Table 1.
Patient and tumor characteristics in the training and validation cohorts.
| Training cohort, no. (%) | Internal validation cohort, no. (%) | p-value | External validation cohort, no. (%) | p-value* | |
|---|---|---|---|---|---|
| FMUUH, n = 1240 | FMUUH, n = 306 | Mayo clinic, n = 111 | |||
| Age, mean years (SD) | 61.5 (11.2) | 60.4 (11.9) | 0.147 | 68.3 (15.8) | <0.001 |
| Tumor size, mean mm (SD) | 51.1 (24.2) | 52.4 (25.5) | 0.397 | 67.0 (37.3) | <0.001 |
| Examined LNs, mean No (SD) | 36.9 (13.6) | 36.9 (14.6) | 0.999 | 25.2 (15.6) | <0.001 |
| Sex | 0.127 | <0.001 | |||
| Female | 304 (24.5) | 88 (28.8) | 48 (43.2) | ||
| Male | 936 (75.5) | 218 (71.2) | 63 (56.8) | ||
| Tumor location | 0.801 | 0.011 | |||
| Lower | 474 (38.2) | 120 (39.2) | 42 (37.8) | ||
| Middle | 278 (22.4) | 61 (19.9) | 36 (32.4) | ||
| Upper | 316 (25.5) | 79 (25.8) | 28 (25.2) | ||
| Mix | 172 (13.9) | 46 (15.0) | 5 (4.5) | ||
| Differentiation | 0.910 | <0.001 | |||
| Well | 56 (4.5) | 14 (4.6) | 0 (0.0) | ||
| Moderate | 446 (36.0) | 106 (34.6) | 11 (9.9) | ||
| Poor | 738 (59.5) | 186 (60.8) | 100 (90.1) | ||
| Lymphovascular invasion† | 0.493 | NA | |||
| Absent | 804 (64.8) | 192 (62.7) | 0 (0.0) | ||
| Present | 436 (35.2) | 114 (37.3) | 0 (0.0) | ||
| Unknown | NA | NA | 111 (100.0) | ||
| Adjuvant chemotherapy | 0.537 | <0.001 | |||
| Absent | 288 (23.2) | 66 (21.6) | 71 (64.0) | ||
| Present | 952 (76.8) | 240 (78.4) | 40 (36.0) | ||
| pT stage | 0.659 | 0.003 | |||
| T1 | 24 (1.9) | 8 (2.6) | 2 (1.8) | ||
| T2 | 101 (8.1) | 29 (9.5) | 11 (9.9) | ||
| T3 | 572 (46.1) | 144 (47.1) | 64 (57.7) | ||
| T4a | 515 (41.5) | 121 (39.5) | 27 (24.3) | ||
| T4b | 28 (2.3) | 4 (1.3) | 7 (6.3) | ||
| pN stage | 0.113 | 0.028 | |||
| N0 | 195 (15.7) | 43 (14.1) | 30 (27.0) | ||
| N1 | 233 (18.8) | 49 (16.0) | 23 (20.7) | ||
| N2 | 285 (23.0) | 92 (30.1) | 20 (18.0) | ||
| N3a | 322 (26.0) | 79 (25.8) | 24 (21.6) | ||
| N3b | 205 (16.5) | 43 (14.1) | 14 (12.6) | ||
| pTNM stage | 0.493 | 0.031 | |||
| II | 804 (64.8) | 192 (62.7) | 49 (44.1) | ||
| III | 436 (35.2) | 114 (37.3) | 62 (55.9) |
Continuous data represented as mean ± SD and categorical data as n (%).
*
Compared with the training cohort.
†
Unavailable for the external validation cohort. FMUUH indicates Fujian Medical University Union Hospital; LN, lymph node; NA, not applicable.