Table 4.

Predictors of pathologic complete response after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer by univariate and multivariate analyses using logistic regression

Variables	n	Univariate analysis*			Multivariate analysis*
		OR	P-value**	95% CI	OR	P-value**	95% CI
Age (years)					Not included in the model
≤60	140	ref
≥60	55	1.497	0.314	0.683-3.282
Gender					Not included in the model
Male	143	ref
Female	52	0.668	0.380	0.272-1.643
Pre-treatment clinical tumor stage
3	129	ref			Not included in the model
4	66	0.546	0.166	0.232-1.285
Pre-treatment clinical node stage
N0	37	ref			ref
N1	65	0.611	0.314	0.234-1.594	1.592	0.997	0.000-NA
N2	93	0.400	0.058	0.155-1.030	0.417	0.155	0.125-1.393
Pre-treatment clinical stage					Not included in the model
II	37	ref
III	158	0.484	0.092	0.208-1.127
Histological types†
Non SRCC	177	ref			ref
SRCC	18	70.667	0.000**	15.019-332.503	4.065	0.027**	1.176-14.085
Histologic grade†					Not included in the model
Well	23	ref
Moderate	114	0.720	0.561	0.238-2.177
Poor	58	0.750	0.639	0.225-2.496	Not included in the model
Tumor budding†
Low	87	ref
Intermediate	31	0.137	0.059	0.017-1.079	Not included in the model
High	77	1.080	0.843	0.503-2.319
PDC†
Grade 1	93	ref			ref
Grade 2	42	1.491	0.446	0.534-4.163	1.511	0.441	0.529-4.312
Grade 3	60	2.711	0.022	1.158-6.346	0.000	0.997	0.00-NA
Pre-treatment CEA (ng/ml)					Not included in the model
≤5	103	ref
>5	92	1.766	0.137	0.834-3.740
Interval from completion of CRT to surgery (weeks)					Not included in the model
≤7	80	ref
>7	115	0.643	0.244	0.306-1.351

Abbreviations: OR: Odds ratio, CI: Confidence interval, NA: not achieved, SRCC: Signet ring cell component, PDC: Poorly differentiated clusters;

^†In pre-treatment biopsies, CEA: Carcinoembryonic antigen, CRT: Chemoradiotherapy.

^*Univariate and multivariate logistic regression analysis was performed to identify the potential predictors of pCR.

^** P-values ≤0.05 were considered statistically significant.