Meta-Analysis
Copyright ©The Author(s) 2017.
World J Gastrointest Oncol. Dec 15, 2017; 9(12): 475-491
Published online Dec 15, 2017. doi: 10.4251/wjgo.v9.i12.475
Table 1 Characteristics of the included studies
Ref.Country of originStudy typeStudy periodFemale(number, L/O)Mean age (yr, L/O)Intervention (L-CME) right/transverse/left location of the tumorControl (O-CME) right/transverse/left location of the tumorAdjuvant chemotherapy
Kim et al[23], 2016South KoreaCase control, unicentre, prospective database2008-201362/4469/67116/0/099/0/0L-CME = 68 pts (58.62%), O-CME = 78 pts (78.78%), recommended to all stage II and III
Storli et al[22], 2016NorwayProspective non RT, unicentre2007-201422/1373/230/33/00/23/0L-CME = 8 (61.5%), O-CME = 5 (62.5%), all stage III below 75 yr
Huang et al[24], 2015ChinaCase control, unicentre2012-201320/2156/5553/0/049/0/0NR
Yamamoto et al[20], 2014JapanRCT, multicentre2004-2009248/21564/64144/0/389156/0/368NR, recommended for all stage III
Munkedal et al[25], 2014DenmarkProspective nonRT, unicentre2008-201130/3869.1/72.930/0/5341/0/38NR
Bae et al[27], 2014South KoreaCase control, unicentre2006-200840/3864/6573/12/076/9/0All stage III and II with poor prognosis
Han et al[26], 2014ChinaCase control, unicentre2003-201094/6767/65177/0/0147/0/0NR, recommended for high risk stage II and stage III
Zhao et al[28], 2014ChinaCase control, multicentre2000-200953/4461.3/64.589/30/065/36/0NR, recommended for high risk stage II and stage III
Cong et al[29], 2014ChinaCase control, unicentre2008-201153/4561.5/62.396/0/082/0/0NR
Storli et al[30], 2013NorwayProspective nonRT, unicentre2007-201049/6071.9/73.150/18/60 2 pts - multiple35/44/42All stage III below 75 yr
Gouvas et al[31], 2012GreeceProspective nonRT, multicentric2006-201019/1762.1/66.37/9/339/9/23NR
Sun et al[32], 2012ChinaCase control, unicentre2000-200858/4560.1/61.949/7/9143/9/74NR, according to stage
L-CME: Laparoscopic complete mesocolic excision; O-CME: Open complete mesocolic excision; RT: Randomized control trial; Non RT: Non randomized control trial; L/O: Laparoscopy/open groups; NR: Not reported.
Table 2 Quality assessment of included non-randomized controlled trials
Quality evaluation criteriaKim et al[23], 2016Storli et al[22], 2016Storli et al[30], 2016Huang et al[24], 2015Munkedal et al[25], 2014Bae et al[27], 2014Han et al[26], 2014Zhao et al[28], 2014Cong et al[29], 2014Gouvas et al[31], 2012Sun et al[32], 2012
Clear stated aim22222222222
Inclusion of consecutive patients22222222122
Prospective data collection22202000020
Endpoints appropriate to the study aim22222222222
Unbiased assessment of study end-point22222221121
Appropriate follow-up period22212222222
Loss to follow-up less than 5%12212221121
Prospective calculation of the study size00000000000
Adequate group control22222222022
Contemporary groups22222222222
Baseline equivalence22222222222
Adequate statistical analysis22222222221
Total2122221822202018152217
0: Non-reported; 1: Reported but inadequate; 2: Reported and adequate.
Table 3 Results of meta-analysis comparing laparoscopic with open complete mesocolic excision for colon cancer
Outcome or subgroupsNo. of StudiesParticipantsStatistical method (95%CI)Effect estimate (95%CI)P valueHeterogeneity P, I2 (%)
Survival and recurrences
Overall survival61777OR (M-H, random)1.32 (0.83, 2.10)0.240.002, 70
Three-year41010OR (M-H, random)2.02 (1.31, 3.12)0.0010.24, 28
Five-year3767OR (M-H, random)0.77 (0.44, 1.37)0.380.07, 63
Disease free survival4856OR (M-H, random)1.15 (0.70, 1.87)0.580.09, 54
Three-year3686OR (M-H, random)1.45 (1.00, 2.10)0.050.89, 0
Five-year1170OR (M-H, random)0.50 (0.24, 1.05)0.07NA
Local recurrences51233OR (M-H, fixed)0.67 (0.38, 1.17)0.160.60, 0
One-year2466OR (M-H, fixed)0.52 (0.20, 1.35)0.180.30, 7
Five-year3767OR (M-H, fixed)0.77 (0.38, 1.54)0.460.52, 0
Distant recurrences41018OR (M-H, random)0.98 (0.61, 1.58)0.940.17, 40
Three-year1251OR (M-H, random)1.28 (0.54, 3.03)0.58NA
Five-year3767OR (M-H, random)0.90 (0.48, 1.69)0.750.10, 57
Port site metastasis2494OR (M-H, fixed)1.52 (0.20, 11.42)0.690.55, 0
Quality of the resected specimen
Lymphnodes retrieved102647MD (IV, random)-1.06 (-3.65, 1.53)0.42< 0.001, 92
RCTs11057MD (IV, random)1.00 (-0.34, 2.34)0.14NA
NRCTs91590MD (IV, random)-1.32 (-4.42, 1.78)0.40< 0.001, 92
Lymphnodes retrieved102647MD (IV, random)-1.06 (-3.65, 1.53)0.42< 0.001, 92
< 100 patients4478MD (IV, random)-3.18 (-8.69, 2.33)0.26< 0.001, 85
> 100 patients62169MD (IV, random)0.29 (-1.64, 2.21)0.77< 0.001, 83
Lymphnodes retrieved102647MD (IV, random)-1.06 (-3.65, 1.53)0.42< 0.001, 92
Europe4559MD (IV, random)-3.33 (-8.31, 1.64)0.19< 0.001, 90
Asia62088MD (IV, random)0.56 (-1.33, 2.46)0.56< 0.001, 77
Tumor to arterial high tie (mm)2252MD (IV, random)14.26 (-4.30, 32.82)0.13< 0.001, 92
Resected mesocolon surface (cm2)2252MD (IV, fixed)11.75 (9.50, 13.99)< 0.0010.55, 0
Complete mesocolic plane excision190OR (M-H, fixed)0.77 (0.20, 2.96)0.71NA
Operative data
Duration of surgery72266MD (IV, random)26.26 (5.06, 47.46)0.02< 0.001, 94
Incision length (cm)21159MD (IV, random)-14.01 (-14.35, -13.66)< 0.0010.89, 0
Blood loss (mL)51868MD (IV, random)-52.11 (-78.57, -25.65)< 0.001< 0.001, 89
Transfusion requirement21272OR (M-H, random)0.45 (0.27, 0.75)0.0020.54, 0
Intraoperative morbidity11057OR (M-H, fixed)2.12 (0.95, 4.72)0.07NA
Postoperative course
Time to first flatus (d)41771MD (IV, random)-0.90 (-1.46, -0.34)0.002< 0.001, 97
Time to liquid diet (d)51031MD (IV, random)-1.84 (-2.93, -0.74)0.001< 0.001, 98
Short-term morbidity and mortality
Thirty-day overall morbidity72144OR (M-H, fixed)0.57 (0.46, 0.71)< 0.0010.76, 0
RCTs11057OR (M-H, fixed)0.66 (0.49, 0.89)0.006NA
NRCTs61087OR (M-H, fixed)0.49 (0.36, 0.68)< 0.0010.89, 0
Wound complications82322OR (M-H, fixed)0.43 (0.30, 0.61)< 0.0010.80, 0
Postoperative bleeding41662OR (M-H, fixed)1.20 (0.46, 3.12)0.710.75, 0
Pneumonia5867OR (M-H, random)0.61 (0.20, 1.84)0.380.21, 32
Anastomotic leakage82471OR (M-H, fixed)0.82 (0.54, 1.25)0.360.77, 0
Need for reoperation21113OR (M-H, fixed)0.59 (0.28, 1.23)0.160.79, 0
Thirty-day mortality62237OR (M-H, fixed)0.42 (0.16, 1.12)0.070.98, 0
Hospital stay (d)92573MD (IV, random)-4.07 (-5.87, -2.28)< 0.001< 0.001, 91
M-H: Mantel-haenszel analysis method; IV: Inverse variance analysis method; RCT: Randomized control trial; NRCs: Non-randomized control trials; MD: Mean difference; OR: Odds ratio; NA: Not applicable.