Increased risk of colorectal neoplasia in inflammatory bowel disease patients with post-inflammatory polyps: A systematic review and meta-analysis

Table 1 Characteristics of the included studies, n (%)

Ref.	Magazine	Design	Study type	Surveillance period	Sources of patients	Race	Age at IBD diagnosis(years)	IBD type	IBD with/without PIPs	Male gender (%)	Outcome
de Jong et al[31], 2020	Inflamm Bowel Dis	Retrospective	Cohort	January 2012 -December 2017	The Netherlands	Caucasian	28.5 (± 11.8)/28.9 (± 12.4)1	Mixed IBD	154/365	284 (48.2)	Neoplasia
Gu et al[35], 2019	Journal of Digestive Diseases	Retrospective	Cohort	June 1986 -July 2018	China	Asian	29.5-54.0	UC	57/189	120 (48.8)	Neoplasia
Mahmoud et al[32], 2019	Gastroenterology	Retrospective	Cohort	January 1997 - January 2017	America, The Netherlands	Caucasian	NA	Mixed IBD	462/1120	835 (52.8)	Neoplasia
Ünal et al[34], 2019	Turkish Journal of Gastroenterology	Retrospective	Cohort	1993-2016	Turkey	Asian	40.5 ± 15	UC	100/701	475 (59.3)	Neoplasia
Ma et al[36], 2017	Laboratory Investigation	Retrospective	Cohort	2006-2016	NA	NA	NA	Mixed IBD	102/220	NA	Neoplasia
Jegadeesan et al[37], 2016	Inflamm Bowel Dis	Retrospective	Case–control	1998-2011	America	Caucasian	37 (30.5–50.5)/38 (28.2–23.4)2	UC	138/329	251 (53.7)	Neoplasia
Lutgens et al[38], 2015	Clinical Gastroenterology and Hepatology	Retrospective	Case–control	1990-2011	Belgium, The Netherlands	Caucasian	NA	Mixed IBD	259/271	276 (52.1)	Cancer
Badamas et al[40], 2014	Gastroenterology	Retrospective	Case–control	2007-2013	NA	NA	30.3 (± 15.6)/29.3 (± 13.2)	Mixed IBD	90/93	93 (50.8)	Neoplasia
Freire et al[39], 2014	Scand J Gastroenterol	Prospective	Cross-sectional	April 2011 -December 2013	Portugal	Caucasian	33.3 ± 11.6	UC	33/43	30 (39.5)	Neoplasia
Baars et al[41], 2011	Am J Gastroenterol	Retrospective	Case – control	January 1990 – July 2006	The Netherlands	Caucasian	NA	Mixed IBD	147/366	266 (47.1)	Cancer
Velayos et al[29], 2006	Gastroenterology	Retrospective	Case – control	January 1976 -December 2002	America	Caucasian	25 (6–76)/27 (8–66)	UC	184/192	266 (70.7)	Cancer
Rutter et al[14], 2004	Gut	Retrospective	Case – control	January 1988 - January 2002	Britain	Caucasian	33 (6–65)	UC	95/109	117 (57)	Neoplasia

¹Data expressed as mean ± SD.

²Data expressed as median (range).

IBD: Inflammatory bowel disease; PIPs: Post-inflammatory polyps; UC: Ulcerative colitis; NA: Not available.