Optimal postoperative surveillance strategies for stage III colorectal cancer

Table 3 Factors affecting recurrence-free interval of participants

Factors	Univariate		Multivariate
	OR (95%CI)	P value	OR (95%CI)	P value
Age (yr)	0.995 (0.987–1.002)	0.165	0.999 (0.991–1.006)	0.715
Sex	0.907 (0.765–1.076)	0.262
Surveillance intensity	2.218 (1.870–2.632)	< 0.001	1.999 (1.680–2.377)	< 0.001
Differentiation
WD/MD	Ref.		Ref.
PD/SRC/MUC	1.507 (1.151–1.974)	0.003	1.287 (0.979–1.694)	0.071
(y) pT stage
0–2	Ref.		Ref.
3–4	2.118 (1.610–2.785)	< 0.001	1.596 (1.197–2.127)	0.001
(y) pN stage
1c	Ref.		Ref.
1	2.737 (0.682–10.989)	0.156	2.501 (0.621–10.063)	0.197
2	5.260 (1.308–21.156)	0.019	3.813 (0.943–15.413)	0.060
Lymphovascular invasion	1.460 (1.236–1.724)	< 0.001	1.143 (0.957–1.364)	0.140
Perineural invasion	1.949 (1.641–2.313)	< 0.001	1.431 (1.192–1.719)	< 0.001
Resection margin1	2.192 (1.529–3.144)	< 0.001	1.565 (1.083–2.262)	0.017

¹Resection margin indicated circumferential resection margin, and were calculated with rectal cancer patients. OR: Odds ratio; CI: Confidence interval; Ref: Reference; WD: Well differentiated; MD: Moderately differentiated; PD: Poorly differentiated; SRC: Signet ring cell type; MUC: Mucinous carcinoma.