Table 3.
Multivariate analysis of survival
| Variable | HR | 95% CI | P value |
|---|---|---|---|
| Gender | |||
| Female | 1.00 | Reference | |
| Male | 1.77 | 1.52 - 2.06 | < 0.001 |
| Married status | |||
| Married | 1.00 | Reference | |
| Widowed | 1.72 | 1.45 - 2.05 | < 0.001 |
| Separated or divorced | 1.04 | 0.79 - 1.30 | 0.778 |
| Single or unmarried | 1.15 | 0.90 - 1.46 | 0.875 |
| Ethnicity | |||
| White | 1.00 | Reference | |
| African-American | 0.73 | 0.50 - 1.07 | 0.110 |
| Other | 1.20 | 0.97 - 1.47 | 0.091 |
| Histology subgroup | |||
| C-PTC | 1.00 | Reference | |
| V-PTC | 0.56 | 0.44 - 0.71 | < 0.001 |
| FTC | 1.39 | 1.05 - 1.83 | 0.021 |
| MTC | 2.87 | 2.10 - 3.91 | < 0.001 |
| ATC | 41.57 | 34.27 - 50.44 | < 0.001 |
| Grade | |||
| Well differentiated | 1.00 | Reference | |
| Moderately differentiated | 2.77 | 1.42 - 5.38 | 0.003 |
| Poorly differentiated | 25.30 | 15.07 - 42.47 | < 0.001 |
| Undifferentiated | 120.98 | 75.56 - 193.68 | < 0.001 |
| Tumor size(cm) | |||
| < 1.0 | 1.00 | Reference | |
| 1.1 - 2.0 | 2.70 | 1.71 - 4.26 | < 0.001 |
| 2.1 - 4.0 | 8.79 | 5.89 - 13.13 | < 0.001 |
| > 4.0 | 25.86 | 17.53 - 38.13 | < 0.001 |
| Surgery | |||
| No surgery | 1.00 | Reference | |
| Lobectomy | 0.07 | 0.05 - 0.09 | < 0.001 |
| Total thyroidectomy | 0.08 | 0.07 - 0.10 | < 0.001 |
| Radiotherapy | |||
| Yes | 1.00 | Reference | |
| No | 0.67 | 0.58 - 0.78 | < 0.001 |
| Lymph nodes resection | |||
| Yes | 1.00 | Reference | |
| No | 0.90 | 0.77 - 1.05 | 0.166 |
| AJCC 6th TNM stage | |||
| I | 1.00 | Reference | |
| II | 2.73 | 1.29 - 5.76 | < 0.001 |
| III | 5.32 | 2.96 - 9.56 | < 0.001 |
| IV | 100.87 | 61.38 - 165.77 | < 0.001 |
Abbreviations: HR: Hazard ratio, CI: Confident Index, AJCC: American Joint Committee on Cancer, TNM: tumor-node-metastasis, C-PTC: Classic Papillary Thyroid Cancer, VPTC: Variant Papillary Thyroid Cancer, FTC: Follicular thyroid cancer, MTC: Medullary thyroid cancer, ATC: Anaplastic thyroid cancer.