Table 2.
Baseline characteristics and clinical factors that could influence molecular marker tests results and rates of resection.
| All ITNs | Test positive | Test negative | ||||
|---|---|---|---|---|---|---|
| Cohort, % (n) | Resected, % (n) | Cohort, % (n) | Resected, % (n) | Cohort, % (n) | Resected, % (n) | |
| Patient level | ||||||
| Total | 100 (182) | 53 (97) | 25 (45) | 71 (33) | 75 (137) | 47 (64) |
| Age (mean) | 56.9 | 55.7 | 56.4 | 54.9 | 57.0 | 56.1 |
| Male gender | 24 (44) | 45 (20) | 16 (7) | 43 (3) | 27 (37) | 46 (17) |
| Thyroid function | ||||||
| Normal | 80 (146) | 53 (77) | 76 (34) | 73 (25) | 82 (112) | 46 (52) |
| Hypothyroidism | 17 (31) | 58 (18) | 20 (9) | 78 (7) | 16 (22) | 50 (11) |
| Hyperthyroidism | 2 (3) | 33 (1) | 2 (1) | 100 (1) | 1 (2) | −(0) |
| N/A | 1 (2) | 50 (1) | 2 (1) | −(0) | 1 (1) |
100 (1) |
| MNGa | 66 (120) | 48 (58) | 69 (31) | 65 (20) | 65 (89) | 43 (38) |
| Significant bilateral MNGb | 32 (59) | 54 (32) | 27 (12) | 67 (8) | 34 (47) | 51 (24) |
| Nodule level | 100 (190) | 54 (102) | 24 (45) | 73c (33) | 76 (145) | 48c (69) |
| Bethesda category | ||||||
| III (AUS/FLUS) | 55 (104) | 50 (52) | 49 (22) | 73 (16) | 57 (82) | 44 (36) |
| IV (FN/HCN) | 45 (86) | 58 (50) | 51 (23) | 74 (17) | 43 (63) | 52 (33) |
| Size by ultrasound, cm | 2.6 | 2.8d | 2.5 | 2.5 | 2.6 | 2.9d |
| <2 | 39 (75) | 47 (35) | 33 (15) | 73 (11) | 41 (60) | 40 (24) |
| 2–3.9 | 49 (94) | 57 (54) | 58 (26) | 77 (20) | 47 (68) | 50 (34) |
| ≥4 | 11 (21) | 62 (13) | 9 (4) | 50 (2) | 12 (17) | 65 (11) |
Two patients had 1 nodule with mutation and ≥1 nodule without mutation; both are included in the test-positive cohort. Three nodules in this series measured ≤1 cm in largest diameter, and none had surgical follow-up. One had a TSHR mutation, another one had a BRAF-V600E mutation at low allelic frequency (4% and considered test negative), and no molecular alterations were identified in the other one. All other nodules were >1 cm. No association was found between any of the variables evaluated and the test result.
MNG = at least 2 nodules >5 mm in the thyroid gland.
Significant bilateral MNG = at least one nodule >1 cm in the contralateral lobe to the biopsied nodule.
Nodules with a positive test result were more likely to be resected (P = 0.0004).
Larger nodules were more likely resected (P = 0.048, OR 1.26 (1.00–1.58)), but only among test-negative nodules (P = 0.02, OR 1.36 (1.05–1.76)). Other variables were not significantly associated with the resection rates in any of the cohorts.
ITN, indeterminate thyroid nodule; MNG, multinodular goiter; N/A, not available.