Table 3.
Risk factors distributions of three cohorts in low and high risk groups
| Factors | Low risk group (score, 0-4) | High risk group (score, 5-8) | ||||||
|---|---|---|---|---|---|---|---|---|
| Development cohort (N=55) | External validation cohort 1 (N=31) | External validation cohort 2 (N=42) | P1 | Development cohort (N=65) | External validation cohort 1 (N=30) | External validation cohort 2 (N=53) | P2 | |
| N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||
| Age (point, 0 vs. 1) | ||||||||
| ≤46 | 41 (74.5) | 21 (67.7) | 21 (50.0) | 0.040 | 26 (40.0) | 7 (23.3) | 14 (26.4) | 0.156 |
| >46 | 14 (25.5) | 10 (32.3) | 21 (50.0) | 39 (60.0) | 23 (76.7) | 39 (73.6) | ||
| UICC N stage (point, 0 vs. 2) | ||||||||
| N0 | 16 (29.1) | 9 (29.0) | 5 (11.9) | 0.099 | 1 (1.5) | 1 (3.3) | 0 (0.0) | 0.443 |
| N>0 | 39 (70.9) | 22 (71.0) | 37 (88.1) | 64 (98.5) | 29 (96.7) | 53 (100.0) | ||
| HGB (g/L) (point, 0 vs. 2) | ||||||||
| >130*/120▲ | 46 (83.6) | 30 (96.8) | 36 (85.7) | 0.191 | 25 (38.5) | 16 (53.3) | 10 (18.9) | 0.004 |
| ≤130*/120▲ | 9 (16.4) | 1 (3.2) | 6 (14.3) | 40 (61.5) | 14 (46.7) | 43 (81.1) | ||
| BMFI (month) (point, 0 vs. 1) | ||||||||
| >12 | 23 (41.8) | 13 (41.9) | 22 (52.4) | 0.532 | 10 (15.4) | 3 (10.0) | 9 (17.0) | 0.683 |
| ≤12 | 32 (58.2) | 18 (58.1) | 20 (47.6) | 55 (84.6) | 27 (90.0) | 44 (83.0) | ||
| Primary site RT (point, 0 vs. 1) | ||||||||
| Yes | 52 (94.5) | 31 (100.0) | 41 (97.6) | 0.357 | 44 (67.7) | 15 (50.0) | 46 (86.8) | 0.001 |
| No | 3 (5.5) | 0 (0.0) | 1 (2.4) | 21 (32.3) | 15 (50.0) | 7 (13.2) | ||
| First metastasis site RT (point, 0 vs. 1) | ||||||||
| Yes | 33 (60.0) | 18 (58.1) | 30 (71.4) | 0.403 | 11 (16.9) | 1 (3.3) | 22 (41.5) | <0.001 |
| No | 22 (40.0) | 13 (41.9) | 12 (28.6) | 54 (83.1) | 29 (96.7) | 31 (58.5) | ||
Footnote: *for male; ▲for female. P1 is the P value of Χ2 test for the comparison of factors distributions among three cohort in low risk group; P2 is the P value of Χ2 test for the comparison of factors distributions among three cohort in high risk group.
Abbreviations: BMFI: bone metastasis free interval; RT: radiotherapy.