Table 2. Pathological Characteristics of Differentiated Thyroid Cancer Patients According to the Year of Initial Diagnosis.
| Characteristic | Year of initial diagnosis | P value | ||
|---|---|---|---|---|
| 1996–2000 (n=1,672, 21%) | 2001–2005 (n=6,386, 79%) | |||
| Pathology | <0.001 | |||
| PTC | 1,441 (86) | 5,904 (92) | ||
| FTC | 231 (14) | 482 (8) | ||
| Size of primary tumor, cm | <0.001 | |||
| ≤2 | 984 (59) | 5,075 (79) | ||
| 2.1–4.0 | 563 (34) | 1,089 (17) | ||
| >4 | 125 (7) | 222 (3) | ||
| Extra-thyroidal extension | 0.56 | |||
| Microscopic | 769 (46) | 2,938 (46) | ||
| Gross | 59 (4) | 194 (3) | ||
| LN metastasis | <0.001 | |||
| N0/Nx | 884 (53) | 3,956 (62) | ||
| N1a | 567 (34) | 1,786 (28) | ||
| N1b | 221 (13) | 644 (10) | ||
| TNM stage | <0.001 | |||
| Stage I | 1,037 (62) | 3,962 (62) | ||
| Stage II | 71 (4) | 125 (2) | ||
| Stage III | 418 (25) | 1,870 (29) | ||
| Stage IV | 146 (9) | 429 (7) | ||
P value was evaluated by the chi-square test. TNM stage was determined by the 7th American Joint Committee on Cancer TNM staging system.
PTC, papillary thyroid cancer; FTC, follicular thyroid cancer; LN, lymph node; TNM, tumor node metastasis.