1. 53.3 33.3 100.0 26.7 66.7 20.0 60.0 66.7 46.7 86.7 53.3 86.7 Table 1. Clinicopathological features in 57 TNM stage I pediatric DTC patients Recurrence Age (  13) Male gender Histology (papillary carcinoma) Specific variant Tumor size (>3.0 cm) Extrathyroid extension Multifocality Tumor stage (T3,T4a) Clinical lymphadenopathy (cN) Pathological node metastasis (pN) Subtotal/total thyroidectomy Modified neck dissection 15 2 31 11 28 4 9 20 5 24 15 25 P-value Yes (n=15) No. % No (n=42) No. % NS 0.011 NS 0.010 NS 0.009 0.040 NS 23 7 46 15 38 7 18 30 12 37 23 38 40.4 12.3 80.7 26.3 66.7 12.3 31.6 52.6 21.1 64.9 40.4 66.7 Clinicopathological features 8 5 15 4 10 3 9 10 7 13 8 13 35.7 4.8 73.8 26.2 66.7 9.5 21.4 47.6 11.9 57.1 35.7 59.5 Total (n=57) No. % NS: not significance

2. Male gender Tumor stage (T3, T4a) Multifocality Clinical lymphadenopathy Table 2. Risk factor analysis for disease free survival (DFS) in 57 TNM stage I pediatric DTC patients. 1.31-15.5 1.01-1.12 0.71-6.41 1.55-14.7 Multivariate Univariate 4.51 1.06 2.14 4.77 HR: hazard ratio. CI: confidence interval. 4.36 1.06 3.36 3.51 1.46-13.0 1.00-1.11 1.19-9.43 1.27-9.71 HR95%CI HR95%CIP-value 0.008 0.050 0.022 0.016 0.017 0.029 0.175 0.006

3. [11/29] [21/51] [15/34] [8/12] [4-11] [14/42] [5/6] [10/10] [6/10] [-] [10/38] [22/63] [80/34] [7/16] [5/13] [33/76] [7/23] [14/34] [7/14] [5/27] [17/39] [19/55] [6/19] [8/15] [13/29] [1/7] [4/16] Table 3A. Clinicopathological features and outcomes from previous studies for pediatric DTC patients in Europe Authors Patients [M/F] 73 74 73 65 - 34 45 60 38 44 73 40 52 70 67 39 57 13 43 23 - 26 59 78 67 - 1986 [1929-1975] 1987 [1945-1984] 1988 [1971-1987] 1989 [1960-1985] 1989 [1953-1984] 1994 [1968-1988] 1994 [1974-1992] 1995 [1976-1990] 1995 [1974-1993] 1996 [1962-1994] 1997 [1980-1994] 1997 [1958-1995] 1997 [1980-1993] 1997 [1970-1994] 1999 [-] 2000 [1972-1995] 2000 [1917-?] 2002 [1977-1998] 2003 [1974-1999] 2004 [1991-2000] 2004 [1988-2001] 2004 [1985-2001] 2004 [1962-2002] 2005 [1987-2004] 2006 [1968-2001] Patient age (year) [range] 5.0 18 25 12 26.7 18 36 0 13 2.8 4.2 19 25 8.7 11 16 10 14 6.3 0 5.4 14 13 12 0 Published year [study period] Follow up (year) [range] [5-35] - [1-17] [2-23] [3.5-33] [0.3-19.0] [9.0-18.0] [3.4-18.7] [1-20] - [0.17-15.8] [0.08-27] - [0.6-19.4] [1-26] [1-23] [1-66] [0.2-24.5] [2-26] [1-8.2] - [0.9-39.4] [1.3-17] [3.3-30.7] [3.3-23.2] [5.7-30.8] Sweden France Italy Denmark Finland Italy Germany Italy Netherlands Hungary Italy Germany U.K Austria Poland UK Italy Netherlands Czech Italy France Netherlands Greece Italy 33 67 53 33 27 36 35 25 2.8 19 24 29 - 39 - 20 52 38 3.8 7.1 22 32 17 52 50 most 93 - 71 - 54 73 85 63 31 85 72 - 67 - 88 71 - 52 - 40 72 49 20 15 56 11 20 16 36 48 85 114 23 18 109 30 48 21 32 56 74 25 23 42 8 20 [3-16] [6-18] [6-19] [4-16] [4-20] [5-16] [3-14] [6-16] [8-20] [11-20] [5-18] [3-18] [7-18] [9-20] [6-17] [-16] [7-20] [7-17] - [4-16] [2-20] [5-19] [8-20] [4-17] [4-15] [6-17] Thyroid mass (%) Extension (%) cN (%) SDM (%) b Mean, c Median Tallroth Schlumberger Ceccarelli Merrick Lamberg Fassina Jocham Massimino Stael Balázs Danese Dottorini Farahati Sykes Hallwirth Jarzab Landau Giuffrida Haveman Astl Spinelli Borson-Chazot Santen Pazaitou-Panayiotou Collini Massimino (59) (28) (1) (62) (29) (2) (30) (26) (31) (8) (3) (4) (15) (48) (32) (23) (33) (34) (35) (49) (13) (16) (50) (36) (51) (52) PTC (% ) a Including a few cases of medullary thyroid carcinoma or other types of thyroid carcinoma. 85 a 69 90 a 85 a 87 77 a 73 a 95 63 a 83 a 85 a 85 78 61 94 71 97 83 81 78 a 100 96 76 91 100 14 b [M], 16 b [F] 11.0 b [6-16 in 29 cases] 15 b 12.4 b 15 b 9.5 c 11 c 11 b 15.3 b 18 c 14.7 b 13.2 b 15 b 16 b 13.6 b [  10 in 10 cases] 18.1 c 14 c 14.7 b 11.5 b 17 c 12.5 b 15.9 b 14 c 12.5 c 13.5 c 22 b 13.0 c 7.7 b 9.1 b 16.2 b 9.3 c 10.3 c 10 c 11.5 c - 4.9 b 9.3 c 3.8 b 5.6 c 12.5 c 5 b 22.5 c 7.1 b 11 c - 5.5 b 5.1 c 14.2 c 5.5 b 15.8 c 5.9 c 19.3 c cN: clinical lymphadenopathy, SDM: synchronous distant metastasis

4. Authors Tallroth Schlumberger Ceccarelli Merrick Lamberg Fassina Jocham Massimino Stael Balázs Danese Dottorini Farahati Sykes Hallwirth Jarzab Landau Giuffrida Haveman Astl Spinelli Borson-Chazot Santen Pazaitou-Panayiotou Collini Massimino 18 22 100 29 73 79 64 0 100 2.8 67 88 100 52 100 78 43 100 86 100 34 55 91 31 0 20 24 - 12 - 3.6 45 35 0 28 2.1 7.1 - 17.4 e 17 15 40 35 9.5 0 27 18 32 26 21 25 30 40 100 76 73 96 45 70 100 50 92 54 100 61 94 74 40 100 94 66 61 92 91 79 0 100 5.0 8.3 2.0 0 6.7 0 18.2 0 2.7 0 4.3 e 0 16.7 0 Early recurrence Complete surgery Total Tx, RI, TSHs Long follow-up Adequate surgery, RI Total Tx, RI Total Tx, LND, RI, TSHs, Tg Limited surgery, TSHs Total Tx, selective LND, RI Less aggressive surgery Total Tx, RI PTC, advanced tumor stage Less aggressive surgery Total Tx, selectiveLND, Tg Total Tx, RI Total Tx, LND, RI,TSHs Total Tx, LND Total Tx, LND, RI Selective strategy Total Tx in a single step Clinical lymphadenopathy Step surgery? Total Tx, LND, RI, Tg, Conservative therapyConservative therapy pN (%) Multifocality (%) - 81 - 42 - 20 - 22 - 23 13 29 - 23 35 - 48 42 0 20 - 90 65 73 55 70 50 70 50 60 47 - 83 59 - 54 52 46 45 - 59 78 92 50 100 RI therapy (%) Total Tx d (%) PHP (%) RLN palsy (%) TSHs (%) Recurrence (%) Mortality (%) Risk factors or recommendations Table 3B. Clinicopathological features and outcomes from previous studies for pediatric DTC patients in Europe d In some studies, total Tx includes near total or subtotal Tx. Tx: thyroidectomy, TSHs: TSH suppression therapy, pN: pathological node metastasis, PHP: permanent hypoparathyroidism, RLN: recurrent laryngeal nerve, LND: lymph node dissection. (59) (28) (1) (62) (29) (2) (30) (26) (31) (8) (3) (4) (15) (48) (32) (23) (33) (34) (35) (49) (13) (16) (50) (36) (51) (52) 98 - 100 50 100 most - 100 - 100 79 100 25 6.9 27 - 0 3.6 9.1 35.7 6.3 - 21 8.2 - 30 0 5.5 - 4.2 0 3.1 7.1 - 32 0 26 0 30 23 25 41 - 0 1.8 27.3 29 0 - 8.3 3.5 - 0 10 - 0 5.4 - 24 0 9.5 0 10 e Including a few cases of medullary thyroid carcinoma.

5. 58 100 15 117 89 19 41 26 11 82 112 329 137 33 14 38 56 38 47 36 566 Authors Patients [M/F] cN (%) 1988 1990 1992 1993 1994 1995 1997 1998 2000 2002 2003 2005 Patient age (year) [range] SDM (%) Published year [study period] Follow up (year) [range] [12-40] - [0.8-20] - [0.4-25] - [0.3-27] [3.0-22] [1-33] [10-52] [1-41] [0.2-39] [0.7-38] [1-45] - [0.6-30] [1-40] [1.1-30] [1.3-12] - USA Canada USA Canada USA Brazil USA Extension (%) Thyroid mass. (%) [5-16] [  17] [1.8-27] [5-19] [0.5-18] [4-24] [8-20] [6-20] [7-25] - [4-19] [0.4-21] [3-21] [6-21] [9.8-17] [4.5-17] [4-20] [-18] c [3-21] [5-18] - [1946-1975] [1949-1986] - [1949-1987] [1936-1990] [1960-1990] [ -1974] [1963-1993] [1962-1995] - [1944-1986] [1946-1991] [1953-1996] [1937-1998] [1955-1996] [1970-2000] [1961-2000] [1953-1996] [1987-1999] [1988-2000] 6.9 - 13 9.4 15 9.1 0 3.8 0 6 - 25 5.8 3 86 5.3 8.9 13 17 0 - 13 60 53 100 29 42 64 16 - 23 12 - 29 42 34 50 - 24 - 33 21 - 15 - 27 - 32 5.8 3.0 71 42 54 29 13 14 18 - 87 40 51 - 71 77 64 85 - 84 79 - 91 61 85 86 - [18/40] [29/71] [5/10] [30/87] [17/72] [6/13] [18/23] [6/20] [3/8] [25/57] [26/86] [80/249] [33/104] [5/28] [10/4] [10/28] [13/43] [15/23] [17/30] [7/29] [86/480] 59 [20/39] 23 [4/19] 27 [8/19] 61 [14/47] 16 [8/8] 18 [3/15] 80 [35/45] 34 [7/27] 15 [5/10] 60 [7/53] 83 [27/56] 31 [4/27] 14 [5/9] 75 [19/56] 21 [5/16] 24 [13/11] 57 [7/50] 47 - 100 49 56 67 49 26 13 - 58 - 50 45 14 88 21 1991 [1963-1989] 1992 [1969-1989] 1998 [1963-1996] 1998 [1953-1995] 2000 [1973-1995] 2000 [1974-1997] 2001 [1967-2000] 2002 [1964-1999] 2002 [1988-2001] 2004 [1960-1997] 2005 [1964-2000] 2005 [1987-2003] 2005 [1989-2003] 2006 [1954-2001] 2006 [1960-2003] 2008 [1970-1985] 2008 [1962-2002] 15.3 4.3 70.4 6.6 6.3 16.7 6.3 5.9 13.3 6.7 19.3 45.2 - 5.3 23.8 4.2 0 [- 26] - [0.7-26.6] - [0.4-14.1] [4-20] [-25] [1-32.5] [0.4-12.4] - [1.3-12.5] - [3-42] >20(in all) [0.7-45] India Japan India Israel Turkey India China Turkey China India Israel Australia Israel Japan China Japan 6.8 91.3 - 26.2 6.3 - 55.9 - 23.3 - 21.3 9.5 58.3 12.3 54 - 61 - 94 69 97 33 - 60 - 57 49 76 63 93 [-18] c [-18] c [6-20] [2-16] [5-16] [4.5-20] [10-21] [8-21] [8.6-20.9] [-17] [12-25] [5-17] [6-20] [4-15] [11-20] [7-15] Table 4A. Clinicopathological features and outcomes from previous studies for pediatric DTC patients in North and South America and those in Asia and Oceania Zimmerman La Quaglia Desjardins Frankenthaler Harness Vassilopouloii Viswa-than Millman Kuefer Wassmuth Vassilopoulou Newman Welch Dinauer Brink Alessandri Grigsby Kowalski Powers Palmer Shapiro Samuel Mizukami Samuel Segal Arush Bingöl-Koloğlu Bal Lee Arici Chow Chaukar Hod Savio Popovtzer Okada Ji Present study (9) (53) (37) (38) (39) (24) (14) (45) (60) (10) (61) (25) (18) (54) (22) (46) (27) (19) (20) (58) (12) (17) (56) (5) (55) (47) (11) (6) (40) (41) (21) (57) (42) (7) (43) (44) PTC (% ) b Mean, c Median a Including a few cases of medullary thyroid carcinoma or other types of thyroid carcinoma. 100 87 73 91 93 89 88 81 a 100 70 a 89 90 100 33FTCs 100 79 66 76 a 100 91 63 a 91 93 79 75 a 72 85 82 60 82 83 90 100 83 95 100 81 - 13.3 b 13.6 b 16 b 12.8 b 15 c 16.2 c 16.9 b 16 c 13.8 b 15 b 15.2 c 19 c 18 c 13.5 b 12.6 b 15.8 b [  12 in 9 cases] 19 c 16 c 16.0 b 27.6 c 20 c 7.5 b 14.5 b - 4.5 c 25.9 c 12 b 14.2 c 8.6 b 25 b 11.3 c 6.6 c 5 c 19.3 b 18.5 b 11.0 c 9.5 b 5.8 c 5.4 b - [  15 in 31 cases] 13.3 b [M],17.5 b [F] [<10 in 8 cases] 15.8 b 12.5 c 11.6 b 15.8 b 19 c 16.8 b 17 b - 21 c 12.5 b 16.1 b 10.8 b 16.6 b 13.1 b 11 c 9.5 b 7.2 b 14.8 b 5 c 7.0 b 6.0 b 15.2 c 4.8 c 14 b 5.3 c 5 b 5.7 b - 20 c - 17.4 b cN: clinical lymphadenopathy, SDM: synchronous distant metastasis

6. Authors Zimmerman La Quaglia Desjardins Frankenthaler Harness Vassilopouloii Viswa-than Millman Kuefer Wassmuth Vassilopoulou Newman Welch Dinauer Brink Alessandri Grigsby Kowalski Powers Palmer Shapiro RI therapy (%) 26 35 13 29 30 - 39 15 9.1 17 22 32 20 15 14 45 34 26 17 47 - Recurrence (%) Total Tx d (%) Mortality (%) Conservative therapy Total Tx for advanced case Total Tx, LND, RI Total Tx, RI, distant and node meta Radiation induced carcinoma Total Tx, LND, RI Chemotherapy - Long follow-up Total Tx for advanced case Large T, multifocal, distant meta. Stepwise approach Age Total Tx, LND, RI. TSHs Total Tx, RI, TSHs Extensive disease, tumor size Selective RI, LNM, multifocality FTC Risk factors or recommendations PHP (%) RLN palsy (%) TSHs (%) pN (%) Multifocality (%) - 22 - 51 - 31 12 - 57 - 40 36 - 90 71 33 90 88 100 54 46 82 33 - 74 - 93 60 73 55 - 69 37 0 14 - 5.6 - 4.9 0 - 2.1 - 7.7 - 0 5.3 - 2.8 - 24 15 0 - 6.7 - 2.4 0 18 - 12 - 31 - 7.1 16 - 5.6 - 36 46 0 - 89 100 20 23 9.1 27 most 54 61 52 86 66 86 82 72 50 73 21 22 40 - 82 100 12 42 36 30 - 43 58 55 86 32 82 42 87 64 51 - 82 93 100 - 100 - 100 - 100 - 79 82 100 90 100 90 - 1.7 0 4.5 0 1.2 5.4 0.6 0.7 0 5.3 0 - Samuel Mizukami Samuel Segal Arush Bingöl-Koloğlu Bal Lee Arici Chow Chaukar Hod Savio Popovtzer Okada Ji Present study 71 22 100 31 72 100 53 67 60 100 79 89 9.5 21 18 8.5 35 - 4.9 13 33 11 32 0 22 - 0 15 14 21 26 100 61 67 84 94 100 83 79 60 82 84 100 89 33 75 40 1.7 e 4.3 3.7 3.3 0 3.8 2.9 0 3.3 0 3.2 0 2.7 9.5 8.3 0 Lung meta, LNM Male, Tumor stage, multifocality Alive with disease is allowed Total Tx, LND, RI Conservative therapy, long follow-up Total Tx, LND Younger age, male Total Tx, LND, RI, long follow Total Tx, LND, RI RI Total Tx, RI Alive with disease is allowed Total Tx, selective LND Total Tx, CND, RI Total Tx, RI Complete surgery Conservative therapy when no risk factors 12 - 9.8 6.3 5.6 1.3 12 6.7 - 0 7.1 4.0 0 8.3 11 - 9.8 0 11 2.5 1.6 6.7 - 0 4.0 0 8.3 5.3 100 most 100 - 100 - 100 - 9.5 100 84 8.5 78 - 66 - 22 - 27 20 - 29 - 69 - 32 49 83 - 80 - 66 32 27 45 - 61 83 80 57 100 65 Table 4B. Clinicopathological results and outcomes from previous studies for pediatric DTC patients in North and South America and those in Asia and Oceania (9) (53) (37) (38) (39) (24) (14) (45) (60) (10) (61) (25) (18) (54) (22) (46) (27) (19) (20) (58) (12) (17) (56) (5) (55) (47) (11) (6) (40) (41) (21) (57) (42) (7) (43) (44) Tx: thyroidectomy, TSHs: TSH suppression therapy, pN: pathological node metastasis, PHP: permanent hypoparathyroidism, RLN: recurrent laryngeal nerve, LND: lymph node dissection, CND: central node dissection. d In some studies, total Tx includes near total or subtotal Tx. e Including a few cases of medullary thyroid carcinoma.