Indeterminate pulmonary nodules in colorectal cancer

Table 1 Patient characteristics

Characteristic	Lung metastasis (n = 30)	Benign (n = 10)	P value
Gender, male:female	21:9	5:5	0.220
Mean age at diagnosis of CRC, yr	57.6 ± 9.3	60.1 ± 11.6	0.520
Mean age at pulmonary resection, yr	60.6 ± 8.2	61.9 ± 10.7	0.158
Previous hepatic resection for metastasis, n	6	0	0.026
Disease free interval, mo (range)	29.5 (0-104)	16.2 (9-42)	0.078
Timing of thoracotomy, n			0.067
Synchronous	4	0
Metachronous	26	10
> 5 yr after primary CRC surgery	2	2

Disease free interval = the period between primary CRC operation and lung operation. CRC: 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.

Table 3 Characteristics of lung lesions n (%)

Characteristic	Lung metastasis (n = 30)	Benign (n = 10)	P value
Type of lung operation
VATS	25 (83.3)	9 (90.0)	0.526
Open	5 (16.6)	1 (10.0)
Lung operation-related complications	0	0
Number of lung nodules
1	18 (60.0)	6 (60.0)	0.547
2	10 (33.3)	2 (20.0)
3	2 (6.6)	2 (20.0)
Size of lung nodules (mm)	11.8 ± 7.5	11.8 ± 7.0	0.881
Bilaterality
Unilateral	27 (90.0)	10 (100)	0.411
Bilateral	3 (10.0)	0
Pre-thoracotomy serum CEA elevation	0	0
Pre-thoracotomy serum CA19-9 elevation	0	0

CA19-9: Carbohydrate antigen 19-9; CEA: Carcinoembryonic antigen; VATS: Video-assisted thoracoscopic surgery.

Table 4 Clinicopathologic features of patients with benign lung nodules

Case No.	Sex/age	Primary tumor location	Primary operation	TNM stage	Interval to lung OP (mo)	PET	Histology of pulmonary lesions
1	M/70	HF	RHC	0	4	+	Tuberculosis
2	F/35	TC	T-C	II	23	+	Tuberculosis
3	M/66	RS	LAR	II	60	-	Chronic granulomatous inflammation
4	F/58	HF	RHC	II	60	+	Chronic granulomatous inflammation
5	M/70	SC	AR	III	88	-	Chronic granulomatous inflammation
6	M/51	SC	AR	I	29	-	Pleural fibrosis and fatty metaplasia
7	F/69	AC	RHC	II	3	+	Pleural fibrosis and fatty metaplasia
8	M/53	RS	AR	III	34	-	Anthracofibrotic nodule
9	F/58	AC	RHC	IV	26	+	Anthracofibrotic nodule
10	F/71	TC	T-C	II	8	+	Aspergillosis

AC: Ascending colon; AR: Anterior resection; F: Female; HF: Hepatic flexure colon; LAR: Low anterior resection; M: Male; OP: Operation; PET: Positron emission tomography; RHC: Right hemicolectomy; RS: Rectosigmoid colon; SC: Sigmoid colon; T-C: Transverse colectomy; TC: Transverse colon; TNM: Tumor-node-metastasis.