Age and risk factors for colon cancer (United States and Australia): are there implications for understanding differences in case-control and cohort studies?

Regulatory T Cells in Bioactive Peptides-Induced Oral Tolerance; a Two-Edged Sword Related to the Risk of Chronic Diseases: A Systematic Review

This systematic review assesses the literature regarding beneficial and potential detrimental effects of bioactive peptides (BPs), focusing on evidence of regulatory T cells (T-regs) mediated oral tolerance (OT), collagen hydrolysate (CH) supplementation in osteoarthritis (OA) and the association of T-regs with chronic disease. The systematic search was done for articles published from inception to April 2019 using the PubMed and Scopus databases. About 3081 papers were identified by three different search strategies and screened against inclusion criteria which resulted in the inclusion of 22 articles. From the included articles, 12 papers were related to treatment of different disease in vivo by oral administration of BPs, six articles evaluated the effects of CH supplementation, as a rich source of BPs, on OA pain-relief and four observational studies assessed the association of circulating T-regs and risk of cancer and cardiovascular disease (CVD). The evidence obtained from first search strategy, indicated that oral administration of BPs improve clinical manifestations of animal models of allergy, arthritis, atherosclerosis, ulcerative colitis and allograft rejection by T-regs expansion; while, observational studies showed that although higher levels of circulating T-regs reduced risk of CVD and allergy, but, increased risk of solid cancers.

The association between dietary protein intake and colorectal cancer risk: a meta-analysis

BACKGROUND

Association between dietary protein intake and colorectal cancer risk has not been fully quantified, while the results were controversial. This study aimed to evaluate the role of protein intake in the development of colorectal cancer.

METHODS

PUBMED and EMBASE were searched up to December 2016. Two independent reviewers independently extracted data from eligible studies. Relative risk (RR) with 95% confidence intervals (CI) was pooled using random-effects model to estimate the result. Besides, publication bias and sensitivity analysis were conducted.

RESULTS

Thirteen articles involving 21 studies comprising 8187 cases were included in this report. The pooled RR of colorectal cancer was 1.006 (95% CI = 0.857-1.179) indicating that there is no significant association between dietary protein intake and colorectal cancer risk. Furthermore, the pooled RRs for colon cancer and rectum cancer were 1.135(95% CI = 0.871-1.480) and 0.773(95% CI = 0.538-1.111), respectively, with the highest category of dietary protein intake. The association was not significant either in subgroup analysis of study design, protein type (animal protein or vegetable protein), sex, and or geographic locations.

CONCLUSIONS

The present study indicated that the highest category compared to the lowest category of protein intake had no significant association on colorectal cancer risk. Dose-response analysis was not conducted due to limited information provided. Therefore, more studies with large cases and participants as well as detailed amounts of dietary protein intake are wanted to confirm this result.

Cardio-oncology Related to Heart Failure: Common Risk Factors Between Cancer and Cardiovascular Disease

There is a growing body of evidence that suggests cancer and cardiovascular disease have a shared biological mechanism. Although there are several shared risk factors for both diseases, including advancing age, gender, obesity, diabetes, physical activity, tobacco use, and diet, inflammation and biomarkers, such as insulinlike growth factor 1, leptin, estrogen, and adiponectin, may also play a role in the biology of these diseases. This article provides an overview of the shared biological mechanism between cancer and cardiovascular disease.

Calcium intake and colorectal adenoma in a US colorectal cancer early detection program

BACKGROUND

Calcium can reduce the risk of colorectal tumors by binding secondary bile and fatty acids, which leads to antiproliferative effects in the bowel, or by acting directly on the colonic epithelium, which affects differentiation and apoptosis.

OBJECTIVE

We investigated calcium intake and risk of colon adenoma to evaluate the association of calcium intake with early stages of colorectal tumor development.

DESIGN

We compared the supplemental and dietary calcium intakes of 3696 participants with histologically verified adenoma of the distal colon (ie, descending colon, sigmoid colon, or rectum) with the calcium intakes of 34 817 sigmoidoscopy-negative control participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Calcium intake was assessed at study entry with a 137-item food-frequency questionnaire and additional questions on the amount and duration of calcium supplement use.

RESULTS

After adjustment for known risk factors, adenoma risk was lower by 12% for participants in the highest quintile of total calcium intake (>1767 mg/d) than for participants in the lowest quintile (<731 mg/d) (odds ratio: 0.88; 95% CI: 0.76, 1.02; P for trend = 0.04). The protective association between total calcium and colorectal adenoma was largely due to calcium supplement use, with a 27% decrease in adenoma risk for participants taking >1200 mg/d than for nonusers of supplements (odds ratio: 0.73; 95% CI: 0.56, 0.91; P for trend = 0.005). The protective associations of total and supplemental calcium were strongest for colon adenoma (descending and sigmoid colon).

CONCLUSION

High calcium intake, particularly from supplements, is associated with a reduced risk of distal colorectal adenoma.

Gastrointestinal symptoms and subjects cluster into distinct upper and lower groupings in the community: a four nations study

OBJECTIVE

It is unknown whether distinct functional GI (GI) symptom groupings occur in the general population and whether these are similar across different cultures. Although symptom-based diagnostic criteria have been developed for upper and lower GI syndromes (the Rome criteria), the classification is controversial. We aimed to identify whether independent symptom-based subgroups exist in four countries consistent with the Rome criteria.

METHODS

Random samples of the community were mailed a validated questionnaire based on the Bowel Disease Questionnaire in Rochester, MN (n = 2,220), in Sydney, Australia (n = 1,135), and in Essen, Germany (n = 500). A different validated questionnaire was mailed to a random sample in Osthammar, Sweden (n = 1,517). Only the common questions (n = 22) were used in the current analysis, and these were essentially identical in wording. The underlying structure of the item responses was examined using factor analysis. Initial factors were extracted using principal components analysis and then rotated using Varimax. Clustering of symptoms among individuals was examined though cluster analysis, using the factors as the basis for clustering.

RESULTS

Response rates varied from 64% to 80%; responders and nonresponders were similar sociodemographically. All four studies yielded similar factor structures. All countries reported symptom groupings consistent with the irritable bowel syndrome (IBS), dyspepsia and/or gastroesophageal reflux, and constipation; all except Sweden also had a diarrhea group. The cluster analysis yielded slightly more disparate results but a healthy group was present in all populations. All four populations had an IBS and/or bowel dysfunction cluster identified; a gastroesophageal reflux cluster was also present in all countries.

CONCLUSIONS

The similarity of factor and cluster structures found in these four nations suggest that patterns of GI symptoms and groupings of individuals are similar across these Western cultures. These results are consistent with the current international Rome classification for separate upper and lower functional GI disorders.

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.

Clinical models of chemoprevention for colon cancer

Colon cancer is a common malignancy in the westernized world and is incurable in its advanced stages. This article summarizes the currently available information on colorectal cancer chemoprevention. A brief outline of the incidence and etiologic factors is followed by a discussion of the evidence on which chemopreventive strategies for colon cancer are modeled. This includes a description of the development of surrogate endpoint biomarkers and experimental models to study colorectal cancer chemopreventives, a review of the promising colorectal cancer chemopreventives, and a discussion of the issues to be addressed in the design of future chemoprevention trials. The article concludes with an emphasis on the development and validation of biomarkers and selection of high-risk cohorts using genetic and epidemiologic tools as the main goals of future colon cancer chemoprevention trials before large-scale, risk-reduction trials are conducted.

Epidemiology of sociodemographic characteristics, lifestyle, medical history, and colon cancer: a case-control study among French Canadians in Montreal

Colon cancer is the second most common cancer in both men and women in North America and other developed countries. In a population-based case-control study of colon cancer among French Canadians in greater Montreal, a total of 402 cases and 668 controls were interviewed. The cancer cases were identified through the admission offices of five major Francophone teaching hospitals in Montreal from 1989 to 1993. The controls, matched by age, sex, place of residence, and language, were selected by a modified random digit dialing method. The results show that subjects who had ever been married had a lower risk for colon cancer (odds ratio [OR]: 0.58; 95% confidence interval [95% CI]: 0.48-0.84) than did individuals who had never been married. A significant association (OR: 1.90; p for trend = 0.003) was found between the height of subjects and the risk of colon cancer. The OR for individuals with a family history of colorectal cancer was 2.78 with a p value of 0.01. A direct and significant association (OR: 2.01) was found among constipation, use of laxatives (OR: 1.41), and the risk of colon cancer. Among women, a suggestive inverse association was detected between the number of full-term pregnancies and the risk of colon cancer in female subjects (the OR for five or more pregnancies was 0.58 with a p for trend of 0.08). There was also a suggestive linear trend (increased age-decreased risk) between age at menarche and the risk of colon cancer. No association was apparent between other sociodemographic characteristics and the risk of colon cancer. In conclusion, married individuals had lower risk for colon cancer, perhaps due to food habits or other characteristics of being single. Higher height and weight history 10 years before the diagnosis of cancer are risk factors for breast cancer, while both current weight and body mass index seem to be protective. Positive family history of colon cancer increased the risk of colon cancer significantly.

The influence of reproductive and hormonal factors on the risk of colon and rectal cancer in women

A case-control study was conducted between 1992 and 1996 in six Italian areas. It included 537 women with colon cancer, 291 women with rectal cancer and 2081 control women in hospital for acute conditions, unrelated to hormonal or gynaecological diseases. A higher age at menopause was associated with increased colon cancer risk (odds ratio (OR) for > or = 53 years compared with < 50 years = 1.39, 95% confidence interval (CI) 1.04-1.87). Among parous women, a significant trend of decreasing colon cancer risk with increasing number of births was seen for colon (OR for > or = 4 births compared with 1 birth = 0.62, 95% CI 0.42-0.90), but not for rectal cancer. Nulliparous women, however, were at lower risk than women with a single birth, and age at first birth was directly associated with risk. While oral contraceptive use showed no significant influence, ever users of hormone replacement therapy had a reduced risk of rectal cancer (OR = 0.56, 95% CI 0.31-1.01). Thus, the association of colorectal cancer with reproductive and menstrual factors is neither strong nor consistent.

A description of age, sex, and site distributions of colon carcinoma in three geographic areas

BACKGROUND

Site of the carcinoma within the colon in relation to age and sex may provide clues into the etiology of the disease. Incidence of colon carcinoma by age, sex, and tumor site at a population-based level are reported infrequently. The goal of this study was to describe the distribution of colon carcinoma (excluding cancers of the rectosigmoid junction and rectum) by age at diagnosis, sex, and site of the tumor within the colon. These factors were also evaluated in conjunction with disease stage at the time of diagnosis.

METHODS

Data from three geographically distinct populations were used to describe rates of colon carcinoma and the distribution of tumors by age, tumor site, and stage at diagnosis. All colon carcinoma cases diagnosed within a 3-year period within the areas are included.

RESULTS

Approximately 50% of all cancers in men and greater than 50% of cancers in women were in the proximal segment of the colon. Men who were diagnosed prior to age 50 and both men and women diagnosed at age 70 or older had predominantly proximal cancers. People with proximal cancers and people diagnosed prior to age 50 were more likely to have more advanced disease.

CONCLUSIONS

Both men and women have more proximal cancers with advancing age, which are associated with more advanced disease. Observed trends in cancer site distributions could reflect screening practices, environmental and genetic factors, or a combination of these variables.

Physical activity and risk of colorectal cancer in men and women

We examined the association between self-reported occupational and recreational physical activity and the subsequent risk of colorectal cancer in a population-based cohort in Norway. During a mean follow-up time of 16.3 years for males and 15.5 years for females, 236 and 99 colon cancers and 170 and 58 rectal cancers were observed in males and females, respectively, among 53,242 males and 28,274 females who attended the screening between 1972 and 1978. Physical activity at a level equivalent to walking or bicycling for at least four hours a week during leisure-time was associated with decreased risk of colon cancer among females when compared with the sedentary group (RR = 0.62, 95% CI 0.40-0.97). Reduced risk of colon cancer was particularly marked in the proximal colon (RR = 0.51, 95% CI 0.28-0.93). This effect was not observed for occupational physical activity alone, probably due to a narrow range of self-reported physical activity at work among females. However, by combining occupational and recreational physical activity we observed an inverse dose-response effect as increasing total activity significantly reduced colon cancer risk (P for trend = 0.04). Among males 45 years or older at entry to the study, an inverse dose-response effect was observed between total physical activity and colon cancer risk (P for trend = 0.04). We also found in males a stronger preventive effect for physical activity in the proximal as compared to distal colon. In addition, we found a borderline significant decrease in colon cancer risk for occupational physical activity in males 45 years or older when compared to the sedentary group (RR = 0.74, 95% CI 0.53-1.04). All results were adjusted for age, body mass index, serum cholesterol and geographic region. No association between physical activity and rectal cancer was observed in males or females. The protective effect of physical activity on colon cancer risk is discussed in regard to energy balance, dietary factors, age, social class, body mass index and gastrointestinal transit time.

History of childbearing and colorectal cancer risk in women aged less than 60: an analysis of Swedish routine registry data 1960-1984

Data from a computerised linkage between the Swedish Cancer Registry and the Fertility Registry were used to study the influence of reproductive history on the risk of colorectal cancer in women aged less than 60, in the period 1960 to 1984. A "nested" case-control design was used with 1,415 colon cancer cases and 733 rectal cancer cases, and 7,073 and 3,665 age-matched controls, respectively. Conditional logistic regression was employed to study the independent effects of parity, age at first birth and years since last birth on the risk of colorectal cancer. High parity was associated with reduced risk in women older then 50 years at diagnosis, both for the colon as a whole and for colon subsites. Women having had 5 children or more had an odds of colon cancer of 0.44 (95% confidence interval 0.24-0.82) relative to that of nulliparous woman. Contrary to the hypothesis advanced by McMichael and Potter (J. Nat. Cancer Inst., 75, 185-191 [1985]), which predicted a strong protective effect of parity in the proximal compared to the distal colon, we found the reverse. Increasing years since last birth seemed to be associated with a reduced risk of rectal cancer. A significant positive trend with increasing age at first birth was suggested with respect to distal colon cancer and rectal cancer risk. The mutually adjusted effects of the reproductive variables under study were similar to the unadjusted effects. Our data suggest that increasing parity is associated with a decline in risk of colon cancer but not rectal cancer, although the association with colon cancer is restricted to women aged 50 or more. The effects of age at first birth and years since last birth are not consistent or pronounced.

Reproductive factors and colon cancer: the influences of age, tumor site, and family history on risk (Utah, United States)

The Utah (United States) Population Database was used to evaluate the associations between reproductive factors and colon cancer risk and the impact that family history, age at diagnosis, and tumor site have on these associations. From the cohort of (White) women in the database, all first-primary cases of colon cancer (n = 819) and controls who had complete fertility information (n = 3,202) were examined. The majority of tumors (68.6 percent) among women diagnosed at age 64 years or less were in the distal segment of the colon, while among women 65 or older, the majority of tumors (55.7 percent) were proximal. Women diagnosed before age 65 had a lower risk of colon cancer with increasing numbers of liveborn children (odds ratio [OR] = 0.6, 95 percent confidence interval [CI] = 0.3-0.9 for women with five or more children compared with women with one or two children). A long interval between first and second births (first birth-interval) was associated with increased risk of tumors in the distal segment of the colon (OR = 1.4, CI = 1.0-2.0) and among women diagnosed before age 65 (OR = 1.6, CI = 1.0-2.5); a longer, average birth-interval was associated with increased risk of proximal tumors (OR = 1.5, CI = 1.1-2.1).(ABSTRACT TRUNCATED AT 250 WORDS)