Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA.
Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.
JNCI Cancer Spectr. 2024 Jul 1;8(4). doi: 10.1093/jncics/pkae052.
Incidence of early-onset colorectal cancer (CRC) has increased globally in recent decades. We examined early-onset CRC incidence trends worldwide for potential cohort effects, defined as changes associated with time of birth (eg, early-life exposure to carcinogens), and period effects, defined as changes associated with calendar periods (eg, screening programs).
We obtained long-term incidence data for early-onset CRC diagnosed in patients aged 20 to 49 years through the year 2012 for 35 countries in the Cancer Incidence in Five Continents database. We used a smoothing method to help compare cohort and period trends of early-onset CRC and used an age-period-cohort model to estimate cohort and period effects.
Cohort effects had a more dominant role than period effects in the early-onset CRC incidence in Shanghai (China), the United Kingdom, Australia, New Zealand, Canada, the United States, and Osaka (Japan). The smoothed trends show the specific birth cohorts when early-onset CRC began to increase: the 1940s-1950s birth cohorts in the United States; the 1950s-1960s birth cohorts in other Western countries; the 1960s birth cohorts in Osaka; and the 1970s-1980s birth cohorts in Shanghai. Such increases occurred earlier for early-onset cancers of the rectum than of the colon. For the other countries, the results were less clear.
Recent birth cohorts may have been exposed to risk factors different from earlier cohorts, contributing to increased early-onset CRC incidence in several developed countries or regions in the West and Asia. Such increases began in earlier birth cohorts in Western countries than in developed regions of Asia.
近几十年来，全球范围内早发性结直肠癌（CRC）的发病率有所增加。我们研究了全球范围内早发性 CRC 发病率的趋势，以探讨潜在的队列效应，即与出生时间相关的变化（例如，生命早期接触致癌物质），以及时期效应，即与日历时期相关的变化（例如，筛查计划）。
我们通过癌症发病率在五大洲数据库获得了 35 个国家 20 至 49 岁患者早发性 CRC 的长期发病数据，直至 2012 年。我们使用平滑方法来帮助比较早发性 CRC 的队列和时期趋势，并使用年龄-时期-队列模型来估计队列和时期效应。
在上海（中国）、英国、澳大利亚、新西兰、加拿大、美国和大阪（日本），队列效应在早发性 CRC 发病率中比时期效应更具主导作用。平滑趋势显示了早发性 CRC 开始增加的特定出生队列：美国的 1940 年代至 1950 年代出生队列；其他西方国家的 1950 年代至 1960 年代出生队列；大阪的 1960 年代出生队列；以及上海的 1970 年代至 1980 年代出生队列。直肠的早发性癌症比结肠的早发性癌症增加得更早。对于其他国家，结果不太明确。
最近的出生队列可能接触到了与早期队列不同的危险因素，导致几个西方国家和亚洲发达地区的早发性 CRC 发病率增加。西方国家的这些增加开始于更早的出生队列，而亚洲发达地区则较晚。
