Table 3. Univariate association with overall survival (from diagnosis).

Covariate	Level	N	Overall survival (months)
			Hazard ratio (95% CI)	HR P value	Log-rank P value
Received local therapy	No	212	1.40 (1.18–1.66)	<0.001	<0.001
	Yes	948	Reference	–
Local therapy modality	Radical resection	26	0.88 (0.57–1.38)	0.587	0.001
	Local resection	95	0.66 (0.49–0.88)	0.004
	Radiation only	827	0.72 (0.60–0.86)	<0.001
	No local therapy	212	Reference	–
Metastatic involvement site	Others	716	0.80 (0.67–0.96)	0.018	<0.001
	Bone	62	0.91 (0.64–1.29)	0.588
	Lung	72	1.08 (0.79–1.49)	0.619
	Multiple sites	85	1.43 (1.07–1.91)	0.015
	Liver	225	Reference	–
Sequence of chemo and local therapy	During chemo	416	0.75 (0.61–0.91)	0.004	<0.001
	After chemo	274	0.77 (0.62–0.95)	0.015
	Unknown	252	1.09 (0.88–1.34)	0.436
	Before chemo	218	Reference	–
Age at diagnosis, years	>70	146	1.44 (1.18–1.77)	<0.001	0.002
	60–70	328	1.11 (0.95–1.30)	0.203
	<60	686	Reference	–
Sex	Male	407	1.38 (1.20–1.59)	<0.001	<0.001
	Female	753	Reference	–
Race	Unknown	11	0.89 (0.40–1.99)	0.782	0.870
	Other	20	1.20 (0.71–2.05)	0.491
	Hispanic	75	0.89 (0.66–1.20)	0.442
	Non-Hispanic Black	137	0.97 (0.78–1.20)	0.759
	Non-Hispanic White	917	Reference	–
Primary payor	Not Insured	109	1.30 (1.01–1.67)	0.039	<0.001
	Medicaid/Medicare/Other Government	501	1.37 (1.18–1.58)	<0.001
	Unknown	21	1.00 (0.58–1.70)	0.987
	Private	529	Reference	–
Median income quartiles 2000	< $30,000	185	1.23 (1.00–1.52)	0.051	0.043
	$30,000–$35,999	232	1.05 (0.87–1.28)	0.600
	$36,000–$45,999	321	1.10 (0.92–1.31)	0.296
	Not Available	42	0.65 (0.42–1.00)	0.048
	$46,000+	380	Reference	–
Urban/rural 2003	Urban	153	1.10 (0.89–1.35)	0.376	0.701
	Rural	23	1.22 (0.76–1.94)	0.411
	Unknown	23	1.07 (0.66–1.73)	0.790
	Metro	961	Reference	–
Year of diagnosis	≥ 2004, ≤2008	317	1.12 (0.86–1.45)	0.405	0.021
	>2008, ≤2011	286	0.93 (0.71–1.21)	0.568
	>2011, ≤2014	405	0.85 (0.66–1.10)	0.221
	>2014, ≤2015	152	Reference	–
Histology	Squamous cell carcinoma keratinizing	91	0.97 (0.75–1.26)	0.830	0.828
	Squamous cell carcinoma	1069	Reference	–
Primary site	C218-Overlapping lesion of rectum/anal canal	156	1.04 (0.84–1.29)	0.719	0.073
	C212-Cloacogenic zone	4	2.91 (1.08–7.80)	0.034
	C211-Anal canal	502	0.92 (0.79–1.07)	0.289
	C210-Anus, NOS	498	Reference	–
Tumor size, cm	No mass or tumor found	3	1.31 (0.33–5.27)	0.702	0.008
	<0.5	319	0.82 (0.69–0.98)	0.025
	Unknown, size not stated, microscopic focus	393	1.11 (0.95–1.31)	0.194
	≥0.5	445	Reference	–
Surgical margins	Yes	56	1.26 (0.77–2.04)	0.357	0.651
	Not available	1068	1.13 (0.77–1.65)	0.526
	No	36	Reference	–
Grade	Well differentiated, differentiated, NOS	35	1.05 (0.70–1.57)	0.830	0.148
	Moderately differentiated	394	0.84 (0.72–0.99)	0.043
	Cell type not determined, not stated	294	0.86 (0.72–1.03)	0.102
	Poorly differentiated/anaplastic	437	Reference	–
Charlson-Deyo score	2+	72	1.28 (0.96–1.70)	0.090	0.161
	1	118	1.13 (0.90–1.41)	0.306
	0	970	Reference	–
Received surgical resection	Yes	121	0.92 (0.73–1.15)	0.439	0.439
	No	1039	Reference	–
Received radiation	Yes	925	0.72 (0.61–0.85)	<0.001	<0.001
	No	235	Reference	–
Type of surgery	Local	95	0.86 (0.66–1.10)	0.232	0.380
	Radical	26	1.15 (0.75–1.76)	0.517
	No	1039	Reference	–
Age at diagnosis		1,160	1.01 (1.00–1.02)	0.002	–

NOS, not otherwise specified.