Epidemiologic studies have generally reported positive associations between alcohol consumption and risk for colorectal cancer. However, findings related to specific alcoholic beverages or different anatomic sites in the large bowel have been inconsistent.

OBJECTIVE: To examine the relationship of total alcohol intake and intake from specific beverages to the incidence of colorectal cancer and to evaluate whether other potential risk factors modify the association.

DESIGN: Pooled analysis of primary data from 8 cohort studies in 5 countries.

SETTING: North America and Europe.

PARTICIPANTS: 489,979 women and men with no history of cancer other than nonmelanoma skin cancer at baseline.

MEASUREMENTS: Alcohol intake was assessed in each study at baseline by using a validated food-frequency questionnaire.

RESULTS: During a maximum of 6 to 16 years of follow-up across the studies, 4687 cases of colorectal cancer were documented. In categorical analyses, increased risk for colorectal cancer was limited to persons with an alcohol intake of 30 g/d or greater (approximately > or =2 drinks/d), a consumption level reported by 4% of women and 13% of men. Compared with nondrinkers, the pooled multivariate relative risks were 1.16 (95% CI, 0.99 to 1.36) for persons who consumed 30 to less than 45 g/d and 1.41 (CI, 1.16 to 1.72) for those who consumed 45 g/d or greater. No significant heterogeneity by study or sex was observed. The association was evident for cancer of the proximal colon, distal colon, and rectum. No clear difference in relative risks was found among specific alcoholic beverages.

LIMITATIONS: The study included only one measure of alcohol consumption at baseline and could not investigate lifetime alcohol consumption, alcohol consumption at younger ages, or changes in alcohol consumption during follow-up. It also could not examine drinking patterns or duration of alcohol use.

CONCLUSIONS: A single determination of alcohol intake correlated with a modest relative elevation in colorectal cancer rate, mainly at the highest levels of alcohol intake.

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

Nutr Cancer. 1992;18(2):97-111.

Kune GA, Vitetta L.
University of Melbourne, Victoria, Australia.

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.