Table 6.

Multivariable Cox proportional Hazards model

	OS from primary diagnosis				OS from renal metastasis
Variable	HR	95% CI		p-value	HR	95% CI		p-value
Age at diagnosis (per year)	1.02	1.00	1.04	0.034	1.01	0.99	1.03	0.349
Gender
Male (Referent)
Female	1.02	0.67	1.57	0.913	1.08	0.72	1.63	0.700
Tumor size of largest mass	1.05	0.97	1.14	0.187	1.07	0.99	1.15	0.091
Number of symptoms
0 (Referent)
1	1.68	0.96	2.94	0.072	1.28	0.73	2.26	0.388
>=2	1.59	0.87	2.93	0.135	1.47	0.77	2.81	0.238
Primary Histology
Carcinoma (Referent)
Sarcoma	0.77	0.33	1.79	0.541	0.56	0.23	1.34	0.193
Other	0.81	0.34	1.94	0.630	0.95	0.38	2.35	0.909
Primary organ site
Lung (Referent)
Colorectal	0.23	0.11	0.49	<0.001	0.41	0.19	0.89	0.024
Other	0.22	0.12	0.41	<0.001	0.60	0.36	1.01	0.055
Presence of non-renal metastases at time of diagnosis	1.53	0.93	2.50	0.092	0.69	0.42	1.14	0.148
Surgery for renal metastases	0.61*	0.36	1.04	0.069	0.46	0.27	0.80	0.005

^*The assumption of non-proportionality was not met for this term in the model that examines time from primary diagnosis.