Table 1.
Main characteristics of eligible studies.
| Study, Year | Location | Study Design † | Tumor Stage | Tumor Location | Age (SD) | Harvested Number of LN (SD) | mLNR Criteria | Number of Patients | ||
|---|---|---|---|---|---|---|---|---|---|---|
| LNM | High mLNR | Low mLNR | ||||||||
| Dedavid, 2013 [8] | Brazil | R/SI | Stage III | Colorectum | 62.4 (7.3) | 19.3 (2.0) | 0.15 | 70 | 32 | 38 |
| Elsamany, 2014 [9] | Egypt | R/LC | Stage I–III | Colorectum | ND | ND | 0.2 | 84 | 47 | 37 |
| Greenberg, 2011 [10] | Israel | R/SI | Stage III | Colorectum | ND | 20.3 (8.3) | 0.13 | 65 | 35 | 30 |
| Hong, 2011 [11] | Korea | R/SI | Stage III | Colon | ND | 50.7 (21.7) | 0.1638 | 130 | 33 | 97 |
| Leonard, 2016 [12] | Belgium | R/SI | All stage (III, n = 145) | Rectum | 65.6 (12.8) | 12.8 (8.8) | 0.2 | 357 | ND | ND |
| Lu, 2013 [13] | Taiwan | R/SI | Stage III | Colorectum | 64.9 (12.8) | 19.8 (9.5) | 0.17 | 612 | 322 | 290 |
| Park, 2015 [14] | Korea | R/SI | Stage III | Rectum | 54.0 (10.3) | 18.2 (8.5) | 0.25 | 724 | ND | ND |
| Ramos-Esquivel, 2014 [15] | Costa Rica | R/SI | All stage (III, n = 29) | Colon | 62.8 (17.7) | 12.0 (2.7) | 0.25 | 39 | 23 | 16 |
| Rao, 2016 [16] | UK | R/SI | Duke C | Colorectum | 72.0 (10.9) | 20.1 (8.6) | 0.125 | 147 | 81 | 66 |
| Schiffmann, 2013 [17] | Germany | R/SI | Stage III | Colon | 67.7 (9.5) | 23.2 (9.3) | 0.2 | 142 | 54 | 88 |
| Sugimoto, 2013 [18] | Japan | R/SI | Stage III * | Colon | 62.5 (10.0) | 36.6 (17.3) | 0.3 | 311 | 55 | 256 |
| Sugimoto, 2015 [19] | Japan | R/MIDJ | Stage III | Colon | 60.2 (12.2) | 41.3 (20.2) | 0.18 | 4172 | 1428 | 2744 |
| Vaccaro, 2009 [20] | Argentina | R/SI | Stage III | Colon | 67.4 (12.6) | 20.0 (0.3) | 0.25 | 362 | 92 | 270 |
| Zhang, 2018 [7] | USA | R/SEER | Stage III | Colon | 68.1 (13.5) | 14.2 (9.6) | 0.25 | 83,059 | 48,013 | 35,046 |
† The study design is described as follows: R, retrospective; SI, single-institutional study; L, local cancer registry; MIDJ, multi-institutional database in Japan; SEER, surveillance, epidemiology, and end results cancer registry. SD, standard deviation; LN, lymph node; ND, No description; mLNR, metastatic lymph node ratio; LNM, lymph node metastasis.* because there was no information for patients with distant metastasis, the presence of stage IV cannot be excluded.