Table 4.

Multivariate Cox Proportional Hazards Survival Analysis of Adjuvant Chemoradiation therapy and Overall Survival

	RR (95% CI)	P-value
Age, yrs
< 75	1.00	0.755
≥ 75	0.93 (0.57 - 1.50)
Gender
Female	1.00	0.402
Male	0.84 (0.56-1.26)
Institution
Mayo	1.00	0.222
Hopkins	1.30 (0.85-1.99)
Tumor Stage
T1/T2	1.00	0.317
T3/T4	1.24 (0.81-1.91)
Tumor Size
≤ 3 cm	1.00	0.391
> 3 cm	1.20 (0.79-1.80)
Node
Negative	1.00	<0.001
Positive	4.29 (2.5-7.17)
Histology
Grade 1/2	1.00	0.191
Grade 3	1.35 (0.86-2.41)
Adjuvant Treatment
Observation	1.00	<0.001
Adjuvant CRT*	0.41 (0.25 - 0.67)

*CRT = chemoradiation