Interacting trends of colorectal cancer incidence: the combined effects of screening and birth cohort

• Published in: International journal of epidemiology Vol. 53; no. 5
• Main Authors: Kuo, Chih-Lin, Jhuang, Jing-Rong, Su, Shih-Yung, Chiang, Chun-Ju, Yang, Ya-Wen, Lin, Li-Ju, Hsieh, Pei-Chun, Hsu, Tsui-Hsia, Lee, Wen-Chung
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 14-08-2024
• Subjects: Adult; Aged; Aged, 80 and over; Birth Cohort; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - epidemiology; Early Detection of Cancer - statistics & numerical data; Female; Humans; Incidence; Male; Mass Screening; Middle Aged; Sex Distribution; Taiwan - epidemiology; Taiwan; screening programme; incidence; age-period-cohort model; cohort effect; Colorectal cancer
• ISSN: 0300-5771; 1464-3685; 1464-3685
• DOI: 10.1093/ije/dyae123

Abstract
Background
Colorectal cancer remains a major global public health challenge. Its incidence is shaped by a complex interplay of screening programmes and age, period and cohort factors.
Methods
We introduce a novel Age-Period-Cohort-Screening (APCS) model to analyse trends in colorectal cancer incidence in Taiwan from 2000 to 2019.
Results
In 2010, the incidence of colorectal cancer in Taiwan increased by 19.2% (95% CI: 13.5%, 25.3%) for men and 15.6% (95% CI: 9.2%, 22.4%) for women. This was followed by annual declines of 3.4% (95% CI: 2.8%, 4.1%) and 3.1% (95% CI: 2.4%, 3.9%), respectively. By 2015 for men and 2014 for women, the age-standardized incidence had fallen below the levels projected in a no-screening scenario. By 2019, the incidence had further declined by 12.4% (95% CI: 11.8%, 13.1%) for men and 11.6% (95% CI: 10.7%, 12.6%) for women, compared with the no-screening scenario. Cohort effects have shown a persistent rise from 1920 to 1980: incidence increased 5.8-fold for men and 3.1-fold for women. The trend began to plateau after 1980, with a noticeable decline in women.
Conclusion
Through its screening programme, Taiwan has successfully reduced colorectal cancer incidence by 10% as of 2019. Furthermore, the incidence due to cohort effects has plateaued and even begun to decline. However, continued monitoring remains crucial. The advanced APCS model could serve as a robust analytical tool for other researchers and policy makers evaluating the impacts of cancer screening programmes on incidence trends.