Document Type : Original Article


1 Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 Department of Epidemiology and Biostatistics, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran


Background: Records from the cancer registry system of Iran indicate that colorectal cancer is the third most common cancer in Iranian men and fourth most common among Iranian women. In this study we have investigated the environmental factors associated with colorectal cancer in Isfahan, Iran.Methods: In this case-control study, we randomly selected 187 patients with colorectal cancer who had positive results by colonoscopy and pathology (case group) and 250 persons who had negative colonoscopy results (control group) from the Colonoscopy Unit of Al Zahra Hospital and Colorectal Cancer Center of Seyed Al Shohada Hospital from 2014 to mid-2015. This study aimed to find the risk factors for sporadic colorectal cancer; therefore, we excluded patients with positive family history. Participants completed a self-administered questionnaire that asked about sex, age, body mass index, smoking status, job-related physical activity, and nonsteroidal antiinflammatory drug consumption.Results: This study enrolled 187 colorectal cancer patients (98 males and 89 females) and 250 individuals without colorectal cancer (107 males and 143 females). Multiple analysis demonstrated a significant association of age (odds ratio: 1.04; 95% confidence interval: 1.02, 1.06) and body mass index (odds ratio: 1.09; 95% confidence interval: 1.03, 1.15) with colorectal cancer risk. Men had an almost two-fold risk compared with women (odds ratio: 1.85; 95% confidence interval: 1.14, 2.99). Subjects who did not use nonsteroidal anti-inflammatory drugs had an almost three-fold risk compared with nonsteroidal anti-inflammatory drug consumers (odds ratio: 0.34; 95% confidence interval: 0.19, 0.62). Analysis for job-related physical activity, also indicated an association between the no/low active group with colorectal cancer (odds ratio no activity: 36.09; 95% confidence interval: 10.94, 119 and odds ratio low activity: 2.96; 95% confidence interval: 1.43, 6.13).Conclusion: Knowledge of the risk factors involved in colorectal cancer incidence makes it possible to identify people at risk and begin risk reduction strategies as well as screening programs.

1.         Ferlay J, Shin H-R, Bray F, Forman D, Mathers C, Parkin DM. GLOBOCAN 2008, Cancer incidence and mortality worldwide: IARC CancerBase No. 10. Lyon, France: International Agency for Research on Cancer. 2010;2010:29.
2.         Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int J Cancer. 2010;127(12):2893-917. doi: 10.1002/ijc.25516.
3.         Hosseini SV, Izadpanah A, Yarmohammadi H. Epidemiological changes in colorectal cancer in Shiraz, Iran: 1980-2000. ANZ J Surg. 2004;74(7):547-9.
4.         Malekzadeh R, Bishehsari F, Mahdavinia M, Ansari R. Epidemiology and molecular genetics of colorectal cancer in iran: a review. Arch Iran Med. 2009;12(2):161-9.
5.         Poomphakwaen K, Promthet S, Suwanrungruang K, Kamsa-ard S, Wiangnon S. Risk Factors for Colorectal Cancer in Thailand. Asian Pac J Cancer Prev. 2015;16(14):6105-9.
6.         Yee YK, Tan VP, Chan P, Hung IF, Pang R, Wong BC. Epidemiology of colorectal cancer in Asia. J Gastroenterol Hepatol. 2009;24(12):1810-6. doi: 10.1111/j.1440-1746.2009.06138.x.
7.         Mehrabani D, Tabei S, Heydari S, Shamsina S, Shokrpour N, Amini M, et al. Cancer occurrence in Fars Province, Southern Iran. Iran Red Crescent Med J. 2008;2008(4):314-22.
8.         Sadjadi A, Malekzadeh R, Derakhshan MH, Sepehr A, Nouraie M, Sotoudeh M, et al. Cancer occurrence in Ardabil: results of a population-based cancer registry from Iran. Int J Cancer. 2003;107(1):113-8.
9.         Aleksandrova K, Pischon T, Jenab M, Bueno-de-Mesquita HB, Fedirko V, Norat T, et al. Combined impact of healthy lifestyle factors on colorectal cancer: a large European cohort study. BMC Med. 2014;12:168. doi: 10.1186/s12916-014-0168-4.
10.       Sanchez NF, Stierman B, Saab S, Mahajan D, Yeung H, Francois F. Physical activity reduces risk for colon polyps in a multiethnic colorectal cancer screening population. BMC Res Notes. 2012;5:312. doi: 10.1186/1756-0500-5-312.
11.       Fearon ER, Vogelstein B. A genetic model for colorectal tumorigenesis. Cell. 1990;61(5):759-67.
12.       Becker N. Epidemiology of colorectal cancer. [Article in German] Radiologe. 2003;43(2):98-104.
13.       Durko L, Malecka-Panas E. Lifestyle modifications and colorectal cancer. Curr Colorectal Cancer Rep. 2014;10:45-54.
14.       Pohl C, Hombach A, Kruis W. Chronic inflammatory bowel disease and cancer. Hepatogastroenterology. 2000;47(31):57-70.
15.       Lieberman DA, Prindiville S, Weiss DG, Willett W; VA Cooperative Study Group 380. Risk factors for advanced colonic neoplasia and hyperplastic polyps in asymptomatic individuals. JAMA. 2003;290(22):2959-67.
16.       Hong SN, Kim JH, Choe WH, Han HS, Sung IK, Park HS, et al. Prevalence and risk of colorectal neoplasms in asymptomatic, average-risk screenees 40 to 49 years of age. Gastrointest Endosc. 2010;72(3):480-9. doi: 10.1016/j.gie.2010.06.022.
17.       Chung SJ, Kim YS, Yang SY, Song JH, Park MJ, Kim JS, et al. Prevalence and risk of colorectal adenoma in asymptomatic Koreans aged 40-49 years undergoing screening colonoscopy. J Gastroenterol Hepatol. 2010;25(3):519-25. doi: 10.1111/j.1440-1746.2009.06147.x.
18.       W Winawer S, Fletcher R, Rex D, Bond J, Burt R, Ferrucci J, et al. Colorectal cancer screening and surveillance: clinical guidelines and rationale-Update based on new evidence. Gastroenterology. 2003;124(2):544-60.
19.       Haggar FA, Boushey RP. Colorectal cancer epidemiology: incidence, mortality, survival, and risk factors. Clin Colon Rectal Surg. 2009;22(4):191-7. doi: 10.1055/s-0029-1242458.
20.       Aykan NF, Yalçın S, Turhal NS, Özdoğan M, Demir G, Özkan M, et al. Epidemiology of colorectal cancer in Turkey: A cross-sectional disease registry study (A Turkish Oncology Group trial). Turk J Gastroenterol. 2015;26(2):145-53. doi: 10.5152/tjg.2015.5685.
21.       O'Connell JB, Maggard MA, Liu JH, Etzioni DA, Livingston EH, Ko CY. Rates of colon and rectal cancers are increasing in young adults. Am Surg. 2003;69(10):866-72.
22.       Murphy G, Devesa SS, Cross AJ, Inskip PD, McGlynn KA, Cook MB. Sex disparities in colorectal cancer incidence by anatomic subsite, race and age. Int J Cancer. 2011;128(7):1668-75. doi: 10.1002/ijc.25481.
23.       Booth A, Magnuson A, Fouts J, Foster M. Adipose tissue, obesity and adipokines: role in cancer promotion. Horm Mol Biol Clin Investig. 2015;21(1):57-74. doi: 10.1515/hmbci-2014-0037.
24.       Donohoe CL, Doyle SL, Reynolds JV. Visceral adiposity, insulin resistance and cancer risk. Diabetol Metab Syndr. 2011;3:12. doi: 10.1186/1758-5996-3-12.
25.       Ashktorab H, Paydar M, Yazdi S, Namin HH, Sanderson A, Begum R, et al. BMI and the risk of colorectal adenoma in African-Americans. Obesity (Silver Spring). 2014;22(5):1387-91. doi: 10.1002/oby.20702.
26.       Zapatier J, Avalos D, Tandon K, Souqiyyeh A, Hernandez M, Rai S, et al. Can adjusting BMI for age and sex provide for a better predictor of colonic neoplasia?
Eur J Gastroenterol Hepatol. 2015;27(8):974-80. doi: 10.1097/MEG.0000000000000391.
27.       Larsson SC, Wolk A. Obesity and colon and rectal cancer risk: a meta-analysis of prospective studies. Am J Clin Nutr. 2007;86(3):556-65.
28.       Wolin KY, Yan Y, Colditz GA, Lee IM. Physical activity and colon cancer prevention: a meta-analysis. Br J Cancer. 2009;100(4):611-6. doi: 10.1038/sj.bjc.6604917.
29.       Samad AK, Taylor RS, Marshall T, Chapman MA. A meta-analysis of the association of physical activity with reduced risk of colorectal cancer. Colorectal Dis. 2005;7(3):204-13.
30.       Saha D, Roman C, Beauchamp RD. New strategies for colorectal cancer prevention and treatment. World J Surg. 2002;26(7):762-6.
31.       García-Rodríguez LA, Huerta-Alvarez C. Reduced risk of colorectal cancer among long-term users of aspirin and nonaspirin nonsteroidal antiinflammatory drugs. Epidemiology. 2001;12(1):88-93.
32.       Friis S, Riis AH, Erichsen R, Baron JA, Sørensen HT. Low-Dose Aspirin or nonsteroidal anti-inflammatory drug use and colorectal cancer risk: A population-based, case-control study. Ann Intern Med. 2015;163(5):347-55. doi: 10.7326/M15-0039.
33.       Society AC. Colorectal Cancer Facts & Figures 2011-2013. American Cancer Society Atlanta, GA, USA; 2011.
34.       Liang PS, Chen TY, Giovannucci E. Cigarette smoking and colorectal cancer incidence and mortality: systematic review and meta-analysis. Int J Cancer. 2009;124(10):2406-15. doi: 10.1002/ijc.24191.
35.       Bener A, Moore MA, Ali R, El Ayoubi HR. Impacts of family history and lifestyle habits on colorectal cancer risk: a case-control study in Qatar. Asian Pac J Cancer Prev. 2010;11(4):963-8.