Table 4. Association of chemotherapy with survival among CRC patients with different CIMP status.

		Overall survivala			Disease-specific survivala
Factor	N	Deaths (%)	HR	95% CI	Deaths (%)	HR	95% CI
Stages II–IV
CIMP-H
Chemotherapy−	82	20 (24)	1.00	Reference	12 (15)	1.00	Reference
Chemotherapy+	71	28 (39)	0.66	0.25–1.78	23 (32)	0.54	0.15–1.88
CIMP-L/N
Chemotherapy−	415	120 (29)	1.00	Reference	85 (20)	1.00	Reference
Chemotherapy+	537	185 (34)	0.58	0.43–0.79	161 (30)	0.57	0.40–0.80
Stage II
CIMP-H
Chemotherapy−	67	12 (18)	1.00	Reference	6 (9)	1.00	Reference
Chemotherapy+	7	0 (0)	NA	NA	0 (0)	NA	NA
CIMP-L/N
Chemotherapy−	305	58 (19)	1.00	Reference	34 (11)	1.00	Reference
Chemotherapy+	77	11 (14)	1.10	0.55–2.20	7 (9)	1.17	0.48–2.85
Stage III
CIMP-H
Chemotherapy−	13	6 (46)	1.00	Reference	4 (31)	1.00	Reference
Chemotherapy+	43	10 (23)	0.64	0.11–3.62	6 (14)	0.82	0.07–9.46
CIMP-L/N
Chemotherapy−	85	38 (45)	1.00	Reference	29 (34)	1.00	Reference
Chemotherapy+	320	69 (22)	0.67	0.42–1.07	54 (17)	0.63	0.37–1.07
Stage IV
CIMP-H
Chemotherapy−	2	2 (100)	1.00	Reference	2 (100)	1.00	Reference
Chemotherapy+	21	18 (86)	NA	NA	17 (81)	NA	NA
CIMP-L/N
Chemotherapy−	25	24 (96)	1.00	Reference	22 (88)	1.00	Reference
Chemotherapy+	140	105 (75)	0.32	0.18–0.55	100 (71)	0.34	0.19–0.60

Abbreviations: CI=confidence interval; CIMP=CpG island methylator phenotype; CIMP-H=CIMP-high; CIMP-L/N=CIMP-low/negative; CRC=colorectal cancer; HR=hazard ratio; NA=not available.

^aAdjusted for age, sex, education level, alcohol consumption, tumour location, cancer stage, number of invaded lymph nodes, chemotherapy, microsatellite instability and BRAF mutation; additional adjustment for time-dependent effects of age and chemotherapy.