Table 2.
Comparison of characteristics of patients with unifocal versus multifocal PTC patients.
| Unifocal PTC n = 218 (%) | Multifocal PTC n = 152 (%) | p value | |
|---|---|---|---|
| Age at diagnosis [median; (IQR)] | 47 years old (38–56) | 46 years old (36.5–58) | NS |
| Gender | NS | ||
| Male | 46 (21.1%) | 42 (27.6%) | |
| Female | 172 (78.9%) | 110 (72.4%) | |
| PTC histological classification | NS | ||
| Classical variant | 146 (66.9%) | 102 (67.2%) | |
| Follicular variant | 15 (6.9%) | 9 (5.9%) | |
| Oxyphilic variant | 20 (9.2%) | 11 (7.2%) | |
| Aggressive Variants | 37 (17.0%) | 30 (19.7%) | |
| Primary tumor size [median; (IQR)] | 15 mm (11–20.25) | 13 mm (10–20) | NS |
| Primary tumor size | NS | ||
| ⩽10 mm (microPTC) | 45 (20.6%) | 44 (28.9%) | |
| >10 mm | 172 (79.4%) | 108 (71.1%) | |
| Vascular invasion | 55 (57.3%) | 68 (68%) | NS |
| Extrathyroidal extension | 115 (57.2%) | 85 (58.6%) | NS |
| Cervical lymph node involvement | 88 (43.8%) | 72 (51.4%) | NS |
| Cervical lymph node involvement | NS | ||
| Central, N1a | 57 (28.4%) | 42 (30%) | |
| Lateral, N1b | 31 (15.4%) | 30 (21.4%) | |
| Distant metastases | 6 (2.8%) | 2 (1.3%) | NS |
| TNM stage (8th edition) | NS | ||
| Stage I | 184 (84.4%) | 130 (85.5) | |
| Stage II | 29 (13.3%) | 21 (13.8%) | |
| Stage III | 0 | 1 (0.7%) | |
| Stage IV | 5 (2.3%) | 0 | |
| T-categories (TNM, 8th edition) | 0.04 | ||
| T1a | 47 (21.6%) | 43 (28.3%) | |
| T1b | 113 (51.8%) | 68 (44.7%) | |
| T2 | 47 (21.6%) | 22 (14.5%) | |
| T3a | 6 (2.8%) | 11 (7.2%) | |
| T3b | 2 (0.9%) | 4 (2.6%) | |
| T4a | 3 (1.4%) | 4 (2.6%) | |
| T4b | 0 | 0 | |
| Postoperative RAI therapy | NS | ||
| Yes | 208 (95.4%) | 139 (91.4%) | |
| No | 10 (4.6%) | 13 (8.6%) | |
| Administered activity of RAI [median; (IQR)] | 100 mCi (100–150) | 100 mCi (70–150) | NS |
| Second treatment | 20 (9.2%) | 22 (14.5%) | NS |
| Median follow-up period [median; (IQR)] | 70.5 months (40–94) | 65 months (44.5–87) | NS |
| BRAF mutation (FNAC) | 132 (60.8%) | 100 (66.2%) | NS |
| TERT promoter mutation (FNAC) | 12 (5.5%) | 6 (3.9%) | NS |
| Initial risk stratification system scores | NS | ||
| Low | 74 (33.9%) | 41 (27%) | |
| Intermediate | 135 (61.9%) | 100 (65.8%) | |
| High | 9 (4.1%) | 11 (7.2%) | |
| Disease status at latest follow-up (ongoing risk stratification) | NS | ||
| ER | 190 (87.2%) | 120 (78.9%) | |
| IR | 16 (7.3%) | 21 (13.8%) | |
| BPD | 5 (2.3%) | 6 (3.9%) | |
| SPD | 5 (2.3%) | 4 (2.6%) | |
| TCD | 2 (0.9%) | 1 (0.7%) | |
| Final oncological outcome | NS | ||
| ER | 190 (87.2%) | 120 (79.8%) | |
| IR | 16 (7.3%) | 21 (13.8%) | |
| BPD + SPD + TCD | 12 (5.5%) | 11 (7.2%) |
BPD, biochemically persistent disease; ER, excellent response; FNAC, fine needle aspiration cytology; IQR, interquartile range; IR, indeterminate response; NS, not significant; PTC, papillary thyroid cancer; RAI, radioactive immunotherapy; SPD, structurally persistent disease; TCD, death due to thyroid cancer.