The impact of COVID-19 on the incidence of rectal cancer in Kazakhstan: results of component analysis

Abstract

Relevance: Every year, 732,210 new cases of RC are registered globally, with an incidence of 7.6 per 100,000. The COVID-19 pandemic has affected the screening, case detection, and referral of patients with an asymptomatic cancer diagnosis.
The aim was to assess the trends in rectal cancer incidence in the entire population of Kazakhstan before and during the COVID 
pandemics.
Methods: The data obtained from the Ministry of Healthcare of the Republic of Kazakhstan concerning RC (Form no. 7) was retrospectively studied by descriptive and analytical epidemiology methods. The component method was used to analyze RC incidence dynamics based on the number of cases from 2010  to 2020.
Results: From 2010 to 2020, the risk of getting RC went down. An increase in incidence in 2010-2020 (+24.8%) was lower than in the preCOVID period of 2010-2019 (+37.2%). We found a sharp decrease in RC incidence from 2019 to 2020. The overall decrease was 
0.89‰⁰⁰ due to changes in the age structure of the population (∑ΔA =+0.13‰⁰⁰ ), the risk of getting RC (∑ΔR =−1.02‰⁰⁰ ), and the combined impact of age structure and the risk of getting RC (∑ΔAR =−0.002‰⁰⁰ ). According to the component analysis, 1,662 patients with RC were expected in 2020; instead, only 1,471 cases were registered. Such a decline in cases was mainly due to a reduced risk of getting RC.
Conclusion: The analysis of RC incidence trends in Kazakhstan shows a negative impact of COVID-19 on cancer care indicators and 
effectiveness. All oncological examinations were strengthened with the resumption of work after COVID restrictions. However, the number of screening visits remains lower than in previous years. Untimely diagnosis can increase the number of cases of late-stage CRC and an overall loss of years of life due to the lack of proper treatment. However, these forecasts can be mitigated by proper follow-up.