Table 5. The non-extension sign-positive rate by depth of submucosal invasion in submucosal cancer.

Depth of vertical invasion in the submucosal layer	Positive rate of non-extension sign	P value
< 1000 μm	12.2 % (5/41)
1000 – 1999 μm	32.3 % (10/31)	0.031 1
2000 – 2999  μm	71.9 % (23/32)	< 0.001 2
≥ 3000 μm	89.2 % (23/37)	< 0.001 3

¹12.2 % vs. 32.3 %

²12.2 % vs. 71.9 %

³12.2 % vs.89.2 %