Proton pump inhibitors and colorectal cancer: A systematic review

Table 4 Summary of epidemiological studies assessing the effect of proton pump inhibitors exposure on the risk of developing colorectal cancer

Author, year, place	Accrual year	Study design	Grouping	Number of patients	Developed CRC	Did not develop CRC	HR (95%CI)	Adjustments	PPI use and CRC risk
Hwang et al 2017[34] (Korea)	2007-2013	P	PPI users	49520	Total cases (including PPI users and non-PPI users) 5304	NR	NR	Sex, age, smoking, alcohol, BMI, consumption, physical activity, type 2 diabetes, CCI score, aspirin use, metformin use, stain use, socioeconomic status	No association
			Non-PPI users	401764
Babic et al 2020[35] (United States)	1988-2015	P	PPI users	13205	83	13122	0.84 (0.67-1.04)	Age, physical activity, BMI, family history of CRC, alcohol, smoking, history of lower endoscopy, caloric intake, vitamin D, calcium intake, regular aspirin use, folate intake, menopausal hormone therapy use, and red meat	No association
			Non-PPI users	162654	1172	161482
Lei et al 2020[36] (Taiwan)	1999-2011	R	PPI users	45382	172	45210	2.03 (1.56-2.63)	Sex, age, year of index date, diabetes, coronary artery disease, HTN, dyslipidemia, COPD, cirrhosis, CCI, aspirin/NSAID use, statin use, antidiabetic use	Increased risk
			Non-PPI users	45382	93	45289

BMI: Body mass index; CCI: Charlson comorbidity index; COPD: Chronic obstructive pulmonary disease; CRC: Colorectal cancer; CI: Confidence interval; HR: Hazard ratio; HTN: Hypertension; NSAID: Nonsteroidal anti-inflammatory drugs; NR: Not reported; PPI: Proton pump inhibitor; P: Prospective study; R: Retrospective study.