Table 3.

Subgroup analysis of recurrent free survival and overall survival in the patients with 3 or more adverse features (n=27)

Variable		Recurrence-free survival				Overall survival
		Univariate		Multivariate		Univariate		Multivariate
		HR (95% CI)	P-value	HR (95% CI)	P-value	HR (95% CI)	P-value	HR (95% CI)	P-value
Age		1.003 (0.868−1.160)	0.964			1.125 (1.010−1.254)	0.032*	1.088 (0.980−1.208)	0.113
Sex
	Female	1				1
	Male	0.412 (0.118−1.438)	0.165			1.075 (0.357−3.238)	0.898
Body mass index		1.072 (0.865−1.328)	0.526			1.228 (0.988−1.525)	0.064	1.194 (0.944−1.512)	0.139
Charlson comorbidity index
	3–4	1				1
	5–7	0.534 (0.115−2.476)	0.423			1.881 (0.625−5.667)	0.261
Pathologic grading
	Poorly differentiated, mucinous	2.751 (0.576−13.147)	0.205			1.876 (0.411−8.559)	0.417
	Others	1				1
pT stage
	pT3	1				1
	pT4	1.905 (0.490−7.409)	0.352			0.936 (0.320−2.736)	0.903
Tumor location
	Right	1				1
	Left	1.568 (0.455−5.406)	0.476			1.251 (0.431−3.626)	0.680
Margin < 5 mm		0.668 (0.141−3.166)	0.611			1.137 (0.354–3.654)	0.830
No. of lymph nodes retrieved < 12		0.708 (0.181−2.768)	0.620			1.615 (0.539–4.839)	0.392
Lymphatic invasion		21.784 (0.000−13,101,349.717)	0.650			21.874 (0.000−3,231,279.450)	0.611
Venous invasion		0.666 (0.187−2.370)	0.531			0.833 (0.279−2.493)	0.744
Perineural invasion		2.019 (0.498−8.189)	0.325			2.231 (0.634−7.854)	0.211
Obstruction		0.619 (0.162−2.364)	0.483			0.501 (0.139−1.804)	0.291
Perforation		24.980 (1.562−399.590)	0.023*	12.611 (0.768−207.113)	0.076	0.043 (0.000−424.262)	0.503
Preoperative serum CEA level (ng/mL)		0.995 (0.973−1.018)	0.662			0.992 (0.967−1.018)	0.563
Adjuvant chemotherapya		0.207 (0.060−0.717)	0.013*	0.228 (0.064−0.819)	0.023*	0.313 (0.107−0.910)	0.033*	0.535 (0.151−1.891)	0.332

HR, hazard ratio; CI, confidence interval; pT stage, pathologic T stage; CEA, carcinoembryonic antigen.

^aDefined as completion of more than 80% of the planned adjuvant chemotherapy cycle.

^*P<0.05.