Table 4.
Different staging systems for SEER cause-specific survival (CSS) of SEER patients with salivary gland cancer
| Staging system | Patients no.a | 5-year CSS survival (%) | Log-rank χ2 (P value) |
Multivariate analysisb | ||
|---|---|---|---|---|---|---|
| HR (95% CI) | C-index | AIC | ||||
| N classification | 755.366 | 0.830 | 11,304.72 | |||
| N0 | 3052 | 88.6 | (< 0.001) | Reference | ||
| N1 | 456 | 66.0 | 1.866 (1.500–2.322) | |||
| N2 | 725 | 40.2 | 2.643 (2.197–3.179) | |||
| N3 | 29 | 43.3 | 4.381 (2.685–7.149) | |||
| R classification | 722.815 | 0.832 | 11,287.32 | |||
| R0 | 3052 | 88.6 | (< 0.001) | Reference | ||
| R1: 0–0.17 | 430 | 57.2 | 1.703 (1.363–2.127) | |||
| R2: 0.17–0.56 | 384 | 53.1 | 2.215 (1.789–2.742) | |||
| R3: > 0.56 | 396 | 39.7 | 3.348 (2.738–4.095) | |||
| TNM staging | 964.290 | 0.823 | 10,583.18 | |||
| I | 1069 | 96.6 | (< 0.001) | Reference | ||
| II | 753 | 93.2 | 1.788 (1.163–2.749) | |||
| III | 908 | 79.1 | 4.601 (3.188–6.640) | |||
| IVA | 990 | 52.5 | 8.457 (5.868–12.189) | |||
| IVB | 131 | 42.3 | 12.999 (8.477–19.934) | |||
| IVC | 93 | 17.6 | 26.937 (17.476–41.518) | |||
| TRM stagingc | 1000.667 | 0.828 | 10,551.61 | |||
| I | 1069 | 96.6 | (< 0.001) | |||
| II | 753 | 93.2 | 1.784 (1.161–2.743) | |||
| III | 890 | 77.1 | 4.428 (3.066–6.395) | |||
| IVA | 725 | 61.1 | 7.037 (4.859–10.191) | |||
| IVB | 414 | 40.6 | 12.397 (8.519–18.041) | |||
| IVC | 93 | 17.6 | 26.557 (17.246–40.895) | |||
| TNM + R staging | 0.830 | 10,536.22 | ||||
aFor N classification and R classification, a total of 4262 patients with the number of lymph nodes examined were analyzed. For TNM staging, TRM staging, TNM + R staging, a total of 3944 patients were enrolled for sufficient TNM staging information
bN classification and R classification were adjusted for primary site, histologic type, histologic grade, site-directed surgery, radiotherapy, the number of lymph nodes examined, T classification, M classification and age of the SEER patients (variables identified in Supplement Table 2). TNM staging, TRM staging and TNM + R staging (TNM staging and R classification as two variables enrolled in the Cox regression together) were adjusted for primary site, histologic type, histological grade, site directed surgery, radiation, the number of lymph nodes examined and age of the SEER patients (variables identified in Supplement Table 3)
cTRM staging system was defined as I: T1-R0-M0; II: T2-R0-M0; III: T3-R0-M0, T1-R1-M0, T2-R1-M0, T3-R1-M0; IVA: T4a-R0-M0, T4a-R1-M0, T1-R2-M0, T2-R2-M0, T3-R2-M0, T4a-R2-M0; IVB: T4b-Any R-M0, Any T-R3-M0; IVC: any T-Any R-M