Global pattern and trends of colorectal cancer survival: a systematic review of population-based registration data

This review will describe the global patterns and trends of colorectal cancer survival, using data from the population-based studies or cancer registration. We performed a systematic search of China National Knowledge Infrastructure (CNKI), Wanfang Data, PubMed, Web of Science, EMBASE, and SEER and collected all population-based survival studies of colorectal cancer (up to June 2020). Estimates of observed and relative survival rates of colorectal cancer by sex, period, and country were extracted from original studies to describe the temporal patterns and trends from the late 1990s to the early 21st century. Globally, 5-year observed survival rates were higher in Seoul, Republic of Korea (1993-1997; 56.8% and 54.3% for colon and rectum cancers, respectively), Zhejiang province (2005-2010; 52.9% for colon cancer), Tianjin (1991-1999; 52.5% for colon cancer), Shanghai (2002-2006; 50.0% for rectum cancer) of China, and in Japan (1993-1996, 59.6% for colorectal cancer). Five-year relative survival rates of colorectal cancer in the Republic of Korea (2010-2014), Queensland, Australia (2005-2012), and the USA (2005-2009) ranked at relatively higher positions compared to other countries. In general, colorectal cancer survival rates are improving over time worldwide. Sex disparities in survival rates were also observed in the colon, rectum, and colorectal cancers in most countries or regions. The poorest age-specific 5-year relative survival rate was observed in patients > 75 years of age. In conclusion, over the past 3 decades, colorectal cancer survival has gradually improved. Geographic variations, sex differences, and age gradients were also observed globally in colorectal cancer survival. Further studies are therefore warranted to the factors of colorectal cancer.