TABLE 1.
Demographic and tumor characteristics for entire cohort.
| Characteristics | All (%) | Patients with <6 LNs examined (%) | Patients with ≥6 LNs examined (%) | P value |
| Total No. | 1723 | 1353 | 370 | |
| Age, years | <0.001 | |||
| Median (range) | 68 (21–96) | 69 (22–96) | 65 (21–91) | |
| Sex | 0.879 | |||
| Male | 516 (29.9%) | 404 (29.9%) | 112 (30.3%) | |
| Female | 1207 (70.1%) | 949 (70.1%) | 258 (69.7%) | |
| Race | 0.762 | |||
| White | 1338 (77.7%) | 1049 (77.5%) | 289 (78.1%) | |
| Black | 191 (11.1%) | 148 (11.0%) | 43 (11.6%) | |
| Others | 194 (11.2%) | 156 (11.5%) | 38 (10.3%) | |
| Grade | 0.533 | |||
| I + II | 1004 (58.3%) | 779 (57.6%) | 225 (60.8%) | |
| III + IV | 603 (35.0%) | 481 (35.6%) | 122 (33.0%) | |
| Unknown | 116 (6.7%) | 93 (6.8%) | 23 (6.2%) | |
| Stage | <0.001 | |||
| I | 226 (13.1%) | 193 (14.3%) | 33 (8.9%) | |
| II | 443 (25.7%) | 341 (25.2%) | 102 (27.6%) | |
| III | 924 (53.6%) | 758 (56.0%) | 166 (44.9%) | |
| IV | 130 (7.6%) | 61 (4.5%) | 69 (18.6%) | |
| Histological type | 0.763 | |||
| Adenocarcinoma | 1576 (91.5%) | 1239 (91.6%) | 337 (91.1%) | |
| Other* | 147 (8.5%) | 114 (8.4%) | 33 (8.9%) | |
| No. of LNs examined | <0.001 | |||
| Mean | 3.8 | 1.9 | 10.7 |
*Including cystic, mucinous and serous neoplasms, and epithelial neoplasms, etc.