Table 3. Comparison of the rates of non-lobe specific lymph node metastasis between the lobe specific lymph node positive and negative groups according to the locations of primary tumors.

Tumor locations	LSLNS (+) N-LSLNS (+)	LSLNS (−) N-LSLNS (+)	P value
RUL	15.79% (6/38)	0	<0.001
RML	40% (2/5)	2.15% (2/93)	0.012
RLL	21.42% (6/28)	0	<0.001
LUL	22.86% (8/35)	0.61% (2/330)	<0.001
LLL	22.22% (4/18)	1.42% (3/212)	0.001

LSLNS, lobe specific lymph node stations; N-LSLNS, non-lobe specific lymph node stations; RUL, right upper lobe; RML, right middle lobe; RLL, right lower lobe; LUL, left upper lobe; LLL, left lower lobe.