Adjuvant chemotherapy for isolated resectable colorectal lung metastasis: A retrospective study using inverse probability treatment weighting propensity analysis

Table 7 Clinical, radiological, and histological characteristics of the population: Pre-imputation and post-imputation, n (%)

Factors	Levels	Post-imputation (n = 96)	Pre-imputation (n = 96)	P value
Gender	Male	58 (60.4)	58 (60.4)	1.000
	Female	38 (39.6)	38 (39.6)
Age at CRC diagnosis	mean ± SD	59.7 ± 9.9	59.7 ± 9.9	1.000
Age at time of pulmonary surgery	mean ± SD	62.6 ± 9.6	62.6 ± 9.6	1.000
Smoking history	No	68 (70.8)	68 (70.8)	1.000
	Yes	28 (29.2)	28 (29.2)
Adjuvant chemotherapy for CRC	No	30 (31.2)	30 (31.2)	1.000
	Yes	66 (68.8)	66 (68.8)
CRC differentiation	Moderate	84 (87.5)	57 (83.8)	0.760
	Moderate to poor	4 (4.2)	3 (4.4)
	Well to moderate	8 (8.3)	8 (11.8)
Primary tumor T stage	T1 or T2	10 (10.4)	8 (11.8)	0.985
	T3 or T4	86 (89.6)	60 (88.2)
Primary tumor N stage	N0	39 (40.6)	28 (39.4)	1.000
	N1 or N2	57 (59.4)	43 (60.6)
Prior extra-thoracic metastasis	No	86 (89.6)	86 (89.6)	1.000
	Yes	10 (10.4)	10 (10.4)
Access	Open	20 (20.8)	20 (20.8)	1.000
	VATS	76 (79.2)	76 (79.2)
Type of resection	Lobe	42 (43.8)	42 (43.8)	1.000
	Segmental wedge	54 (56.2)	54 (56.2)
Number of metastatic lesions	1	76 (79.2)	76 (79.2)	1.000
	> 1	20 (20.8)	20 (20.8)
Tumor size (cm)	≤ 2	53 (55.2)	51 (54.8)	1.000
	> 2	43 (44.8)	42 (45.2)
Bilateral pulmonary nodules	No	91 (94.8)	91 (94.8)	1.000
	Yes	5 (5.2)	5 (5.2)
LN sampling at PM	No	51 (53.1)	51 (53.1)	1.000
	Yes	45 (46.9)	45 (46.9)
Positive LN at PM	No	90 (93.8)	90 (93.8)	1.000
	Yes	6 (6.2)	6 (6.2)
CEA levels	≤ 5 ng/mL	61 (63.5)	47 (60.3)	0.774
	> 5 ng/mL	35 (36.5)	31 (39.7)
CRC LVI	No	81 (84.4)	45 (81.8)	0.858
	Yes	15 (15.6)	10 (18.2)
CRC PNI	No	77 (80.2)	41 (74.5)	0.545
	Yes	19 (19.8)	14 (25.5)
Adjuvant chemotherapy	No	62 (64.6)	62 (64.6)	1.000
	Yes	34 (35.4)	34 (35.4)
DFI	mean ± SD	1026.2 ± 708.9	1026.2 ± 708.9	1.000
Primary tumor location	Left colon	29 (30.2)	29 (33)	0.921
	Rectal	48 (50)	42 (47.7)
	Right colon	19 (19.8)	17 (19.3)

CRC: Colorectal cancer; CEA: Carcinoembryonic antigen; LN: Lymph nodes; PM: Pulmonary metastases; VATS: Video-assisted thoracoscopic surgery; DFI: Disease-free interval; LVI: Lymphovascular invasion; PNI: Perineural invasion.