Author/Authors :
Mehrzad, Jamshid Department of Biochemistry - Neyshabur Medical Sciences Branch, Islamic Azad University, Neyshabur, Iran , Dayyani, Mahdieh Radiation Oncology Department - Reza Radiotherapy and Oncology Center, Mashhad, Iran , Erfanian-Khorasani, Mohammadreza Department of Biotechnology - Islamic Azad University Neyshabur Branch, Neyshabur, Iran
Abstract :
Background: Several environmental and genetic factors have contributed to the development of colorectal cancer (CRC). We aimed
to investigate the independent and combined effects of some selected risk factors and Arg399Gln XRCC1 polymorphism on CRC.
Methods: A total of 180 patients with CRC and 160 healthy individuals who were matched for sex, age, and place of residence
(Northeast of Iran) participated in this case-control study. Before collecting blood samples and filling out questionnaires, a written
consent form was obtained from all participants. Genotypes were determined by RFLP-PCR. The comparison of genotype and allele
frequencies was performed using p value based on the results of chi-square test. The odds ratios (OR) and 95% confidence intervals
(CI) were calculated by employing a logistic regression model. All statistical calculations were performed using SPSS. Each of the 2-
sided p values less than 0.05 were considered statistically significant.
Results: The level of literacy, physical activity, consumption of vegetables and fruits, and tea intake of the patients were
significantly lower than healthy individuals, but gastrointestinal disorders, family history of cancer, BMI, and fast food consumption
were significantly higher in cases than in controls. No significant difference was observed between the 2 groups regarding smoking,
opioid addiction, alcohol consumption, diet, fish consumption, and liquid intake, using the kitchen hood, diabetes, and cardiovascular
disease. Arg/Gln + Gln/Gln and Arg/Gln genotypes were involved in increased CRC risk (The crude or =1.781 with a 95% CI of
1.156-2.744 and or = 1.690 with a 95% CI of 0.787-3.630). Also, Gln/Gln genotype was more frequent in CRC group than in control
group. However, none of the risk factors interacted with polymorphism, and thus did not have an effect on CRC.
Conclusion: Some risk factors, such as reducing the consumption of vegetables and fruits or reducing physical activity as well as
polymorphism of the XRCC1 Arg399Gln alone, increase the risk of CRC, but they do not interact with each other.
Keywords :
Risk factors , Polymorphism , XRCC1 , Colorectal cancer
