• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1203-1208
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• 2012

Background: Previous studies concerning the association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and colorectal cancer risk in Asian populations generated conflicting results. A meta-analysis was therefore performed to allow a more reliable estimate of any link. Methods: Relevant studies concerning the association between the MTHFR C677T polymorphism and risk of colorectal cancer were included into this meta-analysis. The quality of the studies was assessed according to a predefined scale. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for this gene-disease association using fixed or random effect models according to the heterogeneity between included studies. Results: Finally, 21 studies with a total of 6692 cases and 8266 controls were included. Meta-analyses showed that there was an obvious association of the MTHFR 677T allele with decreased risk of colorectal cancer (OR = 0.91, 95%CI=0.85-0.98, P=0.011). Subgroup analyses by country further identified this association, with dietary folate as the main source of heterogeneity. Conclusion: The MTHFR 677T allele is associated with a lower risk of colorectal cancer in Asian populations, and there is effect modification by population plasma folate.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3735-3740
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• 2015

Context: Insulin-like growth factor peptides play important roles in regulating cell growth, cell differentiation, and apoptosis, and have been demonstrated to promote the development of colorectal cancer (CRC). Objective: To examine the association of insulin-related biomarkers including insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3) and C-peptide with CRC risk and assess their relevance in predictive models. Materials and Methods: The odds ratios of colorectal cancer for serum levels of IGF-1, IGFBP-3 and C-peptide were estimated using unconditional logistic regression models in 100 colorectal cancer cases and 100 control subjects. Areas under the receiving curve (AUC) and integrated discrimination improvement (IDI) statistics were used to assess the discriminatory potential of the models. Results: Serum levels of IGF-1 and IGFBP-3 were negatively associated with colorectal cancer risk (OR=0.07, 95%CI: 0.03-0.16, P for trend <.01, OR=0.06, 95%CI: 0.03-0.15, P for trend <.01 respectively) and serum C-peptide was positively associated with risk of colorectal cancer (OR=4.38, 95%CI: 2.13-9.06, P for trend <.01). Compared to the risk model, prediction for the risk of colorectal cancer had substantially improved when all selected biomarkers IGF-1, IGFBP-3 and inverse value of C-peptide were simultaneously included inthe reference model [P for AUC improvement was 0.02 and the combined IDI reached 0.166% (95 % CI; 0.114-0.219)]. Conclusions: The results provide evidence for an association of insulin-related biomarkers with colorectal cancer risk and point to consideration as candidate predictor markers.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7883-7887
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• 2015

Background: Colorectal cancer is one of the most common cancers worldwide. Viruses including human papillomavirus (HPV) have been reported to be associated with different cancers but any association with colorectal cancers remains controversial. Aim: To evaluate any association between HPV infection and adenocarcinoma of the colon and adenomatous polyps. Materials and Methods: Paraffin-embedded tissue specimens of 70 colorectal adenocarcinomas, 70 colorectal adenomatous polyps, and 70 colorectal normal tissues were subjected to DNA extraction. The quality of the extracted DNA was confirmed by amplification of a ${\beta}$-globin fragment using polymerase chain reaction (PCR). PCR using specific primers were performed to detect HPV DNA. Specific primers targeting the E6 region of the HPVs 16 and 18 were used for genotyping. Results: HPV DNA was detected in 2 (2.85%) out of 70 adenocarcinoma colorectal tissues and 4 (5.71 %) out of 70 adenomatous colorectal tissues. All normal colorectal tissues were negative for HPV DNA. HPV-16 was the most predominant genotype (5 sample) followed by HPV-18 (4 sample). Despite the above observations, statistical analyses indicated no significant differences in the frequencies of HPV positive subjects between the cancerous and normal samples. Conclusions: Although the differences observed in the frequencies of HPV positive cases in our study was not significant relative to those of control subjects, the fact of 6 positive samples among cancerous tissues, may still suggest a role of HPV in colorectal carcinogenesis. The study collectively indicated that some colorectal cancerous tissues are infected with high risk HPV genotype. The findings merit more investigation.

• Journal of Preventive Medicine and Public Health
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• v.47 no.2
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• pp.84-93
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• 2014

Objectives: The incidence and survival rate of colorectal cancer in Korea are increasing because of improved screening, treatment technologies, and lifestyle changes. In this aging population, increases in economic cost result. This study was conducted to estimate the economic burden of colorectal cancer utilizing claims data from the Health Insurance Review and Assessment Service. Methods: Economic burdens of colorectal cancer were estimated using prevalence data and patients were defined as those who received ambulatory treatment from medical institutions or who had been hospitalized due to colorectal cancer under the International Classification of Disease 10th revision codes from C18-C21. The economic burdens of colorectal cancer were calculated as direct costs and indirect costs. Results: The prevalence rate (per 100 000 people) of those who were treated for colorectal cancer during 2010 was 165.48. The economic burdens of colorectal cancer in 2010 were 3 trillion and 100 billion Korean won (KRW), respectively. Direct costs included 1 trillion and 960 billion KRW (62.85%), respectively and indirect costs were 1 trillion and 160 billion (37.15%), respectively. Conclusions: Colorectal cancer has a large economic burden. Efforts should be made to reduce the economic burden of the disease through primary and secondary prevention.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.377-381
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• 2012

The aim of this study was to screen for polypeptides binding specifically to LoVo human colorectal cancer cells using a phage-displayed peptide library as a targeting vector for colorectal cancer therapy. Human normal colorectal mucous epithelial cells were applied as absorber cells for subtraction biopanning with a c7c phage display peptide library. Positive phage clones were identified by enzyme-linked immunosorbent assay and immunofluorescence detection; amino acid sequences were deduced by DNA sequencing. After 3 rounds of screening, 5 of 20 phage clones screened positive, showing specific binding to LoVo cells and a conserved RPM motif. Specific peptides against colorectal cancer cells could be obtained from a phage display peptide library and may be used as potential vectors for targeting therapy for colorectal cancer.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1969-1974
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• 2013

The objective of this study was to determine the knowledge and associated factors regarding colorectal cancer screening among university students in Malaysia. The questionnaire consisted of three parts: socio-demographic characteristics, lifestyle practice and knowledge of colorectal screening. A cross-sectional study was conducted among 300 students ($21.3{\pm}1.4$ years old). The majority of the participants were Malay with a monthly family income of less than 5,000 Ringgit Malaysia (equal to 1,700 USD) (67.0% and 76.0%, respectively). Regarding their lifestyle practices, the majority were non-smokers and had never consumed alcohol (83.7%, and 88.0%, respectively). The majority of the participants had no knowledge of digital rectal examination, colonoscopy, barium enema and fecal occult blood screening (63.3%, 60.7%, 74.0% and 62.3%, respectively). Univariate and multivariate analysis revealed that their age and the discipline which the students were studying significantly influenced their level of knowledge about colorectal screening. The present study results indicate that education campaigns about colorectal cancer should be promoted.

• Journal of Korean Academy of Nursing
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• v.48 no.5
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• pp.545-553
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• 2018

Purpose: The increasing survival rate of colorectal cancer demands various nursing interventions and continuous care for patients to adapt to their psychosocial daily lives. The purpose of this study was to identify factors associated with psychosocial adjustment in colorectal cancer survivors. Methods: A cross-sectional descriptive study with face-to-face interviews was conducted of 156 colorectal cancer survivors after surgery visiting an outpatient cancer clinic at a tertiary hospital in S city, Korea. Posttraumatic growth, health-promoting behavior, length of treatment, difficulty in activities of daily living, and having a stoma were entered into the linear regression model. Results: The strongest factor influencing the level of psychosocial adjustment was health-promoting behavior (${\beta}=.33$, p<.001), followed by difficulty in activities of daily living (${\beta}=-.24$, p=.001), posttraumatic growth (${\beta}=.20$, p=.004), and having a stoma (${\beta}=-.19$, p=.004). Conclusion: Nursing interventions for psychosocial adjustment in colorectal cancer survivors need to include the contents for posttraumatic growth, as well as health-promoting behavior, and activities of daily living.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4323-4326
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• 2016

Background: The cancer mortality-to-incidence ratio (MIR) has been established as an important measure of health disparities in local and global circumstances. Past work has corroborated a linkage between the colorectal cancer MIR and the World Health Organization (WHO) Health System ranking. The literature further documents many Asian countries having incomplete cancer registries and a lack of comprehensive colorectal cancer screening guidelines. Materials and Methods: The colorectal cancer MIR values for 23 Asian countries were calculated from data obtained from the 2012 GLOBOCAN database. The 2000 World Health Organization (WHO) Health System rankings were used as a proxy for health system infrastructure and responsiveness. A regression equation was calculated with the MIR as the dependent variable and the WHO Health System ranking as the independent variable. Predicted MIR values were next calculated based on the regression results. Actual MIR values that exceeded 0.20 from the predicted MIR were removed as 'divergent' points. The regression equation was then re-plotted. Goodness-of-fit for both regressions was assessed by the R-squared test. Results: Asian countries have a relatively wide colorectal cancer MIR range, from a minimum of 0.24 to a maximum of 0.86. For the full dataset, the adjusted R-squared value for this regression was 0.53. The equation was then used to calculate a predicted MIR, whereby two data points were identified as 'divergent' and removed. The adjusted R-squared for the edited dataset increased to 0.66. Conclusions: Asian countries have a marked range in their colorectal cancer MIR values and there is a strong correlationwith the WHO Health System ranking. These results corroborate the contribution of the MIR as a potentially robust tool in monitoring changes in colorectal cancer care for Asian nations.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.7
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• pp.3113-3121
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• 2014

Colorectal cancer remains one of the most common types of cancer and a leading cause of cancer death worldwide. In this study, we aimed to investigate effects of DuP-697, an irreversible selective inhibitor of COX-2 on colorectal cancer cells alone and in combination with a promising new multi-targeted kinase inhibitor E7080. The HT29 colorectal cancer cell line was used. Real time cell analysis (xCELLigence system) was conducted to determine effects on colorectal cell proliferation, angiogenesis was assessed with a chorioallantoic membrane model and apoptosis was determined with annexin V staining. We found that DuP-697 alone exerted antiproliferative, antiangiogenic and apoptotic effects on HT29 colorectal cancer cells. For the antiproliferative effect the half maximum inhibition concentration ($IC_{50}$) was $4.28{\times}10^{-8}mol/L$. Antiangiogenic scores were 1.2, 0.8 and 0.5 for 100, 10 and 1 nmol/L DuP-697 concentrations, respectively. We detected apoptosis in 52% of HT29 colorectal cancer cells after administration of 100 nmol/L DuP-697. Also in combination with the thyrosine kinase inhibitor E7080 strong antiproliferative, antiangiogenic and apoptotic effects on HT29 colorectal cancer cells were observed. This study indicates that DuP-697 may be a promising agent in the treatment of colorectal cancer. Additionally the increased effects observed in the combination with thyrosine kinase inhibitor give the possibility to use lower doses of DuP-697 and E7080 which can avoid and/or minimize side effects.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1975-1979
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• 2013

Aim: To investigate the level of expression of proto-oncogene Wip1 and its physiological significance in colorectal cancer. Methods: Immunohistochemistry, semi-quantitative RT-PCR, and Western blotting were used to analyze Wip1 mRNA and protein expression in 120 cases of colorectal cancer and normal tissues to study relationships with clinical symptoms and disease prognosis. Results: The level of Wip1 protein expression was found to be significantly higher in colorectal cancer tissues (85% (102/120)) than in normal tissues (30% (36/120)) (P<0.05). The relative amount of Wip1 protein in colorectal cancer tissue was also found to be significantly higher (P<0.05) than in normal tissues ($1.060{\pm}0.02$ and $0.640{\pm}0.023$, respectively). Semi-quantitative RT-PCR showed average Wip1 mRNA expression levels to be $1.113{\pm}0.018$ and $0.658{\pm}0.036$ for colorectal cancer tissue and adjacent normal tissue (P<0.05). The level of Wip1 protein expression was not correlated with age, gender, or tumor site, but appeared linked with lymph node metastasis, Dukes stage, histological grade, and liver metastasis. Individuals with high and low levels of Wip1 expression showed statistically significant differences in the five-year overall survival and recurrence-free survival rates (P<0.05). Conclusion: Wip1 mRNA and protein are highly expressed in colorectal cancers and may be associated with colorectal cancer development and progression.