**3.1 Childhood colorectal cancer**

In terms of colorectal cancer in under-18 year-old people, 52 cases (1.13% of 4646 cases) were found [14]. Children and adolescents are not employed and therefore they are not exposed to occupational carcinogens. They are also rarely exposed to tobacco smoking and alcoholic beverages, according to a recent report on student health surveillance by WHO [26], as well as to dioxins in herbicides during the Vietnam War. What were the risk factors that induced colorectal cancer during the 1990s in Vietnam among children and adolescents?
