Table 1.

Baseline Characteristics of 320 Included Patients at ATA High Risk of Recurrence

	Result	n = 320
Age, y; median (range)	49.3 (6.8–82.4)
Sex, female	57.5%	184
Surgery at MSK	63.8%	204
Median follow-up, y (range)	7 (0.13–17)
Histology
Papillary	67.8%	217
Classical variant	32.8%	105
Tall cell variant	16%	51
Follicular variant	6.25%	20
Diffuse sclerosing variant	4.1%	13
Microcarcinoma	2.2%	7
Other	6.6%	21
Poorly differentiated	20.9%	67
Hurthle cell carcinoma	7.2%	23
Follicular carcinoma	4.1%	13
Median tumor size, cm (range)	2.7 (0.3–14.5)
Multicentricity	41.0%	131
Neck dissection performed	57.8%	185
Median number of lymph nodes resected (range)	9 (0–116)
Median number of positive lymph nodes (range)	6 (0–99)
N0	27.5%	88
N1a	27.5%	88
N1b	35%	112
Nx	10%	32
Presence of extranodal extension	36.0%	115
Tumor capsule
Unencapsulated	42.5%	136
Partially encapsulated	30.3%	97
Completely encapsulated	27.0%	86
Capsular invasion
None	64.5%	205
Focal	9.7%	31
Extensive	25.6%	82
Blood vessel invasion
None	27.5%	88
Focal	16.3%	52
Extensive	56.3%	180
Minor extrathyroidal extension	61%	195
Gross extrathyroidal extension	32.5%	104
Completeness of resection
R0	59.1%	189
R1	23.1%	74
R2	7.8%	25
AJCC (8th Edition)
I	59%	185
II	25%	79
III	6.3%	20
IV	9%	29
RAI therapy	98.4%	315
Median cumulative activity, mCi (range)	150 (0–1085)
External beam radiation therapy	20.9%	67

Abbreviation: MSK, Memorial Sloan-Kettering Cancer Center.