| Study (year) | Node negative | Node positive |
| Goss et al. (1999) [83] | 68 | 47 |
| Stranzl et al. (1999) [120] | 91 | 71 |
| Guinee et al. (1993) [163] | 78 | 45 |
| Borgen et al. (1992) [14] | 87 | 30 |
| Giordano et al. (2004) [31] | 76 | 54 |
| Teo et al. (2012) [22] | 70 | <54 |
| Kiluk et al. (2011) [195] | 87.5 | 68.5 |
| Salehi et al. (2011) [25] | 68 | 45 |