Imaging Characteristics and Prognostic Value of Isolated Pulmonary Metastasis from Colorectal Cancer Demonstrated with¹⁸F-FDG PET/CT

Table 1

Clinical characteristics of the 62 patients with isolated lung nodules.

Characteristic	All ( =62) (%)	Metastasis; ( =33) (%)	Primary lung cancer; ( =20) (%)	Benign nodule; ( =9) (%)	-value^a	-value^b
Gender					0.035	0.866
Male	45 (72.58)	21 (63.6)	18 (90.0)	6 (66.7)
Female	17 (27.42)	12 (36.4)	2 (10.0)	3 (33.3)
Age (year)					0.629	0.554
Mean ±	65.02 ±	66.27 ±	65 ± 7.81	60.44 ±
SD	9.44	10.01		10.21
Primary tumor (%)					0.547	0.565
Rectum	34 (54.84)	17 (51.5)	12 (60.0)	5 (55.6)
Colon	28 (45.16)	16 (48.5)	8 (40.0)	4 (44.4)
Initial TNM stage					0.765	0.312
I-III	53 (85.48)	27 (81.8)	17 (85.0)	9 (100)
IV	9 (14.52)	6 (18.2)	3 (15.0)	0 (0.0)
Histological type					0.388	0.05
WD	1(1.61)	1 (3.03)	0 (0.00)	0 (0.0)
MD	41 (66.13)	22 (66.67)	15 (75.00)	4 (15.4)
PD	11 (17.74)	8 (24.24)	2 (10.00)	1 (11.1)
Unknown	9 (14.52)	2 (6.06)	3 (15.00)	4 (66.7)
Treatment of CRC
Adjuvant chemotherapy					0.305	0.454
+	29 (46.77)	18 (54.5)	8 (40.0)	3 (33.3)
-	33 (53.23)	15 (45.5)	12 (60.0)	6 (66.7)
Adjuvant radiotherapy					0.512	0.475
+	4 (6.45)	3 (9.1)	1 (5.0)	0 (0.0)
-	58 (93.55)	30 (90.9)	19 (95.0)	9 (100)
CEA (ng/ml) level					0.472	0.253
≥5	18 (29.03)	12 (36.4)	5 (25.0)	1 (11.1)
<5	40 (64.52)	20 (60.6)	13 (65.0)	7 (77.8)
Unknown	4 (6.45)	1 (3.0)	2 (10.0)	1 (11.1)
CA19-9 (U/ml) level					0.349	0.846
≥37	7 (11.29)	5 (15.2)	1 (5.0)	1 (11.1)
<37	49 (79.03)	26 (78.8)	16 (80.0)	7 (77.8)
Unknown	6 (9.68)	2 (6.1)	3 (15.0)	1 (11.1)
ITP (months)
≥3/<3 months	42 (67.74)/20 (32.26)	25 (75.8)/8 (24.2)	11 (55.0)/9 (45.0)	6 (66.7)/3 (33.3)	0.117	0.582
≥6/<6 months	41 (66.13)/21 (33.87)	25 (75.8)/8 (24.2)	11 (55.0)/9 (45.0)	5 (55.6)/4 (44.4)	0.117	0.44
≥12/<12 months	33 (53.23)/29 (46.77)	18 (54.5)/15 (45.5)	10 (50.0)/10 (50.0)	5 (55.6)/4 (44.4)	0.748	0.629
≥24/<24 months	24 (38.71)/38 (61.29)	10 (30.3)/23 (69.7)	9 (45.0)/11 (55.0)	5 (55.6)/4 (44.4)	0.279	0.313
Overall survival (months)					0.492	0.147
Median	Not reached	Not reached	Not reached	Not reached

WD: well-differentiated; MD: moderately differentiated; PD: poorly differentiated; CEA: carcinoembryonic antigen; CA19-9: carbohydrate antigen 19-9; ITP: interval to pulmonary nodules. ^aTest for difference between the isolated lung metastasis group and the second primary lung cancer group. ^bTest for difference between the isolated lung metastasis group and the benign nodule group. Statistically significant -values are highlighted in bold.