• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6105-6109
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• 2015

Background: Colorectal cancer (CRC) is one of the most common cancers worldwide. This study aimed to investigate the risk factors for colorectal cancer in the Thai population. Materials and Methods: A cohort study was carried out in Khon Kaen, Thailand, including 71 cases of histologically confirmed CRC patients among 19,861 participants, aged 30-69 years, who were recruited for a cohort study during the period 1990-2001. Participants were followed-up until 31 December, 2013. To identify factors associated with the incidence of colorectal cancer, hazard ratios were evaluated using Cox proportional hazard regression. Results: No environmental variables could be shown to be significantly related to the risk of CRC. Although in our sample, CRC was more prevalent among males, ex-smokers, and those who drank alcohol beverages ${\geq}50gram/day$, but we could not demonstrate significantly associations (HRmale= 1.67, 95% CI, 0.80-3.49, HR ex-smokers = 1.34, 95% CI, 0.52-3.46, and HRalc ${\geq}50=1.08$, 95% CI, 0.43-2.71). Individuals within the sample with a family history of cancer, working hour >8 hours per day, and current-smokers appeared to have decrease risk of CRC, but again these relationship could not be shown to be significantly associated (HRfam cancer= 0.96, 95% CI, 0.85-1.09, HRwork>8= 0.84, 95% CI, 0.36-1.93, and HRcurrent-smoker = 0.51, 95% CI, 0.18-1.38). Conclusions: We found no evidence of environmental factors effecting the risk of CRC. There is a need for further research to determine why factors identified risk in other populations appear to not be associated with CRC risk in Thais.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2949-2953
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• 2012

The glutathione S transferase (GST) family is a major part of cellular defense mechanisms against endogenous and exogenous substances, many of which have carcinogenic potential. Alteration in the expression level or structure of the glutathione-S-transferase (GST) enzymes may lead to inadequate detoxification of potential carcinogens and consequently contribute to cancer development. A member of the glutathione-S-transferase (GST) family, GSTP1, is an attractive candidate for involvement in susceptibility to carcinogen-associated colorectal cancer. An $Ag{\rightarrow}G$ transition in exon 5 resulting in an Ile105Val amino acid substitution has been identified which alters catalytic efficiency. The present study investigated the possible impact of Ile105Val GSTP1 polymorphism on susceptibility to colorectal cancer. in Jordan We examined 90 tissue samples previously diagnosed with colorectal carcinoma, and 56 non-cancerous colon tissues. DNA was extracted from paraffin embedded tissues and the status of the GSTP1 polymorphism was determined using a polymerase chain reaction restriction fragment length polymorphism (RFLP) method. No statistically significant differences were found between colorectal cancer cases and controls for the GSTP1 Ile/Ile, Ile/Val and Val/Val genotypes. The glutathione S-transferase polymorphism was not associated with risk in colorectal cancer cases in Jordan stratified by age, sex, site, grade or tumor stage. In conclusion, the GSTP1 Ile105Val polymorphism is unlikely to affect the risk of colorectal cancer.

• Journal of Digestive Cancer Research
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• v.4 no.1
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• pp.17-20
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• 2016

Colorectal cancer is the 2^nd most common cancer in men, and the 3^rd most common cancer in women in Korea. This incidence has been increasing steadily since the data analysis began in 1999. Guidelines from many countries including Korea recommend annual or biennial fecal occult blood test as a national colorectal cancer screening program, however, colonoscopy, stool DNA test, double contrast barium enema, and sigmoidoscopy are recommended in some countries. I will summarize the Korean National Screening Guideline for colorectal cancer revised by multi-society expert committee in Korea last year. They recommend annual or biennial fecal immunochemical test between 45 and 80 year-old asymptomatic average risk people. Selective use of colonoscopy is recommended, taking into consideration of individual preference and the risk of colorectal cancer. There is no evidence for the risks or benefits of double contrast barium enema or computed tomographic colonography for colorectal cancer screening.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4087-4091
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• 2012

To evaluate the relationship between polymorphisms (28 bp repeated sequences in 5'-UTR and 6-bp ins/del in 3'-UTR) in then thymidylate synthetase gene (TS) and risk of colorectal, colon and rectal cancers, we conducted a case-control study with 315 cases of colorectal cancer and 439 population-based controls in Jiangsu province, China. TS genotypes were identified using PCR.RFLP (restriction fragment length polymorphism) methods. Odds ratios (ORs) were estimated with an unconditional logistic regression model. We found that the distributions of 5'-UTR genotypes in TS were significantly different between controls and male colon cases (${\chi}^2$=8.25, P = 0.016). Compared with 3R/3R genotype, individuals with the 2R allele were at an increased risk of colon cancer (age-, BMI-, smoking- and alcohol drinking-adjusted OR=1.98, 95%CI: 1.11-3.53) among men. In ccontrast, the 6-bp ins/del polymorphism at the TS 3'- UTR did not influence risk of the colorectal, colon and rectal cancers. When combined genotypes for both TS 5'-UTR and 3'-UTR polymorphisms were evaluated, individuals with the 5'-UTR 2R allele had a OR of 3.61 (95%CI: 1.38-9.49) for colon cancer among men with the 3'-UTR .6bp/-6bp genotype. These results show that the polymorphism of the 28 bp repeated sequences in TS 5'-UTR could influence susceptibility to colon cancer and that there was a coordinated effect between TS 3'-UTR and 5'-UTR polymorphisms in increasing risk of colon cancer among Chinese men.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7337-7341
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• 2014

Background: The physiological role of vitamin D extends beyond bone health and calcium-phosphate homeostasis to effects on cancer risk, mainly for colorectal cancer. Vitamin D may have an anticancer effect in colorectal cancer mediated by binding of the active form $1,25(OH)_2D$ to the vitamin D receptor (VDR). The Taq1 VDR gene polymorphism, a C-to-T base substitution (rs731236) in exon 9 may influence its expression and function. The aim of this study wass to determine the 25(OH)D vitamin D level and to investigate the association between circulating vitamin D level and Taq1VDR gene polymorphism among Jordanian colorectal cancer patients. Materials and Methods: This case control study enrolled ninety-three patients and one hundred and two healthy Jordanian volunteers from AL-Basheer Hospital/Amman (2012-2013). Ethical approval and signed consent forms were obtained from all participants before sample collection. 25(OH)D levels were determined by competitive immunoassay Elecsys (Roche Diagnostic, France). DNA was extracted (Promega, USA) and amplified by PCR followed by VDR Taq1 restriction enzyme digestion. The genotype distribution was evaluated by paired t-test and chi-square. Comparison between vitamin D levels among CRC and control were assessed by odds ratio with 95% confidence interval. Results: The vitamin D serum level was significantly lower among colorectal cancer patients (8.34 ng/ml) compared to the healthy control group (21.02ng/ml). Patients deficient in vitamin D (less than 10.0 ng/ml) had increased colorectal cancer risk 19.2 fold compared to control. Only 2.2% of CRC patients had optimal vitamin D compared to 23.5% among healthy control. TT, Tt and tt Taq1 genotype frequencies among CRC cases was 35.5%, 50.5% and 14% compared to 43.1%, 41.2% and 15.7% among healthy control; respectively. CRC patients had lower mean vitamin D level among TT ($8.91{\pm}4.31$) and Tt ($9.15{\pm}5.25$) genotypes compared to control ($21.3{\pm}8.31$) and ($19.3{\pm}7.68$); respectively. Conclusions: There is significant association between low 25(OH)D serum level and colorectal cancer risk. The VDRTaq1 polymorphism was associated with increased colorectal cancer risk among patient with VDRTaq1 TT and Tt genotypes. Understanding the functional mechanism of VDRTaq1 TT and Tt may provide a strategy for colorectal cancer prevention and treatment.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3377-3381
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• 2014

Background: The incidence of colorectal cancer increases with vitamin D deficiency as shown in recently published studies. In addition, prospective investigations have indicated that low vitamin D levels may be associated with increased mortality of colorectal cancer, especially in stage III and IV cases. However, the exact incidence of vitamin D deficiency and the relation between vitamin D deficiency and osteopenia/osteporosis is still not known. The aim of this study is to identify severity of vitamin D deficiency and absolute risk factors of osteopenia/osteoporosis in colorectal cancer survivors. Materials and Methods: A total of 113 colorectal cancer survivors treated with surgery and/or chemotherapy ${\pm}$ radiotherapy were recruited from medical oncology outpatient clinics during routine follow-up visits in 2012-2013. Bone mineral densitometry (BMD) was performed, and serum 25-OH vitamin D levels were also checked on the same day of the questionnaire. The patients was divided into 2 groups, group A with normal BMD and group B with osteopenia/osteoporosis. Results: The median age of the study population was 58 (40-76). Thirty (30.0%) were female, whereas 79 (70.0%) were male. The median follow-up was 48 months (14-120 months). Vitamin D deficiency was found in 109 (96.5%); mild deficiency (20-30 ng/ml) in 19 (16.8%), moderate deficiency (10-20 ng/ml) in 54 (47.8%) and severe deficiency (<10 ng/ml) in 36 (31.9%). Osteopenia was evident in 58 (51.4%) patients whereas osteoporosis was noted in 17 (15.0%). Normal BMD was observed in 38 (33.6%). No apparent effects of type of surgery, presence of stoma, chemotherapy, radiotherapy and TNM stage were found regarding the risk of osteopenia and osteoporosis. Also, the severity of the vitamin D deficiency had no effect in the risk of osteopenia and osteporosis (p=0.93). In female patients, osteopenia/osteoporosis were observed in 79.5% patients as compared to 60.7% of male patients (p=0.04). Conclusions: In our study, vitamin D deficiency and osteopenia/osteoporosis was observed in 96.5% and 66.4% of colorectal cancer survivors, respectively. There is no defined absolute risk factor of osteopenia and osteoporosis in colorectal cancer survivors. To our knowledge, in the literature, our study is the first to evaluateall the risk factors of osteopenia and osteoporosis in colorectal cancer survivors.

• Journal of Preventive Medicine and Public Health
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• v.36 no.3
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• pp.279-288
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• 2003

Objectives : Evidence for an effect of rerroductive factors on colorectal carcinogenesis is not yet consistent. Little research has been conducted to investigate whether reproductive factors were associated with colorectal adenomas that are the precursors of colorecta1 cancer, We evaluated the relationships between reproductive factors and the degree of dysplasia of the colorectal adenoma and cancer as colorectal adenoma-carcinoma sequence. Methods : For this study, 241 adenoma cases with histopathologically confirmed incident colorectal adenoma, 76 cancer cases with colorectal cancer and 1677 controls were collected from Our Lady of Mercy Hospital, The Catholic University of Korea, during 1994-1999. Before colonoscopy, information on demographic characteristics, reproductive factors, life style habits and dietary intake were obtained by interviewed questionnaire. Adjusted OR and 95% CI were estimated by using polytomous logistic regression model, Potential confounders that were selected based on the goodness of fit Statistics and interaction between risk factors were considered in this adjustment. The Wald statistic was calculated to test the heterogeneity of the odds ratios for each case. Results .: Postmenopausal women with natural menopause were found to be positively associated with the risk of mild dysplasia adenoma (multivariate-adjusted OR : 2.59, 95% CI=1.1-0.2). Parity was found to be negatively associated with the risk of colorectal lancer (age-adjusted OR : 0.40, 95% CI=0.2-0.9), but did not significantly decrease the risk of colorectal cancer (multivariate-adjusted OR : 0.95, 95% CI=0.3-2.9). Me associations were seen between a9e at menarche, breast feeding, induced abortion, oral contraceptive use, menopausal types, menopausal age or hormone replacement therapy (HRT and the degree of dysplasia of the colorectal adenoma and cancer. However, none of these associations differed' significantly between the degree of dysplasia of the colorectal adenoma and cancer. Conclusions : These findings suggest that postmenopausal women with natural menopause may experience increased risk of mild dysplasia adenorna among colorectal adenoma-carcinoma sequence.

• Safety and Health at Work
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• v.10 no.2
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• pp.141-150
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• 2019

Background: Evidence on associations between occupational diesel exhaust and gasoline exposure and colorectal cancer is limited. We aimed to assess the effect of workplace exposure to diesel exhaust and gasoline on the risk of colorectal cancer. Methods: This case-control study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway, and Sweden. Cases and controls were identified from the Nordic Occupational Cancer Study cohort and matched for country, birth year, and sex. Diesel exhaust and gasoline exposure values were assigned by country-specific job-exposure matrices. Odds ratios and 95% confidence intervals were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work and occupational exposure to benzene, formaldehyde, ionizing radiation, chlorinated hydrocarbons, chromium, and wood dust. Results: Diesel exhaust exposure was associated with a small increase in the risk of rectal cancer (odds ratio - 1.05, 95% confidence interval 1.02-1.08). Gasoline exposure was not associated with colorectal cancer risk. Conclusion: This study showed a small risk increase for rectal cancer after workplace diesel exhaust exposure. However, this finding could be due to chance, given the limitations of the study.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5183-5188
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• 2012

Colorectal cancer remains one of the most widespread malignancies in the world. However, there is a lack of comprehensive studies considering colorectal cancer risk factors among Russian populations, particularly in Siberia. The aim of this investigation was to determine the impact of various lifestyle, dietary, family, and socioeconomical factors on colorectal cancer risk in South-East Siberia. We recruited 185 Russian colorectal cancer cases and 210 gender-, age-, and ethnicity-matched asymptomatic controls with no history of any malignant tumor, using a specially designed questionnaire to obtain relevant information. After the statistical analysis, we defined several significant factors affecting colorectal cancer risk. Among these were smoking (OR=2.13, 95%CI=1.4-3.24, P=0.0004), being overweight (BMI between 25-30, OR=2.45, 95%CI=1.49-4.03, P=0.0004), alcohol drinking (OR=8.73, 95%CI=5.49-13.87, P<0.0001), beer drinking (OR=9.24, 95%CI=5.14-16.61, P<0.0001), consumption of hard liquor (OR=9.37, 95%CI=5.92-14.82, P<0.0001), excessive red meat consumption (P<0.0001), excessive intake of red meat products (P<0.0001), excessive intake of dairy products (P<0.0001), excessive sour cream and cheese consumption (P<0.0001 and 0.0002, respectively), spicy food consumption (OR=2.87, 95%CI=1.9-4.33, P<0.0001), family history of gastrointestinal malignant tumors (OR=3.99, 95%CI=2.09-7.59, P<0.0001), and income exceeding twice the subsistence minimum (OR=5.34, 95%CI=3.35-8.53, P<0.0001). Certain factors, such as high concentration of salt in the food and precancerous colonic lesions, demonstrated borderline significance (OR=3.45, 95%CI=1.68-7.1, P=0.0008, and OR=5.25, 95%CI=1.94-14.22, P=0.001, respectively). Some factors were established as protective, like consumption of rye bread and both rye and wheat bread (OR=0.32, 95%CI=0.21-0.5, P<0,0001, and OR=0.07, 95%CI=0.02-0.21, P<0.0001, respectively), and also low concentration of salt in the food, although this was of borderline significance (OR=0.43, 95%CI=0.26-0.69, P=0.0006). ABO and Rhesus blood antigens were not associated with increased colorectal cancer risk. These results should be definitely applied for elaboration of programs of colorectal cancer prevention in Russia, particularly in Siberia.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3747-3752
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• 2015

Background: Colorectal cancer is one of the most commonly occurring cancers in China. Dietary fibre has been thought to decrease the risk of colorectal cancer in Western countries. However, studies investigating the association between dietary fibre (particularly soluble and insoluble fibres) and colorectal cancer have hitherto been lacking in China. Objective: This case-control study examined the effect of dietary fibre intake on the risk of colorectal cancer, stratified by tumour site. Materials and Methods: The study included 265 cases (colon cancer, 105; rectal cancer, 144; colon and rectal cancer, 16) and 252 controls residing in Qingdao. A food frequency questionnaire that included 121 food items was used to collect dietary information. Odds ratio (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis. Results: For food groups, controls in the study consumed more vegetables, soy food and total fibre than did colorectal cancer patients (p<0.05). The intakes of fruit, meat and sea-food did not differ significantly between cases and controls. However, we did not find any association between soy food intake and colon cancer. We observed inverse associations between total fibre intake and colorectal, colon and rectal cancer (Q4 vs Q1: OR=0.44, 95%CI, 0.27-0.73; OR=0.40, 95%CI, 0.21-0.76; OR=0.52, 95%CI, 0.29-0.91). Vegetable fibre intake showed similar inverse associations (Q4 vs Q1: OR=0.51, 95%CI, 0.31-0.85; OR=0.48, 95%CI, 0.25-0.91; OR=0.53, 95%CI, 0.29-0.97). In addition, inverse associations were observed between soluble fibre and insoluble fibre and both colorectal cancer and colon cancer. No relationship was found between colorectal cancer and fruit, soy or grain fibre intakewhen the results were stratified by tumour site. Conclusions: The present study suggests that vegetable fibre and total fibre play very important roles in protecting against colorectal cancer. Soluble and insoluble fibres were inversely associated with only colorectal cancer and colon cancer.