Table 1. Cohort Characteristics of 291 Patients With Low-Risk Papillary Thyroid Cancer With Active Surveillance for More Than 6 Months.
| Variable | Value | Tumor Diameter Increase ≥3 mm (n = 11) |
Tumor Volume Increase ≥50% (n = 36) |
|---|---|---|---|
| Age at diagnosis, y | |||
| Median (range) | 51 (20-86) | 42 (31-57) | 46 (20-86) |
| Mean (SD) | 52 (15) | 41.8 (9.6) | 46.4 (14.1) |
| Sex, No. (%) | |||
| Female | 219 (75.3) | 10 (90.9) | 29 (80.6) |
| Male | 72 (24.7) | 1 (9.1) | 7 (19.4) |
| Cytology, No. (%) | |||
| Bethesda category VI | 243 (83.5) | 9 (81.8) | 26 (72.2) |
| Bethesda category V | 48 (16.5) | 2 (18.2) | 10 (27.8) |
| Tumor size, No. (%) | |||
| ≤1.0 cm | 232 (79.7) | 9 (81.8) | 31 (86.1) |
| 1.1-1.5 cm | 59 (20.3) | 2 (18.2) | 5 (13.9) |
| History of autoimmune thyroid disease, No. (%) | |||
| None | 250 (85.9) | 7 (63.6) | 28 (77.8) |
| Autoimmune thyroiditis | 38 (13.1) | 4 (36.4) | 8 (22.2) |
| Graves disease | 3 (1.0) | 0 | 0 |
| Family history of thyroid cancer, No. (%) | |||
| Yes | 40 (13.7) | 0 | 1 (2.8) |
| No | 251 (86.3) | 11 (100) | 35 (97.2) |
| Personal history of another cancer, No. (%) | |||
| Yes | 52 (17.9) | 1 (9.1) | 4 (11.1) |
| No | 239 (82.1) | 10 (90.9) | 32 (88.9) |
| Radiation exposure, No. (%) | |||
| Yes | 2 (0.7) | 0 | 0 |
| No | 289 (99.3) | 11 (100) | 36 (100) |
| Appropriateness for active surveillance, risk category, No. (%) | |||
| Ideal | 13 (4.5) | 0 | 1 (2.8) |
| Appropriate | 273 (93.8) | 9 (81.8) | 33 (91.7) |
| Inappropriate | 5 (1.7) | 2 (18.2) | 2 (5.6) |
| Duration of active surveillance, mo | |||
| Median (range) | 25 (6-166) | 38 (12-54) | 27 (20-68) |
| Mean (SD) | 29 (19) | 34.1 (15.5) | 29.7 (16.1) |
| Increase in tumor diameter ≥3 mm during observation, No. (%) | |||
| Yes | 11 (3.8) | 11 (100) | 11 (30.6) |
| No | 280 (96.2) | 0 | 25 (69.4) |
| Increase in tumor volume >50% during observation, No. (%) | |||
| Yes | 36 (12.4) | 11 (100) | 36 (100) |
| No | 255 (87.6) | 0 | 0 |
| Metastasis detected during observation, No. (%) | |||
| Yes | 0 | 0 | 0 |
| No | 291 (100) | 11 (100) | 36 (100) |
| Status at final follow-up, No. (%) | |||
| Continue on active surveillance | 279 (95.9) | 6 (54.5) | 31 (86.1) |
| Surgery for increase in tumor size | 5 (1.7) | 5 (45.5) | 5 (13.9) |
| Surgery despite stable tumor size | 5 (1.7) | 0 | 0 |
| Lost to follow-up | 2 (0.7) | 0 | 0 |
Bethesda system for reporting thyroid cytopathology: category VI (malignant), category V (suspicious for malignancy).