Radiofrequency ablation with or without capecitabine maintenance therapy for lung oligometastases from colorectal cancer

Table 3 Univariate analysis of factors associated with overall survival in colorectal cancer patients with lung metastases

Variables	HR (95%CI)	P value (Wald’s test)
Sex
Female	1 (Reference)
Male	0.74 (0.34-1.64)	0.464
Age	0.96 (0.93-1)	0.065
KRAS
Wild-type	1 (Reference)
Mutated	1.43 (0.64-3.18)	0.388
CA19-9
< 27 U/mL	1 (Reference)
≥ 27 U/mL	1.23 (0.42-3.61)	0.703
CEA
< 5 ng/mL	1 (Reference)
≥ 5 ng/mL	1.82 (0.8-4.15)	0.155
Location
Left	1 (Reference)
Right	0.91 (0.41-2.01)	0.821
Diameter	3.2 (1.57-6.55)	0.001
Distance between the lesion and the mediastinum or great vessels
≤ 1 cm	1 (Reference)
> 1 cm	0.77 (0.34-1.74)	0.529
Distance between the lesion and the pleural surface
≤ 1 cm	1 (Reference)
> 1 cm	0.38 (0.17-0.86)	0.02
Primary lesion pathology
Rectum	1 (Reference)
Left half colon	2.38 (0.93-6.09)	0.07
Right half colon	2.2 (0.83-5.87)	0.115
Neural invasion
None	1 (Reference)
Exist	1.27 (0.57-2.83)	0.562
Lymphovascular invasion
None	1 (Reference)
Exist	0.84 (0.35-2.02)	0.699
Synchronous or metachronous
Metachronous	1 (Reference)
Synchronous	0.68 (0.31-1.52)	0.348
Pneumothorax
None	1 (Reference)
Exist	0.19 (0.03-1.42)	0.105
Alveolar hemorrhage
None	1 (Reference)
Exist	7.5 (3.34-16.84)	< 0.001

CEA: Carcinoembryonic antigen; CA19-9: Carbohydrate antigen 19-9; HR: Hazard ratio; CI: Confidence interval.