Table 5.
Study Characteristics, No Surgery vs. Surgery
| Author study design country study period | Thyroid cancers included | Sample size | Duration of follow-up | Nonsurgical follow-up | Surgery | Age | Percent female | Tumor size | T classification |
|---|---|---|---|---|---|---|---|---|---|
| Ho et al. (18) Cohort (SEER analysis) United States 1975–2015 |
Papillary thyroid carcinoma T1–4N0M0, ≤10 cm | Total: 56,171 Nonsurgical: 1453 Surgical: 54, 718 |
Nonsurgical: median 51.0 months [CI 48–54] Surgical: Median 61.0 months [CI 61–62] |
Not described | Surgery occurred within one year of diagnosis; otherwise not described | Nonsurgical: mean 55.4 (SD 18.3) Surgical: mean 50.3 (SD 14.5) |
Nonsurgical: 73% Surgical: 80% |
Nonsurgical: mean 21.8 mm (SD 14.8) Surgical: mean 13.4 mm (SD 17.3) |
T1: 56% vs. 75%c T2: 31% vs. 12% T3: 11% vs. 12% T4: 1.9% vs. 1.5% |
| Kuo et al. (23) Cohort (California Cancer Registry and California Office of Statewide Health Planning and Development) United States 2004–2012 |
Differentiated thyroid cancer (93% papillary and 4.2% follicular) with no size restriction; low-risk defined as <4 cm without extrathyroidal extension, nodal involvement, or distant metastasis; localized summary stage and no chemotherapy or radiation administered | Total: 29,978 Nonoperative: 318 (low risk 161) Operative: 29,660 (low risk 10,473) |
Median 50.5 months (range 27.7–77.5) | Not described | Not described | Nonoperative: 61.2 years (SD 19.4) Operative: 49.3 years (SD 15.0) |
Nonoperative: 67% Operative: 78% |
Nonoperative: 2.9 cm (SD 2.1) Operative: 2.0 cm (SD 2.5) |
≤2 cm: 47% vs. 66% 2.1 to 4 cm: 28% vs. 24% >4 cm: 25% vs. 9.9% |
| Lin et al. (30) Retrospective cohort (Kaiser Permanente Northern California) United States 1973–2012 |
Papillary thyroid cancer (no size restriction) untreated within one year of tumor diagnosis, propensity matched with treated papillary thyroid cancer patients | Total: 180 Untreated: 31 Treated: 149 |
Median 5.3 years (IQR 1.7–12.3) for untreated and 8.6 years (IQR 5.9–13.1) for treated | Not described | Not described | Untreated: 57.1 years (SD 20.1) Treated: 55.5 years (SD 17.2 years) |
Untreated: 71% Treated: 72% |
Untreated: 2.6 cm (SD 1.6) Treated: 2.1 cm (SD 1.3) |
TNM stage I: 61% vs. 61% II: 3.2% vs. 8.7% III: 3.2% vs. 3.4% IV: 32.3% vs. 18.1% |
| Megwalu (24) Cohort (SEER analysis) United States 1988–2009 |
Papillary thyroid carcinoma ≤1 cm, 65 years of age or older | Total: 2,323 Nonsurgical: 15 Surgical: 2,308 |
Not reported | Not described | Not described | Nonsurgical: mean 73.3 Surgical: mean 71.4 |
Nonsurgical: 67% Surgical: 80% |
Not reported | All T1 (≤1 cm) |
SEER, Surveillance, Epidemiology, and End Results.