Table 1.

General information of all the included studies

Author, year	Type of study	Location	Study period	Groups	No. of cases	Age (years)a	Genderb	Tumor locationc	Pathological typesd	TNM stagee	Quality
Liu et al. 2018	RCT	China	2012/01–2016/01	Single-port	31	58.8 ± 13.7	25/6	11/20	8/21/2	13/14/4	4*
[25]				Triple-port	31	56.3 ± 11.9	22/9	12/17	8/21/2	14/12/5
Shi et al. 2018	RCT	China	2017/02–2017/10	Single-port	80	61.77 ± 10.07	34/46	28/52	8/65/7	62/14/4	4*
[27]				Triple-port	96	60.04 ± 9.15	51/45	39/57	10/81/5	77/9/10
Ye et al. 2019	RCT	China	2015/07–2017/01	Single-port	74	62.67 ± 9.16	43/31	24/50	10/59/5	59/15/0	5*
[13]				Triple-port	82	61.83 ± 8.26	59/23	29/53	14/61/7	64/18/0
Han et al. 2017	Cohort study	Korea	2006/01–2015/06	Single-port	203	62.9(33–84)	132/71	79/124	46/113/8	120/33/14	8**
[20]				Triple-port	168	64.1(40–86)	105/63	73/95	49/86/19	89/33/23
Hao et al. 2017	Cohort study	China	2015/03–2015/12	Single-port	208	59.2 ± 5.3	110/98	78/130	80/118/10	154/24/31	7**
[21]				Triple-port	103	59.7 ± 5.1	61/42	41/62	42/56./5	67/16/20
Li et al. 2013	Cohort study	China	2011/02–2013/01	Single-port	87	63.86 ± 12.10	65/22	34/53	39/48/0	31/38/18	7**
[24]				Triple-port	75	66.20 ± 8.72	52/23	31/44	42/33/0	30/29/16
Mu et al. 2015	Cohort study	China	2014/11–2015/05	Single-port	47	56.67 ± 11.62	25/22	18/29	2/45/0	27/9/2	9**
[23]				Triple-port	47	60.77 ± 11.04	14/33	20/30	5/42/0	26/5/1
Rao et al. 2019	Cohort study	China	2017/08–2018/03	Single-port	153	56.1 ± 8.5	67/86	—	54/87/12	—	7**
[26]				Triple-port	102	54.4 ± 7.4	43/59	—	41/56/5	—
Song et al. 2017	Cohort study	Korea	2011/12–2016/08	Single-port	26	64.8 ± 9.7	15/11	8/18	8/17/1	17/9/0	9**
[18]				Triple-port	26	65.0 ± 9.4	15/11	13/13	7/19/0	20/5/1
Wang et al. 2017	Cohort study	China	2015/01–2015/12	Single-port	73	57.12 ± 6.43	31/42	—	16/34/23	27/21/3	9**
[14]				Triple-port	98	61.32 ± 7.54	53/45	—	13/52/33	34/30/7
Wang 2018	Cohort study	China	2016/01–2017/08	Single-port	153	61.52 ± 9.70	82/71	57/96	26/115/12	115/14/24	7**
[19]				Triple-port	113	62.27 ± 10.08	69/44	47/66	25/81/7	72/10/31
Xu et al. 2018	Cohort study	China	2017/09–2017/11	Single-port	60	61.4 ± 10.8	33/27	27/33	10/47/3	35/14/11	6**
[22]				Triple-port	60	63.5 ± 9.6	31/29	27/33	8/48/4	34/16/10
Zhu et al. 2015	Cohort study	China	2014/08–2014/10	Single-port	33	62(25–79)	11/22	14/19	5/26/2	23/8/2	8**
[28]				Triple-port	49	59(31–81)	19/30	20/29	11/35/3	34/11/4

Abbreviation: RCT, randomized controlled trial; TNM, tumor node metastasis.

^aValues are presented as mean ± standard deviations or median (interquartile range); ^bMale/Female; ^cRight/Left; ^dSquamous carcinoma/Adenocarcinoma/Others; ^estage I/stage II/stage III.

^*Assessed using the Jadad scale; ^**Assessed using NOS.