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

Table 2 Baseline characteristics and clinical outcomes of patients among groups before propensity analysis, n (%)

Factors	Levels	Surgery alone (n = 62)	Adjuvant chemotherapy (n = 34)	P value
Gender	Male	39 (62.9)	19 (55.9)	0.649
	Female	23 (37.1)	15 (44.1)
Age at CRC diagnosis	mean ± SD	61.3 ± 9.9	56.9 ± 9.4	0.038
Age at time of pulmonary surgery	mean ± SD	64.4 ± 9.6	59.4 ± 9.0	0.014
Smoking history	No	39 (62.9)	29 (85.3)	0.038
	Yes	23 (37.1)	5 (14.7)
Prior extra-thoracic metastasis	No	55 (88.7)	31 (91.2)	0.977
	Yes	7 (11.3)	3 (8.8)
Access	Open	16 (25.8)	4 (11.8)	0.175
	VATS	46 (74.2)	30 (88.2)
Type of resection	Lobe	30 (48.4)	12 (35.3)	0.307
	Segmental wedge	32 (51.6)	22 (64.7)
Number of metastatic lesions	1	50 (80.6)	26 (76.5)	0.827
	> 1	12 (19.4)	8 (23.5)
Tumor size (cm)	≤ 2cm	33 (53.2)	20 (58.8)	0.754
	> 2 cm	29 (46.8)	14 (41.2)
Bilateral pulmonary nodules	No	59 (95.2)	32 (94.1)	1.000
	Yes	3 (4.8)	2 (5.9)
LN sampling at PM	No	31 (50)	20 (58.8)	0.539
	Yes	31 (50)	14 (41.2)
Positive LN at PM	No	59 (95.2)	31 (91.2)	0.741
	Yes	3 (4.8)	3 (8.8)
CEA	≤ 5 ng/mL	40 (64.5)	21 (61.8)	0.963
	> 5 ng/mL	22 (35.5)	13 (38.2)
DFI	mean ± SD	1070.1 ± 754.2	946.0 ± 620.6	0.415
Primary tumor location	Left colon	18 (29)	11 (32.4)	0.340
	Rectal	29 (46.8)	19 (55.9)
	Right colon	15 (24.2)	4 (11.8)

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