Table 3.
Comparison between unilateral multifocal and bilateral multifocal PTC.
| Unilateral multifocal PTC n = 41 (%) | Bilateral multifocal PTC n = 111 (%) | p value | |
|---|---|---|---|
| Age at diagnosis (mean ± DS) | 46 years old ± 14 | 48 years old ± 15 | NS |
| Gender | NS | ||
| Male | 12 (29.3%) | 30 (27%) | |
| Female | 29 (70.7%) | 81 (73%) | |
| PTC histological classification | NS | ||
| Classical variant | 31 (75.6%) | 71 (64%) | |
| Follicular variant | 2 (4.9%) | 7 (6.3%) | |
| Oxyphilic variant | 1 (2.4%) | 10 (9%) | |
| Aggressive Variants | 7 (17.1%) | 23 (20.7%) | |
| Primary tumor size [median; (IQR)] | 11 mm (8–16) | 14 mm (11–21.75) | 0.01 |
| Primary tumor size | 0.02 | ||
| ⩽10 mm (microPTC) | 18 (43.9%) | 26 (23.4%) | |
| >10 mm | 23 (56.1%) | 85 (76.6%) | |
| Vascular invasion | 21 (84%) | 47 (62.7%) | NS |
| Cervical lymph node involvement | 17 (44.7%) | 55 (53.9%) | NS |
| Cervical lymph node involvement | NS | ||
| Central, N1a | 9 (23.7%) | 33 (32.4%) | |
| Lateral, N1b | 8 (21.1%) | 22 (21.6%) | |
| Distant metastases | 0 | 2 (1.8%) | NS |
| TNM stage (8th edition) | NS | ||
| Stage I | 37 (90.2%) | 93 (83.3%) | |
| Stage II | 3 (7.3%) | 18 (16.2%) | |
| Stage III | 1 (2.4%) | 0 | |
| Stage IV | 0 | 0 | |
| T-categories (TNM, 8th edition) | 0.04 | ||
| T1a | 19 (46.3%) | 24 (21.6%) | |
| T1b | 15 (36.6%) | 53 (47.7%) | |
| T2 | 5 (12.2%) | 17 (15.3%) | |
| T3a | 0 | 11 (9.9%) | |
| T3b | 1 (2.4%) | 3 (2.7%) | |
| T4a | 1 (2.4%) | 3 (2.7%) | |
| T4b | 0 | 0 | |
| Postoperative RAI therapy | 35 (85.4%) | 103 (93.6%) | NS |
| Administered activity of RAI [median; (IQR)] | 100 mCi (77.5–150) | 100 mCi (70–150) | NS |
| Second treatment | 5 (12.2%) | 17 (15.3%) | NS |
| Follow-up period (mean ± DS) | 71.5 months ± 35 | 65.5 months ± 30 | NS |
| BRAF mutation (FNAC) | 27 (65.9%) | 73 (66.4%) | NS |
| TERT promoter mutation (FNAC) | 1 (2.4%) | 5 (4.5%) | NS |
| Initial risk stratification system scores | NS | ||
| Low | 13 (31.3%) | 28 (25.2%) | |
| Intermediate | 25 (61%) | 75 (67.6%) | |
| High | 3 (7.3%) | 8 (7.2%) | |
| Disease status at latest follow-up (ongoing risk stratification) | NS | ||
| ER | 34 (82.9%) | 86 (77.5%) | |
| IR | 6 (14.6%) | 15 (13.5%) | |
| BPD | 1 (2.4%) | 5 (4.5%) | |
| SPD | 0 | 4 (3.6%) | |
| TCD | 0 | 1 (0.9%) | |
| Final oncological outcome | NS | ||
| ER | 34 (82.9%) | 86 (77.5%) | |
| IR | 6 (14.6%) | 15 (13.5%) | |
| BPD + SPD + TCD | 1 (2.4%) | 10 (9%) |
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.