TABLE 3.

Hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) of metachronous colon cancer following proctectomy for rectal cancer in mismatch repair gene mutation carriers

	Univariable		Multivariablea
	HR (95 % CI)	P value	HR (95 % CI)	P value
Sex
Female	1.00 (referent)		1.00 (referent)
Male	0.96 (0.41–2.27)	0.93	0.67 (0.12–3.84)	0.65
Age at diagnosis (years)
<40	1.00 (referent)		1.00 (referent)
40–49	0.62 (0.23–1.68)	0.97b	0.52 (0.07–4.16)	0.99b
≥50	1.36 (0.42–4.34)		1.84 (0.17–20.14)
Country of recruitment
Australia and New Zealand	1.00 (referent)		1.00 (referent)
Canada	0.82 (0.24–2.75)	0.75	7.63 (0.25–232)	0.24
United States	0.71 (0.27–1.86)	0.48	0.84 (0.24–2.96)	0.79
Cigarette smoking
Never user	1.00 (referent)		1.00 (referent)
Ever user	1.06 (0.44–2.57)	.90	0.84 (0.17–4.18)	0.83
Synchronous tumor
Absent	1.00 (referent)		1.00 (referent)
Present	5.65 (0.67–47.68)	0.11	11.54 (1.06–125)	0.04
Maximum dimension of tumor (per cm)	1.04 (0.86–1.25)	0.72	0.93 (0.65–1.32)	0.68
AJCC stage of tumor (per stage)	1.68 (0.84–3.36)	0.14	6.14 (1.21–13.14)	0.03
Histological grade (per grade)	1.48 (0.85–2.57)	0.17	2.00 (0.61–6.53)	0.25

AJCC the American Joint Committee on Cancer

^aAdjusted for variables in the table and taken account into familial correlation

^bP trend: calculated from Cox regression models with ordinal variables as continuous measures