Table 3. Spearman correlation analysis of the multicollinearity for node ratio (Nr).

Factors	Correlation coefficient (r)	P value
Tumor differentiation	0.166*	< 0.001
Lymphovascular invasion	0.214*	< 0.001
T Stage	0.290*	< 0.001
N Stage	0.724*	< 0.001

^*Correlation is significant at the 0.01 level (2 tailed);

r: correlation coefficient; |r| < 0.3: no correlation; 0.3 ≥ |r|: correlation exists.