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 P-value Yes (n=15) No. % No (n=42) No. % NS NS NS NS Clinicopathological features Total (n=57) No. % NS: not significance

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 Multivariate Univariate HR: hazard ratio. CI: confidence interval HR95%CI HR95%CIP-value

[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] [ ] 1987 [ ] 1988 [ ] 1989 [ ] 1989 [ ] 1994 [ ] 1994 [ ] 1995 [ ] 1995 [ ] 1996 [ ] 1997 [ ] 1997 [ ] 1997 [ ] 1997 [ ] 1999 [-] 2000 [ ] 2000 [1917-?] 2002 [ ] 2003 [ ] 2004 [ ] 2004 [ ] 2004 [ ] 2004 [ ] 2005 [ ] 2006 [ ] Patient age (year) [range] Published year [study period] Follow up (year) [range] [5-35] - [1-17] [2-23] [3.5-33] [ ] [ ] [ ] [1-20] - [ ] [ ] - [ ] [1-26] [1-23] [1-66] [ ] [2-26] [1-8.2] - [ ] [1.3-17] [ ] [ ] [ ] 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 most [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 a 85 a a 73 a a 83 a 85 a a 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 b 9.3 c 3.8 b 5.6 c 12.5 c 5 b 22.5 c 7.1 b 11 c 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

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 e e 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 (%) 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) most e Including a few cases of medullary thyroid carcinoma.

Authors Patients [M/F] cN (%) 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] - [ ] [ ] - [ ] [ ] [ ] [ -1974] [ ] [ ] - [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [ ] [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] [ ] 1992 [ ] 1998 [ ] 1998 [ ] 2000 [ ] 2000 [ ] 2001 [ ] 2002 [ ] 2002 [ ] 2004 [ ] 2005 [ ] 2005 [ ] 2005 [ ] 2006 [ ] 2006 [ ] 2008 [ ] 2008 [ ] [- 26] - [ ] - [ ] [4-20] [-25] [1-32.5] [ ] - [ ] - [3-42] >20(in all) [0.7-45] India Japan India Israel Turkey India China Turkey China India Israel Australia Israel Japan China Japan [-18] c [-18] c [6-20] [2-16] [5-16] [4.5-20] [10-21] [8-21] [ ] [-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 a a FTCs a a a 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 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 b cN: clinical lymphadenopathy, SDM: synchronous distant metastasis

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 (%) 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 (%) most Samuel Mizukami Samuel Segal Arush Bingöl-Koloğlu Bal Lee Arici Chow Chaukar Hod Savio Popovtzer Okada Ji Present study e 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 most 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.