Table 4. C/N ratio for the microvascular density in the differentiated and undifferentiated types of carcinoma using NBI.

	Differentiated type carcinoma	Undifferentiated type carcinoma	P value
C/N ratio of NBI vascular density	3.94 ± 8.22	0.43 ± 0.19	< 0.001

C, carcinoma; N, non-carcinomatous mucosa; NBI, narrow-band imaging.