Table 5.

Comparison of prognostic homogeneity between the 7^th and 8^th AJCC schemes and the RPA staging scheme for the validation set

Staging scheme	RPA-IA		RPA-IB		RPA-IIA		RPA-IIB		RPA-III		P valuea
	No.	Median survival	No.	Median survival	No.	Median survival	No.	Median survival	No.	Median survival
7th AJCC stage
IA	143	43 monthsd	-	-	-	-	-	-	-	-	-
IB	-	-	198	24 months	-	-	-	-	-	-	-
IIA	-	-	116	24 months	431	22 months	160	16 months	-	-	0.03
IIB	-	-	-	-	256	21 months	977	16 months	551	15 months	<0.001
P valueb	-	-		0.72		0.49		0.22		-
8th AJCC stage
IA	143	43 monthsd	116	24 months	-	-	-	-	-	-	<0.001
IB	-	-	156	24 months	431	22 months	-	-	-	-	<0.05
IIA	-	-	42	19 months	-	-	160	16 months	-	-	0.11
IIB	-	-	-	-	210	21 months	977	16 months	-	-	<0.01
III	-	-	-	-	46	21 months	-	-	551	15 months	0.01
P valuec		-		0.84		0.77		0.22		-

AJCC, American Joint Committee on Cancer; RPA, recursive partition analysis

^aComparison of overall survival within different RPA stages. Bold P values indicate statistical significance (i.e., P < 0.05).

^bComparison of overall survival within different 7^th AJCC stages. Bold P values indicate statistical significance (i.e., P < 0.05).

^cComparison of overall survival within different 8^th AJCC stages. Bold P values indicate statistical significance (i.e., P < 0.05).

^dThe median survival was not reached, and hence the mean survival time was provided instead.