Table 5.

χ² test of independence of LVI and RLN metastasis among systemic metastasis negative and systemic metastasis positive patients

No systemic metastasis patients		RLN metastasis
		No	Yes
LVI	No	2185 (95%)	116 (5%)	p value
	Yes	400 (86%)	65 (14%)	< 0.001
Systemic metastasis patients		RLN metastasis
		No	Yes
LVI	No	190 (92%)	17 (8%)	p value
	Yes	200 (79%)	52 (21%)	< 0.001

There was a significant association between LVI and positive RLN for Smets negative patients (p < 0.001). There was also a significant association between LVI and positive RLN for Smets positive patients (p < 0.001)

LVI lymphovascular invasion; RLN regional lymph node