Table 3.
Clinical features of 200 cases of well-differentiated thyroid cancer∗ with second primary malignancy (SPM) as breast cancer or other cancers.
| Clinical characteristic | All patients | Breast cancer | Other cancers | p value |
|---|---|---|---|---|
| Patient number | 200 | 45 (22.5%) | 155 (77.5%) | |
| Gender (female) | 139 (69.5%) | 45 (100.0%) | 94 (60.6%) | 0.0001 |
| Age at diagnosis (year) | 51.6 ± 13.2 | 47.1 ± 10.2 | 52.9 ± 13.7 | 0.0099 |
| Mean tumor size (cm) | 2.4 ± 1.5 | 2.2 ± 1.2 | 2.4 ± 1.6 | 0.5271 |
| Thyroid operative method | 0.4470 | |||
| Total thyroidectomy | 155 (77.5%) | 33 (73.3%) | 122 (78.7%) | |
| Less than total thyroidectomy | 45 (22.5%) | 12 (26.7%) | 33 (21.3%) | |
| TNM stage | 0.0518 | |||
| Stage I | 101 (50.5%) | 26 (57.8%) | 75 (48.4%) | |
| Stage II | 27 (13.5%) | 9 (20.0%) | 18 (11.6%) | |
| Stage III | 25 (12.5%) | 6 (13.3%) | 19 (12.3%) | |
| Stage IV | 47 (23.5%) | 4 (8.9%) | 43 (27.7%) | |
| Nonremission | 48 (24.0%) | 5 (11.1%) | 43 (27.7%) | 0.0215 |
| Follow-up period (year) | 9.2 ± 6.6 | 9.6 ± 6.0 | 9.1 ± 6.7 | 0.6467 |
| Postoperative 131I accumulative dose (mCi) | 166.3 ± 258.2 | 95.1 ± 102.1 | 187.0 ± 284.8 | 0.0357 |
| 131I dose ≥ 30 mCi | 167 (83.5%) | 40 (88.9%) | 127 (81.9%) | 0.2686 |
| Radiation therapy | 24 (12.0%) | 1 (2.2%) | 23 (14.8%) | 0.0219 |
| Time to metachronous SPM diagnosis (year) [range] | 7.7 ± 5.7 [0.5–22.2] | 7.5 ± 5.2 [0.6–21.2] | 7.8 ± 5.8 [0.5–22.2] | 0.8190 |
| Multifocality | 50 (25.0%) | 10 (22.2%) | 40 (25.8%) | 0.6250 |
| Mortality due to thyroid cancer | 18 (9.0%) | 1 (2.2%) | 17 (11.0%) | 0.0711 |
| Overall mortality | 74 (37.0%) | 6 (13.3%) | 68 (43.9%) | 0.0002 |
∗Papillary, follicular, and Hürthle's cell thyroid cancer.