Fig. 3.

a Actuarial survival curves of 847 patients according to the current TNM classification. The 5-year survival rate was not significantly different between stage IA (100%) and stage IB (43.6%; P = 0.08) or between stage IB and stage IIA (34.4%; P = 0.66), while there was a significant difference between stages IIA and IIB (16.0%; P < 0.01). b Actuarial survival curves of 847 patients according to the new TNM classification. The 5-year survival rate was not significantly different between stage IB (43.6%) and the new stage IIA (44.0%; P = 0.79), while there were significant differences between new stages IIA and IIB (21.1%; P < 0.02) and between new stages IIB and IIC (16.0%; P = 0.03). The P value was calculated using the log-rank test for each two-group comparison