IJC International Journal of Cancer

Coffee intake and the risk of colorectal adenoma: The colorectal adenoma study in Tokyo Sanjeev Budhathoki, Motoki Iwasaki, Taiki Yamaji, Shizuka Sasazuki and Shoichiro Tsugane Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan

Colorectal cancer (CRC) is one of the most common cancers, and accounts for 10% of all cancer cases worldwide.1 Considerable geographic variation in the incidence of CRC has been observed, with almost 60% of cases occurring in developed regions, suggesting that environmental factors, including dietary factors, are implicated in the etiology of CRC.1,2 Among dietary factors, however, only intake of red and processed meat and alcohol (in men) are classified as “convincing” risk factors, while foods containing dietary fiber are classified as protective factors.2 Key words: coffee, colorectal adenoma, epidemiology Grant sponsor: Ministry of Health, Labour and Welfare of Japan (Grant-in-Aid for the 3rd Term Comprehensive 10-Year-Strategy for Cancer Control and Grant-in-Aid for Cancer Research 17-9); Grant sponsor: Ministry of Education, Culture, Sports, Science, and Technology of Japan (Grants-in-Aid for Scientific Research on Innovative Areas: 221S0001); Grant sponsor: Japan Society for the Promotion of Science, and Foundation for Promotion of Cancer Research in Japan (Grant-in-Aid for Scientific Research C-24501366 and Grant-in-Aid for Scientific Research C-24590830) DOI: 10.1002/ijc.29390 History: Received 12 Aug 2014; Accepted 4 Dec 2014; Online 10 Dec 2014 Correspondence to: Motoki Iwasaki, Epidemiology and Prevention Group, Research Center for Cancer Prevention and Screening, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan, Tel.: 181-3-3542-2511, Fax: 181-3-3547-8578, E-mail: [email protected]

C 2014 UICC Int. J. Cancer: 137, 463–470 (2015) V

Coffee is among the most commonly consumed beverages worldwide, and its potential role in the etiology of CRC has drawn considerable interest.3,4 A meta-analysis of 13 casecontrol studies found that regular coffee drinkers had an 17% lower risk of CRC than non/occasional drinkers.5 Although a pooled6 and a meta-analysis7 of prospective cohort studies including >5000 cancer cases found no measurable association between coffee and colon or colorectal cancer, a recent large prospective study8 with more cases than the pooled or meta-analysis reported a significant inverse association of coffee intake with CRC risk. Coffee contains several bioactive compounds, including chlorogenic acid, caffeic acid, cafestol and kahweal, which have shown anticarcinogenic effects in in vitro and in vivo studies, and which may play a protective role in colorectal carcinogenesis.9–11 Coffee drinking may also protect against colon neoplasia by reducing the synthesis and secretion of bile acids, which are the potential promoters of colon carcinogenesis, and by increasing colonic motility, thereby reducing exposure of the epithelium to potential carcinogens.12 Further, studies have also reported an inverse association between coffee consumption and biomarkers of inflammation and insulin resistance, which have been positively associated with CRC.13–16 As an established precursor lesion of CRC, colorectal adenomas (CRAs) are an informative endpoint in the process of colon carcinogenesis, and studying adenoma will allow the evaluation of risk factors early in the colorectal neoplastic process among asymptomatic individuals.17,18 However, only a few studies have evaluated the effect of coffee intake in

Epidemiology

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 5 0.48–0.93; ptrend 5 0.02). The inverse association of coffee intake was limited to proximal (OR 5 0.64; 95%CI 5 0.44–0.95; ptrend 5 0.04) and distal colon adenoma (OR 5 0.62; 95%CI 5 0.39–0.99; ptrend 5 0.06), and appeared to be more evident with small (OR 5 0.68; 95%CI 5 0.49–0.96; ptrend 5 0.04) and single adenomas (OR 5 0.65; 95%CI 5 0.44– 0.95; ptrend 5 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.

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Coffee intake and colorectal adenoma

What’s new? The presence of cancer-fighting compounds in coffee is of considerable interest to the understanding of colorectal cancer etiology. But data on the relationship between coffee intake and colorectal adenoma is limited, and studies have arrived at varying conclusions. In the present analysis of the coffee-drinking habits of 1,435 individuals, coffee intake was found to be inversely associated with the risk of proximal and distal colon adenoma, precursors of malignant disease. The association was evident particularly in individuals with single and small adenomas. The findings support the idea that coffee consumption helps defend against colorectal carcinogenesis.

relation to CRA risk; of these, two small studies suggested beneficial effects of coffee in CRA,19,20 while other studies21–26 did not support this effect. Thus, evidence for the effect of coffee on CRA remains inconsistent. Here, we evaluated the association between coffee intake and CRA risk in a large group of asymptomatic men and women who underwent total colonoscopy as part of as cancer screening program. We also investigated whether the association differed by adenoma site, size or number.

Material and Methods

Epidemiology

Study population

The study participants were selected from examinees who underwent magnifying colonoscopy with dye spreading as part of a cancer screening program provided by the Research Center for Cancer Prevention and Screening, National Cancer Center, Tokyo, Japan. Details of the study have been described previously.27,28 Men aged 50–79 years and women aged 40–79 years undergoing total colonoscopy from the anus to the cecum and without a history of CRA, any malignant neoplasm, ulcerative colitis, Crohn’s disease, familial adenomatous polyposis, carcinoid tumor or colectomy were defined as eligible for inclusion in the study. From February 2004 to February 2005, a total of 3,212 examinees underwent total colonoscopy, among whom 2,234 satisfied the above conditions and were eligible for inclusion in the study. Based on the pit pattern classification of colorectal lesions, 782 individuals (526 men and 256 women) were found to have at least one or more adenomas and were included as adenoma cases. Of the remaining 1,452 individuals, we identified 482 men and 721 women as potential controls who were also free from other benign lesions (e.g., hyperplastic polyps, inflammatory polyps, and diverticula). We included all potential male controls in the study, as there were fewer male controls than cases. Female controls were randomly selected from potential controls and frequency-matched to the female cases in 5 age categories (40–49, 50–54, 55–59, 60–64 and 65 years of age) and two screening periods (first and second halves). The screening period was matched because standard operating procedures were improved during the first half period after the establishment of the Research Center, which might have influenced, for example, the accuracy of diagnosis.29 All examinees gave written informed consent to participate in the study. The study protocol was approved by the institutional review board of the National Cancer Center, Tokyo, Japan.

Lifestyle and dietary factor assessment

Data on lifestyle and behavioral factors, as well as personal and family medical history and supplemental drug use were collected by a self-administered questionnaire survey prior to the screening procedure. Information on dietary intake factors was assessed by a 138-item food frequency questionnaire with pre-specified standard portion sizes and nine intake frequency categories for most food items. Information on consumption of coffee and canned coffee was obtained by two closed-ended questions with nine precoded frequency categories (10 cups/ day). The amount of coffee or canned coffee consumed was calculated by multiplying the frequency of intake by the standard portion size of each beverage (120 ml per cup for regular coffee and 250 ml per can for can coffee), and the sum of these two were taken as total coffee intake. Similarly, the combination of sencha (portion size 200 ml per cup) and bancha/ genmaicha (portion size 120 ml per cup) was taken as green tea. The validity of food and nutrient intake estimated from the questionnaire was evaluated by comparison with estimates from 4-day dietary records provided by a subsample of the screening examinees.30 The Spearman rank correlation coefficient between estimates from the questionnaire and diet record was 0.80 (men) and 0.82 (women) for coffee, and 0.67 (men) and 0.42 (women) for green tea consumption. Statistical analysis

For the present analysis, we excluded 74 individuals with extreme energy intake (top and bottom 2.5% of total energy intake distribution) and 11 individuals with missing values for covariates, leaving a total of 738 cases and 697 controls for final analysis. All participants were divided into quartile categories based on coffee intake among controls. Logistic regression models were used to compute the odds ratio (OR) and 95% confidence interval (CI) with the first quartile as reference group. Adjustment was made for age (40–49, 50– 54, 55–59, 60–64, 65 years), sex, screening period (first or second half), body mass index (

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 h...
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