Table 1.

(A) Clinical characteristics of subgroups in the Discovery Cohort. (B) Clinical characteristics of subgroups in the Validation Cohort. (C) Clinical characteristics of Combined Discovery and Validation Cohort.

(A) Clinical characteristics of subgroups in the Discovery Cohort
	Subgroup A (n = 7)	Subgroup B (n = 25)	Comparison p value
% Male	14%	36%	p = 0.27
Median age (IQR)	23 (16–44)	37 (23–52)	p = 0.26
% Stage IV	14%	22%	p = 0.67
% Total resection (stage I/II)a	57%	45%	p = 0.68
% with BWS	29%	12%	p = 0.64
# with WT1 mutation	1	0	p = 0.63
% Bilateral	29%	20%	p = 0.64
# Relapses	0	4	p = 0.55
# with unfavourable histology	0	4	p = 0.55
# Relapse or unfavourable histology	0	5	p = 0.55

(B) Clinical characteristics of subgroups in the Validation Cohort
	Subgroup A (n = 15)	Subgroup B (n = 37)	Comparison p value
% Male	33%	46%	p = 0.60
Median age (IQR)	33 (24–46)	36 (12–55)	p = 0.59
% Total resection (stage I/II)b	64%	51%	p = 0.51
% Bilateral	87%	30%	p = 0.0002
# Relapses	0/3c	1/6c	p = NS
# with unfavourable histology	0	2	p = 1

(C) Clinical characteristics of combined Discovery and Validation Cohort
	Subgroup A (n = 22)	Subgroup B (n = 62)	Comparison p value
% Male	27%	42%	p = 0.31
Median age (IQR)	24 (21–47)	36 (20–56)	p = 0.46
% Total resection (stage I/II)d	61%	51%	p = 0.43
% Bilateral	68%	26%	p = 0.0007
# Relapses	0/10c	5/31c	p = 0.57
# with unfavourable histology	0	6	p = 0.33
# Relapse or unfavourable histology	0	7	p = 0.18

^aExcluding cases with incomplete data on local staging (7 evaluable in Subgroup A, 22 evaluable in Subgroup B).

^bExcluding cases with incomplete data on local staging (11 evaluable in Subgroup A, 35 evaluable in Subgroup B).

^cOnly local cases have outcome data (see Supplementary Table 2B).

^dExcluding cases with incomplete data on local staging (18 evaluable in Subgroup A, 57 evaluable in Subgroup B).