Statistics on cases of colorectal cancer diagnosis were collected in 36 countries (including Australia, Finland, New Zealand, Norway, Sweden, and the USA) until 2012 and the dynamics of incidence were analyzed in two age categories (20–49 years and 50 years and older) . The results found that the incidence of colorectal cancer over the past decade among people under 50 years of age was stable in 14 of 36 countries; decreased in Austria, Italy and Lithuania; and increased in 19 countries. However, in 9 of the 19 countries (including Australia, Canada, Denmark, Germany, New Zealand, Slovenia, Sweden, the United Kingdom and the United States) in which premature onset of colorectal cancer in people aged 20–49 years increased, the incidence rates among older people were either stable or decreased.
In most high-income countries, the incidence of early-onset colorectal cancer began to increase in the mid-1990s. The highest rates of growth among young people were observed in Korea and New Zealand. In Cyprus, the Netherlands and Norway, the incidence in young people was 2 times higher than that in older people (for example, the average annual change in this indicator in Norway was 1.9 versus 0.5).
Experts noted that the study was limited by some factors (for example, the lack of high-quality data for many low- and middle-income countries). However, the findings suggest that increasing awareness of the increasing incidence of colorectal cancer among people under 50 years of age will encourage better family history and symptom monitoring in younger people, many of whom are diagnosed late in life. stages.