Indeterminate pulmonary nodules in colorectal cancer

Table 2 Pathologic features of primary colorectal cancer n (%)

Feature	Lung metastasis (n = 30)	Benign (n = 10)	P value
Primary tumor site			0.001
Colon	4 (13.3)	7 (70.0)
Rectum	26 (86.6)	3 (30.0)
Primary tumor size, cm	5.2 ± 1.5	5.7 ± 2.9	0.505
T stage			0.015
Tis	0	1 (10.0)
T1	0	1 (10.0)
T2	1 (3.3)	0
T3	28 (93.3)	5 (50.0)
T4	1 (3.3)	3 (30.0)
N stage			0.001
N0	5 (16.6)	8 (80.0)
N1	17 (26.6)	2 (20.0)
N2	8 (26.6)	0
TNM stage			0.011
0	0	1 (10.0)
I	1 (3.3)	1 (10.0)
II	3 (10.0)	5 (50.0)
III	16 (53.4)	2 (20.0)
IV	10 (33.3)	1 (10.0)
Metastatic LN (n)	33 ± 23	22 ± 9	0.034
LN ratio1	0.171 ± 0.155	0.031 ± 0.072	0.009
Histologic differentiation			0.195
WD	0	1 (10.0)
MD	26 (86.6)	8 (80.0)
PD	3 (10.0)	0
Mucinous	1 (3.3)	1 (10.0)
Lymphatic invasion	22 (73.3)	2 (20.0)	0.005
Vascular invasion	4 (13.3)	1 (10.0)	0.633
Perineural invasion	5 (16.6)	1 (10.0)	0.526
Adjuvant chemotherapy	23 (76.7)	3 (30.0)	0.048

¹Involved LN (n)/total LN (n). LN: Lymph node; MD: Moderately differentiated; PD: Poorly differentiated; TNM: Tumor-node-metastasis; WD: Well differentiated.