Table 4.
Association between HT and Thyroid Cancer According to Primary Cytology Classification Using TBSRTC
| TBSRTC Categorya | HT (n = 2,651) | Non-HT (n = 7,200) | P Value | RR | 95% CI |
|---|---|---|---|---|---|
| Nondiagnostic | 0.08 | 2.34 | 0.877–6.292 | ||
| Total no. | 87 | 458 | |||
| Thyroid cancer, no. (%)b | 6 (6.8) | 14 (3.0) | |||
| No malignant cells | <0.01 | 2.10 | 1.450–3.063 | ||
| Total no. | 1602 | 4707 | |||
| Thyroid cancer, no. (%)b | 48 (2.9) | 68 (1.4) | |||
| Indeterminate | 0.05 | 1.19 | 0.999–1.436 | ||
| Total no. | 696 | 1572 | |||
| Thyroid cancer, no. (%)b | 300 (43.1) | 609 (38.7) | |||
| AUS, FLUS | 0.02 | 1.48 | 1.045–2.095 | ||
| Total no. | 250 | 537 | |||
| Thyroid cancer, no. (%)b | 69 (27.6) | 110 (20.4) | |||
| SFN | 0.50 | 1.11 | 0.808–1.538 | ||
| Total no. | 235 | 589 | |||
| Thyroid cancer, no. (%)b | 79 (33.6) | 184 (31.2) | |||
| SUSP | 0.71 | 1.07 | 0.745–1.541 | ||
| Total no. | 211 | 446 | |||
| Thyroid cancer, no. (%)b | 152 (72.0) | 315 (70.3) | |||
| Positive for malignancy | 0.39 | 2.32 | 0.258–20.907 | ||
| Total no. | 265 | 460 | |||
| Thyroid cancer, no. (%)b | 264 (99.6) | 456 (99.1) |
Abbreviations: AUS, atypia of undetermined significance; FLUS, follicular lesion of undetermined significance; SFN, suspicious for follicular or Hürthle cell neoplasm; SUSP, suspicious for malignancy.
a
Patients with more than one evaluable nodule were classified according to the highest TBSRTC score of the multiple nodules.
b
Thyroid cancer was defined using histopathology as well as TBSRTC 6 cytology in cases where surgery did not occur.