Environmental factors affect colon carcinoma and rectal carcinoma in men and women differently

Polyphenols in the Prevention and Treatment of Colorectal Cancer: A Systematic Review of Clinical Evidence

Polyphenols are plant metabolites with potential anti-inflammatory and anti-proliferative effects, which may be advantageous for disorders like colorectal cancer (CRC). Despite promising in vitro and in vivo evidence, human clinical trials have yielded mixed results. The present study aimed to evaluate the clinical evidence of polyphenols for CRC prevention or treatment. A systematic review was performed according to PRISMA. Based on a PROSPERO registered protocol (CRD42024560044), online databases (PubMed and COCHRANE) were utilized for the literature search. A total of 100 studies articles were initially identified. After reviewing, 12 studies with a low risk of bias were selected, examining the effect of a variety of compounds. Curcumin demonstrated promise in various trials, mainly decreasing inflammatory cytokines, though results varied, and it did not lower intestinal adenomas or improve outcomes after chemotherapy. Neither epigallocatechin gallate nor artepillin C reduced the incidence of adenomas. Finally, fisetin seemed to improve the inflammatory status of patients under chemotherapy (5-fluorouracil). In summary, although certain polyphenols appear to exert some effect, their role in the prevention or treatment of CRC is inconclusive, and more clinical studies under more controlled conditions are needed.

PVT1 (rs13281615) and miR-146a (rs2910164) polymorphisms affect the prognosis of colon cancer by regulating COX2 expression and cell apoptosis

In this study, we aimed to investigate the potential correlation between rs13281615/rs2910164 polymorphisms and the prognosis of colon cancer (CC). Taqman was utilized to genotype the rs13281615/rs2910164 polymorphisms in recruited subjects. Kaplan-Meier survival curves were calculated to study the prognostic values of different genotypes of rs13281615/rs2910164 polymorphisms. Real-time polymerase chain reaction, enzyme-linked immunosorbent assay, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were conducted to establish a potential signaling pathway underlying the role of rs13281615/rs2910164 polymorphisms, whereas bioinformatics analysis and luciferase reporter assays were performed to identify plasmacytoma variant translocation 1 (PVT1) and cyclooxygenase-2 (COX2) as targets of microRNA-146a (miR-146a). No significant difference was observed in respect to clinical characteristics among subjects with different genotypes. However, patients genotyped as GG/CC + GC showed the lowest chance of survival, whereas patients of GA + AA/GG genotype showed the highest chance of survival. Moreover, the relative expressions of PVT1, prostaglandin E2 (PGE2), and COX2 were the lowest and the relative expression of miR-146a was the highest in GA + AA/GG subjects, validating the roles of PVT1, miR-146a, and COX2 in CC. In addition, both PVT1 and COX2 were identified as virtual targets of miR-146a, and the luciferase activities of cells cotransfected with wild-type PVT1/COX2 and miR-146a mimics were significantly reduced. Moreover, the presence of PVT1 decreased the level of miR-146a whereas increasing the messenger RNA and protein levels of COX2, thus establishing a PVT1/miR-146a/COX2 signaling pathway underlying the pathogenesis of CC. The presence of rs13281615 G > A polymorphism on PVT1 and the rs2910164 C > G polymorphism on miR-146a contributes to a favorable prognosis in CC patients via modulating the activity of the PVT1/miR-146a/COX2 signaling pathway.

Estimating cancer induction risk from abdominopelvic scanning with 6- and 16-slice computed tomography

PURPOSE

The biological effects of ionizing radiation (BEIR VII) report estimates that the risk of getting cancer from radiation is increased by about a third from current regulation risk levels. The propose of this study was to estimate cancer induction risk from abdominopelvic computed tomography (CT) scanning of adult patients using 6- and 16-slice CT scanners.

MATERIALS AND METHODS

A cross-sectional study on 200 patients with abdominopelvic CT scan in 6- and 16-slice scanners was conducted. The dose-length product (DLP) and volume CT Dose Index (CTDI_vol) values from the scanners as well as the effective dose values from the ImPACT CT patient dosimetry calculator with the biological effects of ionizing radiation (BEIR VII) method were used to estimate the cancer induction risk.

RESULTS

The mean (and standard deviation) values of CTDI_vol and DLP were 6.9 (±1.07) mGy and 306.44 (± 60.57) mGy.cm for 6-slice, and 5.19 (±0.91) mGy and 219.7 (±49.31) mGy.cm for 16-slice scanner, respectively. The range of effective dose in the 6-slice scanner was 2.61-8.15 mSv and, in the 16-slice scanner, it was 1.47-4.72 mSv. The mean and standard deviation values of total cancer induction risk in abdominopelvic examinations were 0.136 ± 0.059% for men and 0.135 ± 0.063% for women in the 6-slice CT scanner. The values were 0.126 ± 0.051% for men and 0.127 ± 0.056% for women in the 16-slice scanner.

CONCLUSIONS

The cancer induction risk of abdominopelvic scanning was noticeable. Therefore, radiation dose should be minimized by optimizing the protocols and applying appropriate methods.

Genomic instability and radiation risk in molecular pathways to colon cancer

Colon cancer is caused by multiple genomic alterations which lead to genomic instability (GI). GI appears in molecular pathways of microsatellite instability (MSI) and chromosomal instability (CIN) with clinically observed case shares of about 15–20% and 80–85%. Radiation enhances the colon cancer risk by inducing GI, but little is known about different outcomes for MSI and CIN. Computer-based modelling can facilitate the understanding of the phenomena named above. Comprehensive biological models, which combine the two main molecular pathways to colon cancer, are fitted to incidence data of Japanese a-bomb survivors. The preferred model is selected according to statistical criteria and biological plausibility. Imprints of cell-based processes in the succession from adenoma to carcinoma are identified by the model from age dependences and secular trends of the incidence data. Model parameters show remarkable compliance with mutation rates and growth rates for adenoma, which has been reported over the last fifteen years. Model results suggest that CIN begins during fission of intestinal crypts. Chromosomal aberrations are generated at a markedly elevated rate which favors the accelerated growth of premalignant adenoma. Possibly driven by a trend of Westernization in the Japanese diet, incidence rates for the CIN pathway increased notably in subsequent birth cohorts, whereas rates pertaining to MSI remained constant. An imbalance between number of CIN and MSI cases began to emerge in the 1980s, whereas in previous decades the number of cases was almost equal. The CIN pathway exhibits a strong radio-sensitivity, probably more intensive in men. Among young birth cohorts of both sexes the excess absolute radiation risk related to CIN is larger by an order of magnitude compared to the MSI-related risk. Observance of pathway-specific risks improves the determination of the probability of causation for radiation-induced colon cancer in individual patients, if their exposure histories are known.

Prospective of colon cancer treatments and scope for combinatorial approach to enhanced cancer cell apoptosis

Colorectal cancer is the leading cause of cancer-related mortality in the western world. It is also the third most common cancer diagnosed in both men and women in the United States with a recent estimate for new cases of colorectal cancer in the year 2012 being around 103,170. Various risk factors for colorectal cancer include life-style, diet, age, personal and family history, and racial and ethnic background. While a few cancers are certainly preventable but this does not hold true for colon cancer as it is often detected in its advanced stage and generally not diagnosed until symptoms become apparent. Despite the fact that several options are available for treating this cancer through surgery, chemotherapy, radiation therapy, immunotherapy, and nutritional-supplement therapy, but the success rates are not very encouraging when used alone where secondary complications appear in almost all these therapies. To maximize the therapeutic-effects in patients, combinatorial approaches are essential. In this review we have discussed the therapies previously and currently available to patients diagnosed with colorectal-cancer, focus on some recent developments in basic research that has shaded lights on new therapeutic-concepts utilizing macrophages/dendritic cells, natural killer cells, gene delivery, siRNA-, and microRNA-technology, and specific-targeting of tyrosine kinases that are either mutated or over-expressed in the cancerous cell to treat these cancer. Potential strategies are discussed where these concepts could be applied to the existing therapies under a comprehensive approach to enhance the therapeutic effects.

Trends in colorectal cancer incidence in Norway 1962-2006: an interpretation of the temporal patterns by anatomic subsite

There have been rapid increases in the incidence of colorectal cancer in Norway since the 1960s, and rates rank among the highest worldwide. The primary objectives are to describe trends in left- and right-sided colon cancer and rectal cancer by calendar period and birth cohort and to generate hypotheses as to the etiological factors in operation. Although the age-adjusted incidence rates of both colon and rectal cancer increased in Norway in both sexes up to the 1980s, subsite- and age-specific analyses reveal a deceleration in the rate of increase thereafter, apparent in the rates of both left-sided colon and rectal cancer. Overall trends in incidence of right-sided colon cancer continue to increase in both sexes. Rates in both left- and right-sided colon cancers have tended to stabilize or decrease among successive generations born after 1950, however, while incidence rates of rectal cancer appear to be increasing in recent generations. The all-ages rates are thus in keeping with the commonly reported "left to right shift" of colon cancer, although standardization masks important observations. The cohort patterns provide further evidence that factors earlier in life are important, and while the complex etiology makes interpretation difficult, modifications in diet, obesity and physical activity in Norway are likely among the drivers of the trends in one or more of the colorectal subsites examined. In summary, the recent downturn in the disease at younger ages provides some reason for optimism, although possible increases in rectal cancer among recent birth cohorts are of concern.

Relationship between meat and cereal consumption and colorectal cancer in Korea and Japan

BACKGROUND AND AIM

The incidence of colorectal cancer in Asian countries is increasing. The change to a more westernized diet is known to be related to these increases, and there are reports on the relationship between meat consumption and colorectal cancer in Japan. The aim of this study was to investigate the relationship between dietary change and colorectal cancer in Korea and Japan.

METHODS

The data of meat and cereal consumption in Japan (1950-2002) and Korea (1970-2003), and the data of colorectal cancer incidence in Japan (1975-1998) and Korea (1992-2002) were investigated with a 20-year difference between the two countries.

RESULT

We found that the changes in meat and cereal consumption, as well as the increases in the incidence of colon and rectal cancer, were similar between those two countries with a 20-year difference.

CONCLUSION

These similarities between Korea and Japan could be helpful for predicting future colorectal cancer incidences for Korea and other Asian countries.

Solid cancer incidence in atomic bomb survivors: 1958-1998

This is the second general report on radiation effects on the incidence of solid cancers (cancers other than malignancies of the blood or blood-forming organs) among members of the Life Span Study (LSS) cohort of Hiroshima and Nagasaki atomic bomb survivors. The analyses were based on 17,448 first primary cancers (including non-melanoma skin cancer) diagnosed from 1958 through 1998 among 105,427 cohort members with individual dose estimates who were alive and not known to have had cancer prior to 1958. Radiation-associated relative risks and excess rates were considered for all solid cancers as a group, for 19 specific cancer sites or groups of sites, and for five histology groups. Poisson regression methods were used to investigate the magnitude of the radiation-associated risks, the shape of the dose response, how these risks vary with gender, age at exposure, and attained age, and the evidence for inter-site variation in the levels and patterns of the excess risk. For all solid cancers as a group, it was estimated that about 850 (about 11%) of the cases among cohort members with colon doses in excess of 0.005 Gy were associated with atomic bomb radiation exposure. The data were consistent with a linear dose response over the 0- to 2-Gy range, while there was some flattening of the dose response at higher doses. Furthermore, there is a statistically significant dose response when analyses were limited to cohort members with doses of 0.15 Gy or less. The excess risks for all solid cancers as a group and many individual sites exhibit significant variation with gender, attained age, and age at exposure. It was estimated that, at age 70 after exposure at age 30, solid cancer rates increase by about 35% per Gy (90% CI 28%; 43%) for men and 58% per Gy (43%; 69%) for women. For all solid cancers as a group, the excess relative risk (ERR per Gy) decreases by about 17% per decade increase in age at exposure (90% CI 7%; 25%) after allowing for attained-age effects, while the ERR decreased in proportion to attained age to the power 1.65 (90% CI 2.1; 1.2) after allowing for age at exposure. Despite the decline in the ERR with attained age, excess absolute rates appeared to increase throughout the study period, providing further evidence that radiation-associated increases in cancer rates persist throughout life regardless of age at exposure. For all solid cancers as a group, women had somewhat higher excess absolute rates than men (F:M ratio 1.4; 90% CI 1.1; 1.8), but this difference disappears when the analysis was restricted to non-gender-specific cancers. Significant radiation-associated increases in risk were seen for most sites, including oral cavity, esophagus, stomach, colon, liver, lung, non-melanoma skin, breast, ovary, bladder, nervous system and thyroid. Although there was no indication of a statistically significant dose response for cancers of the pancreas, prostate and kidney, the excess relative risks for these sites were also consistent with that for all solid cancers as a group. Dose-response estimates for cancers of the rectum, gallbladder and uterus were not statistically significant, and there were suggestions that the risks for these sites may be lower than those for all solid cancers combined. However, there was emerging evidence from the present data that exposure as a child may increase risks of cancer of the body of the uterus. Elevated risks were seen for all of the five broadly classified histological groups considered, including squamous cell carcinoma, adenocarcinoma, other epithelial cancers, sarcomas and other non-epithelial cancers. Although the data were limited, there was a significant radiation-associated increase in the risk of cancer occurring in adolescence and young adulthood. In view of the persisting increase in solid cancer risks, the LSS should continue to provide important new information on radiation exposure and solid cancer risks for at least another 15 to 20 years.

The influence of gender on colorectal cancer stage: the state of Ohio, 1996-2001

PURPOSE

The authors sought to determine if colorectal cancer stage at diagnosis varies by gender in the state of Ohio.

METHODS

We conducted a retrospective cohort study. Included in the cohort were patients diagnosed with colorectal cancer from 1996 to 2001 who had their data reported to the State of Ohio Tumor Registry. We collected data on gender, stage of cancer, and three potential confounding variables: age, location of colon cancer, and race. The colorectal cancer was determined to be at one of four stages: (1) carcinoma in situ, (2) local disease, (3) regional disease, and (4) distant disease. In addition, we combined stages 1 and 2 to create a good prognosis category, and we combined stages 3 and 4 to create a bad prognosis category.

RESULTS

Our cohort consisted of 27,041 patients [13,807 women (51%) and 13,234 men]. The women with colon cancer were significantly older and had more right-sided colon cancer, (p < 0.05). With the use of logistic regression, the women were significantly less likely to have carcinoma in situ compared with the men (OR = 0.82, 95% CI 0.75-0.89). The women also had a significant decrease in local disease (OR = 0.94, 95% CI 0.89-0.99). In contrast, the women showed significantly more regional disease than men (OR = 1.11, 95% CI 1.05-1.16). The women were less likely to have a good prognostic stage (OR = 0.89, 95% CI 0.85-0.94) and more likely to have a bad prognostic stage (OR = 1.12, 95% CI 1.07-1.18).

CONCLUSIONS

In the State of Ohio from 1996 to 2001, women had more advanced colon cancer at diagnosis than men.

Association of Nut and Seed Intake with Colorectal Cancer Risk in the European Prospective Investigation into Cancer and Nutrition

A link between unsaturated fatty acids or phytonutrients and reduced risk of colorectal cancer has been suggested. However, the effects of higher intake of dietary sources of these nutrients, such as the nuts and seeds food group, are less clear. The objective of this study was to determine the effects of nut and seed intake on colorectal cancer risk within the European Prospective Investigation into Cancer and Nutrition study, a large prospective cohort study involving 10 European countries. Total nut and seed intake was determined from country-specific dietary questionnaires. The data set included 478,040 subjects (141,988 men, 336,052 women) with a total of 855 (327 men, 528 women) colon and 474 (215 men, 259 women) rectal cancer cases. A multivariate Cox proportional hazards model, stratified by center and controlled for fruit intake, dietary fiber, energy, height, weight, sex, age, physical activity, and smoking, was used. The data show no association between higher intake of nuts and seeds and risk of colorectal, colon, and rectal cancers in men and women combined, but a significant inverse association was observed in subgroup analyses for colon cancer in women at the highest (&gt;6.2 g/d) versus the lowest (nonconsumers; hazard ratio, 0.69; 95% confidence interval, 0.50-0.95) category of intake and for the linear effect of log-transformed intake (hazard ratio, 0.89; 95% confidence interval, 0.80-0.98), with no associations in men. It is not evident from this data why there may be a stronger association in women or why it may be limited to the colon, suggesting that much further research is necessary.