Right Then, Wrong Now: Early-Onset Colorectal Cancer in Korea

Right Then, Wrong Now: Early-Onset Colorectal Cancer in KoreaThe rising incidence of early-onset colorectal cancer (EOCRC), which is defined as a diagnosis of colorectal cancer (CRC) before the age of 50, has been a hot issue in the oncology field.Generally, this is explained by the starting age of cancer screening in most countries being 50, which limits access to screening of younger adults, and the transition of lifestyle and metabolic risk factors such as obesity.There is the notion in the media and academic communities that the incidence and the increase in EOCRC are the highest in Korea.This notion is based on two articles.The first paper by Sung et al. [1] was published in 2019 and compared the incidence of EOCRC in 4 Asian countries/regions, including Korea.The abstract presented the average annual percent change (AAPC) between 1999 and 2014, and Korean patients showed the highest AAPC of 6% for male rectal cancer [1].The second paper by Patel et al. published in 2022 [2] referred to an article by Siegel et al. [3] in the figure; the incidence (12.9/100,000) as well as the AAPC (4.2%) between 2008 and 2012 was the highest in South Korea among 42 countries [2].The data used for both articles were Korea Central Cancer Registry (KCCR) data, which are of very high quality.Notably, the study periods were limited to 1999 to 2014 (Sung et al. [1]) and 2008 -2012 (Patel et al. [2] (Patel et al. [2]) when the incidence of CRC sharply increased [4].Since 2011, CRC in most age groups among both men and women has started to decrease [4,5].Fig. 1 shows the incidence of colon, rectal, and colorectal cancer among population aged 20-49 years from the KCCR between 1999 and 2019.The incidence of CRC significantly increased until 2011 among men and 2012 among women and then significantly decreased among men between 2011 and 2016.Although there were fluctuations for both men and women, the trends were not statistically significant.Similar trends were observed for colon and rectal cancers, respectively.Even in the most recent estimates from the