Impact of primary tumour location on colorectal liver metastases: A systematic review

Table 1 Summary of characteristics of included studies

Ref.	Year	Country of study	Number of patients included	Median follow up (mo)	Primary tumour location (n)			Median age (yr)
					L	R	Rectum	L	R	Rectum
Zhou et al[27]	2017	China	295	24	89	94	112	57	59	61
Zhang et al[30]	2017	China	194	12	144	50		60	55.5
Makowiec et al[37]	2018	Germany	221		158	63		64	65
Chafai et al[29]	2005	Australia	398	26.8	277	71
Rougier et al[15]	1995	France	537		197	117	223
Wang et al[38]	2018	China	420	26	334	86		57	58.5
Gu et al[28]	2018	China	102		51	51		63	61.5
Gasser et al[12]	2019	Austria	259	38.1	200	59		64	66
de Haas et al[24]	2010	France	750	39	413	154	200
Marques et al[11]	2018	Brazil	151	42	124	27		57	61
Russolillo et al[21]	2019	Italy	686	81	364	322		63	66
Umeda et al[34]	2013	Japan	100	36	40	23	37
Zheng et al[31]	2018	China	318		233	85
Mavros et al[39]	2013	United States	97	26.4	44	24	27
Viganò et al[20]	2014	Italy	749	51.4	63	87	48
Connor et al[40]	2016	Canada	63	31.5	27	10	21
Eefsen et al[41]	2015	Denmark	254	44.6	125	51	78
Schirripa et al[33]	2015	Italy	309	45.6	138	87	82
Loosen et al[42]	2018	Germany	125		102	23
Amikura et al[32]	2018	Japan	342	52.7	236	106
Yamashita et al[26]	2018	United States	725	27/41	487	238		56	58
Dulundu et al[19]	2017	Turkey	108		40	24	44	58.5	63.2	63.8
Creasy et al[9]	2016	United States	907	132	578	329		62.4	65.4
Sasaki et al[23]	2016	United States	426	28.9	297	129
Palkovics et al[43]	2018	Hungary	319		114	72	133
Dupré et al[8]	2018	United Kingdom	364	41.8	290	74		65.1	68.6
Heise et al[22]	2017	Germany	160	21	113	47
Shigematsu et al[44]	2018	Japan	396	36.4	155	93	148
Rhu et al[45]	2017	South Korea	410	30.5	289	121		58.41	59.56
Lionti et al[25]	2018	Italy	63	40	22	23	18
Wang et al[46]	2017	China	159		130	29
Norén et al[18]	2015	Sweden	3125		1109	1092	924
Berardi et al[47]	2018	Belgium	62	24	11	4	47
Cremolini et al[16]	2018	Italy	159	42.1	40	64	52
McCracken et al[48]	2019	United States	612		388	226		55	62
McVey et al[49]	2019	United States	732	26.8	397	336		59	62
Imai et al[35]	2019	Japan	163	38.8	127	36
Koch et al[36]	2018	Germany	30		24	5	1
Liao et al[10]	2018	Taiwan	1442	58.	888	554		62.4	64.6
Adam et al[50]	2011	France	186	37	106	35	41
Wang et al[17]	2019	China	1508		557	593	358

De Haas et al[24]: Transverse colon grouped with left rather than right sided primaries; Yamashita et al[26]: Data for study and validation sets respectively, midgut vs hindgut not left vs right. L: Left; R: Right.