Colorectal cancer incidence increases in those aged less than 50 years
Background The aim was to study colorectal cancer incidence in the population younger than 50 years in Finland from 1970 to 2019.
Methods The change in incidence was studied using a statistical Poisson regression model and a breakpoint analysis.
Results The incidence of colorectal cancer in those below 50 years of age has increased steadily in both men (1,25% per year, 95% confidence interval 1,00%-1,50%) and women (0,98% per year, 95% confidence interval 0,75%-1,21%). The mean yearly number of incident cases at age below 50 years has nearly doubled between 1970-1979 (men 45,9/year and women 56,8/year) and 2010-2019 (88,4/year and 90,6/year, respectively). The proportion of colorectal cancers diagnosed below age 50 out of all colorectal cancers has decreased by 50% in men (from 10,2% to 5.2%) and 30% in women (from 9,2% to 6,0%).
Conclusions Colorectal cancer incidence increases more among men and women below age 50 than in those older but the proportion of new patients is decreasing due to the aging population of Finland. The reason for the increase in the young population is likely to be explained by changes in lifestyle related habits.
Janne Pitkäniemi, Heidi Ryynänen, Tomas Tanskanen, Nea Malila, Karri Seppä
