A27 INCREASING INCIDENCE OF COLORECTAL CANCER IN ADULTS UNDER AGE OF 50 IN ALBERTA

Abstract

Abstract Background Overall colorectal cancer (CRC) incidence has been decreasing in Canada since the early 2000s, most likely due to increased use of colorectal cancer screening for adults over the age of 50. However, the incidence of CRC may be rising in adults younger than age 50 both in Canada and the USA. The American Cancer Society in 2018 issued a qualified recommendation that people with an average risk of CRC should start screening at age 45. The burden of CRC in adults under the age of 50 is not well-characterized in Alberta. Aims The aim of this study is to determine the incidence trends in colorectal cancer in adults under the age of 50 compared to those over the age of 50 in Alberta. Methods This cohort study determined the incidence of colorectal cancer in patients under the age of 50 compared to those over the age of 50 reported to the Alberta Cancer Registry (ACR) from 2010 to 2017. Annualized percentage changes (APCs) in incidence rate were estimated using the Joinpoint Regression Program 4.7.0.0 (Nation Cancer Institute). APCs in relative risk of CRC in different age groups compared to the 50–74 age group were also estimated in the same methodology. Results From 2010 to 2017 there were 17167 incident cases of colorectal cancer. Of these, 92% were in adults over the age of 50 while 8% were in those under the age of 50. For adults under the age of 50, incidence of CRC increased from 6 to 7.2 per 100,000 with a mean annual percentage change of 2.58% between 2010 and 2017. This is in contrast to adults over the age of 50, where the incidence of CRC decreased from 170 to 128 per 100,000 with a mean annual percentage change of -1.64% from 2010 to 2015 and -9.42% from 2015 to 2017. Compared to the 50–74 age group, the average relative risk of CRC in the 46–49 age group is 0.26 with an annual increase of 0.55%; while in the 40–45 age group the average relative risk of CRC is 0.15 with an annual increase of 2.61%. Conclusions Similar to national incidence trends, the incidence of CRC in adults under the age of 50 is increasing in Alberta. Although the overall incidence in this population is relatively low, suspicion of CRC in adults under age 50 can help prevent delays in diagnosis. Incidence of colorectal cancer in Alberta for adults under the age of 50 increased from 6 to 7.2 per 100,000 with a mean annual percentage change of 2.58% between 2010 and 2017. Funding Agencies None