Proton pump inhibitors and colorectal cancer: A systematic review

Table 3 Summary of epidemiological studies assessing the exposure of proton pump inhibitors in colorectal cancer patients

Author, year, place	Accrual year	Study design	Grouping	Number	Exposed	Unexposed	OR (95%CI)	Adjustments	Risk of CRC
Robertson et al[28] 2007 (Denmark)	1989-2005	CC	CRC patients	5589	295	5294	1.11 (0.97-1.27)	Age, sex, place of residence (matched), H2 blocker use, aspirin/NSAIDs, statins/diabetics use, history of cholecystectomy, alcohol	No increased risk
			Non-CRC control	55890	2692	53198
Van Soest et al[29] 2008 (Netherland)	1996-2005	CC	CRC patients	594	53	541	0.85 (0.63-1.16)	Age, sex, calendar time, follow-up duration (matched), comorbidities	No increased risk
			Non-CRC control	7790	725	7065
Yang et al[30] 2007 (United Kingdom)	1987-2002	CC	CRC patients	4432	769	3663	1.2 (0.8-1.9)	Age, sex, alcohol, smoking, BMI, H2 blocker use, aspirin/NSAID use, calendar time, follow-up, general practice site (matched), HRT use, history of colonoscopy/flexible sigmoidoscopy	No increased risk
			Non-CRC control	44292	5133	39159
Lee et al[31] 2020 (San Francisco, United States)	1996-2016	CC	CRC patients	18595	1406	17189	NR	Age, sex, ethnicity, general practitioner site, enrolment duration, smoking, alcoholism, BMI, history of colonoscopy, family history of CRC, Crohn’s disease, Ulcerative colitis	No increased risk
			Non-CRC control	160122	10813	149309
Chubak et al[32] 2009 (Washington State, United States)	2000-2003	CC	CRC patients	641	16	482	1.7 (0.8-4.0)	Age, sex, calendar time, follow-up duration (matched)	No increased risk
			Non-CRC control	641	9	471
Kuiper et al[33] 2020(Netherlands)	2007-2014	CC	CRC patients	1978	1041	937	1.08 (0.97-1.21)	Age, sex, calendar time, H2 blocker use, aspirin, NSAIDs, statins, antidiabetics use	No increased risk
			Non-CRC control	7912	4161	3751

BMI: Body mass index; CC: Case-control; PPI: Proton pump inhibitors; CRC: Colorectal cancer; CI: Confidence interval; H2: Histamine-2 receptor; HRT: Hormone replacement therapy; NSAIDs: Nonsteroidal anti-inflammatory drugs; NR: Not reported; OR: Odds ratio.