Cholecystectomy and the risk of alimentary tract cancers: A systematic review

Table 12 Descriptive characteristics of studies on the association between cholecystectomy and rectal cancer

Ref.	Period of study	Study design	No. of cases	No. of controls	Exposure ascertainment	Outcome ascertainment	Follow-up (yr)	Effect estimate	Adjustments	Quality of publication
Chiong et al[70], 2012	1950-2012	Meta-Analysis	14226/460262	NA	Mixed sources	Mixed sources	Variable	OR = 1.14 (0.92-1.41)	Age, gender	54
Zeng et al[62], 1993	1965-1986	Case-Control	1/264	18/2188	Hospital records	Hospital records	≥ 2.5	OR = 0.46 (0.06-3.45)		26
Kune et al[65], 1988	1980-1981	Case-Control	29/715	57/727	Hospital records	Self-reporting and hospital records		RR = 1.22 (0.7-2.0)		36
Friedman et al[63], 1987	1971-1984	Case-Control	43/1921	773/27687	Medicare database	Cancer registry	≥ 2	OR = 0.9 (0.6-1.2)	Age, gender, geographical area, calendar year	47
Weiss et al[53], 1982	1976-1977	Case-Control	49	687	Cancer registry	Self-reporting	≥ 1	RR = 1.0 (0.4-2.4)	Age	40
Shao et al[56], 2005	1987-2002	Cohort	83/55960	574668	National database	National database		IRR = 1.00 (0.85-1.17)	Age, gender	54
1Schernhammer et al[59], 2003	1982-1998	Cohort	32/6669	78515	National database of nurses	Self-report and National death registry	16	RR = 1.58 (1.05-2.36)	Age, smoking, BMI, lifestyle factors, comorbidities	57
2Johansen et al[64], 1996	1977-1989	Cohort	119/42098	NA	Hospital register	Cancer registry	1-16	RR = 1.07 (0.9-1.3)	Age, gender, calendar year	43
Linos et al[57], 1981	1950-1969	Cohort	17/168134/1681		Hospital database	Hospital records and self reporting		1RR = 0.5 (0.1-1.3)3RR = 2.3 (0.9-4.8)		34

¹Women only;

²Excluding rectal cancer;

³Men only. NA: Not available; BMI: Body mass index.