We aimed to assess cancer knowledge and screening practice among a cohort of individuals at average-risk for colorectal cancer.

This study was conducted as part of an ongoing joint screening cohort between Digestive Diseases Research Institute (DDRI) of Tehran University of Medical Sciences (TUMS) and the International Agency for Research on Cancer (IARC) in France. We invited individuals aged 50-75 years who were at average-risk for colorectal cancer (CRC) to participate in a free of charge stool-based screening program. We enrolled 3122 in the study between 2018 and 2019 and measured their data on demographics, cancer knowledge, and prior screening practice.

The mean age was 59.4 years and female participants were 68.2% of the total cohort. In total, 85.1% were from urban area and about 83.7% of participants were either illiterate or less than 9 class of education. The vast majority of participants (>87%) stated that they had never heard about colorectal polyps or cancer. Among the minority who had heard about colorectal cancer (13.1%), most of them knew that people with a family history of CRC are at higher risk (75.8%) and that polyps may turn into cancer over time (66.3%). Among the total participants, only few minority (<6.0%) of the participants had heard of colorectal cancer screening tests (i.e., occult blood stool test) and knew that CRC screening can save life or prevent CRC death, and were aware of the correct age for CRC screening. In sum, only 1.4% of the participants reported a prior CRC screening experience.

Our data indicated that remarkable numbers of FDRs were not still informed of colorectal cancer and screening tests, and that they almost had no previous screening practice. This has important implications to increase cancer awareness among Iranian adults and other developing nations.