Effect of perioperative chemotherapy on resection of isolated pulmonary metastases from colorectal cancer: A single center experience

Table 2 Comparison of baseline and tumor characteristics among groups, n (%)

Factors	Levels	Surgery alone (n = 66)	Perioperative chemotherapy (n = 54)	P value
Sex	Male	43 (65.2)	30 (55.6)	0.377
	Female	23 (34.8)	24 (44.4)
Age at CRC diagnosis	mean ± SD	61.2 ± 9.7	56.6 ± 10.1	0.012
Age at time of pulmonary surgery	mean ± SD	64.1 ± 9.4	58.6 ± 9.9	0.002
Smoking history	No	40 (60.6)	46 (85.2)	0.006
	Yes	26 (39.4)	8 (14.8)
Adjuvant chemotherapy for CRC	No	24 (36.4)	11 (20.4)	0.086
	Yes	42 (63.6)	43 (79.6)
CRC differentiation	Moderate	36 (81.8)	40 (87.0)	0.744
	Moderate to poor/poor	2 (4.5)	1 (2.2)
	Well/well to moderate	6 (13.6)	5 (10.9)
Primary tumor T stage	0	1 (2.5)	2 (4.3)	0.969
	II	4 (10.0)	4 (8.7)
	III	29 (72.5)	33 (71.7)
	IV	6 (15.0)	7 (15.2)
Primary tumor N stage	0	17 (39.5)	20 (41.7)	0.560
	1	18 (41.9)	17 (35.4)
	2	8 (18.6)	11 (23.0)
MSS	pMMR	26 (100.0)	31(100.0)
RAS	Wild type	5 (71.4)	9 (47.4)	0.517
	Mutant type	2 (28.6)	10 (52.6)
Access	Open	18 (27.3)	7 (13.0)	0.090
	VATS	48 (72.7)	47 (87.0)
Type of resection	Lobe	33 (50.0)	17 (31.5)	0.063
	Segmental wedge	33 (50.0)	37 (68.5)
Number of metastatic lesions	1	53 (80.3)	43 (79.6)	1.000
	> 1	13 (19.7)	11 (20.4)
Tumor size (cm)	≤ 2 cm	32 (50.0)	31 (58.5)	0.465
	> 2 cm	32 (50.0)	22 (41.5)
Bilateral pulmonary nodules	No	62 (93.9)	51 (94.4)	1.000
	Yes	4 (6.1)	3 (5.6)
LN sampling at PM	No	32 (48.5)	34 (63.0)	0.161
	Yes	34 (51.5)	20 (37.0)
Positive LN at PM	No	63 (95.5)	49 (90.7)	0.508
	Yes	3 (4.5)	5 (9.3)
CEA	≤ 5 ng/mL	33 (61.1)	29 (61.7)	1.000
	> 5 ng/mL	21 (38.9)	18 (38.3)
Pulmonary metastasis	Synchronous	3 (4.5)	9 (16.7)	0.058
	Metachronous	63 (95.5)	45 (83.3)
DFI	mean ± SD	1005.3 ± 774.6	771.9 ± 701.5	0.089
Primary tumor location	Left colon	18 (31.0)	17 (34.0)	0.363
	Rectum	27 (46.6)	27 (54.0)
	Right colon	13 (22.4)	6 (12.0)

CRC: Colorectal cancer; CEA: Carcinoembryonic antigen; LN: Lymph nodes; PM: Pulmonary metastases; MSS: Microsatellite instability; RAS: Rat sarcoma; pMMR: Proficient mismatch repair; VATS: Video-assisted thoracoscopic surgery; DFI: Disease-free interval.