Trends in colorectal cancer incidence according to an increase in the number of colonoscopy cases in Korea

Table 2 The incidence of preinvasive colorectal cancer by age and gender between 2004 and 2020, n (%)

	2004	2005	2006	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020
Number of patients	165	186	325	598	959	1462	2078	3045	3434	3531	3635	4428	5422	5476	6017	5886	5422
Age category (yr)
Male	96	125	202	380	601	968	1376	1979	2255	2320	2344	2862	3454	3481	3879	3726	3368
< 50	13 (13.5)	22 (17.6)	43 (21.3)	64 (16.8)	90 (15.0)	164 (16.9)	195 (14.2)	269 (13.6)	286 (12.7)	257 (11.1)	292 (12.5)	294 (10.3)	391 (11.3)	348 (10.0)	407 (10.5)	374 (10.0)	327 (9.7)
50-75	79 (82.3)	97 (77.6)	151 (74.8)	299 (78.7)	477 (79.4)	752 (77.7)	1104 (80.2)	1584 (80.0)	1808 (80.2)	1863 (80.3)	1829 (78.0)	2249 (78.6)	2694 (78.0)	2742 (78.8)	2988 (77.0)	2888 (77.5)	2593 (77.0)
≥ 76	4 (4.2)	6 (4.8)	8 (4.0)	17 (4.5)	34 (5.7)	52 (5.4)	77 (5.6)	126 (6.4)	161 (7.1)	200 (8.6)	223 (9.5)	319 (11.1)	369 (10.7)	391 (11.2)	484 (12.5)	464 (12.5)	448 (13.3)
Female	69	61	123	218	358	494	702	1066	1179	1211	1291	1566	1968	1995	2138	2160	2054
< 50	18 (26.1)	14 (23.0)	31 (25.2)	37 (17.0)	69 (19.3)	101 (20.4)	123 (17.5)	192 (18.0)	155 (13.1)	173 (14.3)	181 (14.0)	220 (14.0)	195 (9.9)	236 (11.8)	223 (10.4)	250 (11.6)	236 (11.5)
50-75	45 (65.2)	46 (75.4)	83 (67.5)	164 (75.2)	271 (75.7)	367 (74.3)	527 (75.1)	790 (74.1)	919 (77.9)	917 (75.7)	982 (76.1)	1167 (74.5)	1503 (76.4)	1466 (73.5)	1569 (73.4)	1538 (71.2)	1452 (70.7)
≥ 76	6 (8.7)	1 (1.6)	9 (7.3)	17 (7.8)	18 (5.0)	26 (5.3)	52 (7.4)	84 (7.9)	105 (8.9)	121 (10.0)	128 (9.9)	179 (11.4)	270 (13.7)	293 (14.7)	346 (16.2)	372 (17.2)	366 (17.8)