Clinical characteristics of incidental or unsuspected gallbladder cancers diagnosed during or after cholecystectomy: A systematic review and meta-analysis

Table 1 Summary of the publications included

Ref.	Year	Study period	Country	Study setting	No. of IGC	Revisional surgery	T stage					Study quality
							Tis	T1	T2	T3	T4
Z'graggen et al[8]	1998	1992-1995	Swiss	Swiss registry	37	6	0	9	16	8	4	4
Sarli et al[9]	2000	1986-1995	Italy	Single center	20	6	1	6	4	9	0	5
Suzuki et al[10]	2000	1992-1998	Japan	Multicenter	41	11	1	25	14	1	0	5
Wakai et al[11]	2002	1992-1999	Japan	Single center	28	10	0	15	13	0	0	5
Toyonaga et al[12]	2003	1982-2000	Japan	Multicenter	73	21	0	23	43	7	0	6
de Aretxabala et al[13]	2004	Unavailable	Chile	Single center	64	26	2	5	39	18	0	4
Yildirim et al[14]	2005	1990-2003	Turkey	Single center	65	28	0	13	34	18	0	4
Lam et al[15]	2005	1998-2002	Hong Kong	Multicenter	63	4	1	4	23	26	7	6
Xu et al[16]	2007	1990-2005	China	Single center	23	6	0	11	7	5	0	3
Pawlik et al[17]	2007	1984-2006	United States, Brazil, Italy, Germany	Multicenter	148	109	0	18	85	41	4	5
Shih et al[18]	2007	1995-2004	United States	Single center	535	39						5
Shukla et al[19]	2008	2003-2007	India	Single center	90 (761)	54	0	23	33	20	0	4
Kwon et al[20]	2008	1992-2004	Japan	Single center	38	14	0	20	17	1	0	5
Zhang et al[21]	2009	1999-2007	China	Single center	20	7	4	4	6	4	2	5
Choi et al[22]	2009	2002-2007	Korea	Single center	33	7	2	10	17	4	0	5
Butte et al[23]	2010	2000-2008	Chile	Single center	49	20	0	8	32	9	0	4
Glauser et al[24]	2010	1994-2004	Swiss	Swiss registry	89 (691)	19	2	14	34	14	5	6
Kim et al[25]	2010	1997-2008	Korea	Single center	26	2	1	6	17	2	0	4
de Aretxabala et al[26]	2010	2005-2009	Chile	Single center	23	15	0	3	15	5	0	3
Goetze et al[27]	2010	1997-	German	German registry	6242	231	22	118	300	143	30	6
Fuks et al[28]	2011	1998-2008	France	Multicenter	218	148	0	24	84	81	29	6
Clemente et al[29]	2012	1998-2009	Italy	Single center	443	34	0	5	19	10	0	4
Maker et al[30]	2012	1992-2009	United States	Single center	1626	162	0	12	71	79	0	5
Lendoire et al[31]	2012	1999-2010	Argentina	Single center	404	24	0	1	12	11	0	4
Yi et al[32]	2013	1992-2009	China	Single center	38	10	0	14	4	12	8	6
Xu et al[33]	2013	1993-2011	China	Single center	36	20	0	16	11	9	0	5

¹Number of available data;

²11 patients were Tx (unknown T stage);

³The exact T stages of 10 patients were not described;

⁴ The exact T stages of 16 patients were not described;

⁵Exact T stages were not described. Instead, AJCC TNM stages were shown;

⁶All patients included in this publication received revisional surgery. IGC: Incidental gallbladder cancer.

Table 2 Distribution of T stage in incidental gallbladder cancer in 25 studies[8-17,19-33]

T stage	Range of proportion reported by primary studies	Pooled proportion	95%CI
Tis	0%-20.0%	2.4%	1.5%-3.8%
T1	4.2%-61.0%	23.0%	17.8%-29.1%
T2	13.2%-75.0%	47.0%	42.1%-51.9%
T3	0.0%-69.8%	25.1%	19.5%-31.7%
T4	0.0%-21.1%	4.2%	2.6%-6.5%