Table 2.

Overall survival and brain relapse-free survival.

	Overall Survival				Brain Failure Risk
	Univariate Analysis		Multivariate Analysis		Univariate Analysis		Multivariate Analysis
Covariates	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value	HR (95% CI)	p-value
PCI (no vs. yes [ref])	1.77 (1.31–2.40)	<0.001*	1.88 (1.32–2.69)	<0.001*	2.93 (1.85–4.63)	<0.001*	4.66 (2.58–8.40)	<0.001*
Age at diagnosis	1.03 (1.01–1.04)	<0.001*	1.03 (1.01–1.05)	0.0016*	1.00 (0.97–1.02)	0.90	0.97 (0.95–1.01)	0.11
Stage		0.062		0.095		0.13		0.15
(III vs. I [ref])	1.50 (0.91–2.49)		1.50 (0.89–2.53)		3.08 (1.02–9.27)		3.19 (0.98–10.41)
(II vs. I [ref]	0.92 (0.47–1.8)		0.95 (0.48–1.88)		3.21 (0.92–11.24)		2.63 (0.67–10.29)
ECOG (2–3 vs. 0–1 [ref])	1.30 (0.88–1.94)	0.19	1.16 (0.73–1.84)	0.53	1.26 (0.67–2.37)	0.47	1.67 (0.83–3.40)	0.15
CCI Score	0.98 (0.81–1.18)	0.80	0.93 (0.75–1.15)	0.49	1.05 (0.77–1.43)	0.77	1.15 (0.88–1.51)	0.30
Diagnosis Date (historical vs. contemporary [ref])	1.03 (0.78–1.37)	0.83	1.11 (0.79–1.57)	0.53	0.88 (0.56–1.38)	0.58	0.98 (0.56–1.73)	0.95
Brain Imaging Follow Up (No-MRI vs. MRI [ref])	1.32 (1.00–1.75)	0.049*	1.15 (0.83–1.59)	0.40	0.62 (0.38–1.00)	0.052	0.35 (0.18–0.66)	0.0013*

Abbreviations: ECOG, Eastern Cooperative Oncology Group; PCI, prophylactic cranial irradiation; CCI, Charlson Comorbidity Index.

^*Statistically significant associations.