Table 2.
Comparison of predictors of tumor aggressiveness
| Parameter | m-MTC (n = 89) | b-MTC (n = 45) | p value |
|---|---|---|---|
| pN1 status | 43 (48.3%) | 5 (11.1%) | 0.0001 |
| Extrathyroid tumor extension | 27 (30.3%) | 1 (2.2%) | <0.0001 |
| RET mutation | 12 (13.4%) | 2 (4.4%) | 0.13 |
| C cell hyperplasia | 6 (6.7%) | 0 | 0.09 |
| Multifocal lesions | 11 (12.3%) | 1 (2.2%) | 0.06 |
| Associated MEN-2 | 2 (2.2%) | 0 | 0.55 |
| Presence of >1 of the above parameters | 61 (68.5%) | 8 (17.8%) | <0.0001 |
| Detectable postoperative serum CT | 42.2% | 20% | 0.04 |
Abbreviations: pN1 status: neck lymph node involvement, MEN: multiple endocrine neoplasia, m-MTC: medullary thyroid cancer with “malignant” US appearance; b-MTC: medullary thyroid cancer with “benign or indeterminate” US appearance.