Table 1.
Clinical features of 2,864 cases of well-differentiated∗ thyroid cancer with or without second primary malignancies (SPMs) between 1984 and 2013.
| Clinical characteristic | Total | With SPM | Without SPM | p |
|---|---|---|---|---|
| Patient number | 2,864 | 200 (7.0%) | 2,664 (93.0%) | |
| Gender (female) | 2,256 (78.8%) | 139 (69.5%) | 2,117 (79.5%) | 0.0009 |
| Age at diagnosis (year) | 44.0 ± 14.4 | 51.6 ± 13.2 | 43.5 ± 14.4 | 0.0001 |
| Mean tumor size (cm) | 2.4 ± 1.7 | 2.4 ± 1.5 | 2.4 ± 1.7 | 0.6793 |
| Thyroid operative method | 0.0035 | |||
| Total thyroidectomy | 2425 (84.7%) | 155 (77.5%) | 2270 (85.2%) | |
| Less than total thyroidectomy | 439 (15.3%) | 45 (22.5%) | 394 (14.8%) | |
| TNM stage | 0.0001 | |||
| Stage I | 1950 (68.1%) | 101 (50.5%) | 1849 (69.4%) | |
| Stage II | 287 (10.0%) | 27 (13.5%) | 260 (9.8%) | |
| Stage III | 229 (8.0%) | 25 (12.5%) | 204 (7.6%) | |
| Stage IV | 398 (13.9%) | 47 (23.5%) | 351 (13.2%) | |
| Nonremission | 466 (16.3%) | 48 (24.0%) | 418 (15.7%) | 0.0021 |
| Follow-up period (year) | 9.5 ± 6.7 | 9.2 ± 6.6 | 9.5 ± 6.7 | 0.5575 |
| Postoperative 131I accumulative dose (mCi) | 130.6 ± 193.6 | 166.3 ± 258.2 | 127.9 ± 187.6 | 0.0068 |
| Radiation therapy | 143 (5.0%) | 24 (12.0%) | 119 (4.5%) | 0.0001 |
| Multifocality | 662 (23.1%) | 50 (25.0%) | 612 (23.0%) | 0.5119 |
| Mortality due to thyroid cancer | 163 (5.7%) | 18 (9.0%) | 145 (5.4%) | 0.0362 |
| Overall mortality | 301 (10.5%) | 74 (37.0%) | 227 (8.5%) | 0.0001 |
∗Well-differentiated: including papillary, follicular, and Hürthle's cell thyroid cancer.