Table 2. Univariate and multivariate survival analyses of DTCs according to various clinicopathological variables.
| Variable | No. Case | Overall Survival | Cancer-specific Survival | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Univariate analysis (Unadjusted analysis) | Multivariate analysis (Adjusted analysis) | Univariate analysis (Unadjusted analysis) | Multivariate analysis (Adjusted analysis) | ||||||||
| Log rank χ2 test | Pvalue | HR4 | 95%CI | P value | Log rank χ2 test | Pvalue | HR5 | 95%CI | P value | ||
| Race | |||||||||||
| Black | 2651 | 17.864 | 0.001 | 1.0 | Reference | 17.488 | 0.001 | 1.0 | Reference | ||
| White | 40844 | 0.7 | 00.6–0.9 | 0.0–01 | 1.1 | 0.7–1.7 | 0.797 | ||||
| Other1 | 6897 | 0.6 | 0.5–0.8 | 0.001 | 1.1 | 0.7–1.8 | 0.773 | ||||
| Unknown | 669 | 0.2 | 0.1–0.7 | 0.007 | – | – | – | ||||
| Sex | |||||||||||
| Male | 11156 | 264.902 | 0.001 | 1.0 | Reference | 120.124 | 0.001 | 1.0 | Reference | ||
| Female | 39905 | 0.6 | 0.6–0.7 | 0.001 | 0.7 | 0.6–0.9 | 0.002 | ||||
| Age | |||||||||||
| ≤20 | 1382 | 3188.966 | 0.001 | 1.0 | Reference | 1168.245 | 0.001 | 1.0 | Reference | ||
| 21–30 | 5626 | 1.4 | 0.5–4.1 | 0.534 | 1.1 | 0.1–10.1 | 0.915 | ||||
| 31–40 | 10207 | 1.9 | 0.7–5.1 | 0.232 | 1.4 | 0.2–11.1 | 0.748 | ||||
| 41–50 | 12624 | 3.7 | 1.4–10.1 | 0.009 | 2.4 | 0.3–17.6 | 0.389 | ||||
| 51–60 | 11237 | 6.7 | 2.5–18.0 | 0.001 | 4.4 | 0.6–32.2 | 0.140 | ||||
| 61–70 | 6492 | 12.4 | 4.6–33.4 | 0.001 | 7.5 | 1.0–54.1 | 0.047 | ||||
| ≥71 | 3493 | 33.4 | 12.5–89.7 | 0.001 | 13.5 | 1.9–97.8 | 0.010 | ||||
| Grade2 | |||||||||||
| I/II | 9382 | 2082.423 | 0.001 | 1.0 | Reference | 4545.199 | 0.001 | 1.0 | Reference | ||
| III/IV | 512 | 5.0 | 4.0–6.2 | 0.001 | 9.4 | 6.8–13.0 | 0.001 | ||||
| Unknown | 41167 | 1.0 | 0.9–1.2 | 0.783 | 1.1 | 0.8–1.5 | 0.562 | ||||
| Histology | |||||||||||
| Papillary | 48086 | 47.526 | 0.001 | 1.0 | Reference | 46.145 | 0.001 | 1.0 | Reference | ||
| Follicular | 2975 | 1.1 | 0.9–1.3 | 0.219 | 1.2 | 0.9–1.5 | 0.231 | ||||
| Summary Stage | |||||||||||
| Regional/Localized | 49442 | 1.0 | Reference | 4425.317 | 0.001 | 1.0 | Reference | ||||
| Distant | 1482 | 3.6 | 3.1–4.1 | 0.001 | 7.6 | 6.2–9.4 | 0.001 | ||||
| Unknown | 137 | 1.3 | 0.6–2.8 | 0.508 | 4.8 | 2.0–11.4 | 0.001 | ||||
| AJCC 7th Stage | |||||||||||
| I/II | 40317 | 1206.620 | 0.001 | 1.0 | Reference | 1378.796 | 0.001 | 1.0 | Reference | ||
| III/IV | 8765 | 1.8 | 1.6–2.0 | 0.001 | 5.5 | 4.0–7.5 | 0.001 | ||||
| Unclassified | 1979 | 1.9 | 1.5–2.3 | 0.001 | 4.8 | 3.2–7.2 | 0.001 | ||||
| Radiation3 | |||||||||||
| No | 26914 | 2.761 | 0.251 | 1.0 | Reference | 48.602 | 0.001 | 1.0 | Reference | ||
| Yes | 23330 | 1.3 | 1.1–1.4 | 0.001 | 0.9 | 0.7–1.1 | 0.232 | ||||
| Known | 817 | 1.3 | 0.9–2.0 | 0.194 | 0.8 | 0.4–1.8 | 0.651 | ||||
1Including American Indian/AK Native, Asian/Pacific Islander.
2Grade I, well differentiated; Grade II, moderately differentiated; Grade III, poorly differentiated; Grade IV, undifferentiated; anaplastic.
3Including radioisotopes, radioactive implants, beam radiation, and combination of beam with implants or isotopes.
4HR is presented as risk of overall mortality when specific groups are compared with reference groups.
5HR is presented as risk of cancer-specific mortality when specific groups are compared with reference groups.
Abbreviations: DTC, differentiated thyroid cancer; HR, hazard ratio; CI, confidence interval.