Table 3.

Logistic regression analysis of risk factors for dMMR status

Factors	Univariate analysis		Multivariate analysis
	OR (95% CI)	p-value	OR (95% CI)	p-value
Age at diagnosis (≥ 60)	0.44 (0.28–0.69)	< 0.001	0.48 (0.25–0.94)	0.032
Gender (female)	0.77 (0.49–1.19)	0.241
Primary tumor site		< 0.001		0.001
Left colon	0.55 (0.30–0.99)	0.045	0.43 (0.17–1.09)	0.076
Right colon	1.98 (1.11–3.53)	0.02	2.28 (0.86–6.07)	0.098
Rectum (reference)	–	–	–	–
Stage (7th AJCC)		0.965
I	0.79 (0.28–2.21)	0.651
II	0.78 (0.31–1.98)	0.603
III	0.80 (0.30–2.13)	0.653
IV (reference)	–	–
Tumor stage		0.007		0.004
T1	0.26 (0.07–0.90)	0.034	0.04 (0.01–0.33)	0.002
T2	0.39 (0.18–0.88)	0.024	0.38 (0.11–1.37)	0.139
T3	0.33 (0.17–0.63)	0.001	0.20 (0.07–0.59)	0.004
T4 (reference)	–	–	–	–
Node stage (positive)		0.819
Negative lymph nodes (high)	2.09 (1.34–3.24)	0.001	1.10 (0.52–2.30)	0.810
Tumor histological grade		0.002		0.588
Well-differentiated	0.25 (0.02–2.87)	0.266	7.91 (0.38–163.50)	0.181
Moderately differentiated	0.35 (0.21–0.60)	< 0.001	1.12 (0.48–2.63)	0.788
Poorly differentiated	0.50 (0.25–1.00)	0.051	0.93 (0.30–2.89)	0.896
Mucinous (reference)	–		–	–
Nerve invasion (no)	2.22 (1.07–4.58)	0.032	1.80 (0.59–5.45)	0.299
Vascular invasion (no)	2.32 (1.10–4.91)	0.028	3.66 (1.04–12.98)	0.044
MHC class I expression (low)	15.16 (7.81–29.42)	< 0.001	24.66 (8.74–69.64)	< 0.001
CD3 expression (high)	0.90 (0.57–1.43)	0.662
CD4 expression (high)	0.43 (0.27–0.68)	< 0.001	0.34 (0.14–0.83)	0.017
CD8 expression (high)	1.89 (1.17–3.06)	0.01	2.97 (1.30–6.78)	0.01
CD56 expression (high)	0.37 (0.23–0.59)	< 0.001	0.92 (0.78–1.08)	0.294
PD-1 expression (high)	1.19 (0.73–1.93)	0.483
PD-L1 expression (positive)	0.58 (0.38–0.90)	0.015	0.55 (0.27–1.13)	0.103

OR: odds ratio; 95% CI: 95% confidence interval

Only the meaningful factors (p < 0.05) in univariate analysis were brought into the multivariate analysis