Table 2.

Univariate analyses for PFS and duration of maintenance therapy in Cet group.

		PFS		Duration of maintenance therapy
Factors		95% CI	P-value	95% CI	P-value
Age at maintenance
	<62	1.00 (reference)		1.00 (reference)
	≥62	1.21 (0.72–2.04)	0.47	1.01 (0.62–1.64)	0.99
Gender
	Female	1.00 (reference)		1.00 (reference)
	Male	0.74 (0.43–1.27)	0.27	0.67 (0.40–1.13)	0.14
Smoking
	No	1.00 (reference)		1.00 (reference)
	Yes	1.20 (0.71–2.02)	0.50	1.53 (0.92–2.54)	0.11
Primary tumor site
	Left colon	1.00 (reference)		1.00 (reference)
	Right colon	0.63 (0.30–1.35)	0.24	0.52 (0.24–1.09)	0.24
Resection of primary tumor
	No	1.00 (reference)		1.00 (reference)
	Yes	0.90 (0.49–1.65)	0.74	1.01 (0.57–1.81)	0.97
Preoperative chemotherapy
	No	1.00 (reference)		1.00 (reference)
	Yes	0.96 (0.54–1.71)	0.89	0.88 (0.51–1.52)	0.65
Simultaneous resection
	No	1.00 (reference)		1.00 (reference)
	Yes	0.64 (0.29–1.42)	0.27	0.84 (0.12–6.10)	0.86
Resection of metastatic sites
	No	1.00 (reference)		1.00 (reference)
	Yes	0.62 (0.35–1.08)	0.09	0.66 (0.39–1.10)	0.11
Metastatic time
	Synchronous	1.00 (reference)		1.00 (reference)
	Metachronous	1.18 (0.67–2.08)	0.56	1.26 (0.75–2.13)	0.38
Number of metastatic sites at start of maintenance therapy
	1	1.00 (reference)		1.00 (reference)
	2	2.20 (1.19–4.06)	0.01	2.12 (1.17–3.84)	0.01
	≥3	2.39 (1.14–5.01)	0.02	2.39 (1.14–5.01)	0.01
Line of maintenance therapy initiated
	1	1.00 (reference)		1.00 (reference)
	2	1.95 (1.06–3.56)	0.03	1.66 (0.94–2.94)	0.08
	≥3	1.26 (0.61–2.59)	0.54	1.45 (0.75–2.81)	0.27
Maintenance therapy regimen
	Single therapy	1.00 (reference)		1.00 (reference)
	Combination chemo	1.43 (0.77–2.66)	0.25	1.16 (0.63–2.13)	0.64

PFS, progression-free survival; CI, confidence intervals; chemo, chemotherapy.