prevalence of positive family history of colorectal cancer in the iranian general population

background: individuals with a positive family history of colorectal cancer have an increased risk of developing this type of cancer. the number of affected relatives and the age at diagnosis are two factors that increase the risk of colorectal cancer. the aim of this study was to assess the prevalence of a positive family history of colorectal cancer in a random sample among the iranian general population. methods: five thousand five hundred (5500) subjects' aged≥20 years were randomly selected by cluster sampling and invited to participate in an interview about the occurrence of colorectal cancer in their first- or second-degree relatives. results: of all the responders, 162 (2.9%) subjects reported a positive family history of colorectal cancer; 71 (1.24%) reported having one first-degree relative with colorectal cancer diagnosed before the age of 50; or reported two or more first-degree relatives with colorectal cancer. in addition, 83 (1.51%) and 14 (0.25%) subjects reported having one and two or more second-degree relatives with colorectal cancer respectively. conclusion: the prevalence of a positive family history of colorectal cancer in iran is lower than the united states and european countries. identifying high-risk population for colorectal cancer and encouraging them to participate in surveillance protocols is the first step in targeting preventive measures. key words: colorectal cancer; family history; prevalence; general population; iran references 1. u.s. preventive services task force. screening for colorectal cancer: recommendations and rationale. annals of internal medicine. 2002; 137:129–31. 2. smith ra, cokkinides v, eyre hj. american cancer society guidelines for the early detection of cancer, 2005. ca: a cancer journal for clinicians. 2005 jan-feb; 55(1):31-44; quiz 55-6. 3. slattery ml, levin tr, ma k, goldgar d, holubkov r, edwards s. family history and colorectal cancer: predictors of risk. cancer causes control. 2003 nov; 14(9):879-87. 4. moghimi-dehkordi b, safaee a, zali mr. prognostic factors in 1,138 iranian colorectal cancer patients. international journal of colorectal disease. 2008 jul; 23(7):683-8. 5. azadeh s, moghimi-dehkordi b, fatem sr, pourhoseingholi ma, ghiasi s, zali mr. colorectal cancer in iran: an epidemiological study. asian pac j cancer prev. 2008 jan-mar; 9(1):123-6. 6. esna-ashari f, sohrabi m, abadi a, mehrabian a, mofid b, bohluli m, et al. colorectal cancer prevalence according to survival data in iran-2007. ijcp  2009; 2(1):15-8. 7. moradi a, khayamzadeh m, guya mm, mirzaei hr, salmanian r, rakhsha a, et al. survival of colorectal cancer in iran. asian pac j cancer prev. 2009 oct-dec; 10(4):583-6. 8. yazdizadeh b, jarrahi am, mortazavi h, mohagheghi ma, tahmasebi s, nahvijo a. time trends in the occurrence of major gi cancers in iran. asian pac j cancer prev. 2005 apr-jun; 6(2):130-4. 9. safaee a, moghimi-dehkordi b, pourhoseingholi ma, vahedi m, maserat e, ghiasi s, et al. risk of colorectal cancer in relatives: a case control study. indian journal of cancer.  2010; 47(1):27-30. 10. u.s. preventive services task force. guide to clinical preventive services. cancer screening. available at: http://wwwahrqgov/clinic/cps3dixhtm#cancer. 2009. 11. national center for chronic disease prevention and health promotion. centers for disease control and prevention, division of cancer prevention and control. available at: http://wwwcdcgov/cancer/index/htm. 2009. 12. 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 feb; 124(2):544-60. 13. national cancer institute. screening and testing to detect cancer. available at: http://wwwcancergov/ cancertopics/screening. 2009. 14. american cancer society. acs cancer detection guidelines. available at: http://wwwcancerorg/docroot/ped/content/ped_2_3x_acs_cancer_detection_guidelines_36asp. 2009. 15. national comprehensive cancer network. guidelines for detection, prevention, and risk reduction of cancer. available at: http://wwwnccnorg/professionals/ physician_gls? f_guidelinesasp? button= i+agree#detection. 2009. 16. de jong ae, vasen hf. the frequency of a positive family history for colorectal cancer: a population-based study in the netherlands. the netherlands journal of medicine. 2006 nov; 64(10):367-70.