Trends in colorectal cancer incidence in western Kazakhstan through the first decade of the screening implementation, 2009‒2018

Abstract

IntroductionThe study is aimed to outline the vector of colorectal cancer incidence in the industrial Aktobe province of western Kazakhstan through the first decade of the screening implementation, 2009–2018. MethodsRough incidence rates and annual percent changes were estimated for each age group at diagnosis, ethnicities, gender, residences, the disease stages and anatomic subsites (total N 1128) via regression analysis. ResultsWithin 2009–2018 colorectal cancer rates increased from 14.74 to 23.19, with annual percent changes of 4.69%. The most significant growth was traced in men compared to women, up to 28.39 by 2018, with annual percent changes 6.64% vs. 2.64% (p=0.0009). Annual percent changes in Kazakhs reached 8.7%, whereas Slavic groups showed decline in the incidence, annual percent changes −4.3% (p=0.002). Declining in rates was also observed in urban population compared to rural one, annual percent changes −3.3% vs. 17.6%, respectively. Patients aged 60–69 made 31% of all cases and showed the largest annual percent changes 9.37% (p=0.002). Patients at Stage II made 61% of all observations, but general trend evidenced sharp growth in the group of Stage I (annual percent changes 28.91%, p<0.0001). ConclusionOverall, during the last decade colorectal cancer incidence increased 1.5 fold with expected further rise. However, the increment of Stage I portion by 2018 vs. advanced stages at diagnosis and the trend to decrease in rates among urban population inspire a definite assurance in potential efficiency of the screening program in long run. The next researches on colorectal cancer should include scenarios to reveal the role of disadvantaged environment in the region and consuming unhealthy ultra-processed food.