Table 3.

Analyses of Overall Survival (OS) for Patients with Clinically Localized Disease

				Multivariate Analyses
		Univariate Analyses		Full Model		Reduced Model
Patient Characteristic		Hazard Ratio (95% CI)	P-value	Hazard Ratio (95% CI)	P-value	Hazard Ratio (95% CI)	P-value
Tumor Stage	T3 vs T1/T2	0.8 (0.4, 1.6)	0.55	1.6 (1.1, 2.3)	0.02	1.6 (1.1, 2.4)	0.01
	T4 vs T1/T2	2.4 (1.1, 5.1)	0.03	1.9 (1.1, 3.2)	0.02	2.0 (1.2, 3.3)	0.005
LN Positive	Yes vs No	2.6 (1.4, 4.8)	0.002	1.9 (1.4, 2.6)	<0.001	2.0 (1.5, 2.8)	<0.001
Year of Nephrectomy	1996–2005 vs 1986–1995	0.9 (0.4, 1.9)	0.73	0.8 (0.5, 1.3)	0.44	0.8 (0.5, 1.3)	0.45
	2006–2011 vs 1986–1995	1.0 (0.4, 2.4)	>0.99	1.3 (0.9, 2.0)	0.15	1.3 (0.9, 2.0)	0.16
Positive Margin	Yes vs No	1.6 (0.8, 3.2)	0.20	1.0 (0.7, 1.5)	0.81	NI
LVI	Yes vs No	2.1 (1.1, 4.2)	0.03	1.3 (0.9, 1.9)	0.14	NI
Age	>55 vs <=55	1.0 (0.5, 1.7)	0.87			NI
ECOG Status	1 vs 0	0.9 (0.5, 1.6)	0.69			NI
	>=2 vs 0	1.1 (0.1, 8.1)	0.94			NI
Clear Cell Histology	Yes vs No	0.7 (0.4, 1.3)	0.30			NI
Percent Sarcomatoid	25–49 vs 1–24	1.3 (0.5, 3.2)	0.54			NI
	50–74 vs 1–24	1.3 (0.5, 3.5)	0.56			NI
	75–99 vs 1–24	1.0 (0.4, 2.1)	0.93			NI
Necrosis	Yes vs No	0.8 (0.4, 1.5)	0.54			NI

With only 55 deaths among 77 applicable patients, only 5 characteristics could be included in a multivariable model and maintain model stability. Tumor stage, LN positivity, year of nephrectomy, positive margins, and LVI were selected based on known or suspected clinical importance combined with new interest based on univariable analyses. The remaining variables were explored in univariable analyses only.

NI=Not included. After step-wise backward selection, variables that did not remain in the full model due to lack of statistical significance were not included in the final reduced model.

^*Even though each individual comparison for year of nephrectomy is not significant in the multivariate model, it remains in the model because the overall p-value for any difference among the 3 time groups is significant (p=0.03).